New Non-Opioid painkiller shows promise for knee surgery patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Is scheduled to undergo primary unilateral TKA under spinal anesthesia. * Has not previously undergone TKA in either knee. * Has an American Society of Anesthesiologists (ASA) Physical Status of I, II, or III. * Is able to walk at least 20 feet with optional use of a 4-legged walker for balance. * Female subjects are eligible only if not pregnant, not lactating, not planning to become pregnant during the study, sterile; or is at least 2 years post-menopausal; or is in a monogamous relationship with a partner who is surgically sterile; or using acceptable contraceptives. Exclusion Criteria: * Has a planned concurrent surgical procedure. * Has other pre-existing concurrent acute or chronic painful physical/restrictive condition expected to require analgesic treatment in the postoperative period for pain. * Has a contraindication or a known or suspected history of hypersensitivity or clinically significant idiosyncratic reaction to required study medications. * Using or expected to use Factor IX Complex or anti-inhibitor coagulant concentrates during the study. * Has known or suspected daily use of opioids for 7 or more consecutive days within the previous 6 months. * Has taken NSAIDs within 10 days prior to the scheduled surgery with the exception of subjects on low-dose (≤100 mg) daily acetylsalicylic acid for cardioprotection. * Has taken opioids within 24 hours prior to the scheduled surgery (3 days for long-acting). * Has been administered bupivacaine within 5 days prior to the scheduled surgery. * Has been administered any local anesthetic within 72 hours prior to the scheduled surgery. * Has initiated treatment with medications within 1 month prior to study drug administration that can impact pain control. * Has been administered systemic steroids within 5 half-lives or 10 days prior to administration of study drug. * Received an investigational product or device in a clinical trial within 30 days or within 5 elimination half lives. * Has a known or suspected history of drug abuse, a positive drug screen on the day of surgery, or a recent history of alcohol abuse. * Has a medical condition such that, in the opinion of the Investigator, participating in the study would pose a health risk to the subject or confound the postoperative assessments. * Is currently undergoing treatment for hepatitis B, hepatitis C, or HIV. * Has uncontrolled anxiety, psychiatric, or neurological disorder that, in the opinion of the Investigator, might interfere with study assessments. * Has acquired defective color vision or acute gastrointestinal ulcers, either of which could interfere with scheduled study medications. * Has any chronic neuromuscular deficit of either femoral nerve function or thigh musculature. * Has any chronic condition or disease that would compromise neurological or vascular assessments. * Had a malignancy in the last year, with the exception of nonmetastatic basal cell or squamous cell carcinoma of the skin or localized carcinoma in situ of the cervix. * Has undergone 3 or more surgeries within 12 months. * Has a body mass index (BMI) \>39 kg/m2.