Crisugabalin

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.

Chronic pain is a public health problem because current treatments are unsatisfactory with small therapeutic index. Although pregabalin is effective for treating chronic pain, the clinical use is limited because of its side effects. Therefore, improving its therapeutic index is essential. In this study, HSK16149 was found to be a novel ligand of voltage-gated calcium channel (VGCC) α ₂ δ subunit. HSK16149 inhibited [³H]gabapentin binding to the α ₂ δ subunit and was 23 times more potent than pregabalin. In two rat models of neuropathic pain, the minimum effective dose (MED) of HSK16149 was 10 mg/kg, and the efficacy was similar to that of 30 mg/kg pregabalin. Moreover, the efficacy of HSK16149 could persist up to 24 hours postadministration at 30 mg/kg, whereas the efficacy of pregabalin lasted only for 12 hours at 30 mg/kg in streptozotocin-induced diabetic neuropathy model, indicating that HSK16149 might be a longer-acting drug candidate. HSK16149 could also inhibit mechanical allodynia in intermittent cold stress model and decrease phase II pain behaviors in formalin-induced nociception model. In addition, the locomotor activity test showed that the MED of HSK16149 was similar to that of pregabalin, whereas in the Rotarod test, the MEDs of HSK16149 and pregabalin were 100 and 30 mg/kg, respectively. These findings indicated that HSK16149 might have a better safety profile on the central nervous system. In summary, HSK16149 is a potent ligand of VGCC α ₂ δ subunit with a better therapeutic index than pregabalin. Hence, it could be an effective and safe drug candidate for treating chronic pain. SIGNIFICANCE STATEMENT: As a novel potent ligand of voltage-gated calcium channel α ₂ δ subunit, HSK16149 has the potential to be an effective and safe drug candidate for the treatment of chronic pain.