The following article features coverage from the European Society of Medical Oncology (ESMO) 2017 Congress in Madrid, Spain. Click here to read more of Cancer Therapy Advisor’s conference coverage.

The addition of pertuzumab to trastuzumab and chemotherapy does not significantly prolong overall survival (OS) in patients with HER2-positive (HER2+) metastatic gastric or gastro-esophageal junction cancer (mGC/GEJC), according to the a study presented at the European Society for Medical Oncology (ESMO) 2017 Congress in Spain.1

Separate studies demonstrated that trastuzumab and chemotherapy significantly improved OS in patients with HER2-positive mGC/GEJC compared to CT alone, and adding pertuzumab to trastuzumab and docetaxel significantly improved OS and progression-free survival (PFS) in HER2+ breast cancer.

For this phase 3 JACOB study (ClinicalTrials.gov Identifier: NCT01774786), researchers randomly assigned 780 patients with mGC/GEJC to receive pertuzumab, trastuzumab, and chemotherapy or trastuzumab, chemotherapy, and placebo.

At a median follow-up of nearly 2 years, 504 patients died. Patients who received pertuzumab, trastuzumab, and chemotherapy achieved an OS of 17.5 months compared to 14.2 months in patients who received trastuzumab, chemotherapy, and placebo (hazard ratio [HR], 0.84; 95% CI, 0.71-1.00; P = .0565).

The median PFS was 8.5 months in patients who received pertuzumab, trastuzumab, and chemotherapy, and 7.0 months in patients who received trastuzumab, chemotherapy, and placebo (HR, 0.73; 95% CI, 0.62-0.86).

Both treatment arms had comparable safety profiles, but 61.6% of patients in the pertuzumab, trastuzumab, and chemotherapy arm experienced diarrhea compared to just 35.1% of patients in the trastuzumab, chemotherapy, and placebo arm. Both treatment arms had a low incidence of symptomatic and asymptomatic left ventricular systolic dysfunction.

RELATED: Phase 2 Study of Andecaliximab and Nivolumab for Gastroesophageal Junction or Gastric Cancer

The authors concluded that “the study failed to demonstrate a statistically significant improvement in OS with the addition of [pertuzumab] to [trastuzumab] + [chemotherapy], although a 3.3 month increase in median OS was observed.”

Read more of Cancer Therapy Advisor‘s coverage of the European Society of Medical Oncology (ESMO) 2017 Congress by visiting the conference page.

Editor’s note: This article has been corrected to reflect that 780 patients were randomly assigned between the treatment arms in the JACOB study.

Reference

  1. Tabernero J, Hoff P, Shen L, et al. Pertuzumab (P) + trastuzumab (H) + chemotherapy (CT) for HER2-positive metastatic gastric or gastro-oesophageal junction cancer (mGC/GEJC): final analysis of a phase III study (JACOB). Presented at: European Society for Medical Oncology (ESMO) 2017 Congress; September 8-12, 2017; Madrid, Spain.