Objective Lopinavir/ritonavir (Kaletra®) is first line therapy for pediatric HIV infection. In clinical practice, Kaletra® tablets are occasionally crushed for pediatric administration. This study compared lopinavir/ritonavir exposure between whole and crushed tablets in HIV-infected children. Design This was a randomized, open-label, cross-over study of pediatric patients taking lopinavir/ritonavir as part of their antiretroviral regimen. Each subject had two separate (within 30 days) steady-state 12-hour pharmacokinetic (PK) studies with crushed and whole 200/50 mg lopinavir/ritonavir tablets. Methods PK blood samples were drawn at 0 (pre-dose), 1, 2, 4, 6, 8, and 12 hours post-dose. Lopinavir and ritonavir plasma concentrations measured by high performance liquid chromatography were used to calculate non-compartmental area under the concentration versus time curve (AUC) and clearance (CL/F). Wilcoxon signed-rank tests compared PK values between crushed and whole tablets. Results Twelve children, median age of 13 years (10–16 years), took 550/138 mg/m2/day lopinavir/ritonavir divided every 12 hours. The median lopinavir AUC following crushed and whole tablets were 92 mg*hr/L and 144 mg*hr/L, respectively, with an AUC ratio of 0.55 (p=0.003). Median ritonavir AUC of crushed and whole tablets were 7 mg*hr/L and 13.3 mg*hr/L, respectively, with an AUC ratio of 0.53 (p=0.006). Conclusions Administration of crushed 200/50 mg lopinavir/ritonavir tablets to children significantly reduced lopinavir and ritonavir exposure with a decrease in AUC by 45% and 47%, respectively. The administration of crushed tablets would require higher doses and therapeutic drug monitoring to ensure adequate lopinavir exposure in patients requiring this practice. The use of crushed lopinavir/ritonavir tablets should be avoided, if possible.

Mutations at the arginine residue (R132) in isocitrate dehydrogenase 1 (IDH1) are frequently identified in various human cancers. Inhibition of mutant IDH1 (mIDH1) with small molecules has been clinically validated as a promising therapeutic treatment for acute myeloid leukemia and multiple solid tumors. Herein, we report the discovery and optimization of a series of quinolinones to provide potent and orally bioavailable mIDH1 inhibitors with selectivity over wild-type IDH1. The X-ray structure of an early lead 24 in complex with mIDH1-R132H shows that the inhibitor unexpectedly binds to an allosteric site. Efforts to improve the in vitro and in vivo absorption, distribution, metabolism, and excretion (ADME) properties of 24 yielded a preclinical candidate 63. The detailed preclinical ADME and pharmacology studies of 63 support further development of quinolinone-based mIDH1 inhibitors as therapeutic agents in human trials.