A Trial of Atezolizumab and Vigil in Patients With Advanced Gynecological Cancers

The clinical trial was intended as a companion study to protocol CL-PTL-119 (VITAL study; NCT 02346747). Subjects who had tumor harvested at surgery and Vigil successfully manufactured, but then were ineligible for randomization onto the VITAL study or previously randomized to placebo, and also in subjects who have recurrent ovarian cancer were offered the opportunity to participate in this protocol. The trial was a multi-center, randomized, 3-part, open label study of Vigil, the checkpoint inhibitor atezolizumab and the combination of the two agents, in subjects with treatment refractory or recurrent epithelial ovarian cancer, or other gynecological cancers (i.e., cervical, uterine). Part 1 was a safety run-in cohort and intervention (Vigil plus atezolizumab) was combined. The first 3 subjects registered in the trial were assigned to Part 1. Part 2 was conducted after Part 1 participants completed combination therapy without dose-limiting toxicity. The purpose of Part 2 was to determine if Vigil given first then in sequence with atezolizumab would enhance immunotherapeutic anticancer activity. The overall efficacy of administration sequence was assessed. Eligible subjects were randomized to receive two cycles of Vigil alone (n= 11) or two cycles of atezolizumab alone (n=10), followed by combination treatment with both of the agents. Part 3 was an expansion cohort to allow subjects who completed all cycles of Part 2 to continue on atezolizumab alone, after Cycle 12. In this study, only 1 subject from Part 2 received additional treatment with atezolizumab. Pre-approval by sponsor was required by the sponsor before allowing subjects to continue treatment with atezolizumab in Part 3. Subjects remained on treatment until disease progression or death or product toxic effect. Disease progression was determined radiographically by local investigators using the Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1). Part 1, radiological assessment of tumor response was performed at baseline and every third cycle thereafter. Tumor biopsy for correlative studies including scoring of tumor infiltrating lymphocyte (TIL) and PD-1 / PD-L1 expression analysis was obtained at tissue procurement and at any time after the end of cycle 3. Whole blood for correlative studies (immune function) was obtained at baseline, prior to study agent administration at the start of cycle 3 and every third cycle thereafter. Part 2, radiological assessment of tumor response was performed at baseline, at the end of cycle 2 of single agent therapy, and every third cycle thereafter. Tumor biopsy for correlative studies including scoring of tumor infiltrating lymphocyte (TIL) and PD-1 / PD-L1 expression analysis was obtained at tissue procurement, prior to the start of combination therapy and at any time after the end of cycle 3. Whole blood for correlative studies (immune function) was obtained at baseline, prior to study agent administration at the start of cycle 3 (the first cycle of combination therapy) and every third cycle thereafter. Part 3 schedule of assessments continued from Part 2 in which the following was assessed every third cycle: radiological assessments, tumor biopsy (if available), and whole blood collection for correlative studies. The safety evaluation included recording of AEs and SAEs, and changes from baseline in laboratory evaluations, vital signs, electrocardiograms, and physical examinations. Treatment was administered on an outpatient basis. A study cycle is defined as 21 days (3 weeks). Treatment was allowed to continue unless documented disease progression, discontinuation for toxicity, withdrawal of consent, or meeting other criteria for withdrawal from study. After progression, participants were contacted annually for three years for documentation of survival status information.