Convergent Therapeutics Reports 84% PSA50 Response Rate for CONV01-α in Phase 2 Prostate Cancer Study
Convergent Therapeutics Inc., a clinical-stage biotechnology company developing next-generation radiopharmaceuticals for cancer treatment, has announced encouraging results from Part 2 of the Phase 2 CONVERGE-01 study evaluating Ac-225 rosopatamab tetraxetan (CONV01-α) in patients with androgen pathway modulator-resistant (APMR) prostate cancer who have not previously received lutetium-177 prostate-specific membrane antigen (Lu-PSMA) therapy. The investigational radiopharmaceutical demonstrated substantial antitumor activity following a two-dose treatment regimen, alongside a favorable safety and tolerability profile.
The latest findings indicate that CONV01-α achieved a prostate-specific antigen (PSA50) response rate of 84% and a PSA90 response rate of 26%. These results suggest that treatment produced substantial reductions in PSA levels, an important biomarker used to monitor prostate cancer activity and treatment response. The findings are particularly relevant for patients with rapidly progressing disease who require additional therapeutic options.
According to the company, treatment was generally well tolerated at the target dose, with hematologic toxicities considered clinically manageable. Investigators reported no renal or hepatic toxicity and no high-grade xerostomia, or severe dry mouth, in the evaluated population. Direct dosimetry of actinium-225 also demonstrated the feasibility of measuring radiation exposure in normal organs, with absorbed-dose estimates supporting the favorable safety profile observed to date.
The findings were presented at the European Society for Medical Oncology (ESMO) Congress 2026 in Madrid, Spain, on October 23, 2026. The data add to previously reported Phase 2 results in patients who had received Lu-PSMA therapy and strengthen the company’s interest in developing CONV01-α for use across different stages of advanced prostate cancer.
Addressing Unmet Needs in Advanced Prostate Cancer
Prostate cancer is one of the most commonly diagnosed cancers in men worldwide. Although several treatment approaches are available, including hormonal therapies, chemotherapy, targeted treatments, and radiopharmaceuticals, advanced disease can become increasingly difficult to manage as cancer cells develop resistance to successive treatments.
Androgen pathway modulators are widely used in prostate cancer because they interfere with signaling pathways that help cancer cells grow. However, some patients eventually develop resistance to these treatments, allowing the disease to progress despite continued therapy.
In advanced prostate cancer, rising PSA levels, worsening symptoms, and the development of new metastatic lesions can indicate disease progression. Treatment decisions in this setting depend on the patient’s previous therapies, disease characteristics, overall health, and eligibility for available treatment options.
Lu-PSMA radioligand therapy represents an established treatment approach for appropriately selected patients with advanced prostate cancer. It uses a molecule that targets prostate-specific membrane antigen (PSMA), a protein commonly expressed on prostate cancer cells, to deliver radioactive material to tumors.
However, patients who have not received Lu-PSMA therapy and whose disease has become resistant to androgen pathway modulators may still need additional treatment options. Convergent Therapeutics is investigating whether an actinium-225-based targeted radiopharmaceutical could provide meaningful antitumor activity in this population.
The results from Part 2 of CONVERGE-01 offer an early indication of the potential of CONV01-α in patients with APMR prostate cancer before exposure to Lu-PSMA treatment.
Understanding CONV01-α and Targeted Alpha Therapy
CONV01-α, also known as Ac-225 rosopatamab tetraxetan, is an investigational targeted radiopharmaceutical being developed by Convergent Therapeutics for prostate cancer.
Radiopharmaceuticals combine a targeting molecule with a radioactive isotope. The targeting component is designed to recognize a specific biological marker associated with cancer cells, while the radioactive component delivers radiation to the targeted tissue.
Actinium-225 is an alpha-emitting radionuclide. Alpha particles release energy over a short distance and can produce substantial biological damage to cells in their path. This property makes alpha-emitting radionuclides of interest in oncology, where the objective is to deliver radiation to cancer cells while limiting exposure to surrounding healthy tissues.
Targeted alpha therapy is being investigated as a way to improve the precision and potency of radiation-based cancer treatment. However, its clinical performance depends on several factors, including target expression, tumor distribution, radiation delivery, treatment dose, and the ability to manage exposure to normal organs.
In the case of CONV01-α, the company is evaluating whether targeted delivery of actinium-225 can generate substantial antitumor responses while maintaining an acceptable safety profile.
The latest CONVERGE-01 findings provide information on both clinical activity and radiation dosimetry, helping investigators assess the potential relationship between treatment exposure, response, and tolerability.
Phase 2 CONVERGE-01 Study Demonstrates Deep PSA Responses
Part 2 of the Phase 2 CONVERGE-01 study evaluated CONV01-α in patients with APMR prostate cancer who had not previously received Lu-PSMA therapy.
The reported results showed that the investigational therapy achieved a PSA50 response rate of 84%. A PSA50 response generally refers to a reduction in PSA levels of at least 50% from baseline. PSA is a protein produced by prostate cells, and changes in its blood concentration can help clinicians assess disease activity and monitor treatment response.
A reduction of this magnitude can provide evidence of biological activity, although PSA changes alone do not establish the extent of tumor shrinkage or guarantee a survival benefit.
The study also reported a PSA90 response rate of 26%, indicating that approximately one-quarter of the evaluated population experienced a PSA reduction of at least 90%.
These findings suggest that some patients experienced particularly deep biochemical responses after receiving the two-dose regimen. The results are notable because the study population had disease resistant to androgen pathway modulators, a setting in which cancer progression can limit the effectiveness of previously used therapies.
The company characterized the findings as evidence of potent antitumor activity. Nevertheless, further evaluation will be required to determine the durability of PSA responses, how these responses correlate with radiographic disease control, and whether they translate into improvements in progression-free or overall survival.
The response rates also need to be interpreted within the context of the study’s size, eligibility criteria, and follow-up period. Additional clinical data will help establish the consistency of the observed activity and identify which patients may benefit most from treatment.
Two-Dose Regimen Could Reduce Treatment Burden
An important feature of the reported treatment approach is its two-dose regimen. According to Convergent Therapeutics, the combination of substantial PSA responses and a limited number of administrations could make CONV01-α a practical option for further investigation in advanced prostate cancer.
Radiopharmaceutical treatment can involve logistical considerations, including travel to specialized treatment centers, monitoring requirements, and precautions related to radiation exposure. These factors may affect patients and caregivers, particularly when treatment requires repeated visits or extended periods away from home.
A regimen involving two doses could potentially reduce the number of treatment visits compared with approaches requiring more frequent administration, although the actual treatment burden will depend on the final dosing schedule, monitoring requirements, and any necessary radiation-safety precautions.
Praful Ravi, MB, BChir, MRCP, Medical Director of Genitourinary Theranostics at Dana-Farber Cancer Institute, highlighted the clinical significance of the results.
“The depth of PSA responses observed with only two doses of Ac-225 rosopatamab tetraxetan, together with its favorable safety profile, offers a particularly compelling option for patients with metastatic castration-resistant prostate cancer (or APMR) who have not yet received Lu-PSMA, a population for whom novel treatment options are needed,” Ravi said.
He also emphasized the potential practical advantages of the regimen for patients and their families.
“The patient-friendly two-dose regimen also has the potential to substantially reduce treatment burden, allowing patients to resume their usual activities and family lives at home without prolonged radiation-related isolation,” he added.
The potential to reduce treatment burden will remain an important consideration as investigators evaluate the therapy’s clinical utility. Any future treatment protocols will need to balance convenience with the requirements for effective treatment delivery, patient monitoring, and radiation safety.
Favorable Safety Profile at the Target Dose
In addition to evaluating PSA responses, the CONVERGE-01 analysis examined the safety and tolerability of CONV01-α.
The company reported that treatment was generally well tolerated at the target dose, with hematologic toxicity considered clinically manageable.
Hematologic toxicities affect the blood or blood-forming system and can include reductions in blood cell counts. These events are particularly important to monitor during cancer treatment because changes in red blood cells, white blood cells, or platelets can affect oxygen delivery, infection risk, and bleeding risk.
The company also reported no renal or hepatic toxicity and no high-grade xerostomia in the analyzed population.
Renal and hepatic safety are important considerations for radiopharmaceutical development because the kidneys and liver can contribute to the distribution, processing, or elimination of therapeutic agents, depending on their properties. Radiation exposure to normal organs must be carefully assessed to establish an appropriate therapeutic window.
Xerostomia, or dry mouth, can affect comfort, oral health, and quality of life. Its severity is a relevant safety consideration for some targeted radiopharmaceutical approaches, making the reported absence of high-grade xerostomia an important observation in this analysis.
Although the initial findings support a favorable tolerability profile, they do not rule out the possibility of less common or delayed adverse events. Larger patient populations and longer follow-up will be needed to establish the frequency, severity, and duration of treatment-related toxicities.
Continued monitoring will also be necessary to determine whether the observed safety profile remains consistent across different patient groups and treatment settings.
Actinium-225 Dosimetry Supports Further Evaluation
Another component of the CONVERGE-01 results involved direct dosimetry for actinium-225.
Dosimetry is the measurement or estimation of radiation absorbed by tissues and organs. In radiopharmaceutical development, it can help investigators understand how radioactive material is distributed throughout the body and assess exposure to both tumors and normal tissues.
The company reported that direct actinium-225 dosimetry demonstrated the feasibility of measuring radiation exposure in normal organs. The resulting absorbed-dose estimates were described as reassuring and consistent with the favorable safety and tolerability findings observed to date.
These measurements are important because targeted radiopharmaceuticals must deliver sufficient radiation to cancer cells while limiting potential damage to healthy tissues. Understanding organ-level exposure can help researchers assess treatment risks and inform decisions about dose selection, administration schedules, and patient monitoring.
Dosimetry may also provide information that complements clinical safety observations. While the absence of certain toxicities is encouraging, radiation-dose estimates can offer an additional perspective on potential organ exposure.
The reported findings support further investigation of the relationship between radiation delivery, clinical response, and toxicity. Additional analyses will be needed to determine how dosimetry measurements vary among patients and whether they can help guide individualized treatment strategies.
Potential Role Across the Prostate Cancer Treatment Continuum
The latest CONVERGE-01 findings build on previously reported Phase 2 results in patients who had received Lu-PSMA therapy. Together, these clinical data support the company’s objective of evaluating CONV01-α across different stages of advanced prostate cancer.
Philip Kantoff, M.D., Co-Founder and Chief Executive Officer of Convergent Therapeutics, said the findings reinforce the company’s belief that the investigational therapy could become an important treatment option across the prostate cancer treatment continuum.
“These results reinforce our conviction that CONV01-α has the potential to become an important treatment option across the prostate cancer therapy continuum,” Kantoff said.
He added that the observed antitumor activity in patients both before and after Lu-PSMA treatment highlights the potential opportunity for targeted alpha therapies in a disease where curative options remain limited.
“Demonstrating substantial anti-tumor activity in patients both before and after Lu-PSMA treatment underscores the significant opportunity for targeted alpha therapies in a disease where curative options remain limited. We look forward to continuing CONVERGE-01, further exploring its potential in this earlier treatment setting and advancing our development plans to bring this promising therapy to patients,” he said.
The possibility of using CONV01-α at different stages of advanced prostate cancer could be important if future studies confirm its efficacy and safety. However, the treatment’s optimal position relative to existing therapies will depend on further clinical evidence, including the durability of responses, survival outcomes, comparative benefits, and treatment-related risks.
The findings do not yet establish whether CONV01-α should be used before or after Lu-PSMA in routine clinical practice. Rather, they provide a basis for continued investigation in distinct patient populations.
ESMO Congress 2026 Presentation Details
The results from Part 2 of CONVERGE-01 were presented at the ESMO Congress 2026 in Madrid, Spain.
- Abstract title: CONVERGE-01: Ac-225 Rosopatamab Tetraxetan (CONV01-α) in Patients with Androgen Pathway Modulator Resistant Prostate Cancer (APMR)
- Abstract number: 226P
- Presentation format: Poster presentation
- Location: IFEMA, Madrid, Spain
- Date: October 23, 2026
- Time: 3:15 p.m. Central European Summer Time (CEST)
- Presenter: Praful Ravi, MB, BChir, MRCP, Medical Director of Genitourinary Theranostics at Dana-Farber Cancer Institute
The presentation highlighted the PSA response findings, safety observations, and direct actinium-225 dosimetry results from the investigational treatment.
Next Steps for CONV01-α Development
The Phase 2 results provide encouraging preliminary evidence of antitumor activity for CONV01-α in patients with APMR prostate cancer who have not received Lu-PSMA therapy. The reported PSA50 response rate of 84%, PSA90 response rate of 26%, manageable hematologic toxicity, and reassuring organ-dosimetry estimates support continued clinical evaluation.
Future analyses will need to establish how long PSA responses persist, whether they correspond to meaningful improvements in radiographic outcomes, and how treatment affects progression-free survival, overall survival, and patient-reported outcomes.
Additional research will also help clarify the therapy’s optimal dose and schedule, characterize its safety profile in larger populations, and determine where it may fit within existing prostate cancer treatment pathways.
For Convergent Therapeutics, continued development of CONV01-α represents an effort to expand the potential applications of targeted alpha therapy in advanced prostate cancer. While the latest findings are promising, further clinical evidence will be necessary to establish the treatment’s long-term benefits and define its eventual role in patient care.
About CONV01-α
CONV01-α is a PSMA-targeted Ac-225 radioantibody that pairs antibody precision with the localized potency of alpha radiation. CONV01-α, which is being developed to improve the treatment of mCRPC, uses a humanized monoclonal antibody (rosopatamab) directed against PSMA, a well-established and highly expressed antigen in prostate cancer. CONV01-α is differentiated by its ability to precisely deliver actinium-225 (Ac-225) through this PSMA-targeting antibody, enabling precise short-range, high-energy alpha particle radiation that creates focused DNA damage within tumor cells while limiting exposure to surrounding tissues.
Initial studies in more than 120 patients have established clinical proof-of-concept for CONV01-α, showing consistent antitumor activity and a differentiated safety profile. This selectivity, combined with strong tumor retention and minimal salivary and renal uptake, supports the potential of CONV01-α to be a clinically impactful therapy for PSMA-positive cancers.
About Convergent Therapeutics, Inc.
Convergent Therapeutics, Inc. is a clinical-stage biotechnology company developing next-generation radiopharmaceuticals to transform the treatment of cancer. Founded by world-renowned experts in clinical oncology, drug development, and cancer biology, Convergent is advancing a pipeline of tumor-selective radioantibodies that pair the precision of antibody targeting with the localized, cell-destructive potency and extended half-life of Actinium-225 (Ac-225) alpha-emitting isotopes.
The company’s lead program, CONV01-α, is a PSMA-targeted Ac-225 radioantibody in development for metastatic castration-resistant prostate cancer (mCRPC). CONV01-α has demonstrated clinical proof of concept and in Phase 2 studies, consistent antitumor activity, durability and a differentiated safety and tolerability profile, both as monotherapy and in combination with other anti-cancer agents. Convergent has also established a reliable, domestically sourced Ac-225 supply chain to support late-stage and clinical development programs.