(760): ALGRX 4975 reduces pain of intermetatarsal neuroma: Preliminary results from a randomized, double-blind, placebo-controlled, phase II multicenter clinical trial

Abstract

ALGRX 4975 is capsaicin for injection. Subjects with painful intermetatarsal neuroma received a single injection of ALGRX 4975, 100 μg in 0.5 ml, or placebo, 0.5 ml, into the intermetatarsal space 10 minutes following lidocaine with epinephrine, 2 ml of 2% solution. The primary efficacy endpoint was change from baseline in the average foot pain rating scale (11 point NRS). Pain at baseline was 5.7 in both the group that subsequently received ALGRX 4975 (n=30) as well as group that received placebo (n=28). The change in pain scores at the end of weeks 1, 2, 3, and 4 was −2.1 compared to −0.6 (p=0.0205), −2.3 compared to −1.5 (p=0.1422), −2.9 compared to −1.8 (p=0.0719), and −3.5 compared to −2.1 (p=0.0188), respectively. Pain scores summed over the entire observation period were 13.0 in the group that received ALGRX 4975 compared to 17.5 in the group that received placebo (−4.5 ALGRX 4975 compared to placebo, p=0.0235). There were no statistically significant differences between the two groups in the change in averages of the seven interference items from the BPI. Injection of ALGRX 4975 was associated with transient pain on injection. A decrease in sensory perception was apparent at the injection site in both groups following injection, which returned to baseline by the end of week 4. A single injection of ALGRX 4975, 100 μg, was associated with less pain during a four week observation period in subjects with intermetatarsal neuroma compared to placebo.