Three-year follow-up of advanced melanoma patients who received ipilimumab plus fotemustine in the Italian network for tumor biotherapy (NIBIT)-M1 phase II study

Abstract

Background: In the NIBIT-M1 study, we reported a promising activity of ipilimumab combined with fotemustine in metastatic melanoma (MM) patients with or without brain metastases. To corroborate these initial findings, we now investigated the long-term efficacy of this combination. Patients and methods: This analysis captured the 3-year outcome of MM patients who received ipilimumab combined with fotemustine as first- or second-line treatment. Median overall survival (OS), 3-year survival rates, immune-related (ir) progression-free survival (irPFS), brain PFS, and ir duration of response (irDOR) for the entire population and for patients with brain metastases were assessed. Clinical results were correlated with circulating CD3+CD4+ICOS+CD45RO+ or CD45RA+ T cells, neutrophil/lymphocyte (N/L) ratios, and tumorBRAF-V600 mutational status. Results: Eighty-six MM patients, including 20 with asymptomatic brain metastases that had been pre-treated with radiotherapy in 7 subjects, were enrolled in the study. With a median follow-up of 39.9 months, median OS and 3-year survival rates were 12.9 months [95% confidence interval (CI) 7.1-18.7 months] and 28.5% for the whole study population, and 12.7 months (95% CI 2.7-22.7 months) and 27.8% for patients with brain metastases, respectively. Long-term ir adverse events consisting of G1 rush and pruritus occurred in 21% of patients. The absolute increase from baseline to week 12 in 'memory' but not in 'naïve' T cells identified patients with a better survival (P = 0.002). The N/L ratio correlated with a significantly better survival at early time points. BRAF status did not correlate with clinical outcome. Conclusions: Long-term analysis of the NIBIT-M1 trial continues to demonstrate efficacy of ipilimumab combined with fotemustine in MM patients. Fotemustine does not seem to impair the immunologic activity of ipilimumab.