The US FDA has approved a durvalumab (Imfinzi, AstraZeneca)-based regimen for adults with resectable gastric or gastroesophageal junction adenocarcinoma (GC/GEJC). 

Specifically, durvalumab, an anti-programmed death-ligand 1 immunotherapy agent, is now approved with fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) chemotherapy as neoadjuvant and adjuvant treatment, followed by single-agent durvalumab, according to the approval notice.

The approval, which followed priority review, was based on efficacy demonstrated in the randomized, double-blind, placebo-controlled MATTERHORN trial involving 948 patients with previously untreated resectable stages II-IVA GC/GEJC.

Event-free survival, the major efficacy outcome of the multicenter trial, was not reached in patients randomly assigned to the durvalumab plus FLOT arm compared with 32.8 months in those randomly assigned to the placebo plus FLOT arm (hazard ratio [HR], 0.71).

Median overall survival was not reached in either arm (HR, 0.78), and the pathological complete response rates were 19.2% and 7.2% in the treatment and placebo arms, respectively. 

Findings from the trial were presented recently at the European Society of Medical Oncology where, as reported by Medscape Medical News, experts said that the survival benefit “further supports perioperative durvalumab plus FLOT as the new standard of care” for localized GE/GEJC.

The recommended durvalumab dose is weight-based: Patients weighing 30 kg or more should receive 1500 mg every 4 weeks with chemotherapy for up to four cycles, followed by 1500 mg as a single agent every 4 weeks for up to 10 cycles, and those weighing less than 30 kg should receive 20 mg/kg with chemotherapy for up to four cycles (neoadjuvant and adjuvant), followed by 20 mg/kg as a single agent every 4 weeks for up to 10 cycles (adjuvant).

Treatment should continue until disease progression, recurrence, or unacceptable toxicity.

The full prescribing information for durvalumab, which will be posted at Drugs@FDA, includes warnings and precautions for immune-mediated adverse reactions, infusion-related reactions, complications of allogeneic hematopoietic stem-cell transplantation, and embryo-fetal toxicity. 

Sharon Worcester, MA, is an award-winning medical journalist based in Birmingham, Alabama, writing for Medscape Medical News, MDedge, and other affiliate sites. She currently covers oncology, but she has also written on a variety of other medical specialties and healthcare topics. She can be reached at sworcester@mdedge.com or on X @SW_MedReporter.