Five Prime Therapeutics reports positive results from Phase II FIGHT trial

11th November 2020 (Last Updated November 11th, 2020 18:18)

Five Prime Therapeutics, a clinical-stage biotechnology company, has reported positive topline results from the global, randomised, double-blind placebo-controlled Phase II FIGHT trial.

Five Prime Therapeutics reports positive results from Phase II FIGHT trial
Gastric signet ring cell carcinoma. Credit: KGH

Five Prime Therapeutics, a clinical-stage biotechnology company, has reported positive topline results from the global, randomised, double-blind placebo-controlled Phase II FIGHT trial.

The clinical trial compared mFOLFOX6 chemotherapy along with a first-in-class targeted therapy bemarituzumab (bema, FPA144) in patients suffering with fibroblast growth factor receptor 2b-positive (FGFR2b+), non HER2 positive (non HER2+) front-line advanced gastric or gastroesophageal junction (GEJ) cancer.

The FGFR2b Inhibition in Gastric and Gastroesophageal Junction Cancer Treatment (FIGHT) trial (NCT03694522) was intended to analyse the efficacy and safety of bemarituzumab along with modified FOLFOX6 as compared to mFOLFOX6 plus placebo in patients suffering with newly diagnosed FGFR2b positive, locally advanced or metastatic gastric and GEJ cancer.

The trial saw enrolment of 155 patients in 15 countries across Asia, the EU, and the US.

Five Prime executive vice-president and chief medical officer Helen Collins said: “These results bring us one step closer to the first potential targeted therapy for advanced gastric cancer in over a decade.

“Benefit was observed in patients whose tumours overexpressed FGFR2b, even without evidence of amplification, and that may broaden the therapeutic potential of bemarituzumab in more cancer types.

“We are excited about the results of the FIGHT trial and the opportunity to advance the development of bemarituzumab, the first and only investigational treatment targeting FGFR2b+. Five Prime is grateful to the patients and investigators who participated in our clinical trials, and we look forward to discussing next steps with health authorities worldwide.”

The three efficacy endpoints in the trial, PFS, OS and ORR, met pre-specified statistical significance at a two-sided alpha of 0.20.

Furthermore, the incidence of all grade adverse events was comparable in the treatment and control arms of the study, with 100% vs 98.7% respectively, just as were serious adverse events with 31.6% vs 36.4%, and deaths due to adverse events were at 6.6% vs 5.2%.

Adverse events of ≥ Grade 3 were more frequently found in the treatment arm than in the placebo arm with 82.9% vs 74.0%, respectively.

During the trial, corneal and stomatitis adverse events were found more frequently in the bemarituzumab arm, and more patients discontinued bemarituzumab as compared to placebo as a result of an adverse event.

Furthermore, there were no adverse events of retinal detachment or hyperphosphatemia in the bemarituzumab arm.

Inspite of the greater frequency of discontinuation of bemarituzumab compared to placebo, the efficacy endpoints favoured bemarituzumab.

The trial results validate the significance of the novel target, FGFR2b, which is a form of fibroblast growth factor receptor (FGFR) found in epithelial cells, such as those in the stomach.

FGFR2b is overexpressed in approximately 30% of HER2- gastric cancers across the world.

Five Prime Therapeutics plans to finish a complete evaluation of the FIGHT Phase II data.