Cortex’s Second Phase IIa Respiratory Depression Study Meets End Point
Cortex Pharmaceuticals, a neuroscience company, has reported that top-line data from its second Phase IIa study in opioid-induced respiratory depression demonstrated that a single oral dose of 1500mg of the Ampakine compound CX717 achieved statistical significance over placebo on the primary endpoint measure of spontaneous basal respiration without affecting opioid-induced analgesia.
In this placebo-controlled, double-blind, randomized two-way crossover trial (CX717-RD-01), 16 volunteers each received either 1500mg of CX717 or matching placebo that was orally administered two hours before each subject received an intravenous infusion of the opioid, alfentanil.
The primary performance measures were the basal breathing rate, and the minute expiratory volume at 55mmHg CO2 (VE55), and the lack of effect on analgesia. CX717 prevented the reduction in basal breathing rate induced by alfentanil, in comparison to placebo (p = 0.005).
The degree of the reversal of the basal respiratory rate was similar to that obtained with the opioid antagonist, naloxone (Narcan). At the same time, the analgesic properties of alfentanil were maintained in an acute pain model in the presence of CX717, whereas naloxone blocked the analgesic properties.
Cortex plans to continue the development of Ampakine compounds in opioid-induced respiratory depression (RD). An intravenous dosage form of CX717 is being finalized, and a follow-on compound, CX1942, a water soluble pro-drug of a novel Ampakine compound with improved potency over CX717, will shortly enter preclinical development for RD.
Additionally, a novel Ampakine molecule, CX1739, is currently in Phase I clinical trials and is targeted to begin Phase II clinical trials for attention deficit hyperactivity disorder in second quarter of 2009.
Mark Varney, president and CEO of Cortex said: “We are pleased to see statistically significant effects with a single oral dose in these small proof of concept clinical studies.”