Evaluation Of Long Term Survival In Pretreated Metastatic Colorectal Cancer Patients Undergoing Golfig Chemoimmunotherapy Regimen.

e15057 Background: In the last few years, there has been a renewed interest on the potential use of immunotherapy alone or combined to chemotherapy (CHT) for mCRC patients. GOLFIG regimen (biweekly Gemcitabine+FOLFOX and IL2 and GM-CSF) was designed to enhance immunomodulating effects of selected cytotoxic drugs by combining them with cytokines able to promote priming and effector phases of the immune-response. This regimen has been tested in two different phase II and III clinical trials in mCRC patients, whose successful results have been published. Here we present the results a retrospective analyses including all the patients treated in a period of 16 years. Methods: This is a multi-institutional retrospective study including 179 mCRC patients (106 men, 73 women). They received a median of 12 courses of GOLFIG regimen (treated between June 2002 and November 2018). K-RAS mutational status has also been evaluated in 74 pts (41 wild type and 33 mutated); as for sidedness 112 pts had a left disease and 67 pts right disease; 71 pts received only one previous CHT line and 100 more than two lines. PFS and OS were evaluated by Kaplan-Meier curves and Cox-regression analyses in different subgroups (RAS mutational status, sidedness, previous CHT lines) to estimate their effect on survival endpoints. Results: We recorded a mean PFS and OS of 15,28 [95%CI:10,36-20,20] and 24,61 [95%CI:19,07-30,14] months, respectively, with no difference in efficacy outcomes observed among the different subgroups (one vs. more than one previous CHT lines; left vs. right primary side; k-ras status mutated vs. wt). Finally, we recorded a 2, 5 and 10 year OS-rate, in 42, 17 and 14 percent of the patients, respectively. The occurrence of self-limiting autoimmunity was confirmed as highly predictive of longer survival. Conclusions: These results confirm that GOLFIG regimen has strong efficacy in mCRC pts and may represent a reliable option in pretreated setting without evident effect of known prognostic variants. Such data offer a strong basis for future clinical trials in mCRC patients, where GOLFIG may represent a scaffold for combinatory immunotherapy approaches with immune-checkpoint blocking drugs.