RESEARCH SUMMARY

Clinical trial shows that adding Bevacizumab to targeted drug and chemotherapy produces striking activity against HER2-positive Metastatic Gastroesophageal Adenocarcinoma

Study Title: Long-term results and ctDNA correlatives for CAPOX BETR: A multi-center phase II trial of capecitabine, oxaliplatin, bevacizumab and trastuzumab for previously untreated HER2 positive metastatic gastroesophageal adenocarcinoma

Publication: AACR Poster Session, Presentation No. CT155; Poster Board No: 17

Dana-Farber Cancer Institute author: Harshabad Singh, MBBS, MD

Summary: 

Singh, MBBS, MD

Addition of the drug bevacizumab to chemotherapy and a HER2-targeted agent, herceptin, showed striking activity in a clinical trial involving patients with HER2-positive metastatic gastroesophageal adenocarcinoma – comparable to the effect of current standard therapy, which includes an immunotherapy agent targeting the PD-1 protein on T cells. In the trial, 37 patients with previously untreated cancers received standard chemotherapy (capecitabine and oxaliplatin) and trastuzumab (a HER2-targeting agent), followed by bevacizumab, an anti-angiogenic drug that blocks blood vessel growth to tumors. Eighty-one percent of the participants responded to the treatment. At a median follow-up of 23.2 months, all the patients were alive, and the progression-free survival (PFS) was 14 months. That compares with a response rate of 74% for the current standard therapy, which consists of chemotherapy, trastuzumab, and the immunotherapy drug pembrolizumab. The six-month PFS for standard therapy is 70.3%, compared to 77% for the regimen including bevacizumab. The findings may lay the groundwork for a clinical trial of bevacizumab in combination with standard therapy, investigators say.

Impact:

For patients with HER2-positive metastatic gastroesophageal adenocarcinoma, a clinical trial found that a combination of the anti-angiogenic drug bevacizumab, chemotherapy, and a HER2-targeted agent had impressive clinical activity. A median of nearly two years after the trial, all 37 participants were alive. The findings may lay the groundwork for a trial of bevacizumab and standard therapy, which includes an immunotherapy drug. 

Funding: 

The study was funded by Genentech. The analysis of circulating tumor DNA was done in collaboration with Predicine, Inc.