Phase 2 trial of efficacy and tolerability of neoadjuvant talimogene laherparepvec in difficult-to-resect cutaneous basal cell carcinoma

The phase 2 NeoBCC trial at the Medical University of Vienna (Austria) evaluated the oncolytic virus talimogene laherparepvec (T-VEC) as neoadjuvant therapy for difficult-to-resect cutaneous basal cell carcinomas (BCC). The primary end point of the Simon’s 2 stage phase 2 trial, defined as the proportion of patients who after six cycles of T-VEC (13 weeks) became resectable without the need for plastic reconstructive surgery, was already achieved after stage 1 (9 of 18 patients; 50%),thus the trial was discontinued due to early succes. The objective response rate was 55.6% and the complete pathological response rate was 33.3%. Only mild adverse events occurred. The 6-month relapse-free survival and overall survival rates were both 100%. In two patients a new BCC was diagnosed. T-VEC led to a significant increase in cytotoxic T cells, B cells, and myeloid cells and a decrease in regulatory T cells within the tumor microenvironment. The authors conclude that neoadjuvant T-VEC represents a viable treatment option for patients with difficult-to-resect BCC.