PF614 Analgesic Activity in Acute Postoperative Pain (PF614-301)

This will be a Phase 3, multicenter, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of PF614 in the treatment of moderate to severe acute postoperative pain following abdominoplasty. The study will be conducted in 4 phases: Screening, Treatment, Outpatient and Follow-up.

Screening Phase Prospective participants will complete a standard medical screening within 28 days of the abdominoplasty procedure. At Screening, participants will provide written informed consent to participate in the study before any protocol-specified procedures or assessments are conducted.

Treatment Phase The Treatment Phase will begin on the day of the abdominoplasty procedure (Day 1) and will end on postoperative Day 5. Participants will be admitted to the study center on the morning of the scheduled procedure and will be confined throughout the Treatment Phase (5 days, 4 nights).

Days 1-4 (0-72 hours): Randomized Treatment Period Following admission to the study center, presurgical procedures will include participant training on pain intensity assessments, which will be administered as 11-point numerical rating scales (NRS). Participants who continue to meet all study entry criteria will be randomized prior to the abdominoplasty procedure in a 1:1:1:1 ratio to 1 of 4 treatment groups.

Treatment groups will include the following doses: PF614 25 mg, PF614 37.5 mg, PF614 50 mg, and Placebo.

The first dose of study drug will be administered 1 hour (±15 minutes) prior to the scheduled start time of the abdominoplasty procedure (i.e., prior to time of anesthetic induction). Time 0 is defined as the time of first study drug administration. Additional doses of study drug will be provided every 12 hours (BID) (±15 minutes), with the last scheduled study drug administration at 72 hours. Qualified medical personnel and/or investigators who are ACLS (Advanced Cardiovascular Life Support) certified will be present in the clinic during the inpatient treatment phase when participants are administered opioid medications.

Participants will undergo a full abdominoplasty procedure without liposuction or other collateral procedures under a standardized anesthetic protocol. Prior to wound closure, the surgeon will perform a transversalis abdominal plane (TAP) block by infiltrating 1% lidocaine with epinephrine 7 mg/kg with a maximum dose of 500 mg. Participants may be administered supplemental oxygen for at least the first 2 hours postoperatively (end of surgery defined as time of extubation), and the participant will be weaned as clinically appropriate.