Results from an open-label phase 2 randomized clinical trial suggested that the combination of PANVAC and docetaxel in metastatic breast cancer may provide clinical benefit, according to an article published online ahead of print in JAMA Oncology.
Previous phase 1 and 2 trials of PANVAC, a poxviral-based cancer vaccine, have suggested clinical efficacy in patients with different tumor types such as breast, ovarian, and colorectal and have shown evidence of immunologic activity. Preclinical data have demonstrated that docetaxel can modify tumor phenotype, making tumors more amenable to T-cell mediated killing.
Researchers investigated the combination of docetaxel and PANVAC to evaluate if the combination improved clinical outcomes in patients with metastatic breast cancer compared with docetaxel treatment alone.
A total of 48 patients with metastatic breast cancer of all subtypes were enrolled, without limitation on other lines of previous therapy. Twenty-five were randomized to the combination treatment arm (A) and 23 to the docetaxel-alone arm (B).
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In regard to safety, analysis of both arms showed very little difference between the groups. Patients in Arm A had statistically significant increase in the frequency of grades 1 and 2 edema (P=0.02), which was likely associated with a greater median number of docetaxel cycles and injection-site reactions (P<0.001).
Final data analysis showed an advantage for arm A in median progression-free survival (7.9 months versus 3.9 months; HR, 0.65; 95% CI, 0.34, 1.14; P=0.09). The study provides both a rationale and statistical assumptions for a larger definitive randomized study.
- Heery CR, Ibrahim NK, Arlen PM, et al. Docetaxel alone or in combination with a therapeutic cancer vaccine (PANVAC) in patients with metastatic breast cancer: a randomized clinical trial. JAMA Oncol. 2015. [epub ahead of print]. doi: 10.1001/jamaoncol.2015.2736.