Serum lactate dehydrogenase (LDH) as a prognostic selection criterion for ipilimumab treatment in metastatic melanoma.

3036 Background: Ipilimumab, a CTLA4 blocking antibody, has been shown to improve survival in metastatic melanoma patients in phase III trials. However, only a subset of patients experiences long-term survival benefit. Therefore, we analysed two independent retrospective sets of patients treated in ‘real world’ settings to identify prognostic factors that correlate with better outcome after ipilimumab therapy. Methods: Advanced melanoma patients, eligible for ipilimumab therapy, were treated in the Dutch and UK Expanded Access Programs (EAP) and after European licensing on the 3mg/kg schedule. Baseline characteristics and peripheral blood parameters were assessed and patients were monitored for the occurrence of adverse events and responses. Results: A total of 166 patients were enrolled in the Dutch EAP. Best overall response rate and disease control rate were (DCR) 17% and 35%. Median follow-up was 17.9 months, with a median progression free survival of 2.9 months. Median overall survival (OS) was 7.5 m...