Prevalence of immunotherapy-related adverse events due to checkpoint inhibitors: First report in Mexico

e14090 Background: Since 2010, immune checkpoint inhibitors (ICI) have been approved for the treatment of several neoplasms. Their immune-mediated toxicity profile, used as monotherapy (nivolumab [N], Ipilimumab [Ip], pembrolizumab [P]) or in combination (Nivolumab/Ipilimumab [N/Ip]) and their management is still being described, recently. Methods: A retrospective review of medical records, included all cancer patients treated, in our institution, with ICI from January 2014 to February 2018. Frequency, type and grade of immune related adverse events (irAE) by neoplasm, individual agent or combination were recorded. Time to first ir-AE (TTF-irAE) was estimated by Kaplan Meir Method and compared by Cox regression model. Results: 140 patients were evaluated, all in pretreated metastatic setting. Median age 65.8+/-11.8, men in 59.3%. The most frequent neoplasms treated with ICI were: lung (34%), melanoma (33%), genitourinary (17%), H&NC (6%), and GI (6%). Ip alone was indicated in 11.4% cases; N, 30%; P, 54.29%; N/Ip 4.29%. Median number of cycles per drug: Ip: 3 cycles, N/Ip: 4; N: 6; and P: 4 cycles. Toxicity (G1-4) was seen in Ip: 62.5%, N/Ip: 50%, N: 40.5%, P: 31.6%, p > 0.05. The most frequent irAE's were: dermatological 40%, gastrointestinal 18.3%, and endocrine 13.4%; other irAE´s were reported in: pulmonary 7.3%, ophthalmologic 6%, muscle-skeletal 6%, neurologic 2.4%, renal 1.2%, hematologic 1.2%. Severe toxicities (G3-4) were observed with N/Ip: 33.3%, P: 17.4%, Ip: 10%, N: 5.6%. TTF-ir-AE per drug: I: 1st cycle (dermatitis, pruritus, colitis), N/Ip: 2nd cycle (dermatitis, conjunctivitis), N: 3rd cycle (dermatitis, thyroiditis, colitis, hepatitis), P: 1st cycle (pruritus, neuritis, adrenalitis). Ipilimumab was an independent prognostic factor for developing severe ir-AE´s [OR = 12.8, p = 0.038], and any grade toxicity [OR = 1.9 (IC95% 0.92 - 4.1, p = 0.079)]. Conclusions: In this study, the dermatological, gastrointestinal and endocrine toxicities were the most frequent ir-AE´s, and they were observed in a low grade toxicity. The irAE´s profile is different among ICI or their combination and number of cycles administered. Ipilimumab alone or combined was associated to higher risk of severe irAEs.