1349PPrognostic factors for efficacy of Ipilimumab used after anti-PD1 and/or BRAF+MEK inhibitors in melanoma patients: An Italian melanoma intergroup study

Abstract Background Ipilimumab (Ip) is an option in Metastatic Melanoma (MM) patients (pt) in case of disease progression after antiPD1 (AP) treatment and BRAF+MEK inhibitors (BMi) administration (for BRAF mutated melanoma). Clinical trial are evaluating potential Ip-based combinations in 2nd/3rd line setting. Many studies underline the role of some parameters (as LDH, ECOG PS, Neutrophile/Leucocyte ratio) as progostic factors for immunotherapy used in first-line. We evaluate the prognostic role of some relevant clinical or laboratoristic parameters for Ip used in late line after AP, Bmi, in order to define pt that benefit most from Ip monotherapy in this setting. Methods A retrospective multicenter study was conducted in 8 Italian Oncology Centers, evaluating MM pt treated with Ip after AP and/or BMi. Endpoints were OS and PFS, Kaplan Mayer and Cox regression were applied for survival analysis. Results Among 200 pt that received AP or Bmi, 48 were eligible for Ip administration in 2nd/3rd line. Before Ip treatment, ECOG PS was 0 in 21 pt, number of metastatic sites was less then 3 in 14 pt, LDH was within normal range in 19 pt, NLR ratio (= baseline neutrophils/total leukocytes) was less then 0.7 in 28 pt: in univariate analysis, only ECOG PS and NLR resulted significantly associated with better PFS and OS. For pt with ECOG PS 0 or 1 medianPFS was 3.2, 2.3 month respectively (p value 0.0066; HR 0.377 IC95% 0.186-0.762), median OS was 12.1, 4.0 respectively (p value 0.0016 HR 0.287 IC95% 0.132-0.622). For pt with NLR  0,7 medianPFS was 3.2, 2.0 month respectively (p value 0.002 HR 0.241 IC95% 0.0978-0.593), median OS was 7.63, 2.67 respectively (p value 0.0037 HR 0.251 IC95% 0.0986-0.0637) A score was counted for each pt considering the number of favorable basal factors present (ECOG PS 0, NLR Conclusions ECOG PS 0, NLR Legal entity responsible for the study Italian Melanoma Intergroup. Funding Has not received any funding. Disclosure R. Marconcini: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Novartis; Honoraria (self), Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: La Roche; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: MSD; Honoraria (self), Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: BMS; Honoraria (self), Advisory / Consultancy: Incyte; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony: Ipsen. All other authors have declared no conflicts of interest.