Combination of the low anticoagulant heparin CX-01 with chemotherapy for the treatment of acute myeloid leukemia.

Relapses in acute myelogenous leukemia (AML) are a result of quiescent leukemic stem cells (LSCs) in marrow stromal niches, where they resist chemotherapy. LSCs employ CXCL12/CXCR4 to home toward protective marrow niches. Heparin disrupts CXCL12-mediated sequestration of cells in the marrow. CX-01 is a low-anticoagulant heparin derivative. In this pilot study, we combined CX-01 with chemotherapy for the treatment of AML. Induction consisted of cytarabine and idarubicin (7 + 3) with CX-01. Twelve patients were enrolled (median age, 56 years; 3 women). Three, 5, and 4 patients had good-, intermediate-, and poor-risk disease, respectively. Day 14 bone marrows were available on 11 patients and were aplastic in all without detectable leukemia. Eleven patients (92%) had morphologic complete remission after 1 induction (CR1). Eight patients were alive at a median follow-up of 24 months (4 patients in CR1). Three patients received an allogeneic stem cell transplant in CR1. Median disease-free survival was 14.8 months. Median overall survival was not attained at the maximum follow-up time of 29.4 months. No CX-01-associated serious adverse events occurred. Median day to an untransfused platelet count of at least 20 × 109/L was 21. CX-01 is well tolerated when combined with intensive therapy for AML and appears associated with enhanced count recovery and treatment efficacy.

Tecarfarin, a novel vitamin K reductase antagonist, is not affected by CYP2C9 and CYP3A4 inhibition following concomitant administration of fluconazole in healthy participants.

Comparative pharmacokinetics of vitamin K epoxide reductase antagonists tecarfarin and warfarin were assessed before and after coadministration for 21 days of the CYP450 inhibitor fluconazole in a randomized, open-label, single-center drug interaction study. Twenty healthy adult participants were randomized 1:1 to receive approximately equipotent single oral doses of tecarfarin (50 mg) or warfarin (17.5 mg). Following 7 days of baseline serial blood level collections, each participant received oral fluconazole 400 mg daily for 21 days. A second identical single oral dose of tecarfarin or warfarin was given 14 days after starting fluconazole with serial pharmacokinetic sampling. Key pharmacokinetic parameters C(max), t(max), AUC(0-168), apparent clearance, and t(1/2) demonstrated no tecarfarin-fluconazole interaction but a strong warfarin-fluconazole interaction. The ratio of log-transformed mean AUC(0-168) with versus without fluconazole for tecarfarin was 91.2% (90% confidence interval [CI]: 83.3-99.8) and for racemic warfarin was 213% (90% CI: 202-226). The 90% CI was entirely within the standard 80% to 125% bioequivalence interval for tecarfarin but well outside the bioequivalence interval for warfarin, confirming a clinically significant pharmacokinetic interaction between warfarin and fluconazole. In contrast, tecarfarin pharmacokinetics were apparently unchanged by fluconazole.