#1153 Short course of steroids as a treatment for immune checkpoint inhibitors-associated acute kidney injury

Abstract Background and Aims Immune checkpoint inhibitors (ICPi) have been a revolution in oncology. Due to their mechanism of action they can produce inflammatory adverse events, called “immune related adverse events” (IrAEs). Immune-mediated renal toxicity appears to be infrequent (2.2-5%), with acute tubulointerstitial nephritis being the most common form, clinically manifested as acute kidney injury (AKI). Corticosteroids are a highly effective treatment. However, the most suitable regimen has not been established. Method Retrospective multicenter study to evaluate the efficacy and safety of a short course of steroids (Group A) versus a long course (Group B) in patients with a clinical or histologic diagnosis of ICPi-associated acute kidney injury (ICPi-AKI). Short-duration regimen was considered to be that with a duration ≤3 months. Renal response was assessed 3 months after initiation of steroid therapy. Partial and complete renal response rates were compared in both groups, as well as relapses of ICPi-AKI with the lowering or suspension of steroid treatment. The development of adverse effects attributable to corticosteroids and the evolution of the oncologic disease were also evaluated. Results Sixty-three patients were included, 30 (48%) of whom received a short course of corticosteroids. Type of malignancy and oncologic treatment were similar in both groups. Baseline serum creatinine (1.1 mg/dL Group A and 0.9 mg/dL Group B; p = 0.53) and at ICPi-AKI diagnosis (3.0 mg/dL in Group A and 2.8 mg/dL in Group B; p = 0.43) were comparable. As shown in the table below, cumulative prednisone dose was lower in Group A than in Group B (1654 mg vs 4030 mg; p = 0.001). The overall renal response was 92% (87% Group A and 97% Group B; p = 0.2). There were no differences in complete response (40% Group A and 40% Group B; p = 1) or partial response (47% Group A and 57% Group B; p = 0.4). There were no recurrences of AKI after rechallenge of ICPi treatment. Adverse events related to corticosteroids were similar. There was a trend towards greater progression of oncologic disease in group B (64% versus 40%; p = 0.08). Conclusion A short course of steroids (< 3 months) is equally effective as a treatment for ICPi-AKI as longer courses, both in terms of renal response and relapse rate of ICPi-AKI. Adverse events related to steroid treatment were comparable in both groups. There appeared to be greater oncologic progression in the prolonged steroid treatment group.