Abemaciclib Suppresses Kidney Cyst Progression in Preclinical ADPKD Models

Researchers tested the CDK4/6 inhibitor abemaciclib as a potential treatment for autosomal dominant polycystic kidney disease (ADPKD), targeting a pathway that regulates ciliary polycystin abundance. The study used three-dimensional cyst assays, metanephric organ cultures, and Pkd1 R3277C/R3277C mice receiving daily abemaciclib. Tolvaptan served as a therapeutic control. Endpoints included cyst burden, kidney fibrosis, kidney function, and renal epithelial primary cilia.

CDK6 expression was increased in cyst-lining cells from human and mouse polycystic kidneys. Abemaciclib suppressed cyst growth in vitro and ex vivo at doses described as substantially lower than those used in oncology. In mice, long-term early treatment arrested cyst progression more effectively than tolvaptan, without detectable toxicity. Late intervention largely halted cyst growth in females and reversed progression in males. Treatment also restored axonemal polyglutamylation and increased ciliary polycystin levels.

The findings support further investigation of CDK6 inhibition in ADPKD but do not establish clinical superiority to tolvaptan or safety in patients. The supplied report does not provide sample sizes, numerical effect estimates, dosing details, or quantitative kidney-function results. The sex-dependent response to late treatment also warrants clarification before translation to human studies.