Actinium jumps 21.56% premarket on new preclinical data for ATNM-400 and Actimab-A ahead of AACR presentations.

Actinium surged 21.56% in premarket trading following the announcement of new preclinical data for ATNM-400 and Actimab-A, which will be presented at the AACR 2026 meeting. The data highlights the pan-tumor potential of ATNM-400 across multiple solid tumors and a novel, mutation-agnostic mechanism for Actimab-A in AML, reinforcing the company’s Ac-225 platform strategy. The upcoming April 21 poster presentations are expected to serve as key catalysts for the company in 2026, driving optimism among investors about the therapeutic and commercial potential of its pipeline.