The independent data safety monitoring committee has cleared VBL Therapeutics to continue a phase 3 trial of VB-111 in ovarian cancer patients. VBL got the green light after the committee looked at unblinded overall survival (OS) data for the second preplanned interim analysis.
VB-111, also known as ofranergene obadenovec, is a viral-based cancer therapy designed to disrupt the growth of blood vessels and induce an immune response against tumor cells. In a phase 1/2 trial in platinum-resistant ovarian cancer, VBL linked the therapeutic dose of the dual-mechanism drug to a median OS of 16.6 months. Median OS in the cohort that received a sub-therapeutic dose was 5.8 months.
VBL moved the candidate into a phase 3 trial in 2017 to assess the effect of adding it to paclitaxel. The drug came through the first interim analysis in March and has now cleared a second assessment.
The second interim analysis looked at unblinded OS data on the first 100 subjects randomized in the trial, as well as response rates and safety information. No details of the analysis are available publicly but it evidently was free from the sort of red flags that would cause the termination or modification of the study.
VBL shared more data at the time of the first review, which looked at the response rate in the first 60 subjects enrolled in the phase 3. The response rate across the VB-111 and placebo cohorts, both of which received paclitaxel, was 53%. The response rate in people who experienced fever, a side effect of VB-111, was 69%.
In a statement to disclose the continuation of the phase 3 trial, VBL CEO Dror Harats talked up the implications of the limited data released to date, citing “the remarkable response rate observed in our first interim efficacy analysis” as a reason for his confidence in the late-stage study.
VBL is now continuing to enroll patients, working toward its enrollment target of 400 subjects, and generating data that will inform a further interim review by the data monitoring committee in 2021.