FC12 Long term follow-up of 72 melanoma patients after intratumoral treatment with interleukin-2: favorable survival and high rate of objective responses upon subsequent chemotherapy

Abstract

Systemic high dose Interleukin-2 (IL-2) achieves long-term survival in a subset of advanced melanoma patients. As we reported previously, intratumorally applied IL-2 induced complete local responses of all metastases in more than 60% of patients and may be regarded as a promising local treatment option for patients with surgically not curable dermal metastases (Weide et al. Cancer in press). Unexpectedly, we observed frequent objective responses to the first chemotherapy after intratumoral IL-2 and favorable survival rates. This prompted us to ask whether there might be also a beneficial systemic effect after the local IL-2 treatment. Therefore we now reanalyzed the long term outcome of a combined cohort including patients with up to 11 years of follow-up after start of intratumoral IL-2 treatment of a previous study conducted at our institution. For the analysis of long term outcome 72 patients were evaluable. Among them 30 received chemotherapy subsequent to intratumoral IL-2. In more than 10 patients an objective response was observed. Overall survival was favorable particularly for stage IIIb and stage IV M1a patients. Updated survival data will be presented. These data are indicative for a systemic mode of action of locally applied IL-2. Further studies are required to investigate the mode of action and the impact on survival.