# EDGAR Filing Document

**Accession Number:** 0000946486
**File Stem:** 0001437749-26-010838
**Filing Date:** 2026-4
**Character Count:** 6357
**Document Hash:** 8eaa417c4c1b4b052d1199b92345cb0b
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001437749-26-010838.hdr.sgml**: 20260401

**ACCESSION NUMBER**: 0001437749-26-010838

**CONFORMED SUBMISSION TYPE**: NT 10-K

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260401

**DATE AS OF CHANGE**: 20260401

**EFFECTIVENESS DATE**: 20260401

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** WINDTREE THERAPEUTICS INC /DE/
- **CENTRAL INDEX KEY:** 0000946486
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 943171943
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** NT 10-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39290
- **FILM NUMBER:** 26825906

**BUSINESS ADDRESS:**
- **STREET 1:** 2600 KELLY ROAD
- **STREET 2:** SUITE 100
- **CITY:** WARRINGTON
- **STATE:** PA
- **ZIP:** 18976
- **BUSINESS PHONE:** 2154889300

**MAIL ADDRESS:**
- **STREET 1:** 2600 KELLY ROAD
- **STREET 2:** SUITE 100
- **CITY:** WARRINGTON
- **STATE:** PA
- **ZIP:** 18976

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** DISCOVERY LABORATORIES INC /DE/
- **DATE OF NAME CHANGE:** 19971201

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ANSAN PHARMACEUTICALS INC
- **DATE OF NAME CHANGE:** 19961121

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** ANSAN INC
- **DATE OF NAME CHANGE:** 19950609

**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: <u>December 31, 2025</u>

☐ Transition Report on Form 10-K

☐ Transition Report on Form 20-F

☐ Transition Report on Form 11-K

☐ Transition Report on Form 10-Q

For the Transition Period Ended: _________

*Read Instruction (on back page) Before Preparing Form. Please Print or Type.*

**Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.**

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

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**PART I -- REGISTRANT INFORMATION**

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| |
|:---|
| Windtree Therapeutics, Inc. |
| Full Name of Registrant |
| Discovery Laboratories, Inc. |
| Former Name if Applicable |
| 2600 Kelly Rd., Suite 100 |
| Address of Principal Executive Office *(Street and Number)* |
| Warrington, PA 18976 |
| City, State and Zip Code |

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**PART II -- RULES 12B-25(b) AND (c)**

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate)

☒ (a) The reason described in reasonable detail in Part III of this Form could not be eliminated without unreasonable effort or expense; (b) The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-CEN or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and (c) The accountant's statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

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**PART III** – **NARRATIVE**

State below in reasonable detail why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-CEN, N-CSR, or the transition report or portion thereof, could not be filed within the prescribed time period.

As reported in the Company's Quarterly Report on Form 10-Q for the quarter ended September 30, 2025, our existing resources are limited. In response to our limited liquidity, the Company is seeking sources of capital through potential strategic transactions. The Company management has devoted significant resources toward finalizing its financial statements and disclosures, however, the Company was required to devote a significant amount of time and other Company resources to other matters such as financing opportunities, which normally would be devoted to the preparation of the Annual Report on Form 10-K (the "Form 10-K") and related matters. There can be no assurance that a strategic transaction will be consummated. As a result of these factors, the Company's limited resources have caused a delay in the Company's ability to complete and file its Form 10-K for the fiscal year ended December 31, 2025 by the required deadline without unreasonable effort and expense.

The Company expects to be in a position to file the Form 10-K on or before April 15, 2026, the prescribed due date under the fifteen calendar day extension period provided under Rule 12b-25 under the Securities Exchange Act of 1934.

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**PART IV -- OTHER INFORMATION**

(1) Name and telephone number of person to contact in regard to this notification

<u>Jed Latkin </u> <u>(215) </u> <u>488-9300 </u> <br> (Name) (Area Code) (Telephone Number)

(2) Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed? If the answer is no, identify report(s).

☒ Yes ☐ No

(3) Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?

☐ Yes ☒ No

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

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<u>Windtree Therapeutics, Inc. </u> <br> (Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | | |
|:---|:---|:---|:---|
| Date | March 31, 2026 | By | /s/ Jed Latkin |
|  |  |  | Name: Jed :Latkin<br> Title: Chief Executive Officer |

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