Zai Lab’s partner, Five Prime Therapeutics, announced positive topline results from the global Phase 2 FIGHT trial. The trial compared bemarituzumab (FPA144), a potential first-in-class targeted therapy, in combination with mFOLFOX6 chemotherapy to placebo in combination with mFOLFOX6 in patients with fibroblast growth factor receptor 2b-positive (FGFR2b+), HER2-negative front-line advanced gastric or gastroesophageal junction (GEJ) cancer. All three efficacy endpoints -median progression-free survival, median overall survival and overall response rate- met pre-specified statistical significance. The company will complete a full evaluation of the data and work with investigators to share the results at an upcoming medical conference.
FIGHT was a global, randomized, double-blind placebo-controlled trial. The trial enrolled 155 patients in 15 countries across Asia, the European Union, and the United States. The median progression-free survival improved from 7.4 months to 9.5 months; the median overall survival improved from 12.9 months to not reached and the overall response rate improved by 13.1%. The incidence of all grade adverse events was comparable in between the study arms (100% vs 98.7%, respectively) as were serious adverse events (31.6% vs 36.4%) and deaths due to adverse events (6.6% vs 5.2%). Corneal and stomatitis adverse events were reported more frequently in the bemarituzumab arm, and more patients discontinued bemarituzumab (34.2%) compared to placebo (5.2%) due to an adverse event.
Bemarituzumab (anti-FGFR2b, FPA144) is a first-in-class targeted antibody that blocks fibroblast growth factors (FGFs) from binding and activating FGFR2b, inhibiting several downstream pathways. Blocking FGFR2b activation is thought to slow cancer progression. Bemarituzumab is being developed in gastric and GEJ cancer as a targeted therapy for tumors that overexpress FGFR2b.
Five Prime granted an exclusive license to Zai Lab to develop and commercialize bemarituzumab in Greater China. Zai Lab collaborated with Five Prime on the Phase 2 FIGHT trial in Greater China.
About Gastric Cancer
Gastric cancer, also known as stomach cancer, is the third most common cause of cancer death worldwide and, excluding non-melanoma skin cancer, the fifth most common cancer worldwide, with over 1,000,000 new cases diagnosed each year. In countries where routine screening is not readily available, up to 90 percent of patients are diagnosed with advanced disease that is inoperable.
The fibroblast growth factor (FGF)/fibroblast growth factor receptor (FGFR) pathway is implicated in the development and growth of cancer cells. FGFR2b is a form of FGFR found in epithelial cells, such as those in the stomach and skin. Data from the FIGHT trial suggests that approximately 30% of patients with non HER2+ gastroesophageal cancers overexpress FGFR2b.