Weekly issue 2026-W38 ·
CDK4/6 Inhibitor Abemaciclib Arrests and Reverses Kidney Cyst Progression in Preclinical Models of Autosomal Dominant Polycystic Kidney Disease
Plain language
Abemaciclib is a breast-cancer pill. In mice with an ADPKD gene change, low daily doses slowed cyst growth more than tolvaptan, and in later-stage disease it halted cyst growth in females and shrank cysts in males, without obvious side effects. It seems to work by restoring polycystin proteins on the cell’s antenna (cilium). This is animal and lab work only: it has not been tested in people with ADPKD, so it is not a treatment option today.
Clinical note
JASN preclinical study. CDK6 upregulated in cyst-lining epithelium (human and murine PKD). Abemaciclib at sub-oncologic doses suppressed cysts in 3D cultures and metanephric organ culture; in Pkd1 R3277C/R3277C mice, early long-term dosing outperformed tolvaptan without detectable toxicity, and late intervention halted (females) or reversed (males) cyst progression. Mechanism: restored axonemal polyglutamylation and ciliary polycystin abundance. Hypomorphic model, no human data — repurposing hypothesis, not a prescribing signal.
Question for your next visit
When a cancer medicine shrinks cysts in mice, what steps would still be needed before it could be offered to someone like me?