Following a middling phase 3 readout for gastric cancer candidate bemarituzumab, Amgen has now stopped another phase 1b/3 trial of the molecule, the pharma announced in its third-quarter earnings Nov. 4.
The Fortitude-102 trial was testing bemarituzumab, a monoclonal antibody, in combination with chemotherapy and Bristol Myers Squibb’s oncology drug Opdivo in 515 patients with untreated advanced gastric and gastroesophageal junction cancer with FGFR2b overexpression.
The trial was halted due to inadequate efficacy, Jay Bradner, M.D., Amgen’s executive vice president of R&D, said during a Nov. 4 call with investors, after an ad hoc analysis requested by an internal data monitoring committee.
“We remain committed to creating and developing medicines for challenging cancers where unmet need is significant, as for patients with gastric cancer,” Bradner said. “However, the magnitude of observed efficacy did not meet our standard for an Amgen medicine.”
Phase 3 data from the trial had been expected in the second half of 2025 or first half of 2026, Amgen said in its second-quarter earnings presentation back in August.
Fortitude-102’s scrapping comes after a final analysis of another phase 3 gastric cancer trial, Fortitude-101, showed a weak survival benefit that was much smaller than that seen during an earlier interim analysis.
When announcing those disappointing data in September, Amgen’s bemarituzumab partner Zai Lab said that “the magnitude of the previously observed survival benefit has attenuated.”
In a Sept. 3 note, analysts from William Blair called out the importance of Fortitude-102, given it was testing Amgen’s investigational antibody in combination with chemo and Opdivo, the standard of care in the indication.
In a Nov. 5 note, William Blair analysts called Fortitude-102's termination “disappointing” but not surprising “given the mixed results in the Fortitude-101 study.”
Two other trials of bemarituzumab, a phase 1b/2 gastric cancer study called Fortitude-103 and a phase 1b/2 solid tumor study called Fortitude-301, are still ongoing, according to Amgen’s third-quarter presentation.
Amgen acquired bemarituzumab in 2021 by buying Five Prime Therapeutics in a $1.9 billion deal. Zai Lab had licensed rights to the antibody in greater China, which the Shanghai-based biopharma still holds.
Editor's note: This story was updated at 10 a.m. ET on Nov. 5 to include analyst insight.