CAMBRIDGE, Mass. — Convergent Therapeutics said interim Phase 2 data showed its investigational radiopharmaceutical CONV01-α demonstrated promising anti-tumor activity, emerging durability and favorable tolerability in patients with metastatic castration-resistant prostate cancer whose disease had progressed after Lu-177-PSMA therapy.
The Cambridge-based clinical-stage biotechnology company presented the data from Part 3 of its CONVERGE-01 study during an oral symposium at the 2026 American Society of Clinical Oncology Annual Meeting.
CONV01-α, also known as Ac-225 rosopatamab tetraxetan, is a PSMA-targeted alpha radioantibody being developed for metastatic castration-resistant prostate cancer. The interim dataset included 35 patients with progressive disease who had previously received Lu-177-PSMA radioligand therapy. All patients had received prior androgen receptor pathway inhibitor therapy, 80% had received prior taxane chemotherapy and all had received Lu-PSMA therapy.
Convergent said the results support its plan to advance CONV01-α toward a pivotal Phase 3 study in patients previously exposed to taxane chemotherapy and Lu-PSMA therapy, a population for whom no clearly defined standard of care exists.
“Patients whose disease progresses after Lu-PSMA therapy represent a growing population in prostate cancer, with no clearly defined standard of care for what comes next,” said Philip Kantoff, MD, co-founder and CEO of Convergent Therapeutics. “These CONVERGE-01 data begin to establish meaningful benchmarks in the Lu-PSMA-exposed setting, including antitumor activity, emerging durability, manageable safety, and a convenient two-dose regimen in a population where burden of prior treatments is already high. These data also support our central thesis that in the alpha era, the mechanism of delivery is tantamount to the payload. By pairing Actinium-225 with a PSMA-directed antibody designed for enhanced tumor retention and limited normal tissue exposure, we believe CONV01-α has the potential to become an important next-generation therapy for mCRPC and across the disease continuum.”
In the target dose range, median radiographic progression-free survival was 8.4 months. Among 25 patients evaluable for prostate-specific antigen response, 40% had a PSA decline of at least 50%, with similar declines across dose groups and among patients resistant to Lu-PSMA.
The company said no dose-limiting toxicities were observed at any dose level, and no treatment-related adverse events led to discontinuation. Convergent reported clinically manageable hematologic toxicity, with no renal toxicity and no high-grade xerostomia, or dry mouth. Although 48% of patients entered the study with a history of xerostomia, 77% had Grade 0 or Grade 1 xerostomia after treatment with CONV01-α.
“These data are encouraging as Converge-01 demonstrates meaningful anti-tumor activity and emerging durability in patients who have already received Lu-PSMA therapy. These data are striking given that the regimen is comprised of only two treatments, and a reduced treatment burden is important in this very advanced population,” said Michael J. Morris, MD, prostate cancer section head at Memorial Sloan Kettering Cancer Center and co-chair of the CONVERGE-01 scientific advisory committee. “The safety profile observed in CONVERGE-01 shows manageable hematologic toxicity, and no renal toxicity or high-grade xerostomia. These data support the continued evaluation of this PSMA-targeted alpha radioantibody approach in the Lu-PSMA-exposed setting.”
Convergent said CONV01-α has shown differentiated biodistribution compared with radioligands, including strong tumor uptake and retention, with no kidney uptake or salivary gland exposure observed in the study.
The company also said it has secured access to Actinium-225, the radioactive isotope used in CONV01-α, to support late-stage development. Convergent has an expanded agreement with NorthStar Medical Radioisotopes for domestically generated Ac-225 and co-located drug product manufacturing.
“A reliable Ac-225 supply chain is essential to advancing alpha radiotherapies from early stage development through commercial supply,” said Caitlyn Harvey, senior vice president of technical operations at Convergent Therapeutics. “In CONVERGE-01, no patients missed a dose due to Actinium supply, underscoring the strength of our Ac-225 supply and manufacturing infrastructure. We are continuing to build the foundation needed to support CONV01-α through pivotal development and potential commercial production.”
CONVERGE-01 is a Phase 2, randomized, open-label, multicenter study evaluating the safety and efficacy of CONV01-α in patients with metastatic castration-resistant prostate cancer. In Part 3, patients previously exposed to Lu-PSMA therapy received CONV01-α in a two-dose regimen administered on Days 1 and 15.
CONV01-α pairs a humanized monoclonal antibody directed against PSMA with Actinium-225, a radioactive isotope designed to deliver short-range, high-energy alpha radiation to tumor cells while limiting exposure to surrounding tissue. Convergent said studies in more than 120 patients have established clinical proof of concept for the therapy.
