FDA approval summary: Pertuzumab for adjuvant treatment of HER2-positive early breast cancer

On December 20, 2017, the FDA granted regular approval to pertuzumab in combination with trastuzumab and chemotherapy for the adjuvant treatment of patients with HER2-positive early breast cancer (EBC) at high risk of recurrence. Approval was based on data from the APHINITY trial, which randomized patients to receive pertuzumab or placebo in combination with trastuzumab and chemotherapy. After 45.4-month median follow-up, the proportion of invasive disease-free survival (IDFS) events in the intent-to-treat population was 7.1% (n ¼ 171) in the pertuzumab arm and 8.7% (n ¼ 210) for placebo [hazard ratio (HR), 0.82; 95% confidence interval (CI), 0.67–1.00; P ¼ 0.047]. The proportion of IDFS events in patients with hormone receptor–negative disease was 8.2% (n ¼ 71) and 10.6% (n ¼ 91) in the pertuzumab and placebo arms, respectively (HR, 0.76; 95% CI, 0.56–1.04). The proportion of IDFS events for patients with node-positive disease was 9.2% (n ¼ 139) and 12.1% (n ¼ 181) in the pertuzumab and placebo arms, respectively (HR, 0.77; 95% CI, 0.62–0.96). Adverse reactions in 30% of patients receiving pertuzumab were diarrhea, nausea, alopecia, fatigue, peripheral neuropathy, and vomiting. From a regulatory standpoint, the benefits of the addition of pertuzumab to adjuvant treatment outweighed the risks for patients with EBC at high risk of recurrence.