WINT / Windtree Therapeutics, Inc. - Pemfailan SEC, Laporan Tahunan, Penyata Proksi

Windtree Therapeutics, Inc.
US ˙ OTCPK

Statistik Asas
CIK 946486
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Windtree Therapeutics, Inc.
SEC Filings (Chronological Order)
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September 2, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 28, 2025 Windtree Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 28, 2025 Windtree Therapeutics, Inc.

August 20, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 19, 2025 Windtree Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 19, 2025 Windtree Therapeutics, Inc.

August 19, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WIN

August 14, 2025 NT 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING SEC FILE NUMBER 001-37392 CUSIP NUMBER 03763A207 (Check One): ☐ Form 10-K ☐ Form 20-F ☐ Form 11-K ☒ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR For Period Ended: June 30, 2025 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Transit

August 8, 2025 8-K

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 4, 2025 Windtree Therapeutics, Inc.

August 8, 2025 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defi

August 5, 2025 EX-99.1

Windtree Announces Istaroxime Phase 2 Interim Analysis in SCAI Stage C Cardiogenic Shock Patients Istaroxime was added to currently available inotropes and vasopressors in the study - no new safety signals were identified and physiological improvemen

Exhibit 99.1 Windtree Announces Istaroxime Phase 2 Interim Analysis in SCAI Stage C Cardiogenic Shock Patients Istaroxime was added to currently available inotropes and vasopressors in the study - no new safety signals were identified and physiological improvements were consistent with istaroxime responses in previous trials Cardiogenic shock is a severe presentation of heart failure and SCAI Stag

August 5, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2025 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 5, 2025 Windtree Therapeutics, Inc.

August 4, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 29, 2025 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 29, 2025 Windtree Therapeutics, Inc.

July 30, 2025 PRE 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defi

July 24, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2025 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2025 Windtree Therapeutics, Inc.

July 24, 2025 EX-10.2

REGISTRATION RIGHTS AGREEMENT

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of July 23, 2025, is by and between Seven Knots, LLC, a Montana limited liability company (the “Investor”), and Windtree Therapeutics, Inc., a Delaware corporation (the “Company”). RECITALS A. The Company and the Investor have entered into that certain Common Stock Purchase Agreement, dated a

July 24, 2025 EX-4.1

CONVERTIBLE PROMISSORY NOTE

Exhibit 4.1 THIS CONVERTIBLE PROMISSORY NOTE (AS MAY BE AMENDED FROM TIME TO TIME, THE “NOTE”) AND THE SECURITIES INTO WHICH IT MAY BE CONVERTED HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”) OR UNDER THE SECURITIES LAWS OF ANY STATE. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE. THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENT

July 24, 2025 EX-10.1

COMMON STOCK PURCHASE AGREEMENT Dated as of July 23, 2025 by and among WINDTREE THERAPEUTICS, INC., SEVEN KNOTS, LLC TABLE OF CONTENTS

Exhibit 10.1 COMMON STOCK PURCHASE AGREEMENT Dated as of July 23, 2025 by and among WINDTREE THERAPEUTICS, INC., and SEVEN KNOTS, LLC TABLE OF CONTENTS Page ARTICLE I PURCHASE AND SALE OF COMMON STOCK 1 Section 1.1. Purchase and Sale of Stock 1 Section 1.2. Closing Date; Settlement Dates 2 Section 1.3. Initial Public Announcements and Required Filings 2 ARTICLE II PURCHASE TERMS 3 Section 2.1. Res

July 24, 2025 EX-99.1

Windtree Therapeutics Announces Up To $520 Million in New Funding to Amplify BNB Cryptocurrency Treasury Strategy Up to $700 Million Committed to BNB Acquisitions, Reinforcing Innovative Crypto Treasury Strategy Ninety Nine Percent of the proceeds fr

Exhibit 99.1 Windtree Therapeutics Announces Up To $520 Million in New Funding to Amplify BNB Cryptocurrency Treasury Strategy Up to $700 Million Committed to BNB Acquisitions, Reinforcing Innovative Crypto Treasury Strategy Ninety Nine Percent of the proceeds from both issuances to be used to buy BNB WARRINGTON, PA – July 24, 2025 – Windtree Therapeutics, Inc. (“Windtree” or the “Company”) (Nasda

July 17, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report (Date of earliest event reported): July 16, 2025

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of report (Date of earliest event reported): July 16, 2025 Windtree Therapeutics, Inc. (Exact Name of Registrant as Specified in Its Charter) Delaware 001-39290 94-3171943 (State or Other Jurisdiction of Incorporation) (Commissi

July 17, 2025 EX-99.1

Windtree To Launch BNB Crypto Treasury Strategy With Agreement For $60 Million Investment Led By Build And Build Corp. With Up To $140 Million More In Follow On Subscriptions Windtree expected to become a leader and the first NASDAQ-listed company of

Exhibit 99.1 Windtree To Launch BNB Crypto Treasury Strategy With Agreement For $60 Million Investment Led By Build And Build Corp. With Up To $140 Million More In Follow On Subscriptions Windtree expected to become a leader and the first NASDAQ-listed company offering direct exposure to the Binance Smart Chain Ecosystem (BNB) WARRINGTON, PA – July 16, 2025 – Windtree Therapeutics, Inc. (“Windtree

July 17, 2025 EX-10.1

SECURITIES PURCHASE AGREEMENT

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (the “Agreement”), dated as of July 16, 2025, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and each of the investors signatory hereto (individually, a “Buyer” and collectively, the “Buyers”). RECITALS A. The C

July 10, 2025 CORRESP

Windtree Therapeutics Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 July 10, 2025

Windtree Therapeutics Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 July 10, 2025 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, N.E. Washington, D.C. 20549-3561 Re: Windtree Therapeutics Inc. Registration Statement on Form S-1 (the “Registration Statement”) Filed July 10, 2025 File No. 333-287358 Ladies and Gentl

July 10, 2025 S-1/A

As filed with the Securities and Exchange Commission on July 10, 2025

Table of Contents As filed with the Securities and Exchange Commission on July 10, 2025 Registration No.

July 10, 2025 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc.

July 7, 2025 S-1/A

As filed with the Securities and Exchange Commission on July 7, 2025

Table of Contents As filed with the Securities and Exchange Commission on July 7, 2025 Registration No.

July 3, 2025 EX-10.2

Form of Note Purchase Agreement dated July 2, 2025

Exhibit 10.2 NOTE PURCHASE AGREEMENT THIS NOTE PURCHASE AGREEMENT (this “Agreement”), dated as of July 2, 2025 (the “Execution Date”), is entered into by and between WINDTREE THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [●] (the “Buyer”). Each capitalized term used herein shall have the meaning ascribed thereto in Section 10 below, or as otherwise defined herein. WHEREAS, the Co

July 3, 2025 EX-4.2

Convertible Promissory Note, dated July 2, 2025, (incorporated by reference to Exhibit 4.2 to Windtree’s Form 8-K, as filed with the SEC on July 3, 2025).

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

July 3, 2025 EX-4.4

Form of Common Stock Purchase Warrant, dated July 2, 2025 (incorporated by reference to Exhibit 4.4 to Windtree’s Form 8-K, as filed with the SEC on July 3, 2025)

Exhibit 4.4 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

July 3, 2025 EX-10.1

Form of Note Purchase Agreement dated July 2, 2025 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report in Form 8-K, as filed with the SEC on July 3, 2025).

Exhibit 10.1 NOTE PURCHASE AGREEMENT THIS NOTE PURCHASE AGREEMENT (this “Agreement”), dated as of June 27, 2025 (the “Execution Date”), is entered into by and between WINDTREE THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [●] (the “Buyer”). Each capitalized term used herein shall have the meaning ascribed thereto in Section 10 below, or as otherwise defined herein. WHEREAS, the C

July 3, 2025 8-K

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 27, 2025 Windtree Therapeutics, Inc.

July 3, 2025 EX-4.3

Form of Common Stock Purchase Warrant, dated June 27, 2025 (incorporated by reference to Exhibit 4.3 to Windtree’s Form 8-K, as filed with the SEC on July 3, 2025)

Exhibit 4.3 NEITHER THE ISSUANCE NOR SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR T

July 3, 2025 EX-4.1

Convertible Promissory Note, dated June 27, 2025, (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on July 3, 2025).

Exhibit 4.1 NEITHER THE ISSUANCE NOR SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR T

June 27, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2025 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 24, 2025 Windtree Therapeutics, Inc.

June 27, 2025 EX-10.1

Form of Note Purchase Agreement dated June 24, 2025 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report in Form 8-K, as filed with the SEC on June 27, 2025).

Exhibit 10.1 NOTE PURCHASE AGREEMENT THIS NOTE PURCHASE AGREEMENT (this “Agreement”), dated as of June 24, 2025 (the “Execution Date”), is entered into by and between WINDTREE THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [●] (the “Buyer”). Each capitalized term used herein shall have the meaning ascribed thereto in Section 10 below, or as otherwise defined herein. WHEREAS, the C

June 27, 2025 EX-4.1

Convertible Promissory Note, dated June 24, 2025, (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on June 27, 2025).

Exhibit 4.1 NEITHER THE ISSUANCE NOR SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR T

June 27, 2025 EX-4.2

Form of Common Stock Purchase Warrant, dated June 24, 2025 (incorporated by reference to Exhibit 4.2 to Windtree’s Form 8-K, as filed with the SEC on June 27, 2025)

Exhibit 4.2 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

June 20, 2025 8-K

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 18, 2025 Windtree Therapeutics, Inc.

June 11, 2025 EX-99.4

Windtree Receives Offer for Its Preclinical Oncology Drug Candidate Company to receive $7.0 million up front for its preclinical oncology drug candidate Up to $130.0 million in milestone payments starting with initiation of Phase 1 High single digit

Exhibit 99.4 Windtree Receives Offer for Its Preclinical Oncology Drug Candidate Company to receive $7.0 million up front for its preclinical oncology drug candidate Up to $130.0 million in milestone payments starting with initiation of Phase 1 High single digit royalties that could total up to $1.5 billion over the life of the drug WARRINGTON, PA – June 11, 2025 – Windtree Therapeutics, Inc. (“Wi

June 11, 2025 EX-99.3

Windtree Announces Transformational Agreement to Acquire Revenue Generating Environmental Services Business Windtree continues its transformation entering the rapidly growing $85 billion US environmental services space Refocused strategy is expected

Exhibit 99.3 Windtree Announces Transformational Agreement to Acquire Revenue Generating Environmental Services Business Windtree continues its transformation entering the rapidly growing $85 billion US environmental services space Refocused strategy is expected to generate $12 million in revenue over the next 12 months Transaction expected to produce a profitable business with growth opportunitie

June 11, 2025 EX-4.4

Form of Common Stock Purchase Warrant, dated June 9, 2025 (incorporated by reference to Exhibit 4.4 to Windtree’s Form 8-K, as filed with the SEC on June 5, 2025)

Exhibit 4.4 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

June 11, 2025 EX-4.1

Convertible Promissory Note, dated June 5, 2025, (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on June 11, 2025).

Exhibit 4.1 NEITHER THE ISSUANCE NOR SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR T

June 11, 2025 EX-4.2

Form of Convertible Promissory Note, dated June 9, 2025, (incorporated by reference to Exhibit 4.2 to Windtree’s Form 8-K, as filed with the SEC on June 11, 2025).

Exhibit 4.2 NEITHER THE ISSUANCE NOR SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR T

June 11, 2025 EX-4.5

Form of Senior Note issued to Standard Waste Services, LLC on June 5, 2025

Exhibit 4.5 THE ISSUANCE AND SALE OF THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THIS NOTE MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL TO THE HOLDER (IF REQ

June 11, 2025 EX-99.1

Amended and Restated Non Binding Termsheet [●] Purchase of Windtree Therapeutics’ Assets

Exhibit 99.1 7 June, 2025 Attn: Jed Latkin, CEO, Windtree Therapeutics. By Email: [●] Amended and Restated Non Binding Termsheet [●] Purchase of Windtree Therapeutics’ Assets Opportunity Introduction: This Amended and Restated Non-Binding Termsheet hereby supersedes all previous term sheets entered into between the Parties. With reference to the mutual understanding and intentions reached so far b

June 11, 2025 8-K

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 5, 2025 Windtree Therapeutics, Inc.

June 11, 2025 EX-10.2

Form of Note Purchase Agreement dated June 9, 2025 (incorporated by reference to Exhibit 10.2 to Windtree’s Current Report in Form 8-K, as filed with the SEC on June 11, 2025).

Exhibit 10.2 NOTE PURCHASE AGREEMENT THIS NOTE PURCHASE AGREEMENT (this “Agreement”), dated as of June 9, 2025 (the “Execution Date”), is entered into by and between WINDTREE THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [●] (the “Buyer”). Each capitalized term used herein shall have the meaning ascribed thereto in Section 10 below, or as otherwise defined herein. WHEREAS, the Co

June 11, 2025 EX-99.2

[signature pages follow]

Exhibit 99.2 June 6, 2025 Titan Environmental Services, Inc. [●] Attn: Glenn Miller, CEO Re: Potential Acquisition of Titan Environmental Services, Inc. Ladies and Gentlemen: This letter of intent will confirm the agreement by and among Windtree Therapeutics, Inc., a Delaware corporation (“WINT”) and Titan Environmental Services, Inc., a corporation formed under the laws of Nevada (“TESI”), concer

June 11, 2025 EX-10.1

Form of Note Purchase Agreement dated June 5, 2025 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report in Form 8-K, as filed with the SEC on June 11, 2025).

Exhibit 10.1 NOTE PURCHASE AGREEMENT THIS NOTE PURCHASE AGREEMENT (this “Agreement”), dated as of June 5, 2025 (the “Execution Date”), is entered into by and between WINDTREE THERAPEUTICS, INC., a Delaware corporation (the “Company”), and DFU, LLC, a Delaware limited liability company (the “Buyer”). Each capitalized term used herein shall have the meaning ascribed thereto in Section 10 below, or a

June 11, 2025 EX-4.3

Form of Common Stock Purchase Warrant, dated June 5, 2025 (incorporated by reference to Exhibit 4.3 to Windtree’s Form 8-K, as filed with the SEC on June 5, 2025)

Exhibit 4.3 NEITHER THIS SECURITY NOR THE SECURITIES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT TO AN EFFECTIVE REGISTR

May 16, 2025 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 16, 2025 Windtree Therapeutics, Inc.

May 16, 2025 S-1

As filed with the Securities and Exchange Commission on May 16, 2025

Table of Contents As filed with the Securities and Exchange Commission on May 16, 2025 Registration No.

May 16, 2025 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc.

May 16, 2025 EX-99.1

Windtree Therapeutics Reports First Quarter 2025 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports First Quarter 2025 Financial Results and Provides Key Business Updates WARRINGTON, PA – May 16, 2025 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on becoming a revenue generating company and advancing early and late-stage innovative therapies for critical conditions, today reported financial

May 15, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WI

May 1, 2025 8-K

Regulation FD Disclosure, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits

-12-31 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 30, 2025 Windtree Therapeutics, Inc.

May 1, 2025 EX-10.1

Form of Assignment and Conditional Assumption Agreement, by and between WINT Real Estate, LLC. (a wholly owned subsidiary of Windtree Therapeutics, Inc. and Way Maker Growth Fund, LLC dated April 19, 2025 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on May 1, 2025).

Exhibit 10.1 ASSIGNMENT AND CONDITIONAL ASSUMPTION AGREEMENT THIS ASSIGNMENT AND CONDITIONAL ASSUMPTION AGREEMENT (this “Assignment”) is entered into and effective as of April 19, 2025 (the “Effective Date”), by and between WAY MAKER GROWTH FUND, LLC, a Texas limited liability company, whose address is 603 E. Broadway St., Prosper, Texas 75078 (the “Original Purchaser”) and WINT REAL ESTATE, LLC,

May 1, 2025 EX-10.3

First Amendment to Purchase Agreement, by and between WINT Real Estate, LLC. (a wholly owned subsidiary of Windtree Therapeutics, Inc. and Way Maker Growth Fund, LLC dated December 19, 2024 (incorporated by reference to Exhibit 10.3 to Windtree’s Current Report on Form 8-K, as filed with the SEC on May 1, 2025).

Exhibit 10.3 FIRST AMENDMENT TO PURCHASE AND SALE AGREEMENT THIS FIRST AMENDMENT TO PURCHASE AND SALE AGREEMENT (“Amendment”) is made as of the 19th day of December, 2024 (“Effective Date”) by and between TBB CRESCENT PARK DRIVE LLC, Delaware limited liability company (the "Seller"), whose address is c/o The Bancorp Bank, National Association, 155 E. 44th Street, Suite 1015, New York, New York 100

May 1, 2025 EX-10.4

Second Amendment to Purchase Agreement, by and between WINT Real Estate, LLC. (a wholly owned subsidiary of Windtree Therapeutics, Inc. and Way Maker Growth Fund, LLC dated March 25, 2025 (incorporated by reference to Exhibit 10.4 to Windtree’s Current Report on Form 8-K, as filed with the SEC on May 1, 2025).

Exhibit 10.4 SECOND AMENDMENT TO PURCHASE AND SALE AGREEMENT THIS SECOND AMENDMENT TO PURCHASE AND SALE AGREEMENT (“Amendment”) is made as of the 25th day of March, 2025 (“Effective Date”) by and between TBB CRESCENT PARK DRIVE LLC, Delaware limited liability company (the "Seller"), whose address is c/o The Bancorp Bank, National Association, 155 E. 44th Street, Suite 1015, New York, New York 1001

May 1, 2025 EX-10.2

Form of Purchase Agreement , by and between WINT Real Estate, LLC. (a wholly owned subsidiary of Windtree Therapeutics, Inc. and Way Maker Growth Fund, LLC dated June 28, 2024 (incorporated by reference to Exhibit 10.2 to Windtree’s Current Report on Form 8-K, as filed with the SEC on May 1, 2025).

Exhibit 10.2 PURCHASE AND SALE AGREEMENT THIS PURCHASE AND SALE AGREEMENT (the "Agreement") is made as of the Effective Date (as hereafter defined), by and between TBB CRESCENT PARK DRIVE LLC, a Delaware limited liability company ("Seller"), whose address is c/o The Bancorp Bank, National Association, 155 E. 44th Street, Suite 1015, New York, New York 10017 and WAY MAKER GROWTH FUND, LLC a Texas l

May 1, 2025 EX-3.1

Certificate of Designations of the Series D Convertible Preferred Stock (incorporated by reference to Exhibit 3.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on May 1, 2025).

Exhibit 3.1 CERTIFICATE OF DESIGNATIONS OF RIGHTS AND PREFERENCES OF SERIES D CONVERTIBLE PREFERRED STOCK OF WINDTREE THERAPEUTICS, INC. I, Jed Latkin, hereby certify that I am the President and Chief Executive Officer of Windtree Therapeutics, Inc. (the “Company”), a corporation organized and existing under the Delaware General Corporation Law (the “DGCL”), and further do hereby certify: That pur

May 1, 2025 EX-99.1

Windtree Announces Strategic Transaction to Drive Revenue Generation in Support of Ongoing Therapeutic Pipeline Development Initial transaction provides the right to buy the target asset which may provide consistent revenue to Windtree while it conti

Exhibit 99.1 Windtree Announces Strategic Transaction to Drive Revenue Generation in Support of Ongoing Therapeutic Pipeline Development Initial transaction provides the right to buy the target asset which may provide consistent revenue to Windtree while it continues to develop its biotech pipeline drug candidates WARRINGTON, PA – May 1, 2025 – Windtree Therapeutics, Inc. (“Windtree” or the “Compa

April 30, 2025 EX-10.2

Form of Registration Rights Agreement, by and between Windtree Therapeutics, Inc. and the Buyers named therein, dated April 30, 2025 (incorporated by reference to Exhibit 10.2 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 30, 2025).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of April , 2025, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and the undersigned buyers (each, a “Buyer,” and collectively, the “Buyers”). RECITALS A. In connection with the Secur

April 30, 2025 EX-10.1

Form of Securities Purchase Agreement, by and between Windtree Therapeutics, Inc. and the Buyers named therein, dated April 30, 2025 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 30, 2025).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (the “Agreement”), dated as of April 29, 2025, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and each of the investors signatory hereto (individually, a “Buyer” and collectively, the “Buyers”). RECITALS A. Refe

April 30, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2025 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2025 Windtree Therapeutics, Inc.

April 30, 2025 EX-99.1

CERTIFICATE OF DESIGNATIONS OF RIGHTS AND PREFERENCES OF SERIES D CONVERTIBLE PREFERRED STOCK OF WINDTREE THERAPEUTICS, INC.

Exhibit 99.1 CERTIFICATE OF DESIGNATIONS OF RIGHTS AND PREFERENCES OF SERIES D CONVERTIBLE PREFERRED STOCK OF WINDTREE THERAPEUTICS, INC. I, Jed Latkin, hereby certify that I am the President and Chief Executive Officer of Windtree Therapeutics, Inc. (the “Company”), a corporation organized and existing under the Delaware General Corporation Law (the “DGCL”), and further do hereby certify: That pu

April 25, 2025 424B5

Up to 31,247,383 Shares of Common Stock

Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-284976 PROSPECTUS Up to 31,247,383 Shares of Common Stock This prospectus relates to (i) the offer and resale or other disposition from time to time by certain of the selling stockholders identified in this prospectus of (a) up to 8,053,565 shares of our common stock (the “Conversion Shares”), par value $0.001 per share, issua

April 24, 2025 CORRESP

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 April 24, 2024

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 April 24, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, NE Washington, D.C. 20549 Re: Windtree Therapeutics, Inc. Registration Statement on Form S-1 SEC File No. 333-284976 Request for Acceleration To whom it may concern: Pursuant to R

April 24, 2025 S-1/A

As filed with the Securities and Exchange Commission on April 24, 2025

Table of Contents As filed with the Securities and Exchange Commission on April 24, 2025 Registration No.

April 23, 2025 S-1/A

As filed with the Securities and Exchange Commission on April 22, 2025

Table of Contents As filed with the Securities and Exchange Commission on April 22, 2025 Registration No.

April 23, 2025 EX-FILING FEES

Filing Fee Ta

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc.

April 18, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2025 Windtree Therapeutics, Inc.

April 15, 2025 EX-4.30

Exhibit 4.30

Exhibit 4.30 DESCRIPTION OF THE COMPANY’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Windtree Therapeutics, Inc., or the Company, has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended, or the Exchange Act. The Company’s common stock, $0.001 par value per share, or the Common Stock, is registered under Sec

April 15, 2025 EX-10.66

License, Development and Commercialization Agreement, by and between the Company and Lee’s Pharmaceutical (HK) Ltd., dated January 12, 2024.

Exhibit 10.66 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. LICENSE, DEVELOPMENT AND COMMERCIALIZATION AGREEMENT by and between WINDTREE THERAPEUTICS, INC

April 15, 2025 EX-10.75

Employment Agreement by and between Windtree and Jed Latkin, dated as of November 8, 2024 (incorporated by reference to Exhibit 10.75 to Windtree’s Annual Report on Form 10-K, as filed on April 15, 2024).

Exhibit 10.75 EMPLOYMENT AGREEMENT This Employment Agreement (the “Agreement”) is made as of December 1, 2024, by and between Windtree Therapeutics, Inc., a Delaware corporation (the “Company”), and Jed Latkin (“Executive”), subject to the terms and conditions defined in this Agreement. WHEREAS, the Company and Executive desire that Executive be employed by the Company to act as the Company’s Pres

April 15, 2025 EX-10.77

Amendment No. 1 to License and Supply Agreement, by and between Windtree and Evofem Biosciences, Inc., dated as of March 28, 2025 (incorporated by reference to Exhibit 10.77 to Windtree’s Annual Report on Form 10-K, as filed on April 15, 2025).

Exhibit 10.77 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE SUCH TERMS ARE BOTH NOT MATERIAL AND ARE THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS AS [***]. AMENDMENT NO. 1 TO LICENSE AND SUPPLY AGREEMENT This Amendment No. 1 to License and Supply Agreement dated as of March 20, 2025 (the “Amen

April 15, 2025 EX-10.3

Amendment No. 1, effective as of January 17, 2024, to the Amended and Restated License Agreement, between Windtree and Philip Morris USA Inc. dated March 28, 2008.

Exhibit 10.3 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. AMENDMENT NO. 1 TO AMENDED AND RESTATED LICENSE AGREEMENT This Amendment No. 1 to Amended and R

April 15, 2025 EX-10.5

Amendment No. 1, effective as of January 17, 2024, to the License Agreement, between Windtree and Philip Morris Products S.A. dated March 28, 2008.

Exhibit 10.5 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. AMENDMENT NO. 1 TO THE LICENSE AGREEMENT This Amendment No. 1 to the License Agreement (this “A

April 15, 2025 EX-19.1

Windtree Therapeutics, Inc. Insider Trading Policy.

Exhibit 19.1 WINDTREE THERAPEUTICS, INC. POLICY ON INSIDER TRADING1 (Effective April 24, 2019) This Insider Trading Policy describes the policies of Windtree Therapeutics, Inc. and its subsidiaries (the “Company”) on trading, and causing the trading of, the Company’s securities or securities of certain other publicly traded companies while in possession of confidential information. Part I of this

April 15, 2025 EX-10.74

Employment Agreement, by and between Windtree and Jamie McAndrew, dated as of November 8, 2024 (incorporated by reference to Exhibit 10.74 to Windtree’s Annual Report on Form 10-K, as filed on April 15, 2024).

Exhibit 10.74 EMPLOYMENT AGREEMENT This Employment Agreement (the “Agreement”) is made as of November 8, 2024, by and between Windtree Therapeutics, Inc., a Delaware corporation (the “Company”), and Jamie McAndrew (“Executive”), subject to the terms and conditions defined in this Agreement. WHEREAS, the Company and Executive desire that Executive be employed by the Company to act as the Company’s

April 15, 2025 EX-97.1

Windtree Therapeutics, Inc. Compensation Recovery Policy.

Exhibit 97.1 WINDTREE THERAPEUTICS, INC. COMPENSATION RECOVERY POLICY Adopted as of November 15, 2023 Windtree Therapeutics, Inc., a Delaware corporation (the “Company”), has adopted a Compensation Recovery Policy (this “Policy”) as described below. 1. Overview The Policy sets forth the circumstances and procedures under which the Company shall recover Erroneously Awarded Compensation from Covered

April 15, 2025 EX-99.1

Windtree Therapeutics Reports Year-End 2024 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports Year-End 2024 Financial Results and Provides Key Business Updates WARRINGTON, PA – April 15, 2025 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions, today reported financial results for the fiscal year ended December 3

April 15, 2025 EX-10.76

License and Supply Agreement, between the Company and Evofem Biosciences, Inc., dated March 20, 2025 (incorporated by reference to Exhibit 10.76 to Windtree’s Annual Report on Form 10-K, as filed on April 15, 2025).

Exhibit 10.76 SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE SUCH TERMS ARE BOTH NOT MATERIAL AND ARE THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. THESE REDACTED TERMS HAVE BEEN MARKED IN THIS EXHIBIT WITH THREE ASTERISKS AS [***]. License and Supply Agreement This License and Supply Agreement (“Agreement”), dated and effective as of March , 2025 (the “Effective Date”

April 15, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2025 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 15, 2025 Windtree Therapeutics, Inc.

April 15, 2025 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 Or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WINDTRE

April 10, 2025 EX-4.1

Form of 20% OID Senior Secured Promissory Note (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on April 10, 2025).

Exhibit 4.1 THIS NOTE HAS BEEN ISSUED WITH “ORIGINAL ISSUE DISCOUNT” FOR U.S. FEDERAL INCOME TAX PURPOSES. THE ISSUER OF THIS NOTE WILL MAKE AVAILABLE TO ANY HOLDER OF THIS NOTE: (1) THE ISSUE PRICE AND ISSUE DATE OF THE NOTE, (2) THE AMOUNT OF ORIGINAL ISSUE DISCOUNT ON THE NOTE, (3) THE YIELD TO MATURITY OF THE NOTE, AND (4) ANY OTHER INFORMATION REQUIRED TO BE MADE AVAILABLE BY U.S. TREASURY RE

April 10, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 4, 2025 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 4, 2025 Windtree Therapeutics, Inc.

March 31, 2025 NT 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING SEC FILE NUMBER 001-39290 CUSIP NUMBER 97382D 600 (Check One): ☒ Form 10-K ☐ Form 20-F ☐ Form 11-K ☐ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR For Period Ended: December 31, 2024 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Tr

March 25, 2025 EX-99.1

Windtree Announces License and Supply Agreement to Become Sourcing Partner for a Small Biotech with an FDA Approved Product Transaction is part of the Company’s new corporate strategy to become a revenue generating biotech

Exhibit 99.1 Windtree Announces License and Supply Agreement to Become Sourcing Partner for a Small Biotech with an FDA Approved Product Transaction is part of the Company’s new corporate strategy to become a revenue generating biotech WARRINGTON, Pa., March 20, 2025 (GLOBE NEWSWIRE) – Windtree Therapeutics, Inc. (“Windtree” or the “Company”) (NasdaqCM: WINT), a biotechnology company focused on be

March 25, 2025 8-K/A

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K/A (Amendment No.

March 24, 2025 EX-4.1

Form of Senior Secured Note due in 2026 (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on March 24, 2025).

Exhibit 4.1 THE ISSUANCE AND SALE OF THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THIS NOTE MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL TO THE HOLDER (IF REQ

March 24, 2025 EX-99.2

Windtree Therapeutics Regains Compliance with Nasdaq Listing Rules

Exhibit 99.2 Windtree Therapeutics Regains Compliance with Nasdaq Listing Rules WARRINGTON, PA – March 24, 2025 – Windtree Therapeutics, Inc. (“Windtree” or the “Company”) (NasdaqCM: WINT), a biotechnology company focused on becoming a revenue generating biotech and advancing early and late-stage innovative therapies for critical conditions and diseases, today announced that the Company received n

March 24, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 18, 2025 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 18, 2025 Windtree Therapeutics, Inc.

February 18, 2025 EX-3.1

Certificate of Amendment to Amended and Restated Certificate of Incorporation (incorporated by reference to Exhibit 3.1 to Windtree’s Registration Statement on Form 8-K, as filed with the SEC on February 18, 2025).

Exhibit 3.1 CERTIFICATE OF AMENDMENT TO THE AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF WINDTREE THERAPEUTICS, INC. (Pursuant to Sections 228 and 242 of the General Corporation Law of the State of Delaware) The Company was originally incorporated on November 6, 1992, under the name “Ansan, Inc.” The Company changed its name on November 25, 1997, to Discovery Laboratories, Inc. The Company

February 18, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 14, 2025 Windtree Therapeu

-12-31 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 14, 2025 Windtree Therapeutics, Inc.

February 18, 2025 EX-99.1

Windtree Therapeutics, Inc. Announces Reverse Stock Split

Exhibit 99.1 Windtree Therapeutics, Inc. Announces Reverse Stock Split WARRINGTON, Pa., February 18, 2025 (GLOBE NEWSWIRE) – Windtree Therapeutics, Inc. (NasdaqCM: WINT) (“Windtree” or the “Company”), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions and diseases, announces that its board of directors has approved a 1-for-50 reverse stoc

February 14, 2025 S-1

As filed with the Securities and Exchange Commission on February 14, 2025

As filed with the Securities and Exchange Commission on February 14, 2025 Registration No.

February 14, 2025 8-K/A

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K/A (Amendment No.

February 14, 2025 EX-FILING FEES

Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc.

February 3, 2025 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 3, 2025 Windtree Therapeutics, Inc.

January 27, 2025 EX-4.1

Form of Conversion Notice for Series C Convertible Preferred Stock from January 2025 (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on January 27, 2025).

Exhibit 4.1 WINDTREE THERAPEUTICS, INC. CONVERSION NOTICE Reference is made to the Certificate of Designations, Preferences and Rights of the Series C Convertible Preferred Stock of Windtree Therapeutics, Inc. (the “Certificate of Designations”). In accordance with and pursuant to the Certificate of Designations, and in consideration of Windtree Therapeutics, Inc. (the “Company”) agreeing to reduc

January 27, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2025 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2025 Windtree Therapeutics, Inc.

January 13, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2025 Windtree Therapeutics, Inc.

January 13, 2025 EX-99.1

Windtree Announces the Addition of Leanne Kelly to Its Board of Directors

Exhibit 99.1 Windtree Announces the Addition of Leanne Kelly to Its Board of Directors WARRINGTON, PA – January 13, 2025 – Windtree Therapeutics, Inc. (“Windtree” or the “Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions and diseases, today announced the appointment of Leanne Kelly to its board of directors (“

January 8, 2025 EX-99.1

Windtree Therapeutics Announces New Corporate Strategy Seeking to Identify and Acquire FDA-Approved Revenue Assets While Advancing Its Cardiovascular and Oncology Pipeline All-Stock Acquisition Strategy Targets Multiple Small Companies with FDA-Appro

Exhibit 99.1 Windtree Therapeutics Announces New Corporate Strategy Seeking to Identify and Acquire FDA-Approved Revenue Assets While Advancing Its Cardiovascular and Oncology Pipeline All-Stock Acquisition Strategy Targets Multiple Small Companies with FDA-Approved Products to Drive Growth and Shareholder Value WARRINGTON, PA – January 8, 2025 – Windtree Therapeutics, Inc. (“Windtree” or the “Com

January 8, 2025 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Definitive Proxy State

January 8, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2025 Windtree Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2025 Windtree Therapeutics, Inc.

December 30, 2024 PRE 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

December 5, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 2, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 2, 2024 Windtree Therapeutics, Inc.

December 4, 2024 EX-99.1

Windtree Announces Partnership with New Growth Advisors to Leverage Positive Phase 2 Istaroxime Study in Cardiogenic Shock for a Potential Strategic Transaction

Exhibit 99.1 Windtree Announces Partnership with New Growth Advisors to Leverage Positive Phase 2 Istaroxime Study in Cardiogenic Shock for a Potential Strategic Transaction WARRINGTON, PA – December 4, 2024 – Windtree Therapeutics, Inc. (“Windtree” or the “Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions and

December 4, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 4, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 4, 2024 Windtree Therapeutics, Inc.

November 27, 2024 EX-99.1

Windtree Therapeutics Reports Third Quarter 2024 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports Third Quarter 2024 Financial Results and Provides Key Business Updates WARRINGTON, PA – November 27, 2024 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions, today reported financial results for the third quarter ended

November 27, 2024 8-K

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 21, 2024 Windtree Therapeutics, Inc.

November 26, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-3929

November 15, 2024 NT 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING SEC FILE NUMBER 001-39290 CUSIP NUMBER 97382D 501 (Check One): ☐Form 10-K ☐Form 20-F ☐Form 11-K ☒Form 10-Q ☐Form 10-D ☐Form N-CEN ☐Form N-CSR For Period Ended: September 30, 2024 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Transiti

November 15, 2024 8-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 25, 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K/A (Amendment No.

November 14, 2024 EX-99.1

JOINT FILING AGREEMENT

Exhibit 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock, par value $0.001 per share, of Windtree Therapeutics, Inc. shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G. November 14, 2024 LIND GLOBAL FUND II LP By: Lind Global Partners

November 14, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 8, 2024 Windtree Therapeutics, Inc.

November 14, 2024 SC 13G/A

WINT / Windtree Therapeutics, Inc. / Lind Global Fund II LP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* Windtree Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 97382D501 (CUSIP Number) September 30, 2024 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designat

November 14, 2024 SC 13G

WINT / Windtree Therapeutics, Inc. / ARMISTICE CAPITAL, LLC Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.

November 14, 2024 SC 13G/A

WINT / Windtree Therapeutics, Inc. / Flynn James E Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No.

October 28, 2024 424B5

Up to $27,243,504 of Shares of Common Stock

Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-261878 PROSPECTUS SUPPLEMENT (to Prospectus dated January 3, 2022) Up to $27,243,504 of Shares of Common Stock This prospectus supplement relates to the issuance and sale of up to $27,243,504 of shares of our common stock, par value $0.001 per share, or common stock, that we may issue and sell to Seven Knots, LLC, or Seven Kno

October 28, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 28, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 28, 2024 Windtree Therapeutics, Inc.

October 4, 2024 8-K

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 4, 2024 Windtree Therapeutics, Inc.

October 1, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 25, 2024 Windtree Therape

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 25, 2024 Windtree Therapeutics, Inc.

October 1, 2024 EX-99.1

Investor Presentation of Windtree Therapeutics, Inc.

Exhibit 99.1

October 1, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 1, 2024 Windtree Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 1, 2024 Windtree Therapeutics, Inc.

September 30, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 30, 2024 Windtree Therape

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 30, 2024 Windtree Therapeutics, Inc.

September 30, 2024 EX-99.1

Windtree Announces Positive Phase 2b Topline Clinical Results with Istaroxime Significantly Improving Cardiac Function and Blood Pressure in Heart Failure Patients in Early Cardiogenic Shock Istaroxime treatment significantly improved systolic blood

Exhibit 99.1 Windtree Announces Positive Phase 2b Topline Clinical Results with Istaroxime Significantly Improving Cardiac Function and Blood Pressure in Heart Failure Patients in Early Cardiogenic Shock Istaroxime treatment significantly improved systolic blood pressure as well as cardiac output and renal function without increasing heart rate or clinically significant arrythmias NYHA heart failu

September 25, 2024 EX-99.1

Windtree Announces Positive Topline Results from Its Phase 2b SEISMiC Extension Study of Istaroxime in Early Cardiogenic Shock Istaroxime significantly improved primary endpoint of the systolic blood pressure profile over six hours and showed signifi

Exhibit 99.1 Windtree Announces Positive Topline Results from Its Phase 2b SEISMiC Extension Study of Istaroxime in Early Cardiogenic Shock Istaroxime significantly improved primary endpoint of the systolic blood pressure profile over six hours and showed significant improvements in many secondary endpoint assessments Study results to be presented at the Heart Failure Society of America Medical Co

September 25, 2024 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 25, 2024 Windtree Therapeutics, Inc.

September 24, 2024 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 24, 2024 Windtree Therapeutics, Inc.

September 13, 2024 EX-99.1

Investor Presentation of Windtree Therapeutics, Inc.

Exhibit 99.1

September 13, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 13, 2024 Windtree Therapeutics, Inc.

September 3, 2024 424B5

Up to 27,668,106 Shares of Common Stock

PROSPECTUS Filed Pursuant to Rule 424(b)(5) Registration No. 333-281688 Up to 27,668,106 Shares of Common Stock This prospectus relates to the offer and resale by the selling stockholders identified in this prospectus of up to an aggregate of 27,668,106 shares of our common stock, par value $0.001 per share, or the common stock, issuable upon (i) the conversion of shares, referred to as the Prefer

September 3, 2024 424B5

Up to 10,679,758 Shares of Common Stock

Table of Contents PROSPECTUS Filed Pursuant to Rule 424(b)(5) Registration No. 333-281755 Up to 10,679,758 Shares of Common Stock This prospectus relates to the potential resale from time to time by Seven Knots, LLC, or Seven Knots or the Selling Stockholder, of up to 10,679,758 shares of common stock, par value $0.001 per share, or common stock. The shares of common stock to which this prospectus

September 3, 2024 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defi

August 28, 2024 CORRESP

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 August 28, 2024

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 August 28, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, NE Washington, D.C. 20549 Attn: Daniel Crawford Re: Windtree Therapeutics, Inc. Registration Statement on Form S-3 SEC File No. 333-281688 Request for Acceleration Mr. Crawford:

August 28, 2024 CORRESP

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 August 28, 2024

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 August 28, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, NE Washington, D.C. 20549 Attn: Daniel Crawford Re: Windtree Therapeutics, Inc. Registration Statement on Form S-1 SEC File No. 333-281755 Request for Acceleration Mr. Crawford:

August 23, 2024 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc.

August 23, 2024 S-1

As filed with the Securities and Exchange Commission on August 23, 2024.

Table of Contents As filed with the Securities and Exchange Commission on August 23, 2024.

August 21, 2024 EX-FILING FEES

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Windtree Therapeutics, Inc.

August 21, 2024 PRE 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defi

August 21, 2024 S-3

As filed with the Securities and Exchange Commission on August 21, 2024

As filed with the Securities and Exchange Commission on August 21, 2024 Registration No.

August 20, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 20, 2024 Windtree Therapeutics, Inc.

August 20, 2024 EX-99.1

Windtree Therapeutics Reports Second Quarter 2024 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports Second Quarter 2024 Financial Results and Provides Key Business Updates WARRINGTON, PA – August 20, 2024 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions, today reported financial results for the second quarter ended

August 19, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WIN

August 14, 2024 NT 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING SEC FILE NUMBER 001-39290 CUSIP NUMBER 97382D 501 (Check One): ☐ Form 10-K ☐ Form 20-F ☐ Form 11-K ☒ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR For Period Ended: June 30, 2024 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Transi

August 14, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2024 Windtree Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 13, 2024 Windtree Therapeutics, Inc.

July 29, 2024 EX-10.2

Form of Registration Rights Agreement dated July 26, 2024 by and among Windtree and the purchasers party thereto (incorporated by reference to Exhibit 10.2 to Windtree’s Form 8-K, as filed with the SEC on July 29, 2024).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of July , 2024, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and the undersigned buyers (each, a “Buyer,” and collectively, the “Buyers”). RECITALS A. In connection with the Securi

July 29, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 26, 2024 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 26, 2024 Windtree Therapeutics, Inc.

July 29, 2024 EX-10.1

Form of Securities Purchase Agreement dated July 26, 2024 by and among Windtree and the purchasers party thereto (incorporated by reference to Exhibit 10.1 to Windtree’s Form 8-K, as filed with the SEC on July 29, 2024).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (the “Agreement”), dated as of July 26, 2024, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and each of the investors listed on the Schedule of Buyers attached hereto (individually, a “Buyer” and collectively,

July 29, 2024 EX-4.1

Form of Common Stock Warrant issued in the Company’s July 2024 private placement on July 26, 2024 (incorporated by reference to Exhibit 4.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on July 29, 2024).

Exhibit 4.1 [FORM OF WARRANT] NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATI

July 25, 2024 RW

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 July 25, 2024

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 July 25, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, NE Washington, D.C. 20549 Re: Windtree Therapeutics, Inc. Request to Withdraw Registration Statement on Form S-1 File No. 333-279241 Ladies and Gentlemen: Pursuant to Rule 477 unde

July 22, 2024 EX-10.1

Form of Securities Purchase Agreement dated July 18, 2024 by and among Windtree and the purchasers party thereto (incorporated by reference to Exhibit 10.1 to Windtree’s Form 8-K, as filed with the SEC on July 22, 2024).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (the “Agreement”), dated as of July 18, 2024, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and each of the investors listed on the Schedule of Buyers attached hereto (individually, a “Buyer” and collectively,

July 22, 2024 EX-3.1

Certificate of Designations of Series C Convertible Preferred Stock (incorporated by reference to Exhibit 3.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on July 22, 2024).

Exhibit 3.1 CERTIFICATE OF DESIGNATIONS OF RIGHTS AND PREFERENCES OF SERIES C CONVERTIBLE PREFERRED STOCK OF WINDTREE THERAPEUTICS, INC. I, Craig Fraser, hereby certify that I am the President and Chief Executive Officer of Windtree Therapeutics, Inc. (the “Company”), a corporation organized and existing under the Delaware General Corporation Law (the “DGCL”), and further do hereby certify: That p

July 22, 2024 EX-4.1

Form of Common Stock Warrant issued in the Company’s private placement on July 18, 2024 (incorporated by reference to Exhibit 4.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on July 22, 2024).

Exhibit 4.1 [FORM OF WARRANT] NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE EXERCISABLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATI

July 22, 2024 8-K

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Material Modification to Rights of Security Holders, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 -12-31 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 18, 2024 Windtree Therapeutics, Inc.

July 22, 2024 EX-10.2

Form of Registration Rights Agreement dated July 18, 2024 by and among Windtree and the purchasers party thereto (incorporated by reference to Exhibit 10.2 to Windtree’s Form 8-K, as filed with the SEC on July 22, 2024).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of July , 2024, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and the undersigned buyers (each, a “Buyer,” and collectively, the “Buyers”). RECITALS A. In connection with the Securi

July 10, 2024 EX-4.2

Form of Senior Secured Note due 2025 (incorporated by reference to Exhibit 4.2 to Windtree’s Form 8-K, as filed with the SEC on July 10, 2024).

Exhibit 4.2 THE ISSUANCE AND SALE OF THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THIS NOTE MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL TO THE HOLDER (IF REQ

July 10, 2024 EX-4.1

Form of Senior Unsecured Promissory Note due 2025 (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on July 10, 2024).

Exhibit 4.1 THE ISSUANCE AND SALE OF THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THIS NOTE MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL TO THE HOLDER (IF REQ

July 10, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 3, 2024 Windtree Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 3, 2024 Windtree Therapeutics, Inc.

July 3, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 3, 2024 Windtree Therapeutics, Inc.

July 3, 2024 EX-99.1

Investor Presentation of Windtree Therapeutics, Inc.

Exhibit 99.1

July 1, 2024 EX-10.2

Registration Rights Agreement dated June 26, 2024 by and between Windtree and Seven Knots, LLC (incorporated by reference to Exhibit 10.2 to Windtree’s Current Report on Form 8-K, as filed with the SEC on July 1, 2024).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of June 26, 2024, is by and between Seven Knots, LLC, a Montana limited liability company (the “Investor”), and Windtree Therapeutics, Inc., a Delaware corporation (the “Company”). RECITALS A. The Company and the Investor have entered into that certain Common Stock Purchase Agreement, dated a

July 1, 2024 EX-4.1

Convertible Promissory Note, dated June 26, 2024, between Windtree and Seven Knots, LLC (incorporated by reference to Exhibit 4.1 to Windtree’s Form 8-K, as filed with the SEC on July 1, 2024).

Exhibit 4.1 THIS CONVERTIBLE PROMISSORY NOTE (AS MAY BE AMENDED FROM TIME TO TIME, THE “NOTE”) AND THE SECURITIES INTO WHICH IT MAY BE CONVERTED HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”) OR UNDER THE SECURITIES LAWS OF ANY STATE. THESE SECURITIES ARE SUBJECT TO RESTRICTIONS ON TRANSFERABILITY AND RESALE. THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENT

July 1, 2024 EX-4.2

Form of Senior Secured Notes due 2025

Exhibit 4.2 THE ISSUANCE AND SALE OF THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THIS NOTE MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL TO THE HOLDER (IF REQ

July 1, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 25, 2024 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 25, 2024 Windtree Therapeutics, Inc.

July 1, 2024 EX-10.1

Common Stock Purchase Agreement dated June 26, 2024 by and between Windtree and Seven Knots, LLC (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on July 1, 2024).

Exhibit 10.1 COMMON STOCK PURCHASE AGREEMENT Dated as of June 26, 2024 by and among WINDTREE THERAPEUTICS, INC., and SEVEN KNOTS, LLC TABLE OF CONTENTS Page ARTICLE I PURCHASE AND SALE OF COMMON STOCK 1 Section 1.1. Purchase and Sale of Stock 2 Section 1.2. Closing Date; Settlement Dates 2 Section 1.3. Initial Public Announcements and Required Filings 2 ARTICLE II PURCHASE TERMS 3 Section 2.1. Fix

May 15, 2024 EX-10.1

Master Services Agreement and Work Orders Nos. 11 and 12, by and between the Company and Momentum Research, Inc., dated February 13, 2020 (incorporated by reference to Exhibit 10.1 to Windtree’s Quarterly Report on Form 10-Q, as filed on May 15, 2024).

Exhibit 10.1 MASTER SERVICES AGREEMENT This Master Services Agreement ("Agreement") is made between Windtree Therapeutics Inc, a Delaware corporation having its principal place of business at 2600 Kelly Road, Warrington, PA 18976 (hereinafter "WINDTREE"), and Momentum Research Inc. a C corporation having its principal place of business at [***] (hereinafter "MRI"). When signed by both parties, thi

May 15, 2024 EX-10.2

Amendment No. 1 to Master Services Agreement and Work Orders Nos. 11 and 12, by and between the Company and Momentum Research, Inc., effective upon May 9, 2024 (incorporated by reference to Exhibit 10.2 to Windtree’s Quarterly Report on Form 10-Q, as filed on May 15, 2024).

Exhibit 10.2 CERTAIN INFORMATION IN THIS DOCUMENT, MARKED BY [***], HAS BEEN EXCLUDED PURSUANT TO ITEM 601(b)(10)(iv) OF REGULATION S-K. SUCH EXCLUDED INFORMATION IS NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. AMENDMENT NO. 1 TO MASTER SERVICES AGREEMENT AND WORK ORDER NOS. 11 AND 12 This AMENDMENT NO. 1 TO MASTER SERVICES AGREEMENT AND WORK ORDER NOS. 11 AN

May 15, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WI

May 9, 2024 EX-3.1

Amended and Restated Certificate of Incorporation, including Certificate of Designations of Series B Convertible Preferred Stock of Windtree (incorporated by reference to Exhibit 3.1 to Windtree’s Registration Statement on Form S-1, as filed with the SEC on May 9, 2024).

Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF WINDTREE THERAPEUTICS, INC. (Pursuant to Sections 228, 242, and 245 of the General Corporation Law of the State of Delaware) A. The Corporation was originally incorporated on November 6, 1992, under the name “Ansan, Inc.” The Corporation changed its name on November 25, 1997, to Discovery Laboratories, Inc. The Corporation changed it

May 9, 2024 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Windtree Therapeutics, Inc.

May 9, 2024 S-1

As filed with the Securities and Exchange Commission on May 9, 2024.

Table of Contents As filed with the Securities and Exchange Commission on May 9, 2024.

April 23, 2024 8-K

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 23, 2024 Windtree Therapeutics, Inc.

April 23, 2024 EX-99.1

Corporate Presentation of Windtree Therapeutics, Inc.

Exhibit 99.1

April 19, 2024 EX-3.1

Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Windtree Therapeutics, Inc.

Exhibit 3.1 CERTIFICATE OF AMENDMENT TO THE AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF WINDTREE THERAPEUTICS, INC. (Pursuant to Sections 228 and 242 of the General Corporation Law of the State of Delaware) The Company was originally incorporated on November 6, 1992, under the name “Ansan, Inc.” The Company changed its name on November 25, 1997, to Discovery Laboratories, Inc. The Company

April 19, 2024 8-K

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Material Modification to Rights of Security Holders, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 19, 2024 -12-31 Windtree Therapeutics, Inc.

April 17, 2024 EX-99.1

Windtree Therapeutics Reports Fourth Quarter and Year-End 2023 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports Fourth Quarter and Year-End 2023 Financial Results and Provides Key Business Updates WARRINGTON, PA – April 17, 2024 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing early and late-stage innovative therapies for critical conditions, today reported financial results for the fourth qu

April 17, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2024 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2024 Windtree Therapeutics, Inc.

April 17, 2024 S-3/A

As filed with the Securities and Exchange Commission on April 17, 2024

S-3/A 1 wint20240417s3a.htm FORM S-3/A Table of Contents As filed with the Securities and Exchange Commission on April 17, 2024 Registration No. 333-277073 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 TO FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 WINDTREE THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaw

April 17, 2024 CORRESP

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 April 17, 2024

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 April 17, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, NE Washington, D.C. 20549 Attn: Doris Stacey Gama Re: Windtree Therapeutics, Inc. Registration Statement on Form S-3 SEC File No. 333-277073 Request for Acceleration Ms. Gama: Pur

April 16, 2024 EX-97.1

Windtree Therapeutics, Inc. Compensation Recovery Policy.

Exhibit 97.1 WINDTREE THERAPEUTICS, INC. COMPENSATION RECOVERY POLICY Adopted as of November 15, 2023 Windtree Therapeutics, Inc., a Delaware corporation (the “Company”), has adopted a Compensation Recovery Policy (this “Policy”) as described below. 1. Overview The Policy sets forth the circumstances and procedures under which the Company shall recover Erroneously Awarded Compensation from Covered

April 16, 2024 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 Or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WINDTRE

April 16, 2024 EX-10.3

Amendment No. 1, effective as of January 17, 2024, to the Amended and Restated License Agreement, between Windtree and Philip Morris USA Inc. dated March 28, 2008 (incorporated by reference to Exhibit 10.3 to Windtree’s Annual Report on Form 10-K, as filed with the SEC on April 16, 2024).

Exhibit 10.3 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. AMENDMENT NO. 1 TO AMENDED AND RESTATED LICENSE AGREEMENT This Amendment No. 1 to Amended and R

April 16, 2024 EX-10.61

License, Development and Commercialization Agreement, by and between the Company and Lee’s Pharmaceutical (HK) Ltd., dated January 12, 2024 (incorporated by reference to Exhibit 10.61 to Windtree’s Annual Report on Form 10-K, as filed with the SEC on April 16, 2024).

Exhibit 10.61 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. LICENSE, DEVELOPMENT AND COMMERCIALIZATION AGREEMENT by and between WINDTREE THERAPEUTICS, INC

April 16, 2024 EX-4.18

Description of Securities (incorporated by reference to Exhibit 4.18 to Windtree’s Annual Report on Form 10-K, as filed with the SEC on April 16, 2024).

Exhibit 4.18 DESCRIPTION OF THE COMPANY’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Windtree Therapeutics, Inc., or the Company, has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended, or the Exchange Act. The Company’s common stock, $0.001 par value per share, or the Common Stock, is registered under Sec

April 16, 2024 EX-10.5

Amendment No. 1, effective as of January 17, 2024, to the License Agreement, between Windtree and Philip Morris Products S.A. dated March 28, 2008 (incorporated by reference to Exhibit 10.5 to Windtree’s Annual Report on Form 10-K, as filed with the SEC on April 16, 2024).

Exhibit 10.5 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. AMENDMENT NO. 1 TO THE LICENSE AGREEMENT This Amendment No. 1 to the License Agreement (this “A

April 16, 2024 EX-3.1

Amended and Restated Certificate of Incorporation.

Exhibit 3.1 AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF WINDTREE THERAPEUTICS, INC. (Pursuant to Sections 228, 242, and 245 of the General Corporation Law of the State of Delaware) A. The Corporation was originally incorporated on November 6, 1992, under the name “Ansan, Inc.” The Corporation changed its name on November 25, 1997, to Discovery Laboratories, Inc. The Corporation changed it

April 10, 2024 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 10, 2024 Windtree Therapeutics, Inc.

April 8, 2024 EX-10.1

Form of Securities Purchase Agreement by and between Windtree Therapeutics, Inc. and the Buyers named therein, dated April 2, 2024 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 8, 2024).

Exhibit 10.1 SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (the “Agreement”), dated as of April 2, 2024, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and each of the investors listed on the Schedule of Buyers attached hereto (individually, a “Buyer” and collectively,

April 8, 2024 EX-2.1

Form of Asset Purchase Agreement by and between Windtree Therapeutics, Inc. and Varian Biopharmaceuticals, Inc., dated April 2, 2024 (incorporated by reference to Exhibit 2.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 8, 2024).

Exhibit 2.1 ASSET PURCHASE AGREEMENT between VARIAN BIOPHARMACEUTICALS, INC. and WINDTREE THERAPEUTICS, INC. Dated April 2, 2024 TABLE OF CONTENTS Page Article I DEFINITIONS AND TERMS 1 Section 1.1. Certain Definitions 1 Section 1.2. Other Terms 11 Section 1.3. Other Definitional Provisions 11 Article II PURCHASE AND SALE 12 Section 2.1. Purchase and Sale of Assets 12 Section 2.2. Excluded Assets

April 8, 2024 EX-3.1

Certificate of Designations of Series B Convertible Preferred Stock (incorporated by reference to Exhibit 3.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 8, 2024)

Exhibit 3.1 CERTIFICATE OF DESIGNATIONS OF SERIES B CONVERTIBLE PREFERRED STOCK OF WINDTREE THERAPEUTICS, INC. I, Craig Fraser, hereby certify that I am the President and Chief Executive Officer of Windtree Therapeutics, Inc. (the “Company”), a corporation organized and existing under the Delaware General Corporation Law (the “DGCL”), and further do hereby certify: That pursuant to the authority e

April 8, 2024 EX-10.2

Form of Registration Rights Agreement, by and between Windtree Therapeutics, Inc. and the Buyers named therein, dated April 2, 2024 (incorporated by reference to Exhibit 10.2 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 8, 2024).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of April 2, 2024, is by and among Windtree Therapeutics, Inc., a Delaware corporation with offices located at 2600 Kelly Road, Suite 100, Warrington, PA 18976 (the “Company”), and the undersigned buyers (each, a “Buyer,” and collectively, the “Buyers”). RECITALS A. In connection with (a) the

April 8, 2024 8-K

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Unregistered Sales of Equity Securities, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 -12-31 Date of Report (Date of earliest event reported): April 2, 2024 Windtree Therapeutics, Inc.

April 8, 2024 EX-4.1

Form of 10% Convertible Note (incorporated by reference to Exhibit 4.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on April 8, 2024).

Exhibit 4.1 NEITHER THE ISSUANCE AND SALE OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE NOR THE SECURITIES INTO WHICH THESE SECURITIES ARE CONVERTIBLE HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR T

April 2, 2024 NT 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 12b-25 NOTIFICATION OF LATE FILING SEC FILE NUMBER 000-26422 CUSIP NUMBER 97382D 402 (Check One): ☒ Form 10-K ☐ Form 20-F ☐ Form 11-K ☐ Form 10-Q ☐ Form 10-D ☐ Form N-CEN ☐ Form N-CSR For Period Ended: December 31, 2023 ☐ Transition Report on Form 10-K ☐ Transition Report on Form 20-F ☐ Transition Report on Form 11-K ☐ Tr

March 12, 2024 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of

February 16, 2024 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 15, 2024 Windtree Therapeutics, Inc.

February 14, 2024 SC 13G/A

WINT / Windtree Therapeutics, Inc. / Lincoln Park Capital Fund, LLC - SC 13G/A Passive Investment

SC 13G/A 1 tm246286d3sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* WINDTREE THERAPEUTICS, INC. (Name of Issuer) COMMON STOCK, $0.001 PAR VALUE PER SHARE (Title of Class of Securities) 97382D204 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statem

February 14, 2024 EX-99.1

Joint Filing Agreement

EX-99.1 2 tm246286d3ex99-1.htm EXHIBIT 99.1 EXHIBIT 99.1 Joint Filing Agreement The undersigned hereby agree that they are filing this statement jointly pursuant to Rule 13d-1(k)(1). Each of them is responsible for the timely filing of such Schedule 13G, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the comple

February 14, 2024 EX-FILING FEES

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Windtree Therapeutics, Inc.

February 14, 2024 S-3

As filed with the Securities and Exchange Commission on February 14, 2024

Table of Contents As filed with the Securities and Exchange Commission on February 14, 2024 Registration No.

February 13, 2024 EX-99.1

JOINT FILING AGREEMENT

EX-99.1 2 exhibit99-1.htm JOINT FILING AGREEMENT BY AND AMONG THE REPORTING PERSONS Exhibit 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock, par value $0.001 per share, of Windtree Therapeutics, Inc. shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to

February 13, 2024 SC 13G/A

US97382D4025 / WINDTREE THERAPEUTICS INC / Lind Global Fund II LP Passive Investment

SC 13G/A 1 sch13g.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* Windtree Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 97382D402 (CUSIP Number) December 31, 2023 (Date of Event which Requires Filing of this Statement) Check the approp

February 12, 2024 PRE 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of

February 1, 2024 SC 13G

US97382D4025 / WINDTREE THERAPEUTICS INC / Flynn James E Passive Investment

SC 13G 1 e619221sc13g-windtree.htm SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. ) * Windtree Therapeutics, Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 97382D402 (CUSIP Number) January

January 31, 2024 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 31, 2024 Windtree Therapeutics, Inc.

January 31, 2024 EX-99.1

Windtree Therapeutics Announces Engagement of Strategic Advisor to Support Assessment of Strategic Alternatives

Exhibit 99.1 Windtree Therapeutics Announces Engagement of Strategic Advisor to Support Assessment of Strategic Alternatives WARRINGTON, PA, January 31, 2024 (GLOBE NEWSWIRE) - Windtree Therapeutics, Inc. (“Windtree” or the “Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing late-stage interventions for critical cardiovascular disorders, today announced that it has engaged La

January 25, 2024 EX-10.1

Exchange and Termination Agreement, by and between the Company and affiliates of Deerfield Management Company, L.P., effective upon January 24, 2024 (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on January 25, 2024).

Exhibit 10.1 [***] Certain portions of this exhibit have been omitted because they are not material and the registrant customarily and actually treats that information as private or confidential. Certain exhibits and schedules to these agreements have been omitted pursuant to Item 601 of Regulation S-K. EXCHANGE AND TERMINATION AGREEMENT This EXCHANGE AND TERMINATION AGREEMENT (this “Agreement”),

January 25, 2024 EX-10.2

Registration Rights Agreement, by and between the Company and affiliates of Deerfield Management Company, L.P., effective upon January 24, 2024 (incorporated by reference to Exhibit 10.2 to Windtree’s Current Report on Form 8-K, as filed with the SEC on January 25, 2024).

Exhibit 10.2 REGISTRATION RIGHTS AGREEMENT REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of January 24, 2024, by and among Windtree Therapeutics, Inc., a Delaware corporation (the “Company”), Deerfield Private Design Fund II, L.P. (“DPDF II”) and Deerfield PDI Financing II, L.P. (“DPDI Financing II” and together with DPDF II, “Investors,” and each, an “Investor”). WHEREAS: A. In conne

January 25, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 24, 2024 Windtree Therapeutics, Inc.

January 22, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2024 Windtree Therapeutics, Inc.

January 17, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2024 Windtree Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2024 Windtree Therapeutics, Inc.

January 16, 2024 424B5

Up to $1,297,312 Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-261878 PROSPECTUS SUPPLEMENT (To Prospectus Supplement dated November 9, 2023 and Prospectus dated January 3, 2022) Up to $1,297,312 Common Stock This Prospectus Supplement, dated January 16, 2024 (the “Prospectus Supplement”) supplements the prospectus supplement, dated November 9, 2023 (together with the accompanying prospectus, the “ATM Pros

November 9, 2023 EX-1.1

At The Market Offering Agreement, dated as of November 9, 2023, by and between Windtree Therapeutics, Inc. and Ladenburg Thalmann & Co. Inc. (incorporated by reference to Exhibit 1.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on November 9, 2023).

Exhibit 1.1 AT THE MARKET OFFERING AGREEMENT November 9, 2023 Ladenburg Thalmann & Co. Inc. 640 Fifth Avenue, 4th Floor New York, NY 10019 Ladies and Gentlemen: Windtree Therapeutics, Inc., a corporation organized under the laws of Delaware (the “Company”), confirms its agreement (this “Agreement”) with Ladenburg Thalmann & Co. Inc. (the “Manager”) as follows: 1. Definitions. The terms that follow

November 9, 2023 EX-99.2

Investor Presentation of Windtree Therapeutics, Inc.

Exhibit 99.2

November 9, 2023 EX-99.1

Windtree Therapeutics Reports Third Quarter 2023 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports Third Quarter 2023 Financial Results and Provides Key Business Updates WARRINGTON, PA – November 9, 2023 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing late-stage interventions for cardiovascular disorders, today reported financial results for the third quarter ended September 30,

November 9, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-3929

November 9, 2023 424B5

Up to $2,054,024 Common Stock

Filed pursuant to Rule 424(b)(5) Registration No. 333-261878 PROSPECTUS SUPPLEMENT (to Prospectus dated January 3, 2022) Up to $2,054,024 Common Stock We have entered into an At The Market Offering Agreement, or the sales agreement, with Ladenburg Thalmann & Co. Inc., or Ladenburg, relating to shares of our common stock offered by this prospectus supplement. In accordance with the terms of the sal

November 9, 2023 8-K

Regulation FD Disclosure, Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 9, 2023 Windtree Therapeutics, Inc.

September 26, 2023 EX-99.1

Corporate Presentation of Windtree Therapeutics, Inc.

Exhibit 99.1

September 26, 2023 8-K

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 26, 2023 Windtree Therapeutics, Inc.

August 30, 2023 S-8

As filed with the Securities and Exchange Commission on August 30, 2023

As filed with the Securities and Exchange Commission on August 30, 2023 File No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM S-8 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 WINDTREE THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 94-3171943 (State or other jurisdiction of incorporation or organization) (IRS Employer

August 30, 2023 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Windtree Therapeutics, Inc.

August 28, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 23, 2023 Windtree Therapeu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 23, 2023 Windtree Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39290 94-3171943 (State or other jurisdiction of incorporation) (Commis

August 16, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 15, 2023 Windtree Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 15, 2023 Windtree Therapeutics, Inc.

August 16, 2023 EX-10.1

Amended and Restated Windtree Therapeutics, Inc. 2020 Equity Incentive Plan (incorporated by reference to Exhibit 10.1 to Windtree’s Current Report on Form 8-K, as filed with the SEC on August 16, 2023).

Exhibit 10.1 AMENDED AND RESTATED WINDTREE THERAPEUTICS, INC. 2020 EQUITY INCENTIVE PLAN Section 1. Purpose; Definitions. The purposes of the Amended and Restated Windtree Therapeutics, Inc. 2020 Equity Incentive Plan (as amended from time to time, the “Plan”) are to: (a) enable Windtree Therapeutics, Inc. (the “Company”) and its affiliated companies to recruit and retain highly qualified employee

August 7, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WIN

August 7, 2023 EX-99.1

Windtree Therapeutics Reports Second Quarter 2023 Financial Results and Provides Key Business Updates Company plans to initiate a Phase 2 SEISMiC extension study of istaroxime in early cardiogenic shock in Q3; Study start-up for a Phase 2 SCAI Stage

Exhibit 99.1 Windtree Therapeutics Reports Second Quarter 2023 Financial Results and Provides Key Business Updates Company plans to initiate a Phase 2 SEISMiC extension study of istaroxime in early cardiogenic shock in Q3; Study start-up for a Phase 2 SCAI Stage C cardiogenic shock study underway Completed $12.4 million public offering including full exercise of overallotment option WARRINGTON, PA

August 7, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2023 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2023 Windtree Therapeutics, Inc.

June 30, 2023 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

June 30, 2023 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Definitive Proxy State

June 30, 2023 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 ☒ Filed by the Registrant ☐ Filed by a Party other than the Registrant Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defi

June 27, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22, 2023 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 22, 2023 Windtree Therapeutics, Inc.

June 14, 2023 EX-99.1

Corporate Presentation of Windtree Therapeutics, Inc.

Exhibit 99.1

June 14, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 14, 2023 Windtree Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 14, 2023 Windtree Therapeutics, Inc.

May 25, 2023 CORRESP

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 May 25, 2023

Windtree Therapeutics, Inc. 2600 Kelly Road, Suite 100 Warrington, Pennsylvania 18976 May 25, 2023 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance Office of Life Sciences 100 F Street, NE Washington, D.C. 20549 Attn: Jimmy McNamara Re: Windtree Therapeutics, Inc. Registration Statement on Form S-3 SEC File No. 333-272095 Request for Acceleration Mr. McNamara: Purs

May 24, 2023 LETTER

LETTER

United States securities and exchange commission logo May 24, 2023 Craig Fraser President and Chief Executive Officer Windtree Therapeutics, Inc.

May 19, 2023 EX-FILING FEES

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Windtree Therapeutics, Inc.

May 19, 2023 S-3

As filed with the Securities and Exchange Commission on May 19, 2023

S-3 1 wint20230419s3.htm FORM S-3 Table of Contents As filed with the Securities and Exchange Commission on May 19, 2023 Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-3 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 WINDTREE THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 94-3171943 (State or other j

May 19, 2023 S-8

As filed with the Securities and Exchange Commission on May 19, 2023

As filed with the Securities and Exchange Commission on May 19, 2023 File No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM S-8 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 WINDTREE THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 94-3171943 (State or other jurisdiction of incorporation or organization) (IRS Employer Id

May 19, 2023 EX-FILING FEES

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Windtree Therapeutics, Inc.

May 17, 2023 SC 13D/A

WINT / Windtree Therapeutics Inc / Huang James - SC 13D/A Activist Investment

SC 13D/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 4)* Windtree Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 97382D204 (CUSIP Number) James Huang Panacea Venture No. 5, Lane 1350, Fuxing Middle Road Xuhui District, Shanghai China 200031

May 15, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39290 WI

May 15, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 Windtree Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2023 Windtree Therapeutics, Inc.

May 15, 2023 EX-99.1

Windtree Therapeutics Reports First Quarter 2023 Financial Results and Provides Key Business Updates

Exhibit 99.1 Windtree Therapeutics Reports First Quarter 2023 Financial Results and Provides Key Business Updates WARRINGTON, PA – May 15, 2023 – Windtree Therapeutics, Inc. (“Windtree” or “the Company”) (NasdaqCM: WINT), a biotechnology company focused on advancing late-stage interventions for cardiovascular disorders, today reported financial results for the first quarter ended March 31, 2023 an

May 1, 2023 10-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K/A (Amendment No. 1)

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 -12-31FY2022 Or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commissi

April 28, 2023 EX-99.1

JOINT FILING AGREEMENT

Exhibit 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock, par value $0.001 per share, of Windtree Therapeutics, Inc., shall be filed on behalf of each of the undersigned and that this Agreement shall be filed as an exhibit to such Schedule 13G. April 28, 2023 LIND GLOBAL FUND II LP By: Lind Global Partners I

April 28, 2023 SC 13G

US97382D4025 / WINDTREE THERAPEUTICS INC / Lind Global Fund II LP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Windtree Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.001 per share (Title of Class of Securities) 97382D402 (CUSIP Number) April 24, 2023 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the

April 24, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 20, 2023 Windtree Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 20, 2023 Windtree Therapeutics, Inc.

April 24, 2023 SC 13G

WINT / Windtree Therapeutics Inc / Lincoln Park Capital Fund, LLC - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* WINDTREE THERAPEUTICS, INC. (Name of Issuer) COMMON STOCK, $0.001 PAR VALUE PER SHARE (Title of Class of Securities) 97382D204 (CUSIP Number) April 20, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the

April 24, 2023 EX-99.1

Joint Filing Agreement

EXHIBIT 99.1 Joint Filing Agreement The undersigned hereby agree that they are filing this statement jointly pursuant to Rule 13d-1(k)(1). Each of them is responsible for the timely filing of such Schedule 13G, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concer

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