Abstract
INTRODUCTION: Modulation of Factor XIa (FXIa) may provide a novel mechanism for systemic anticoagulation with the potential to improve the risk-benefit profile observed with existing anticoagulants through greater efficacy or a safer bleeding profile. This study assessed the effects of co-administration with strong and moderate CYP3A inhibitors itraconazole and diltiazem, respectively, on the pharmacokinetic and pharmacodynamic properties of milvexian, a Factor XIa inhibitor. METHODS: This was an open-label, non-randomized, two-period crossover study in healthy participants. In period 1, participants received a single oral dose of milvexian (30 mg) on day 1, followed by a washout on days 2 and 3. In period 2, participants received multiple oral doses of itraconazole (200 mg) or diltiazem (240 mg) with a single dose of milvexian. RESULTS: A total of 28 participants entered the treatment period. Following itraconazole co-administration, milvexian exposure was increased; AUC((0-T)), AUC((INF)), and C(24) were 2.5-, 2.5-, and 3.8-fold higher, while mean C(max) was 28% higher versus milvexian alone. Diltiazem co-administration also increased milvexian exposure; AUC((0-T)), AUC((INF)), and C(24) were 38, 38, and 64% higher, and mean C(max) was 9.6% higher versus milvexian alone. Prolongation of activated partial thromboplastin time was observed with milvexian in a concentration-dependent fashion irrespective of co-administration with itraconazole or diltiazem. Administration of a single dose of milvexian, alone or in combination with itraconazole or diltiazem, was generally safe and well tolerated; there were no deaths or serious adverse events. CONCLUSIONS: A moderate increase in milvexian exposure was observed following co-administration of itraconazole while a minimal increase was seen with diltiazem, consistent with the involvement of CYP3A metabolism and P-glycoprotein in drug absorption/elimination. Milvexian was generally safe and well tolerated in healthy participants. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov (NCT02807909; submitted June 17, 2016).