The (Vyloy), a claudin 18.2 (CLDN18.2)-directed cytolytic antibody, in combination with chemotherapy for the first-line treatment of adults with advanced HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma, the agency announced Friday.
"While there have been advances in the first-line treatment of locally advanced unresectable and metastatic gastric and GEJ cancers in the last several years, there is still a tremendous unmet need among our patients," said Samuel J. Klempner, MD, of Massachusetts General Hospital and Harvard Medical School in Boston, in a from Astellas.
"The approval of Vyloy ... brings forward a novel biomarker and new therapy for patients whose tumors are CLDN18.2 positive, and for those on the frontlines of treatment decision making," he added.
Approval was based on results from the phase III SPOTLIGHT and GLOW trials.
In SPOTLIGHT, 565 patients with locally advanced gastric/GEJ cancer and CLDN18.2 expression were randomized to receive zolbetuximab or placebo with modified FOLFOX chemotherapy. Median progression-free survival (PFS) was 10.6 months in the zolbetuximab/chemotherapy arm and 8.7 months in the placebo/chemotherapy arm (HR 0.751, 95% CI 0.598-0.942, P=0.0066), while median overall survival (OS) was 18.2 months and 15.5 months, respectively (HR 0.750, 95% CI 0.601-0.936, P=0.0053).
In GLOW, 507 patients with CLDN18.2-positive locally advanced or metastatic gastric/GEJ cancer were randomized to receive either zolbetuximab or placebo with capecitabine and oxaliplatin. Median PFS was 8.2 months and 6.8 months in the two arms, respectively (HR 0.687, 95% CI 0.544-0.866), P=0.0007), and median OS was 14.4 months and 12.2 months, respectively (HR 0.771, 95% CI 0.615-0.965, P=0.0118).
The FDA also approved the Ventana CLDN18 (43-14A) RxDx Assay as a companion diagnostic device to identify patients with gastric or GEJ adenocarcinoma potentially eligible for treatment with zolbetuximab.
The most common serious adverse reactions in SPOTLIGHT and/or GLOW were vomiting, nausea, neutropenia, febrile neutropenia, diarrhea, intestinal obstruction, pyrexia, pneumonia, respiratory failure, pulmonary embolism, decreased appetite, sepsis, decreased platelet count, and upper gastrointestinal hemorrhage.