Atossa Advances Global Patent Strategy for Z-Endoxifen with New Protection in Israel and Ongoing Renewals

Rhea-AI Summary

Atossa Therapeutics (NASDAQ: ATOS) announced expansion of its global intellectual-property strategy for Z-endoxifen, including issuance of an Israeli patent (No. 304863) granted on July 2, 2025 and a Certificate of Patent Renewal confirming fee payment and active status.

The Israeli claims cover oral delayed-release enteric dosage forms with at least 90% Z-endoxifen, optional impurity limits (<2%), defined gastric/intestinal release characteristics, dose strengths (e.g., 1–4 mg and 8 mg), pharmacokinetic targets, and manufacturing methods that enrich the Z-isomer via crystallization and solvent control.

Positive

• Israeli patent granted (No. 304863) on July 2, 2025
• Claims include enteric oral forms ≥90% Z-endoxifen
• Claims specify impurity limits <2%, dose strengths 1–4 mg and 8 mg
• Received Certificate of Patent Renewal confirming paid fees and active status

Negative

• None.

Insights

IP and Regulatory Strategist

Issuance and renewal of an Israeli patent strengthens Atossa's Z-endoxifen IP coverage relevant to clinical and commercial plans.

The patent (No. 304863) granted in Israel on July 2, 2025 claims high-purity oral, delayed-release formulations (≥90% Z-endoxifen), impurity limits (2%), defined in-vitro release and pharmacokinetic performance targets, dose ranges (e.g., 1–4 mg and 8 mg), and manufacturing methods to enrich the Z-isomer. These elements create technical barriers around product composition, defined performance criteria, and specific manufacturing steps, which support product quality control and life-cycle management in that jurisdiction.

Dependencies and risks include maintaining timely renewals and successful prosecution in other jurisdictions where the company seeks protection; the release notes an Israeli Certificate of Patent Renewal for the same patent. Watch ongoing renewals, the status of parallel filings in other major jurisdictions, and any claim scope changes during prosecution. The relevant near- to mid-term horizon is the period of active prosecution and renewal filings as the program advances through clinical development (2025 onward as stated).

Commercial & Manufacturing IP Analyst

Claims tying formulation, performance, and manufacturing methods create practical exclusivity levers for commercialization and quality control.

By claiming enteric delayed-release dosage forms with explicit purity, release profiles, and pharmacokinetic targets, the patent links product identity to measurable attributes. Coverage of stepwise crystallization and solvent control methods targets the supply-chain and process steps needed to produce the claimed high-purity Z-isomer, which can support enforcement against products that reproduce the same technical route or performance.

Key items to monitor are the exact claim language as allowed during prosecution in each jurisdiction, renewal fee status across the portfolio, and any oppositions or third‑party challenges if they arise. These procedural events will determine practical exclusivity windows and the timing of when patent strength materially affects commercial or partnering discussions over the coming years (2025 and thereafter as filings progress).

Portfolio covers high-purity Z-endoxifen enteric formulations, performance characteristics, and manufacturing methods, part of Atossa's multi-jurisdiction IP strategy to support clinical and commercial plans

SEATTLE, Oct. 13, 2025 /PRNewswire/ -- Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing new approaches in breast cancer treatment and prevention, announces key progress in its global intellectual-property strategy for Z-endoxifen, including the issuance of an Israeli patent and continued renewals that reinforce protection for the Company's lead program across major jurisdictions. The Israeli patent (No. 304863), titled, "Methods for Making and Using Endoxifen," was granted on July 2, 2025, with priority to multiple U.S. provisional applications filed in 2017–2018.

The allowed claims in Israel include oral, delayed-release (enteric) dosage forms comprising at least 90% by weight Z-endoxifen, with optional impurity limits (<2%), defined release characteristics in gastric and intestinal media, dose strengths (e.g., 1–4 mg and 8 mg), and pharmacokinetic performance targets (e.g., plasma exposures and steady-state levels). The claims also cover manufacturing methods that enrich the Z-isomer via stepwise crystallization and solvent control. These protections align with Atossa's quality-by-design approach to deliver a consistent, high-purity Z-endoxifen product.

In parallel, Atossa received a Certificate of Patent Renewal from the Israel Patent Office confirming fee payment and renewal status for Patent No. 304863, further supporting the life-cycle management of Z-endoxifen IP in this jurisdiction.

"Strong, durable patents are foundational to our Z-endoxifen strategy," said Steven Quay, M.D., Ph.D., Atossa Therapeutics Chairman and CEO. "This new protection in Israel, together with our broader global filings, covers what we believe are the critical elements of product quality, performance, and manufacturing needed to bring Z-endoxifen to patients and to create long-term value for shareholders."

About the Patent Scope in Israel
The granted patent includes: (i) enteric oral formulations with ≥90% Z-endoxifen; (ii) optional impurity and residual-solvent limits; (iii) stability and delayed-release attributes (acid resistance and intestinal release); (iv) dose ranges including 1–4 mg and 8 mg; (v) PK targets such as steady-state plasma levels and exposure ranges; and (vi) a multi-step crystallization process to enrich the Z-isomer. Collectively, these claims support Atossa's global protection for Z-endoxifen composition, performance, and process.

About Atossa Therapeutics
Atossa Therapeutics, Inc. (Nasdaq: ATOS) is a clinical-stage biopharmaceutical company developing innovative therapies for significant unmet needs in breast cancer. Atossa's strategy emphasizes disciplined capital allocation, focusing resources on programs and data packages that can enable future regulatory submissions and potential commercialization. For more information, visit www.atossatherapeutics.com and refer to Atossa's filings with the U.S. Securities and Exchange Commission (SEC).

Forward-Looking Statements
This press release contains forward-looking statements, including statements regarding Atossa's commercial readiness, financing strategy, operational plans, and the development and potential commercialization of (Z)-endoxifen. These statements are subject to risks and uncertainties that could cause actual results to differ materially, including market conditions, regulatory outcomes, clinical results, manufacturing and supply, intellectual-property challenges, and the Company's ability to secure sufficient funding on acceptable terms. For a discussion of risks and uncertainties, please refer to Atossa's filings with the U.S. Securities and Exchange Commission. Atossa undertakes no obligation to update forward-looking statements, except as required by law.

Source Documents (Israel)

• Certificate of Patent—No. 304863; Title: Methods for Making and Using Endoxifen; Filing 2018-09-10; Grant 2025-07-02; Priority to U.S. provisionals.
• Certificate of Patent Renewal—No. 304863 (Israel Patent Office).
• Allowed claims, including high-purity Z-endoxifen enteric formulations, release/PK attributes, and manufacturing steps.

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SOURCE Atossa Therapeutics Inc

FAQ

What did Atossa (NASDAQ: ATOS) announce about Z-endoxifen patents on October 13, 2025?

Atossa announced an Israeli patent (No. 304863) granted July 2, 2025, plus a Certificate of Patent Renewal confirming active status.

What specific product attributes does the Israel patent No. 304863 claim for Z-endoxifen?

The patent claims enteric delayed-release oral dosage forms with ≥90% Z-endoxifen, optional impurity limits <2%, defined release profiles, and specified dose strengths.

How do the Israeli patent claims affect Atossa's Z-endoxifen manufacturing rights?

Claims include manufacturing methods to enrich the Z-isomer via stepwise crystallization and solvent control, supporting production quality protection.

When was the Israeli patent for Z-endoxifen granted and what is its priority timeline?

The patent was granted on July 2, 2025 with priority to multiple U.S. provisional applications filed in 2017–2018.

Does the announcement indicate ongoing global IP strategy for Atossa Z-endoxifen?

Yes; Atossa described this Israeli grant as part of broader multi-jurisdiction filings and renewals to support clinical and commercial plans.