In a detail-thin announcement, Amgen said that adding bemarituzumab to chemotherapy improved overall survival, though analysts pledged to wait for more data on safety and tolerability before assessing the drug.
A combination of Amgen’s monoclonal antibody bemarituzumab and chemotherapy improved overall survival in gastric cancer, meeting the main goal of a Phase III clinical trial.
The brief readout comes from an interim analysis of the Phase III FORTITUDE-101 study. Amgen didn’t share detailed results, only saying that patients with certain kinds of gastric cancers who received bemarituzumab in combination with chemotherapy saw “statistically significant and clinically meaningful improvement” in overall survival in comparison to patients who received a placebo plus chemotherapy.
Amgen is aiming for a first-line setting for bemarituzumab in gastric (G) and gastroesophageal (GEJ) cancers.
“While positive topline OS data in 1L G/GEJ is clearly good news for bemarituzumab given G/GEJ has been a challenging tumor type historically,” Guggenheim analysts wrote Tuesday on the news, “we await further details on the magnitude of the benefit and the safety and tolerability profile of the combination.”
Amgen noted that the most common adverse events, accounting for more than 25% of those reported, were mostly eye-related. These included reduced visual acuity, dry eye and corneal epithelium defect, along with other effects like nausea, neutropenia and anemia. Amgen promised to share more details on data and safety at an upcoming medical meeting.
Those adverse events match up with what Amgen saw in the Phase II FIGHT trial, where every patient experienced some adverse effect, often related to the eye or the cornea, though most events were reversible.
“Most patients with gastric cancer are diagnosed at an advanced stage, with poor prognosis, low survival rates and limited therapeutic options,” Jay Bradner, Amgen’s executive vice president for research and development said in the company’s statement. “These first positive top-line results of an FGFR2b targeted monoclonal antibody from our Phase 3 FORTITUDE-101 study mark a meaningful advance in the development of effective targeted therapy for gastric cancer.”
The FORTITUDE-101 trial was run in collaboration with Zai Lab, which holds co-development and commercialization rights for bemarituzumab in mainland China, Hong Kong, Macau and Taiwan. The partnership was originally between Shanghai-based Zai Lab and Five Prime Therapeutics, which was paid $5 million up front and $39 million by Zai Lab in 2017. Five Prime was then acquired by Amgen in 2021 for about $1.9 billion.
The news continues a mixed year for Amgen in oncology. In January, the company got a label expansion for the KRAS inhibitor Lumakras in colorectal cancers. A month later, Amgen shut down development of its PRMT5 inhibitor AMG 193 for non-small cell lung cancer, citing “mutual agreement” with its development partner Ideaya.
