Actinium Pharmaceuticals to Present ATNM-400 Program Update at SNMMI 2026 Conference on May 31-June 2 and Provides NYSE American Listing Standards Notice
Actinium Pharmaceuticals (NYSE American: ATNM) said it will present new ATNM-400 (Actinium-225 antibody radioconjugate) data at SNMMI 2026 in Los Angeles May 30–June 2, with three posters on prostate cancer, NSCLC, and radioconjugate optimization. Separately, NYSE American notified the company it is not in compliance with $4.0m stockholders’ equity requirements; Actinium must submit a compliance plan by June 26, 2026.
How this was made

The 30-second read
Why it matters
The release combines (1) scheduled scientific updates at SNMMI with (2) a procedural exchange-risk timeline that can drive risk premia and liquidity concerns even without immediate delisting action.
Market read
Traders may weigh a near-term risk premium from potential delisting proceedings against incremental event-driven interest ahead of SNMMI data.
What to watch
Market reaction may hinge less on the SNMMI posters themselves and more on whether the compliance plan details are credible and whether equity financing is implied/needed.
Background
Actinium is a targeted radiotherapies company developing Actinium-225 antibody radioconjugates (notably ATNM-400) and received an NYSE American notice for continued listing standards related to stockholders’ equity and net losses.
Ticker impact
Actinium (ATNM) announced SNMMI 2026 ATNM-400 program updates and disclosed an NYSE American continued-listing standards non-compliance notice.
Near-term volatility risk from delisting headlines; incremental upside possible into SNMMI as investors price in clinical-read-through.
The listing notice has explicit procedural timelines (plan due June 26, 2026; potential delisting by Nov 27, 2027) while the SNMMI update is promotional but time-specific for data delivery.
Market effects
Highlights ongoing capital-market/listing risk for pre-commercial biotech while reinforcing investor focus on Actinium-225 radioconjugate platform read-through.
Primarily US microcap/small-cap sentiment via NYSE American listing-risk mechanics.
Limited; conference data and exchange compliance are US-specific though radiopharma interest is global.
Counterpoint
The notice has 'no immediate effect' on trading; investors may over-discount delisting risk if the company submits an acceptable plan.
Key entities
- issuerActinium Pharmaceuticals, Inc.
Subject of the press release; provides ATNM-400 SNMMI 2026 presentation details and discloses NYSE American listing standards non-compliance notice.
- exchangeNYSE American LLC
Issued the continued listing standards non-compliance notice under Section 1003(a)(ii) of the Company Guide.
- programATNM-400
Actinium-225 antibody radioconjugate with three SNMMI 2026 presentations (prostate cancer, NSCLC, and chelator optimization).


