, according to a new study.
Jiafu Ji, MD, PhD, presented this and other findings of the randomized, double-blind, placebo-controlled phase 3 COMPASSION-15 trial at the annual meeting of the American Association for Cancer Research (AACR).
“The consistent survival benefits across all prespecified PD-L1 expression cutoffs, particularly in patients with low PD-L1 expression, have significant implications for clinical practice by expanding treatment options, improving outcomes for patients with PD-L1–low tumors, influencing guidelines, and stimulating further research in advanced G/GEJ adenocarcinoma treatment,” said Dr. Ji, a principal investigator of this trial, in an interview.
Unmet Need
The incidence of gastric cancer is particularly high in China, but as Dr. Ji discussed in his talk, the treatment options for patients with advanced disease remain limited. Although the Food and Drug Administration (FDA) has approved the combination of PD-L1 inhibitors with chemotherapy for the first-line treatment of advanced gastric cancer, not all patients respond to the treatment, explained Dr. Ji, who is a professor of gastrointestinal surgery and president of Peking University Cancer Hospital and Beijing Institute for Cancer Research in China.
He added that the combination of PD-L1 inhibitors and chemotherapy has not yet been approved for the treatment of advanced gastric cancer in China, leaving chemotherapy as the only treatment option for Chinese patients.
Study Design
To evaluate the efficacy and safety of first-line cadonilimab plus standard chemotherapy in patients with advanced or metastatic gastric cancer, the authors of the COMPASSION-15 trial enrolled 610 patients with unresectable, locally advanced, or metastatic G/GEJ adenocarcinoma who had not received any prior treatments. PD-L1 expression status was not used to exclude patients from the trial.
In a press conference held at AACR 2024, Dr. Ji explained the study rationale, design, and endpoints. He said that patients with tumors without PD-L1 expression typically show little to no benefit from anti–PD-1/PD-L1 inhibitors, and their treatment options are limited to chemotherapy.
“Testing the efficacy of this bispecific antibody in this patient population could provide an alternative treatment approach for them,” he added.
Patients were randomized 1:1 to receive either cadonilimab (10 mg/kg every 3 weeks) plus chemotherapy or placebo plus chemotherapy. The primary endpoint of the study was overall survival (OS) in the intent-to-treat (ITT) population, and secondary efficacy endpoints included OS, progression-free survival (PFS), and objective response rate (ORR) in the ITT population, as well as in patients stratified by PD-L1 expression.
Cadonilimab Plus Standard Chemotherapy Improves OS
Interim analysis, conducted with a median follow-up of 18.69 months, showed a significant improvement in OS for the cadonilimab plus chemotherapy group compared with the chemotherapy-alone group, according to data presented at the press conference. The median OS was 15.0 months in the cadonilimab group versus 10.8 months in the placebo group, representing a 38% reduction in the risk of death (hazard ratio [HR], 0.62; 95% CI, 0.50-0.78, P < .001).
