Sublingual Sufentanil Shows Mixed Results in Phase II Pain Study
Higher dose meets primary endpoint, but lower dose doesn’t (Apr. 24)
In a placebo-controlled, dose-finding, phase II study, a higher dose (30 mcg) of the investigational single-dose sublingual sufentanil NanoTab for acute pain (ARX-04, AcelRx Pharmaceuticals) successfully met its primary endpoint, whereas a lower dose (20 mcg) did not.
The results showed that patients receiving the 30-mcg sufentanil dose, administered by a healthcare professional no more frequently than once per hour, experienced significantly greater pain reduction, as measured by the Summed Pain Intensity Difference to baseline, during the 12-hour study period (SPID-12) compared with placebo-treated patients (P = 0.003). Patients treated with the 20-mcg dose of sublingual sufentanil did not achieve SPID-12 scores that differed from those of the placebo group.
The study randomly assigned 101 patients to receive sufentanil 30 mcg, sufentanil 20 mcg, or placebo following bunionectomy surgery. The intent-to-treat (ITT) population had an average age of 42.5 years and was evenly balanced for males and females (51% vs. 49%, respectively) and for ethnicity (54% Caucasian vs. 46% non-Caucasian). Ninety-one percent of the enrolled patients completed the full 12-hour study period.
SPID-12 scores were +6.53 for patients treated with sufentanil 30 mcg versus –7.12 for placebo-treated patients (P = 0.003).
Adverse events (AEs) were generally mild-to-moderate in severity. Two patients treated with the 30-mcg dose dropped out of the study because of AEs. One patient’s discontinuation was considered to be probably related to the study drug.
ARX-04 is a product candidate in development for the treatment of moderate-to-severe acute pain. It consists of sufentanil, a high-therapeutic-index opioid, in a NanoTab, which allows rapid sublingual absorption when the tab is placed under the tongue.
Source: AcelRx Pharmaceuticals; April 24, 2013.