Bristol Myers Squibb Announces Positive Topline Results from Interim Phase 3 ACTION-1 Analysis of RYZ101 in Patients with GEP-NETs

Bristol Myers Squibb (NYSE: BMY) today announced positive topline results from the planned interim analysis of the ACTION-1 trial (NCT05477576) conducted by RayzeBio, Inc., a Bristol Myers Squibb company. The study met the primary endpoint with a statistically significant and clinically meaningful improvement in progression-free survival by blinded independent central review, and safety results consistent with the known RYZ101 safety profile. ACTION-1 is a randomized Phase 3 clinical trial evaluating RYZ101 (225Ac-DOTATATE) versus investigator’s choice of standard of care (high-dose or high-frequency long-acting somatostatin analogues, everolimus, or sunitinib) in patients with somatostatin receptor-positive (SSTR+) gastroenteropancreatic neuroendocrine tumors (GEP-NETs) who have progressed following Lutetium-177 (Lu177)-based therapy.

“The improvement in progression-free survival is a defining moment for RYZ101 and for the patients we built this program around — people with advanced GEP-NETs whose cancer has progressed after Lu177-based therapy and who have few remaining options,” said Amreen Husain, MD, chief medical officer of RayzeBio. “This is the kind of impact we set out to deliver with actinium-based radiopharmaceuticals, and it is an important milestone supporting the pipeline we are building across our RPT platform. These are the first results from a Phase 3 trial of an alpha-isotope based targeted RPT (225Ac) in any indication, and we are moving with urgency to bring these data to the FDA and, ultimately, provide a novel option for patients.”

The FDA granted RYZ101 Orphan Drug Designation for the treatment of GEP-NETs in August 2026 based on the significant unmet need facing patients with this disease. That designation, combined with the results of this interim analysis, supports RayzeBio’s continued development efforts and plans to engage with the FDA to discuss next steps toward a regulatory submission. Detailed results are expected to be presented at a future medical meeting.

“Lu177-based therapy is widely used in GEP-NETs, but unfortunately the vast majority of patients will eventually progress. Determining the optimal treatment after Lu177 has been an important question for my patients, and until now there has been no randomized Phase 3 evidence to guide it,” said Simron Singh, MD, medical oncologist in the Odette Cancer Centre, Sunnybrook Health Sciences Centre, Professor of Medicine at the University of Toronto, and principal investigator of the ACTION-1 study. “ACTION-1 provides the first Phase 3 results for an alpha-based targeted RPT, and a clinically meaningful improvement in progression-free survival is a crucial development in improving the care of patients with GEP-NETs.”

Individuals currently enrolled will continue to receive care consistent with the study protocol, and participants will be followed for overall survival.

 

About Gastroenteropancreatic Neuroendocrine Tumors (GEP-NETs)
GEP-NETs are rare tumors, with an estimated incidence of approximately 18,000 patients diagnosed annually in the United States and a prevalence of fewer than 200,000 patients. Somatostatin receptor type 2 (SSTR2) is expressed in 80–90% of GEP-NET tumors, and metastatic disease is present at diagnosis in the vast majority of cases. Lu177-based radiopharmaceutical therapy has shown significant clinical benefit and is approved for adult patients with SSTR-positive GEP-NETs, but most patients invariably progress following treatment, with few effective treatment options available.

 

About RYZ101
RYZ101 is an investigational, targeted radiopharmaceutical therapy comprised of DOTATATE bound to Actinium-225 (225Ac), a highly potent alpha-emitting radioisotope.225Ac emits a high-energy, short-range alpha particle that can cause double-stranded DNA damage in cancer cells, potentially resulting in higher chance of cancer cell death. In a Phase 1b trial of 17 previously Lu177-treated patients with disease progression, RYZ101 was well tolerated, with no treatment-related serious adverse events or dose discontinuations due to any adverse event. RYZ101 is also being evaluated in earlier-stage trials in hormone receptor-positive (HR+) metastatic breast cancer.

 

About RayzeBio
RayzeBio, Inc., a Bristol Myers Squibb company, develops precision radiopharmaceuticals designed to open new pathways for patients living with cancer. Since its founding in 2020, RayzeBio has built a broad, highly differentiated pipeline supported by capabilities spanning discovery, development, isotope production, and manufacturing across its sites. The company’s lead program, RYZ101, is in Phase 3 development for gastroenteropancreatic neuroendocrine tumors (GEP-NETs), alongside programs targeting GPC3, ACP3, next-generation SSTR2-directed therapies, and a number of undisclosed targets. Together, these programs reflect RayzeBio’s ambition to advance the next generation of radiopharmaceutical therapy in service of unmet need for patients. Headquartered in San Diego, California, RayzeBio pairs a nimble, innovative culture with the scale and resources of Bristol Myers Squibb. For more information, visit rayzebio.com.

 

About Bristol Myers Squibb: Transforming Patients’ Lives Through Science
At Bristol Myers Squibb, our mission is to discover, develop and deliver innovative medicines that help patients prevail over serious diseases. We are pursuing bold science to define what’s possible for the future of medicine and the patients we serve. For more information, visit us at BMS.com and follow us on LinkedIn, X, YouTube, Facebook and Instagram.

 

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