A Full Replicate in vivo Bioequivalence Study of Two Idelalisib 150 mg Tablets in Fasted Healthy Adult Human Subjects

Background: Idelalisib, a PI3K small molecule inhibitor, specifically blocks the phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit delta isoform (PI3Kδ). This is a potent drug which is specifically targeted for relapsed chronic lymphocytic leukemia (CLL). Methods and Findings: A full replicate bioequivalence study of two Idelalisib 150 mg tablets was conducted in 56 healthy adult human subjects under fasting conditions with a washout period of 10 days in between doses. Blood samples were collected up to 72 hours post-dose for measurement of pharmacokinetic parameters in all periods to quantify Idelalisib in human plasma using a validated LC-MS/MS method. Bioequivalence between both the products was established by calculating 90% confidence intervals (90% CI) for the ratio of Cmax and AUC0-t values for the test and reference products. The 90% confidence intervals found for the relation of Test/Reference were Cmax 92.23% - 106.06% and AUC0-t 96.62% - 105.27%. Conclusion: According to FDA's guidelines for Bioequivalence research and based on the ANOVA results obtained, it can be concluded that Idelalisib 150 mg tablets of Abbott Laboratories de Colombia is bioequivalent to Zydelig (Idelalisib) 150 mg tablets of Gilead Sciences Ltd under fasting conditions.