2 October 2018 - - US-based biotechnology company Five Prime Therapeutics, Inc. (NASDAQ: FPRX) and China-based biopharmaceutical company Zai Lab Ltd. (NASDAQ: ZLAB) have dosed the first patient in the Phase 3 FIGHT pivotal trial of bemarituzumab (FPA144), an isoform-selective FGF receptor 2b (FGFR2b) antibody, in combination with chemotherapy in patients with previously untreated, advanced gastric cancer or gastroesophageal junction cancer, the companies said.
The first patient was dosed at a participating investigative site in China on Sept. 28.
According to the companies, the double-blind randomised and controlled Phase 3 FIGHT (FGFR2b Inhibition in Gastric and Gastroesophageal Junction Cancer Treatment) trial will evaluate 15 mg/kg of bemarituzumab or placebo given every two weeks combined with modified FOLFOX6 (mFOLFOX6) chemotherapy in approximately 550 patients with GC or GEJ cancer whose tumors overexpress FGFR2b.
The Phase 3 global registration trial is the first prospective FGFR2b-specific front-line gastric study and will include approximately 250 sites in the US, Europe and Asia, including China, South Korea, Taiwan and Japan, where the incidence of gastric cancer is among the highest worldwide.
Zai Lab and Five Prime have a strategic development collaboration under which Zai Lab will manage the Phase 3 portion of the FIGHT trial in China, where approximately half of the patients in the trial are expected to be enrolled.
The primary endpoint of the FIGHT trial is overall survival, with key secondary endpoints being progression-free survival, objective response rate, safety and pharmacokinetic parameters.
GC, including GEJ cancer, is the fifth most common cancer worldwide and third leading cause of cancer death. Gastric cancer is the second most common cancer in China.
Current first-line chemotherapy treatment delays progression by approximately six months compared to best supportive care, but median OS remains poor with literature-reported ranges of approximately 10 to 11 months and PFS of approximately six months.
The presence of FGFR2b overexpression is present in approximately 10% of patients with GC/GEJ and is associated with a worse prognosis.
Few treatment options following progression are available after first-line chemotherapy, and a significant unmet need remains in the treatment of GC/GEJ worldwide.
Five Prime is developing companion diagnostics to identify FGFR2b overexpression using an immunohistochemistry test and FGFR2 gene amplification using circulating tumor DNA (ctDNA) analysis. Five Prime will use both assays to select patients for the FIGHT trial.
Bemarituzumab is a first-in-class, isoform-selective, humanized monoclonal antibody in clinical development as a targeted immunotherapy for tumors that overexpress FGFR2b, a splice variant of a receptor for some members of the fibroblast growth factor family.
Bemarituzumab blocks FGFs 7, 10 and 22 from binding to FGFR2b, and has been engineered for enhanced antibody-dependent cell-mediated cytotoxicity to increase direct tumor cell killing by recruiting natural killer cells.
Clinical results to date suggest that the specificity of bemarituzumab avoids the dose-limiting toxicities that have been seen with less selective pan-FGFR tyrosine kinase inhibitors that act on multiple FGFRs, including FGFR2.
In December 2017, Five Prime and Zai Lab announced a strategic collaboration for the development and commercialisation of bemarituzumab in Greater China.
Five Prime Therapeutics discovers and develops innovative therapeutics. The company said its discovery platform positions it to explore pathways in cancer, inflammation and their intersection in immuno-oncology, an area with significant therapeutic potential and the focus of the company's R and D activities.
Zai Lab (NASDAQ: ZLAB) is a Shanghai-based innovative biopharmaceutical company focused on bringing transformative medicines for cancer, autoimmune and infectious diseases to patients in China and around the world.
The company's experienced team has secured partnerships with leading global biopharma companies, generating a broad pipeline of innovative drug candidates targeting the fast-growing segments of China's pharmaceutical market and global unmet medical needs.