This six-arm, multi-center, double-blind, randomized, placebo-controlled, Phase 2b study was conducted in the US. The study was double-blinded to dose but not to the administration schedule. Subjects provided a quit date 5-7 days from randomization. Study treatment started the day after randomization such that study treatment was initiated prior to the quit date.
Demographics were similar between schedules and for treatment arms in gender, age, years of prior smoking, and number of previous quit attempts. At baseline, subjects in the study reported smoking a median of 20 cigarettes per day. ORCA-1 was initiated in October 2018 and enrolled 254 smokers at eight centers across the United States.