Michael Morris, MD, on the mechanism of action for AB001 in mCRPC

In September 2025, ARTBIO announced FDA clearance of their phase 1 trial for AB001, a prostate-specific membrane antigen (PSMA)-targeted radioligand therapy for patients with metastatic castration-resistant prostate cancer (mCRPC).¹ 

In a recent interview with Urology Times®, Michael J. Morris, MD, discusses the mechanism of action for AB001 and outlines how the Pb212 isotope, which AB001 utilizes, differs from isotopes in currently approved agents and agents in clinical development. Morris is a medical oncologist and the prostate cancer section head at Memorial Sloan Kettering Cancer Center in New York, New York.

AB001’s payload is Pb212, an alpha-emitting isotope, which offers a novel approach given that there are no currently approved options that utilize Pb212, Morris explained.

Pb212 differs from other isotopes such as lutetium, a beta emitter used in approved therapies, in that alpha emitters deliver higher energy over a shorter distance. This can enhance tumor cell killing while reducing collateral damage to surrounding healthy tissue, such as bone marrow.

Compared with another alpha emitter in development, actinium-225, Pb212 offers certain advantages. For example, it has a simpler manufacturing process, a shorter half-life that may potentially reduce toxicity, and it emits some beta particles, enabling direct imaging.

Overall, Morris concluded, “So, there are differences both between what Pb212 has in contrast to what's currently approved and differences between what is currently in development, with the other alpha emitters that are currently out there in clinical trials.”

REFERENCE

1. ARTBIO announces FDA clearance of IND application for lead alpha radioligand therapy AB001. News release. ARTBIO, Inc. September 9, 2025. Accessed October 14, 2025. https://www.prnewswire.com/news-releases/artbio-announces-fda-clearance-of-ind-application-for-lead-alpha-radioligand-therapy-ab001-302549360.html