Clinical trial in progress: Pivotal study of VB-111 combined with paclitaxel versus paclitaxel for treatment of platinum-resistant ovarian cancer (OVAL, VB-111-701/GOG-3018).

Abstract

TPS6097 Background: Ofranergene obadenovec (VB-111) is a targeted anti-cancer gene therapy with a dual mechanism: a broad antiangiogenic effect and induction of a tumor directed viral immune response. In a phase II trial in platinum resistant ovarian cancer VB-111 in combination with weekly paclitaxel showed a CA-125 response rate (RR) of 58% and median overall survival (OS) of 498 days compared to 172.5 days in the sub-therapeutic dose (p = 0.028). The combination treatment was well tolerated. Favorable outcomes were associated with induction of an immunotherapeutic effect of tumor infiltration with CD-8 T cells. Based on these observations, a phase III randomized controlled trial, VB-111-701/GOG-3018 (OVAL) was initiated in collaboration with the GOG Foundation, Inc. Methods: The OVAL study, NCT03398655, is an international, randomized, double-blind, placebo-controlled, phase III study. Patients with recurrent platinum-resistant epithelial ovarian cancer, who have measurable disease (RECIST 1.1) and were previously treated with up to 5 lines are randomized 1:1 to receive VB-111 (1x1013 VPs) with weekly paclitaxel (80mg/m2), or weekly paclitaxel with placebo. Randomization is stratified by number of prior treatment lines, prior antiangiogenic therapy and platinum refractory disease status. Treatment beyond asymptomatic RECIST progression may continue until progression is confirmed by follow up imaging. The primary endpoints are OS, safety and tolerability. Secondary endpoints include progression free survival, and objective RR by CA-125 (per GCIG criteria) and RECIST 1.1. The sample size calculation of 400 patients (event driven) provides 92% power to detect a difference in survival at the two-sided 5% significance level using the logrank test. A pre-planned interim analysis will take place in Q1 2020 to assess whether the CA-125 RR per GCIG criteria in the treatment arm is sufficiently larger than in the control arm and is comparable to the positive results of the phase II study. Study enrolment is ongoing and over 80 patients were enrolled in the US and Israel. Enrollment expansion to Europe is planned in 2020. Clinical trial information: NCT03398655.