Crisugabalin

China carries a heavy burden of postherpetic neuralgia, with an unmet need for novel drugs with greater efficacy and less prominent neurotoxic effects than existing calcium channel ligands.

To investigate the efficacy and safety of crisugabalin, an oral calcium channel α2δ-1 subunit ligand, for postherpetic neuralgia.

This randomized clinical trial, carried out between November 9, 2021, and January 5, 2023, at 48 tertiary care centers across China had 2 parts. Part 1 was a phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study consisting of a 2-week screening period, a 7-day run-in period, and a 12-week double-blind treatment period. Part 2 was a 14-week open-label extension study. Investigators, statisticians, trial clinicians, and patients were blinded to trial group assignments. Participants included adults with postherpetic neuralgia with an average daily pain score (ADPS) of at least 4 on the 11-point Numeric Pain Rating Scale over the preceding week, with the exclusion of patients with pain not controlled by prior therapy with pregabalin (≥300 mg/d) or gabapentin (≥1200 mg/d).

Patients were randomized 1:1:1 to receive crisugabalin, 20 mg twice daily (ie, 40 mg/d), and crisugabalin, 40 mg twice daily (ie, 80 mg/d), or placebo for 12 weeks. Eligible patients received crisugabalin, 40 mg, twice daily during extension.

The primary efficacy end point was the change from baseline in ADPS at week 12.

The study enrolled 366 patients (121 patients receiving crisugabalin, 40 mg/d; 121 patients receiving crisugabalin, 80 mg/d; 124 patients receiving placebo; median [IQR] age, 63.0 [56.0-69.0] years; 193 men [52.7%]). At week 12, the least squares mean (SD) change from baseline in ADPS was −2.2 (0.2) for crisugabalin, 40 mg/d, and −2.6 (0.2) for crisugabalin, 80 mg/d, vs −1.1 (0.2) for placebo, with a least squares mean difference of −1.1 (95% CI, −1.6 to −0.7; P < .001) and −1.5 (−95% CI, −2.0 to −1.0; P < .001) vs placebo, respectively. No new safety concerns emerged.

Crisugabalin, 40 mg/d, or crisugabalin, 80 mg/d, was well tolerated and demonstrated a statistically significant improvement in ADPS over placebo.

ClinicalTrials.gov Identifier: NCT05140863

HSK16149 is a novel, potent gamma-aminobutyric acid (GABA) analog for the treatment of neuropathic pain. The purpose of this study was to assess the effect of a high-fat and high-calorie meal on the pharmacokinetics of HSK16149 in healthy Chinese subjects. An open-label, two-period crossover design was applied in this study. Twenty-six subjects were enrolled and were randomly divided into two groups: a fasted-fed group and a fed-fasted group, with 13 subjects in each group. Subjects took a single oral dose of 45 mg of HSK16149 under fasted or fed conditions on Day 1 and Day 4. A series of blood samples were collected for PK analysis. Safety was evaluated throughout the study by physical examinations, clinical laboratory tests, 12-lead ECGs, vital signs, and adverse events (AEs). The parameters AUC_0-∞ , AUC_0-t , and C_max of HSK16149 were compared to assess the bioequivalence of HSK16149 under fasted and fed conditions. The geometric mean ratios (GMRs) and their 90% confidence intervals (CIs) of AUC_0-t and AUC_0-∞ under the fed condition compared with the fasted condition were 95.84% (91.94-99.90%) and 95.79% (91.89-99.84%), respectively, which were all within the bioequivalent interval (80.00-125.00%). The GMR (90% CI) of C_max under the fed condition compared with the fasted condition was 66.04% (59.45-73.36%), which was not within the bioequivalent range (80.00-125.00%). All adverse events were transient and resolved. This study demonstrated that HSK16149 can be administered with or without food.