Windtree Therapeutics, Inc.

What they do

Windtree develops drug candidates: istaroxime, a Phase 2 dual-mechanism sodium-potassium ATPase inhibitor and SERCA2a activator for acute heart failure and cardiogenic shock; preclinical SERCA2a activators; rostafuroxin for genetically profiled hypertension; and a preclinical aPKCi inhibitor for oncology. It also operates a licensing model with out-licenses and, since 2025, has positioned itself as a manufacturing sourcing agent for third-party approved products.

Revenue drivers

• Licensing and out-licensing — The company describes a licensing business model with partnership out-licenses in place; historical annual revenue was small and uneven, ranging from $198,000 in 2019 to $2.0M in 2016.
• Manufacturing sourcing services — Since March 2025 Windtree acts as manufacturing sourcing agent for Evofem's FDA-approved product Phexxi, and in June 2025 signed a manufacturing deal with Zhoake (Hong Kong) Ophthalmology Pharmaceutical Limited to produce an approved product at lower cost.
• Acquisition strategy — Announced January 2025, management plans to acquire small companies with FDA-approved products, using equity as acquisition currency, to build a parent company of commercial subsidiaries; no completed acquisitions are disclosed in the excerpts.

Recent performance

No quarterly revenue was reported in the excerpts for 2025; the most recent annual revenue figures shown are 2019 ($198,000) after $1.8M in 2018. Net loss narrowed from $20.3M in 2023 to $1.8M in 2024, and operating cash flow was negative $15.4M in 2024 versus negative $13.4M in 2023. Diluted EPS was negative $104.35 in 2024 and negative $4,718.84 in 2023, reflecting reverse splits. At September 30, 2025, total assets were $16.0M, total liabilities $27.6M, shareholders' equity was negative $11.6M, and cash and equivalents were $204,000.

Strategy

Management stated in January 2025 that it intends to make Windtree a revenue-generating biotech by acquiring small companies and their FDA-approved products, with equity as the intended acquisition currency. It continues to advance the cardiovascular pipeline, including the SEISMiC C Study in SCAI Stage C cardiogenic shock and a preclinical SERCA2a activator program, alongside the aPKCi inhibitor and rostafuroxin. The company also expanded into manufacturing sourcing for approved products, including Phexxi for Evofem and a June 2025 deal with Zhoake. Management cautions that completing the SEISMiC C Study at its intended size depends on securing adequate financing or business development support.

Risks

• Going concern — The auditor's opinion on the 2024 financial statements includes an explanatory paragraph raising substantial doubt about the ability to continue as a going concern, and the 10-Q balance sheet shows negative shareholders' equity of $11.6M and only $204,000 of cash at September 30, 2025.
• Dependence on istaroxime — The 10-K risk factors state the company is substantially dependent on the success of istaroxime, its lead Phase 2 candidate for acute heart failure and cardiogenic shock.
• Third-party reliance — The 10-K risk factors note Windtree relies on third parties, primarily outside the U.S., to conduct many preclinical studies and clinical trials and to manufacture drug candidates.
• New business model risk — The 10-K risk factors state the company may change or diversify the nature of its business, exposing it to new risks, after launching its January 2025 acquisition strategy and manufacturing sourcing arrangements.

Outlook

Management expects enrollment in the SEISMiC C Study, which is designed for up to 100 SCAI Stage C cardiogenic shock subjects, to be completed in Q1 2026, with a planned unblinded review of the first 20 subjects; a preliminary interim review of those 20 subjects occurred in July 2025. The company says its ability to complete the study at its intended sample size depends on securing adequate resourcing through financing or business development. It also intends to pursue acquisitions of small companies with FDA-approved products to generate revenue, though no target deals are disclosed. Recent events include financing-related obligations, a delisting notice in August 2025, and a material agreement in July 2026.