Re-introduction of T-VEC Monotherapy in Recurrent Melanoma is Effective.

Talimogene laherparepvec (T-VEC) is a modified herpes simplex virus type 1, which can be administered intralesionally in patients with stage IIIB/C-IVM1a (American Joint Committee of Cancer; AJCC 7th edition) unresectable melanoma. In the case of disease recurrence, T-VEC can be re-introduced for the same category of patients. Five patients with recurrent disease after a prior achieved complete response (CR) recommenced treatment with T-VEC monotherapy at the Netherlands Cancer Institute. We collected data on response, adverse events and baseline characteristics. All 5 patients that were re-treated with T-VEC presented with in-transit metastases on the lower limb. Median age at baseline was 72.1 years with a median follow-up time of 30.4 months. Histologically proven CR was achieved after a median of 8 T-VEC courses on the initial exposure. Duration of response (time between first CR and recurrence) varied between 3.8 and 14.2 months. All 5 patients achieved a histologically and/or positron emission tomography/computed tomography proven CR again after re-introduction of T-VEC with a median of 5 courses. One patient (20%) developed a second recurrence and is currently still on treatment with T-VEC. No patients developed distant metastases. Grade 1 adverse events occurred in all patients. Mostly, these consisted of fatigue, influenza-like symptoms and injection site pain. Response to re-introduction of T-VEC monotherapy in this select patient population is promising. This real world data on re-introduction of T-VEC monotherapy in stage IIIB/C-IVM1a melanoma suggests T-VEC could be a treatment option for chronic disease control.