Phase IIa study of BVAC-C in HPV type 16 or 18 positive recurrent cervical carcinoma.

5512 Background: BVAC-C is a B cell- and monocyte-based immunotherapeutic vaccine transfected with recombinant HPV E6/E7, which was well tolerated in HPV positive recurrent cervical carcinoma in phase I study (J Clin Med. 2020 Jan 5;9(1):147). This phase IIa study sought to determine the antitumor activity of BVAC-C. Methods: Twenty-one patients with HPV 16 or 18 positive recurrent cervical cancer who had experienced recurrence after one prior platinum-based combination chemotherapy were enrolled. They were allocated to 3 arms; Arm 1, BVAC-C injection at 0, 4, 8 weeks (1x108 cells/dose); Arm 2, BVAC-C injection at 0, 4, 8, 12 weeks (5x107 cells/dose); Arm 3, BVAC-C injection at 0, 4, 8, 12 weeks (5x107 cells/dose) with topotecan at 2, 6, 10, 14 weeks (0.75 mg/m2 for 3 days). Results: The overall response rate was 21% (Arm 1: 29% (2/7), Arm 2: 25% (1/4), Arm 3 : 0 % (0/3)) among the evaluable patients (N = 14), and the median duration of response was 18 months (range, 9 – 26 months). The disease control rate was 43% (Arm 1: 29% (2/7), Arm 2: 50% (2/4), Arm 3 : 67 % (2/3)) and the median duration of stable disease were 12 months (range, 6 - 26 months). The median progression-free survival in all patients was 4 months (95% CI, 2 to Infinite months). Immune responses of patients after vaccination were shown to be correlated with clinical responses of them. Consistent with Phase I study, all evaluated patients showed not only inflammatory cytokine responses (IFN-γ or TNF-α), which might be mediated by the activation of natural killer cells and natural killer T cells, but also potent E6/E7-specific T cell responses upon vaccinations. Conclusions: BVAC-C demonstrated a durable antitumor activity with an immune response in HPV 16- or 18-positive recurrent cervical carcinoma patients who failed 1st line platinum based chemotherapy. Clinical trial information: NCT02866006.