Dendritic cell vaccine (DCVAC) with chemotherapy (ct) in patients (pts) with recurrent epithelial ovarian carcinoma (EOC) after complete response (CR) to 1st-line platinum (Pt)-based ct: Primary analysis of a phase 2, open-label, randomized, multicenter trial.

Abstract

e17515 Background: When pts with EOC relapse, their response to subsequent therapy is reduced. We hypothesized that autologous DCVAC could potentiate the antitumor response to ct and delay progression. Methods: Key eligibility criteria were FIGO stage III - IV EOC (serous, endometrioid, or mucinous), PS 0 - 2, CR after 1st-line Pt-based ct that lasted > 6 months, and at least 1 measurable lesion per RECISTv1.1. We randomized pts up to 6 weeks after relapse was confirmed by CT/MRI, 1:1, into arm A (A; DCVAC concomitantly with ct) and arm B (B; ct alone). Pts were stratified by previous bevacizumab use (yes/no) and duration of remission (6 - 12/ > 12 months). Ct consisted of 6 - 10 cycles of carboplatin (AUC 4 - 5; D1) and gemcitabine (1000mg/m2; D1, D8). Pts in A were to receive 10 doses of DCVAC (1 x 107 DCs/dose). The primary endpoint was investigator-assessed progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), and safety. Results: Between November 2013 and May 2015, 71 pts were randomized in 3 countries (A/B, 39/32). Median age was 58.5 years in A and 60.5 years in B. After excluding pts who failed leukapheresis or manufacturing, the intention-to-treat population included 32 pts in each arm. A mean of 9.8 doses of DCVAC were administered in A. Median follow-up time was 28.2 months (range, 23.8 - 41.6 months). Median PFS was 10.9 months in A and 9.4 months in B; HR (95% CI) = 0.74 (0.42 - 1.30), p = 0.29. The corresponding ORR (95% CI) was 87.5% (71.0% - 96.5%) in A and 62.5% (43.7% - 78.9%) in B. In November 2017, median OS was not reached in A, while it was 30 months in B (44% events); HR (95% CI) = 0.62 (0.29 - 1.34). The majority of adverse events (AEs) were related to ct (thrombocytopenia [A: 64.9%, B: 80.6%], anemia [A: 64.9%, B: 67.7%], neutropenia [A: 59.5%, B: 67.7%], and leukopenia [A: 45.9%, B: 32.3%]). There were no grade ≥ 3 AEs related solely to DCVAC. Most common leukapheresis-related AEs were mild pyrexia and moderate hypocalcemia. Conclusions: Primary analysis showed better ORR and a trend towards improved OS in the DCVAC arm. Clinical trial information: NCT02107950.