1340P - Effective treatment with T-VEC monotherapy in stage IIIB/C-IVM1a melanoma of the head & neck region

Abstract

BackgroundTalimogene laherparepvec (T-VEC) is a modified herpes simplex virus, type 1 (HSV-1), which can be administered intralesionally in patients with stage IIIB/C-IVM1a unresectable melanoma. When surgery is not a treatment option in the head and neck region, i.e. due to the location or the size of the tumor, T-VEC therapy can be an elegant alternative to systemic immunotherapy. Methods9 patients with melanoma in the head and neck region started treatment with T-VEC monotherapy at the Netherlands Cancer Institute, of which 4 are still currently on treatment. We collected data on response, adverse events (AE) and baseline characteristics. For response evaluation, we used clinical evaluation with photography, 3-monthly PET-CT’s and histological biopsies. ResultsMedian age at baseline was 78.3 years. Of the 5 patients who stopped treatment, the median follow-up time was 9.1 months. Of these patients, 3 (60%) had a complete response (CR), 1 (20%) patient had a partial response (PR) and 1 (20%) patient showed progressive disease (PD) as their best response. ORR was 80%. Duration of response varies between 1.6-21.6 months. 2 patients developed distant metastases, 1 during T-VEC treatment and 1 after achieving a CR with a time to progression of 14.2 months. 4 patients are still on treatment today. Grade 1 AE’s occurred in all patients. Mostly, these consisted of fatigue, influenza-like symptoms and injection site pain. PET-CT and histological biopsies proved to be a clinically useful tool to evaluate treatment response for T-VEC monotherapy, confirming pCR or PD to stage IV disease requiring systemic treatment. ConclusionsORR for T-VEC monotherapy for melanoma in the head and neck region at our institute was 80% with 60% achieving a CR. This real world data on T-VEC monotherapy in stage IIIB/C-IVM1a unresectable melanoma of the head and neck region demonstrates interesting results and suggests T-VEC is an elegant alternative to systemic therapy in this select elderly and frail patient population. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureV. Franke: Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): amgen. M.W.J.M. Wouters: Research grant / Funding (institution): Novartis. W.J. van Houdt: Advisory / Consultancy, Research grant / Funding (institution): amgen. A.C.J. van Akkooi: Research grant / Funding (institution): Novartis; Advisory / Consultancy, Research grant / Funding (institution): amgen; Research grant / Funding (institution): BMS; Research grant / Funding (institution): MSD-Merck; Research grant / Funding (institution): Merck-Pfizer. All other authors have declared no conflicts of interest.