Results of a Phase 2 Multicenter Study to Evaluate the Efficacy of VP-315, an Investigational Therapy for Basal Cell Carcinoma

Abstract

Introduction: VP-315 is an intratumorally injected, chemotherapeutic oncolytic peptide in development as a non-surgical immunotherapeutic agent to be utilized as first line therapy in a primary or neoadjuvant setting for patients with basal cell carcinoma (BCC). Objective: In Part 2 of this study, the secondary objective was to evaluate the effect of various dosing regimens on the antitumor efficacy of VP-315 in a larger population of adult subjects with biopsy proven BCC. Methods: Eighty-two (82) subjects with up to 2 target BCC tumors (total 91 tumors) were treated intratumorally with VP-315 for up to 2 weeks. Cohort 3 was not enrolled based on results from Cohorts 1-2. Each 7-day treatment week was comprised of 2 or 3 consecutive treatment days followed by a no-treatment period of at least 4 days. Dosing scheme: Cohort 1: (n=6) Tumor injected 3 days consecutively (3X/week 4 mg loading dose Day 1 followed by 8 mg dose). Cohort 2: (n=3) Tumor injected 3 days consecutively (3X/week 8 mg dose). Cohort 4: (n=36) Each tumor was injected 2 days consecutively (2X/week 8 mg split dose*). Cohort 5: (n=37) Each tumor was injected 3 days consecutively (3X/week 8 mg split dose*). * Dose split into 2 injections, 30% injected initially; 70% injected 15-30 minutes later. Efficacy endpoints included histological clearance of target tumor(s) and estimate of remaining tumor volume (tumor size reduction) at excision (Week 12-13). Results: Eighty-two (82) subjects (n=92 lesions) completed treatment for BCC with VP-315 in Part 2. Approximately 51% of tumors achieved complete histologic clearance. All tumors treated had a reduction in tumor size. Overall tumor size reduction was 86%. Tumor size reduction in subjects who still had any residual tumor was 71%. Conclusion: Complete histological clearance in a majority of VP-315 treated tumors could eliminate the need for surgical intervention in those patients in clinical practice. In subjects with residual tumor burden, the substantial reduction in tumor size after VP-315 treatment would markedly reduce the surgical incision area and the amount of potential post-surgical scarring. Based on the favorable results, further research using VP-315 as a potential non-surgical immunotherapy for BCC as a first line therapy in a primary or neoadjuvant setting is warranted.