Randomized Dose-Ranging Controlled Trial of AQ-13, a Candidate Antimalarial, and Chloroquine in Healthy Volunteers

OBJECTIVES: To determine: (1) the pharmacokinetics and safety of an investigational aminoquinoline active against multidrug–resistant malaria parasites (AQ-13), including its effects on the QT interval, and (2) whether it has pharmacokinetic and safety profiles similar to chloroquine (CQ) in humans. DESIGN: Phase I double-blind, randomized controlled trials to compare AQ-13 and CQ in healthy volunteers. Randomizations were performed at each step after completion of the previous dose. SETTING: Tulane–Louisiana State University–Charity Hospital General Clinical Research Center in New Orleans. PARTICIPANTS: 126 healthy adults 21–45 years of age. INTERVENTIONS: 10, 100, 300, 600, and 1,500 mg oral doses of CQ base in comparison with equivalent doses of AQ-13. OUTCOME MEASURES: Clinical and laboratory adverse events (AEs), pharmacokinetic parameters, and QT prolongation. RESULTS: No hematologic, hepatic, renal, or other organ toxicity was observed with AQ-13 or CQ at any dose tested. Headache, lightheadedness/dizziness, and gastrointestinal (GI) tract–related symptoms were the most common AEs. Although symptoms were more frequent with AQ-13, the numbers of volunteers who experienced symptoms with AQ-13 and CQ were similar (for AQ-13 and CQ, respectively: headache, 17/63 and 10/63, p = 0.2; lightheadedness/dizziness, 11/63 and 8/63, p = 0.6; GI symptoms, 14/63 and 13/63; p = 0.9). Both AQ-13 and CQ exhibited linear pharmacokinetics. However, AQ-13 was cleared more rapidly than CQ (respectively, median oral clearance 14.0–14.7 l/h versus 9.5–11.3 l/h; p ≤ 0.03). QTc prolongation was greater with CQ than AQ-13 (CQ: mean increase of 28 ms; 95% confidence interval [CI], 18 to 38 ms, versus AQ-13: mean increase of 10 ms; 95% CI, 2 to 17 ms; p = 0.01). There were no arrhythmias or other cardiac AEs with either AQ-13 or CQ. CONCLUSIONS: These studies revealed minimal differences in toxicity between AQ-13 and CQ, and similar linear pharmacokinetics.