Actinium Pharma To Present Preclinical Data Supporting ATNM-400's Broad Potential At 39th Annual Congress Of EANM

• Oral presentation to highlight ATNM-400 antitumor activity across KRAS- and ALK-driven NSCLC models, building on earlier EGFR-mutant findings and supporting mutation-agnostic development
   
• Colorectal cancer data demonstrate ATNM-400's potential to enhance responses to standard-of-care therapies
   
• Ovarian cancer data demonstrate the durable antitumor activity of ATNM-400, including in treatment-resistant models
   
• Collectively, the findings support the broad potential of ATNM-400 as a differentiated targeted radiotherapy across multiple large solid tumor indications, both as monotherapy and in combination with existing treatments

NEW YORK, Oct. 16, 2026 /PRNewswire/ -- Actinium Pharmaceuticals, Inc. (NYSE:ATNM) (Actinium or the Company), a pioneer in differentiated targeted radiotherapies with the potential to transform cancer treatment, today announced three presentations, including an oral presentation and two e-posters, highlighting preclinical data supporting ATNM-400's broad potential at the 39th Annual Congress of the European Association of Nuclear Medicine (EANM), October 17–21, 2026, in Vienna, Austria.

The presentations feature ATNM-400, the Company's first-in-class Actinium-225 (²²⁵Ac) radiotherapy, in non-small cell lung cancer (NSCLC), colorectal cancer, and ovarian cancer models. Together, the studies demonstrate preclinical antitumor activity as monotherapy and enhanced activity in combination with standard-of-care agents, supporting both approaches to development across solid tumors. These findings further expand the preclinical evidence supporting ATNM-400's potential across multiple cancer indications, complementing its ongoing clinical development in metastatic castration-resistant prostate cancer (mCRPC).

In NSCLC, ATNM-400 demonstrated antitumor activity as monotherapy and enhanced activity in combination with KRAS or ALK inhibitors, including in resistant models. These findings extend earlier EGFR-mutant results and support mutation-agnostic development both as a standalone therapy and in combination with established treatments.

In colorectal cancer, ATNM-400 demonstrated monotherapy activity in SW620 xenografts and enhanced activity when combined with bevacizumab plus oxaliplatin in HCT15 xenografts, a model with moderate target expression and limited response to the standard-of-care combination. These findings support both monotherapy development and combinations aimed at improving outcomes in poorly responsive disease.

In ovarian cancer, ATNM-400 monotherapy produced durable antitumor activity, including in bevacizumab-refractory tumors. These findings support its potential as a standalone treatment in recurrent disease, with further evaluation of ATNM-400 alone and in combination with standard-of-care therapies extending this development strategy.