Phase II Study Shows Activity of Paclitaxel Added to Trastuzumab/Pertuzumab in HER2-Positive Metastatic Breast Cancer
In a phase II trial reported in Journal of Clinical Oncology, Dang et al found that the addition of weekly paclitaxel to trastuzumab (Herceptin)/pertuzumab (Perjeta) produced good activity in patients with HER2-positive metastatic breast cancer. Paclitaxel may be a less toxic alternative to docetaxel in this setting.
Study Details
In the study, 69 patients with no (n = 51, 74%) or one (n = 18, 26%) prior therapies for metastatic disease were enrolled at Memorial Sloan Kettering Cancer Center between January 2011 and December 2013 and treated with paclitaxel 80 mg/m2 once per week plus trastuzumab 8 mg/kg loading dose followed by 6 mg/kg once every 3 weeks and pertuzumab 840 mg loading dose followed by 420 mg once every 3 weeks. The primary endpoint was 6-month progression-free survival.
Progression-Free Survival
At median follow-up of 21 months (range = 3–38 months), 6-month progression-free survival was 86% (95% confidence interval [CI] = 75%–92%). Overall, median progression-free survival was 19.5 months (95% CI = 14–26 months), including 24.2 months (95% CI = 14 months to not reached) in patients with no prior treatment and 16.4 months (95% CI = 8.5 months to not reached) in those with prior treatment. Progression-free survival at 1 year was 70% (95% CI = 56%–79%) overall, including 71% (95% CI = 55%–82%) in those without prior treatment and 66% (95% CI = 40%–83%) in those with prior treatment.
Among 64 evaluable patients, 7 (11%) had complete response, 31 (48%) had partial response, and 16 (25%) had stable disease.
Adverse Events
The most common grade 1 or 2 adverse events were diarrhea (81%), fatigue (79%), and peripheral neuropathy (79%). The most common grade 3 or 4 adverse events were fatigue (6%), diarrhea (3%), peripheral neuropathy (3%), AST and ALT elevation (3% each), and palmar-plantar erythrodysesthesia syndrome (3%). No febrile neutropenia or symptomatic left ventricular systolic dysfunction was observed.
The investigators concluded: “Paclitaxel given once per week with trastuzumab and pertuzumab is highly active and well tolerated and seems to be an effective alternative to docetaxel-based combination therapy.”
Chau Dang, MD, of Memorial Sloan Kettering Cancer Center, is the corresponding author for the Journal of Clinical Oncology article.
The study was supported by Roche/Genentech. For full disclosures of the study authors, visit jco.ascopubs.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
