Actinium Pharmaceuticals Announces Oral Presentation at EANM 2026 Highlighting First-in-Human Phase 1 Study of ATNM-400, a Non-PSMA Targeting Radiotherapy, in Prostate Cancer

Actinium Pharmaceuticals presented early Phase 1 trial data for ATNM-400, a non-PSMA targeted radiotherapy for metastatic castration-resistant prostate cancer (mCRPC). The study aims to assess safety, biodistribution, and dosimetry of Zirconium-89-labeled ATNM-400, with plans to advance to Actinium-225-labeled therapy. According to the company, ATNM-400 targets a novel antigen and could benefit a broad mCRPC patient population, including those resistant to PSMA-directed therapies.

Actinium Pharmaceuticals (NYSE American: ATNM) said it expanded Actimab-A intellectual property with multiple newly issued US patents and additional pre-grant/allowed applications, covering uses in AML, MDS, and solid tumors, including combinations with venetoclax and CLAG-M. The company also amended its IND to add a manufacturing source and reported NYSE American listing compliance plan acceptance through Nov. 27, 2027.

Actinium Pharmaceuticals said the Canadian Intellectual Property Office issued Notices of Allowance for two patent applications covering its Actimab-A and Iomab-ACT programs. The Actimab-A/CLAG-M AML combination allowance is expected to issue with a term into Jan. 2039; the CD45 conditioning for gene-edited cell therapies is expected to issue with a term into Oct. 2038. Actinium said this adds to a global portfolio of about 250 issued and pending patents.

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.

Estrella Immunopharma (ESLA) reported that the first patient in the expansion phase of its STARLIGHT-1 trial tolerated two doses of EB103 T cells with no serious adverse events. Earlier high-dose escalation showed 100% complete response at Month 1 in evaluable patients, according to the company.

Meta Platforms released open weights for its Muse Spark AI model, designed for coding and agent tasks. Muse Spark Open, with 816 billion parameters, supports mixed media prompts and has a 1M token context window. Meta claims it's the most capable open-weight model from a U.S. lab. Benchmarks show it outperforming some rivals in tool use but lagging behind Chinese models in coding. The model is licensed for commercial use with restrictions.