Encouraging interim efficacy and safety results have been reported from an ongoing phase 3, open-label study of ARX-04 (AcelRx Pharmaceuticals) for the treatment of adult patients who present to the emergency room with moderate-to-severe acute pain associated with trauma or injury. ARX-04 is an investigational product consisting of sufentanil tablets (30 mcg) delivered sublingually via a disposable, prefilled, single-dose applicator.
In the initial single-dose phase of the study, the primary endpoint was the time-weighted summed pain intensity difference compared with baseline during the first hour (SPID1). The 40 patients who have been enrolled and treated to date experienced a substantial clinical reduction in pain intensity, resulting in an SPID1 value that was similar to that seen in previous studies of sublingual sufentanil in postoperative patients. Patients treated with one dose of ARX-04 experienced a mean decrease from baseline of 2.7 on a 0-to-10 numeric rating scale for pain intensity at one hour after dosing. The most common adverse events were nausea and somnolence, each reported in two of the 40 patients (5%). None of the participants has withdrawn from the study early because of adverse events.
The trial will continue to enroll patients, with a goal of 120 participants. The extension arm of the study will allow multiple doses of ARX-04, given hourly as needed for pain for up to four doses. The extension portion of the study is expected to be completed by the end of the first quarter of 2016.
ARX‑04 is being developed for the management of moderate-to-severe acute pain in a variety of medically supervised settings, including the emergency room, outpatient or ambulatory surgery, nonsurgical patients experiencing pain in the hospital, and postoperative patients after short-stay surgery who do not require more long-term patient-controlled analgesia.
Based on market research, it has been estimated that patients in more than 51 million injury-related emergency room visits annually receive an average of two doses of opioids for moderate-to-severe acute pain in the U.S.
Source: AcelRx Pharmaceuticals; February 25, 2016.