Efficacy and safety result of trastuzumab (T-mab) and paclitaxel for T-mab naive patients with HER2-positive previously treated advanced or recurrent gastric cancer (JFMC45-1102): Final report.

Abstract

79 Background: The global, randomized, phase III ToGA study showed that the first-line treatment of trastuzumab (T-mab) combined with capecitabine and cisplatin a survival (OS) benefit for patients (pts) with HER2 positive advanced or recurrent gastric cancer. However, there is no report concerning about the efficacy and safety of T-mab containing second-line treatment for T-mab naïve pts with HER2 positive advanced or recurrent gastric cancer. Therefore, we planned a phase II study of paclitaxel plus T-mab in this setting. Methods: JFMC45-1102 is multicentre phase II study. Pts with HER2 positive (IHC3+ or IHC2+/FISH+), histologically confirmed gastric adenocarcinoma, age ≥ 20, received one or more prior chemotherapy but no prior therapy with T-mab, normal left ventricular ejection fraction (LVEF ≥ 50%) were eligible. Pts received paclitaxel (80 mg/m2 on days 1, 8, and, 15 q4w) plus T-mab (8 mg/kg for the initial dose, followed by 6 mg/kg q3w) until disease progression, unacceptable toxicity or patient’s refusal. The primary endpoint was overall response rate (ORR), and the secondary endpoints include progression free survival (PFS), time to treatment failure (TTF), OS and safety. Results: A total of 47 pts were enrolled from September 2011 to March 2012.The primary endpoint ORR was 37.0% (95%CI, 23 to 52).Complete response was observed in 1 case (2.2%).The PFS data was matured, and the median PFS was 5.09 months (95%CI, 3.79 to 6.49), TTF 5.09 months (95%CI, 3.72 to 6.49), OS 16.81 months (95%CI, 13.54 to 18.65). One patient died of lung pulmonary fibrosis during therapy. The most common grade 3-4 adverse events were leucopenia (17.4%), neutropenia (32.6%), anemia (15.2%). Conclusions: Combination chemotherapy of paclitaxel plus T-mab is generally well tolerated and showed promising activity for T-mab naïve patients with HER2 positive previously treated advanced or recurrent gastric cancer. Clinical trial information: UMIN000006223.