Objectives: To evaluate the efficacy of combination of navitoclax, carboplatin and paclitaxel in ovarian cancer.
Methods: 8 ovarian cancer cell lines were treated with either doublet or triplet combinations of navitoclax, carboplatin and paclitaxel. Interactions were assessed by determining a combination index or measuring caspase activity. The effect of the combinations was also evaluated by measuring the inhibition of cells grown as spheroids.
Results: Navitoclax exhibited modest (IC(50)=3-8 μM) single agent potency. Antagonism between carboplatin and paclitaxel was evident in Ovcar-4, Ovcar-8 and Skov-3 cells. Drug combinations including navitoclax with carboplatin and/or paclitaxel showed significantly less antagonism, or even synergy, in several cell lines than carboplatin/paclitaxel alone. Navitoclax enhanced the activation of caspase 3/7 induced by carboplatin and/or paclitaxel in Igrov-1 cells. Combinations of navitoclax, carboplatin and paclitaxel showed more than additive activity against Igrov-1 spheroids.
Conclusions: Navitoclax improves the activity of combinations of carboplatin and paclitaxel in vitro. Our observations, taken with other published data, provide a rationale for clinical trials of navitoclax in ovarian cancer in combination with chemotherapy.
Copyright © 2012 Elsevier Inc. All rights reserved.