Evaluation of cyclin-dependent kinase 4/6 inhibitor-induced serum creatinine elevations in patients with hormone receptor positive breast cancer

• Published in: Journal of oncology pharmacy practice 2024-12, p.10781552241305417
• Main Authors: Ly, Emily, Howard, Frederick M, Chen, Nan, Hahn, Olwen, Fleming, Gini F, Nanda, Rita, Patel, Shivani, Thimothy, Lida, Yang, Heng
• Format: Article
• Language: English
• ISSN: 1477-092X

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) have improved the efficacy of endocrine therapy in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC) and are now used in both early-stage and metastatic disease. Recent case reports suggest that pseudo-serum creatinine (Scr) elevations are likely a class effect of CDK4/6i. This single-center retrospective analysis included patients aged ≥18 years who received at least one dose of palbociclib, ribociclib, or abemaciclib for the treatment of HR+/HER2- BC in the early or advanced setting. The primary objective was the incidence of pseudo-Scr elevation for each of the three agents. CDK4/6i-induced pseudo-Scr elevation was suspected when the Scr elevation could not be fully attributed to other causes. Secondary endpoints included the grade, onset, duration, and clinical consequences of pseudo-Scr elevation. 143 patients were included. Pseudo-Scr elevation was suspected in patients treated with palbociclib, ribociclib, or abemaciclib, with incidences of 16% (8/50), 14% (6/43), and 20% (10/50), respectively. Rates did not significantly differ between agents (  = 0.727). Among patients with CDK4/6i-induced pseudo-Scr elevation, all events were grade 1 (8.3%) or 2 (91.7%). The median onset from treatment initiation to first Scr elevation was 33.5, 42, and 21.5 days, for palbociclib, ribociclib, or abemaciclib, respectively. Pseudo-Scr elevation appears to be a class effect of CDK4/6i, with similar rates of Scr elevation observed across the three agents currently FDA approved.