ATOSSA THERAPEUTICS, INC. (ATOS)

NASDAQ · Pharmaceuticals & Biotech · Pharmaceutical Preparations

Price
$2.18
Day
-3.54%
Market cap
$21.75M

Close 2026-09-23.

The company

We are a clinical-stage biopharmaceutical company developing proprietary innovative medicines in areas of significant unmet medical need in oncology, with a focus on breast cancer and other breast conditions. Our lead drug candidate is oral (Z)-endoxifen, a selective estrogen receptor modulator (SERM)/ selective estrogen receptor degrader (SERM/D) currently in Phase 2 clinical development. The Company is evaluating potential indications for (Z)-endoxifen based on its pharmacologic profile, including its potential for both reducing the risk of and for the treatment of breast cancer, as well as in other therapeutic areas. Our business strategy is to advance our programs through clinical studies, including with potential partners, and opportunistically add programs in areas of high unmet medical need through acquisition, minority investment, collaboration, or internal development. (Z)-endoxifen is the most active metabolite of Tamoxifen and is substantially more potent as an estrogen receptor antagonist than Tamoxifen and other approved SERMs. Unlike Tamoxifen, which requires metabolic activation through CYP2D6 and other liver enzymes, (Z)-endoxifen does not require first-pass metabolism to achieve therapeutic concentrations. As a result, its activity is not dependent on patient-specific metabolic variability. (Z)-endoxifen is a small-molecule oral agent designed to directly inhibit estrogen receptor signaling, induce estrogen receptor degradation, and promote apoptosis in estrogen receptor positive (ER+) breast cancer cells.

Institutional holders

Largest positions reported on Form 13F for the quarter ended 2026-06-30, by value.

Insider trades

Open-market buys and sales filed on Form 4, newest first. Grants, option exercises and tax withholding are left out.

Recent filings