Safety and discontinuation rate of immune checkpoint inhibitors used in patients with solid and hematological malignancies. A population based retrospective analysis

Background The discovery of immune checkpoint inhibitors caused a paradigm shift in cancer treatment and led to a major improvement in clinical outcomes. However, they may induce inflammatory side effects that are known as immune-related adverse effect (iRAE). This study aimed to assess the safety profile and discontinuation rate of immune checkpoint inhibitors in cancer patients. Methods Adult cancer patients >= 18 years who received at least one dose of immune-checkpoint inhibitor (ICI) were included. The primary endpoint was the rate of permanent discontinuation of immune checkpoint inhibitors due to immune-related adverse effects. The secondary endpoints were rate and type of specific organ iRAEs, interventions used to treat specific organ iRAEs, and discontinuation rate of immune checkpoint inhibitors due to disease progression. Results A total of 75 patients were included in the study with a median age of 60 years [IQR: 46-72 years]. Of 75 patients, 7 patients (9.33%) have permanently discontinued ICIs due to immune-related adverse effects. Seven iRAEs occurred in the 7 patients who have permanently discontinued ICIs. Steroids were the main treatment used for 8 patients, followed by levothyroxine for 2 patients and one patient did not receive any medication. The discontinuation rate due to disease progression was reported in 32 patients (42.66%). Conclusion Immune checkpoint inhibitors were well tolerated in the majority of our patient population with a comparable rate of immunerelated adverse effects in comparison to the published data. Corticosteroids were fundamentally used to treat immune-related adverse effects.