ARTBIO's Alpha Therapy Enters Clinic to Fight Prostate Cancer

CAMBRIDGE, Mass. – January 12, 2026 – A new chapter in the fight against advanced prostate cancer began today as ARTBIO, Inc. announced the start of patient dosing in its Phase 1 clinical trial. The study, named ARTISAN, is evaluating a novel therapy, AB001, for patients with metastatic castration-resistant prostate cancer (mCRPC), a deadly form of the disease that no longer responds to hormone-blocking treatments.

The initiation of this trial marks a critical step forward for a new class of cancer treatments known as alpha radioligand therapies (ARTs). AB001 targets the prostate-specific membrane antigen (PSMA), a protein found in high levels on the surface of prostate cancer cells, and delivers a highly potent, cell-destroying alpha particle payload directly to the tumor.

Significantly, the trial is enrolling two distinct groups of patients: those who have never received a PSMA-targeted radioligand therapy and those whose cancer has progressed after being treated with one, specifically the beta-emitter Lutetium-177 (177Lu) PSMA therapy. This dual-cohort design signals a bold strategy to assess AB001's potential both as a new frontline radiopharmaceutical and as a crucial option for patients who have exhausted existing treatments.

"The ARTBIO team is excited to continue to advance AB001 as our lead clinical asset for patients with and without prior Lu177-PSMA targeted therapy," said Margaret Yu, Chief Medical Officer of ARTBIO. The company is collaborating with clinical sites like BAMF Health and United Theranostics to conduct the trial.

Dr. Brandon Mancini, the trial's principal investigator at BAMF Health, highlighted the therapy's potential, stating, "AB001 PSMA-targeted radioligand therapy has the potential to reshape the treatment landscape for patients with metastatic castration-resistant prostate cancer who urgently need additional pathways forward."

The Power of Alpha vs. Beta

The core innovation behind AB001 lies in its use of Lead-212 (212Pb), an alpha-emitting isotope. This distinguishes it from the current standard in PSMA-targeted radiopharmaceuticals, Pluvicto (lutetium-177 vipivotide tetraxetan), which uses a beta-emitting isotope. While both are designed to deliver radiation to cancer cells, the type of radiation they emit creates a fundamental difference in their biological impact.

Beta emitters, like 177Lu, release electrons that travel several millimeters in tissue. This creates a "cross-fire" effect that can kill nearby cancer cells, but it also has the potential to damage surrounding healthy tissue. Beta particles typically cause single-strand breaks in DNA, which cancer cells can sometimes repair, leading to treatment resistance.

Alpha emitters, in contrast, are the heavy artillery of radiotherapy. They release helium nuclei that are hundreds of times more powerful but travel only a few cell-widths. This high-energy, short-range attack deposits a massive amount of destructive power directly into the target cell, causing complex double-strand DNA breaks that are nearly impossible for the cancer cell to repair. This mechanism suggests alpha therapies could be effective against tumors that have become resistant to beta emitters or other forms of treatment.

For patients with mCRPC, this distinction is critical. While Pluvicto has proven effective in extending survival, as demonstrated in the pivotal VISION and PSMAfore trials, resistance is an eventual reality for many. The hope is that AB001's potent alpha radiation can overcome this resistance, providing a new lifeline for patients.

Solving the Alpha Supply Chain Puzzle

Despite the immense therapeutic promise of alpha emitters, their widespread clinical use has been hampered by a significant logistical challenge: manufacturing and supply. Alpha-emitting isotopes like 212Pb have extremely short half-lives—in the case of 212Pb, just 10.6 hours. This means that from the moment it is produced, half of the isotope's potency is gone in less than half a day, making traditional centralized manufacturing and long-distance shipping impractical.

ARTBIO believes it has a solution to this problem with its proprietary AlphaDirect™ technology. The company states this system enables a distributed manufacturing approach. Instead of relying on a single, distant production facility, this model is designed to allow for the isolation of 212Pb at or near the clinical sites where patients are being treated. By producing the isotope on-demand and locally, ARTBIO aims to ensure a reliable and fresh supply of AB001, maximizing its therapeutic dose and potentially making this advanced treatment more accessible to patients globally.

This innovative approach to logistics is as central to ARTBIO's strategy as the science of AB001 itself. If successful, it could not only secure the supply for the ARTISAN trial but also create a scalable model for the commercial delivery of alpha therapies, a feat that has eluded many in the competitive radiopharmaceutical space.

A Trial Designed for Maximum Impact

The structure of the ARTISAN trial underscores ARTBIO's ambition for AB001. By enrolling a cohort of patients who have already been treated with 177Lu-PSMA, the company is directly tackling one of the most pressing unmet needs in prostate cancer care. Positive results in this group would provide strong evidence that alpha therapy can overcome beta-emitter resistance, establishing a clear place for AB001 in the treatment sequence for advanced disease.

Simultaneously, by testing AB001 in patients naive to PSMA-targeted radioligands, ARTBIO is exploring the drug's potential to become a primary radiopharmaceutical choice, possibly offering a more potent initial attack on the cancer than existing options. The open-label Phase 1 study will focus on establishing the safety, tolerability, and anti-tumor activity of AB001, with initial data eagerly awaited by the oncology community.

"The ARTBIO team are passionate innovators who have constructed this trial with a strong patient-centric mindset," noted Dr. Munir Ghesani of United Theranostics. With plans to expand the trial outside the U.S. in the second half of 2026, ARTBIO is signaling its intent to move AB001 forward on a global scale, bringing this next-generation cancer therapy one step closer to the patients who urgently need it.