Phase 1 Trial of Darigabat for the Reduction of Acute Psychological and Physiological Panic and Fear Symptoms Following CO2 Inhalation in Healthy Participants
Rachel Gurrell1, Ih Chang2, Ann Dandurand2, Sridhard Duvvuri2, Amy Guigliano2, Gina Pastino2, Theresa Pham2, Stacey Versavel2, Gabriel Jacobs3, Koshar Safai Pour3, Rob Zuiker3, Raymond Sanchez2, John Renger2
1Noema Pharma AG, 2Cerevel Therapeutics, 3Centre for Human Drug Research
Objective:
To evaluate the panicolytic effect of 2 dose strengths of darigabat in reducing panic and fear symptoms following carbon dioxide (CO2) inhalation by healthy participants.
Background:
Panic disorder is associated with subjective and physiological symptoms which no single drug class adequately addresses. Darigabat, in development for neurological and psychiatric disorders, was designed to have nonsedative panicolytic potential by selectively enhancing the effect of GABA at α2/3/5, while sparing activity at α1 GABAA receptor subtypes.
Design/Methods:
This phase 1 randomized, double-blind, crossover, placebo- and active-controlled trial (NCT04592536) enrolled adults sensitive to anxiogenic effects of 35% CO2 double-breath inhalation. Participants were randomized to receive placebo and either 1 of 3 active treatments in 3 separate cohorts for 8 days: darigabat 7.5 or 25 mg twice daily (BID) or alprazolam 1 mg BID. Target darigabat doses were achieved following a 4-day titration. After each crossover period, CO2 challenge was performed 3 hours post-dose. Panic and fear symptoms were measured before and immediately after CO2 inhalation using the Panic Symptom List-IV total score (PSL-IV; primary endpoint) and fear visual analog scale (VAS Fear; secondary endpoint). Each participant’s placebo treatment served as their own control.
Results:
Fifty-six participants were randomized. On Day 8, darigabat 7.5-mg and 25-mg BID groups demonstrated a 3.9-point (nominal P=0.036) and 4.5-point (nominal P=0.008) improvement on the PSL-IV versus placebo, respectively. Darigabat groups demonstrated a 12.8-point (nominal P=0.026) and 7.8-point (nominal P=0.282) improvement on the VAS Fear versus placebo, respectively. The positive control (alprazolam 1 mg BID) exhibited panicolytic effect compared with placebo, in line with expectations. Darigabat was generally well tolerated, with no serious adverse events and no discontinuations in darigabat cohorts.
Conclusions:
The panicolytic potential of darigabat was validated, warranting further evaluation in patients with panic disorder.