Food Effect On The Pharmacokinetics Of 200-Mg Abemaciclib In Healthy Subject

Abemaciclib is an oral, selective, and potent small-molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4 and CDK6) being investigated for the treatment of patients with refractory hormone-receptor positive (HR+) advanced or metastatic breast cancer. The absolute bioavailability and effect of food on pharmacokinetics (PK) following a single 200-mg oral dose of abemaciclib in healthy subjects were evaluated in three studies (Table 1). Abemaciclib plasma concentrations were measured serially pre-dose through 192 hours post-dose. Non-compartmental analysis was used to calculate PK parameters, and a mixed-effects model was used for statistical inference. In Study 1 the absolute bioavailability of a 200-mg dose of abemaciclib was 45% (90% CI: 40%, 51%). In Study 2 the ratios of AUC 0-? after a high-fat or standard meal compared to fasting showed no effect (90% CIs within 0.80, 1.25). However, C max increased by 24% and 25% following high-fat and standard meals, respectively, compared to fasting (upper 90% CIs u003e1.25). No differences were found in the AUC 0-? and C max of abemaciclib following a high-fat meal compared to a standard meal (90% CI within 0.80, 1.25). The median t max was delayed by 2 hours following a high-fat meal compared to fasting (p = 0006). However, there was no difference in median t max between the standard meal and fasting (p = .7197). Abemaciclib terminal half-life was similar across fed and fasted conditions. The late-breaking Study-3 results will be presented. In conclusion, abemaciclib oral bioavailability is sufficient to achieve therapeutic exposure. Food with abemaciclib does not reduce or increase the inter-individual PK variability and does not have a clinically-relevant impact on the PK of abemaciclib. Therefore, abemaciclib may be administered without regard to food. Citation Format: Kellie Turner, Jill Chappell, Palaniappan Kulanthaivel, Wee Teck Ng, Jane Royalty. Food effect on the pharmacokinetics of 200-mg abemaciclib in healthy subject. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT152.