Activity of a novel immunotherapy combination of intralesional Coxsackievirus A21 and systemic ipilimumab in advanced melanoma patients previously treated with anti-PD1 blockade therapy.

Abstract

3014 Background: CAVATAK is a novel bio-selected oncolytic and immunotherapeutic strain of Coxsackievirus A21 (CVA21) that when injected into melanoma lesions can increase immune-cell infiltration, up-regulation of γ-INF response and immune-checkpoint genes, including CD122, which may be a potential marker for enhanced anti-tumor activity by anti-CTLA-4 blockade. Intratumoral replication of CVA21 may act as a strong “immune-sequestration signal” to circulating activated T-cells following CTLA-4 blockade. A large unmet need exists for active therapies in melanoma patients (pts) following treatment (tx) with anti-PD1 therapies. We present in a Phase 1 study, the clinical activity of a CVA21/ ipilimumab (ipi) combination following anti–PD1 therapy in advanced melanoma pts. Methods: The Phase Ib MITCI study (NCT02307149) investigated the efficacy and safety of i.t. CVA21 and i.v. ipi in 26 pts with unresectable Stage IIIB/C-IVM1c melanoma with 13 pts previously treated with anti-PD1 therapies. Pts received up to 3 x 108 TCID50CVA21 i.t. on study days 1, 3, 5, 8 and 22, and then q3w for a further 6 series of injections. Ipi (3 mg/kg) q3w was given as 4 i.v. infusions starting at Day 22. Results: Analysis of the prior anti–PD1 treated pts (n=13) revealed that the combination tx was generally well-tolerated with one case of Gr 3 ipi-related liver toxicity observed. Of the tx population, 54% (7/13) had received prior ipi tx in addition to anti-PD1, 85% (11/13) of pts were stage IV M1b/c, with the median time between the last anti-PD1 and first CVA21 and ipi doses being 5.7 and 8.7 weeks, respectively. The mean number of prior systemic therapies including anti-PD1 tx was 2.6. For all pts completing at least the first investigator response assessment (irWHO criteria at Day 106) we observed a confirmed BORR of 38.0% (3/8) and a DCR (CR+PR+SD) of 88% (7/8). Conclusions: Intratumoral CVA21 + ipilimumab treatment in anti–PD1 treated pts has displayed promising clinical activity together with low adverse toxicity and as such this regimen may represent a valuable tx option for pts that have been administered previous lines of immune checkpoint therapy. Clinical trial information: NCT02307149.