Final results of a phase II trial of weekly nab-paclitaxel with GM-CSF as chemoimmunotherapy for platinum-resistant epithelial ovarian cancer.

Abstract

5082^ Background: Ovarian cancer patients with an anti-tumor immune response have a prolonged survival, suggesting that augmenting anti-tumor immunity may be therapeutic. We hypothesized that weekly nab paclitaxel (nabP) followed by GM-CSF may enhance anti tumor immunity and prolong time to progression (TTP). Methods: Eligible subjects had platinum resistant ovarian, primary peritoneal or fallopian tube cancer, and an elevated CA125. Conditional power estimate after 11 subjects showed 22 subjects had 80% power to show a response rate (RR) >21% if the true study RR is 35%. Study end points were RR and TTP. Progression (DP) was doubling of CA125 above the nadir. Complete response (CR) was a decline of CA125 below institutional normal. Partial response (PR) was a decline of >50% from baseline. Stable disease (SD) was all other scenarios. Subjects received nabP, 100mg/m2 days 1,8,15 followed by GM-CSF 250mcg days 16-26 of a 28 day cycle until progression or 6 cycles were complete. Responding subjects received up to 6 more cycles of GM-CSF on days 14-28. Results: 21 subjects received at least one dose of study medications. Median age was 61 (30-91) and had a median of 3 (1-13) prior regimens. Among those completing the study, the median TTP was 132 days vs. 272 days on the prior platinum regimen. 9/21 (43%) had a PR and 4/21 (19%) had a CR. Subjects with a response had a median TTP of 140 days. Assay of serial T-lymphocyte counts against CEA, MUC1, CA125 and tt and influenza controls are planned. Conclusions: Weekly nabP with GM-CSF had manageable toxicity and induced a high response rate (62% by CA125) in patients with platinum resistant ovarian cancer, however this regimen did not prolong the TTP beyond the TTP observed in the prior platinum regimen.