Changes in Beneficial Ownership · 4
Atossa Therapeutics, Inc.
ATOSNASDAQEQUITYCurrent
Changes in Beneficial Ownership
Structured filing — 4
ownership.xml
Filing details
- Report period
- 2026-05-12
- Issuer
- ATOSSA THERAPEUTICS, INC.
- Issuer CIK
- 0001488039
- Trading symbol
- ATOS
Reporting owner 1
- Name
- Steinhart Richard I
- Reporting owner CIK
- 0001293789
- Relationship
- Director
- Address
- CO BIOXCEL THERAPEUTICS, INC., 555 LONG WHARF DRIVE, 12TH FLOOR, NEW HAVEN, CT, 06511
Non-derivative transactions
| Security | Transaction date | Code | Amount | A / D | Price (USD) | Owned after | Ownership |
|---|---|---|---|---|---|---|---|
| Common Stock | 2026-05-12 | A · Form 4 | 10,000[F1] | A | 0 | 10,000 | D |
Table key
- A · Form 4
- Acquisition by grant, award or otherwise under Rule 16b-3(d)
- A
- Acquired
- D
- Direct
Footnotes
- F1
- Represents a grant of restricted stock units ("RSUs"). Each RSU represents a contingent right to receive one share of the Issuer's Common Stock. The RSUs shall vest on the first anniversary of May 12, 2026.↩ 1
Signature 1
- Signed
- Richard I. Steinhart
- Date
- 2026-05-14
Company context
Atossa Therapeutics, Inc. (Nasdaq: ATOS) is a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of significant unmet need. The Company’s lead product candidate, (Z)-endoxifen, is currently in development across several clinical settings. (Z)-Endoxifen is a potent Selective Estrogen Receptor Modulator/Degrader (SERM/D) with demonstrated activity across multiple mechanisms of interest. Atossa is evaluating its potential applications in oncology and rare diseases. The Company’s proprietary oral formulation has shown a favorable safety profile and pharmacology distinct from tamoxifen, including ER-targeted effects and PKC inhibition. Atossa’s (Z)-endoxifen is not approved for any indication.