(HealthDay News) — For patients with human epidermal growth factor receptor 2 (HER2)-negative, locally advanced unresectable or metastatic gastric or gastroesophageal junction (mG/GEJ) adenocarcinoma, zolbetuximab, a monoclonal antibody that targets claudin-18 isoform 2 (CLDN18.2), plus capecitabine and oxaliplatin (CAPOX) prolongs progression-free survival (PFS) and overall survival (OS) versus placebo plus CAPOX, according to a study published online July 31 in Nature Medicine.

Manish A. Shah, M.D., from Weill Cornell Medical College in New York City, and colleagues conducted a phase 3 study to examine zolbetuximab plus CAPOX as first-line treatment for CLDN18.2-positive, HER2-negative, locally advanced unresectable or mG/GEJ adenocarcinoma in 507 patients randomly assigned to zolbetuximab plus CAPOX or placebo plus CAPOX in a 1:1 ratio.

The researchers found that PFS, the primary end point, was significantly prolonged for patients randomly assigned to receive zolbetuximab versus placebo (median, 8.21 versus 6.90 months; hazard ratio [HR], 0.687), as was OS, the key secondary end point (median, 14.39 versus 12.16 months; HR, 0.771). Treatment-emergent adverse events of grade 3 or higher occurred in 72.8 and 69.9 percent of those receiving zolbetuximab and placebo, respectively.

Continue Reading

“We now have evidence from two large trials showing that the addition of zolbetuximab provides a meaningful survival benefit for patients with CLDN18.2-positive gastric cancers,” Shah said in a statement. “If zolbetuximab is approved, patients will be able to decide with their physicians whether zolbetuximab plus CAPOX or mFOLFOX [folinic acid plus 5-fluorouracil and oxaliplatin] is the right regimen for them.”

Several authors disclosed ties to the biopharmaceutical industry, including Astellas Pharma Inc., which funded the study and manufactures zolbetuximab.

Abstract/Full Text