Baseline laboratory parameters predicting clinical outcome in melanoma patients treated with ipilimumab: a single-centre analysis.

BACKGROUND: Overall response rates (ORRs) for ipilimumab in advanced melanoma are only about 10%. Hence, it is important to explore biomarkers predicting ipilimumab responders.
OBJECTIVE: We aimed to explore biomarkers to predict therapy outcome in melanoma patients who have undergone standard ipilimumab therapy in a real-world setting.
METHODS: Databases of cutaneous melanoma patients (n = 52) who had received ipilimumab were reviewed and data collected on patient characteristics and diverse laboratory parameters. We performed univariate and multivariate statistics including logistic regression analysis and Cox proportional-hazards regression.
RESULTS: Baseline leucocytes, lymphocytes, eosinophils, thrombocytes, neutrophil/lymphocyte ratio, thrombocytes/lymphocyte ratio, eosinophil/lymphocyte ratio and serum vitamin D levels were not significantly associated with ORR, progression-free survival (PFS) and melanoma-specific survival (MSS). Multivariate analysis confirmed anti-PD-1 pretreatment as significant predictor for ORR following ipilimumab therapy. Low-LDH levels and more than two ipilimumab cycles turned out to be significant independent predictors for prolonged PFS. Low-S100B levels and anti-PD-1 treatment before or after ipilimumab were significant independent predictors for improved MSS. All aforementioned parameters and faecal calprotectin did not turn out to be predictors for ipilimumab-induced autoimmune-related adverse events and autoimmune colitis, respectively.
CONCLUSIONS: Low serum LDH before ipilimumab treatment is an independent predictor for improved PFS. Furthermore, low serum S100B is an independent predictor for MSS. The number of ipilimumab cycles (>2) is significantly associated with prolonged PFS. Pretreatment calprotectin does not predict the occurrence of autoimmune colitis under ipilimumab therapy.