Introduction
diarrhea
ADVERSE EVENTS, METASTATIC BREAST CANCER, MUCOSAL INFLAMMATION, FEBRILE NEUTROPENIA
Pertuzumab and trastuzumab (PERJETAPertuzumab plus trastuzumab and docetaxel in patients with previously untreated HER2-positive locally recurrent or metastatic breast cancer was shown to improve progression-free and overall survival (PFS and OS) significantly compared with placebo plus trastuzumab and docetaxel in CLEOPATRA (NCT00567190). At CLEOPATRA’s primary analysis, independently assessed median PFS was 18.5 months in the pertuzumab arm and 12.4 months in the placebo arm. The PFS hazard ratio (HR) was 0.62 [95% confidence interval (CI) 0.51, 0.75; Exploratory analyses of safety showed a higher proportion of patients from Asia [China (including Hong Kong) plus Japan, Korea, the Philippines, Singapore, and Thailand] experienced adverse events (AEs) than patients from Europe, North America, and South America combined. The most common AE was febrile neutropenia, which the authors postulated may have been related to increased diarrhea and mucosal inflammation. Despite these differences, comparable survival benefits across regions were observed [PUFFIN (NCT02896855) was a Chinese bridging study to evaluate the efficacy and safety of pertuzumab and to determine consistency with CLEOPATRA. The primary analysis showed that efficacy data were consistent with CLEOPATRA. Median investigator-assessed PFS was 14.5 months and 12.4 months in the pertuzumab and placebo arms, respectively; OS was relatively immature. The PFS HR was 0.69 (95% CI 0.49, 0.99), which was similar to the investigator-assessed PFS HR in CLEOPATRA; 0.62 (95% CI 0.51, 0.75) [