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The following is a summary of “E-52862—A selective sigma-1 receptor antagonist, in peripheral neuropathic pain: Two randomized, double-blind, phase 2 studies in patients with chronic postsurgical pain and painful diabetic neuropathy,” published in the December 2024 issue of Pain by Gálvez et al. 

Researchers conducted a retrospective study to analyze the efficacy and safety of E-52862, a selective sigma-1 receptor antagonist, in patients with moderate-to-severe neuropathic chronic postsurgical pain (CPSP) and painful diabetic neuropathy (PDN).  

They randomized adult patients with CPSP [N=116] and PDN [N=163] at a 1:1 ratio to receive either E-52862 (CPSP [n=55]; PDN [n=85]) or placebo (CPSP [n=61]; PDN [n=78]) once daily for 4 weeks. The pain intensity was assessed using a numerical pain rating scale ranging from 0 (no pain) to 10 (worst pain). The primary analysis included patients with≥1 baseline and on-treatment observation (full analysis set).  

The results showed in CPSP that the mean baseline pain was 6.2 for E-52862 and 6.5 for placebo. At week 4, the change from baseline in pain was −1.6 for E-52862 vs −0.9 for placebo (least squares mean difference [LSMD]: −0.9; P =0.029). In PDN, baseline pain was 5.3 for E-52862 and 5.4 for placebo. The week 4 change from baseline was −2.2 for E-52862 and −2.1 for placebo (LSMD: −0.1; P =0.766). Treatment-emergent adverse events (TEAEs) occurred in 90.9% of E-52862-treated patients vs 76.7% in placebo-treated patients for CPSP and 34.1% vs 26.9% in PDN. Serious TEAEs were reported in CPSP only: E-52862 5.5%, placebo 6.7%.  

Investigators concluded the E-52862 demonstrated superior relief of chronic primary stabbing pain compared to placebo after 4 weeks, with reductions in pain intensity observed in post-herpetic neuralgia, although high placebo response rates may have limited the differentiation between treatments. E-52862 was well-tolerated in both populations. 

Source: onlinelibrary.wiley.com/doi/full/10.1002/ejp.4755