U.S. Food and Drug Administration approval: panitumumab for epidermal growth factor receptor-expressing metastatic colorectal carcinoma with progression following fluoropyrimidine-, oxaliplatin-, and irinotecan-containing chemotherapy regimens.

PURPOSE: To describe the Food and Drug Administration review and marketing approval considerations for panitumumab (Vectibix) for the third-line treatment of patients with epidermal growth factor receptor-expressing metastatic colorectal carcinoma. EXPERIMENTAL DESIGN: Food and Drug Administration reviewed a single, open-label, multicenter trial in which 463 patients with epidermal growth factor receptor-expressing metastatic colorectal cancer who had progressed on or following treatment with a regimen containing a fluoropyrimidine, oxaliplatin, and irinotecan were randomized (1:1) to receive best supportive care (BSC) with or without panitumumab (6 mg/kg every other week) administered until disease progression or intolerable toxicity. Progression and response were confirmed by an independent review committee masked to treatment assignment. At progression, patients in the BSC-alone arm were eligible to receive panitumumab. RESULTS: Although median progression-free survival (PFS) was similar in both treatment arms ( approximately 8 weeks), the mean PFS was approximately 50% longer among patients receiving panitumumab than among those receiving BSC alone (96 versus 60 days, respectively) and the objective response rate in patients receiving panitumumab was 8%. However, no difference in overall survival was shown between the two study arms. CONCLUSIONS: Panitumumab received accelerated approval based on improvement in PFS and an independently confirmed response rate of 8%, similar to that observed with other active agents at this advanced stage of disease. Confirmation of clinical benefit will be required for full approval.

First FDA approval of dual anti-HER2 regimen: pertuzumab in combination with trastuzumab and docetaxel for HER2-positive metastatic breast cancer.

On June 8, 2012, the U.S. Food and Drug Administration (FDA) approved pertuzumab (Perjeta, Genentech) for use in combination with trastuzumab (Herceptin, Genentech) and docetaxel for the treatment of patients with HER2-positive metastatic breast cancer (MBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease. Approval was based on the results of a randomized, double-blind, placebo-controlled trial conducted in 808 patients with HER2-positive MBC. Patients were randomized (1:1) to receive pertuzumab (n = 402) or placebo (n = 406) in combination with trastuzumab and docetaxel. The primary endpoint was progression-free survival (PFS) and a key secondary endpoint was overall survival (OS). A statistically significant improvement in PFS (difference in medians of 6.1 months) was observed in patients receiving pertuzumab [HR, 0.62; 95% confidence interval (CI), 0.51-0.75; P < 0.0001]. A planned interim analysis suggested an improvement in OS (HR, 0.64; 95% CI, 0.47-0.88; P = 0.0053) but the HR and P value did not cross the stopping boundary. Common adverse reactions (>30%) observed in patients on the pertuzumab arm included diarrhea, alopecia, neutropenia, nausea, fatigue, rash, and peripheral neuropathy. No additive cardiac toxicity was observed. Significant manufacturing issues were identified during the review. On the basis of substantial evidence of efficacy for pertuzumab in MBC and the compelling public health need, FDA did not delay availability to patients pending final resolution of all manufacturing concerns. Therefore, FDA approved pertuzumab but limited its approval to lots not affected by manufacturing problems. The applicant agreed to multiple manufacturing and testing postmarketing commitments under third-party oversight to resolve manufacturing issues.