SAN FRANCISCO—Second-line treatment with paclitaxel/trastuzumab showed promising activity in trastuzumab-naïve patients with HER2-positive advanced or recurrent gastric cancer who had received at least one line of chemotherapy, the final report of a multicenter phase 2 study concluded at the 2014 Gastrointestinal Cancers Symposium.
Previously, the global randomized phase 3 ToGA study had demonstrated a survival benefit with first-line treatment of trastuzumab, capecitabine, and cisplatin for this population; however, efficacy and safety data are lacking for second-line treatment containing trastuzumab, noted Tsunehiro Takahashi, MD, PhD, of the School of Medicine at Keio University, Tokyo, Japan, and colleagues.
In this study, 47 patients with HER2-positive histologically confirmed gastric adenocarcinoma received paclitaxel 80 mg/m2 on days 1, 8, and 15 every 4 weeks plus trastuzumab 8 mg/kg for the initial dose, followed by 6 mg/kg every 3 weeks until disease progression, unacceptable toxicity, or patient refusal.
The primary endpoint, overall response rate, was 37% (95% CI: 23%-52%), with one patient (2.2%) having a complete response. Median progression-free survival was 5.09 months (95% CI: 3.79-6.49 months); time to treatment failure, 5.09 months (95% CI: 3.72-6.49 months); and overall survival, 16.81 months (95% CI: 13.54-18.65 months).
Dr. Takahashi stated that paclitaxel plus trastuzumab was generally well tolerated. During treatment, one patient died of lung pulmonary fibrosis. The most common grade 3/4 adverse events were leucopenia (17.4%), neutropenia (32.6%), and anemia (15.2%).
The 2014 Gastrointestinal Cancers Symposium is sponsored by the American Gastroenterological Association (AGA) Institute, the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO), and the Society of Surgical Oncology (SSO).