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Crisugabalin as a treatment for postherpetic neuralgia in adults can lead to significant improvements in pain scores and is well-tolerated, according to study results published in JAMA Dermatology.
There is an unmet need for novel calcium channel blockers that demonstrate good efficacy and less neurotoxic side effects in postherpetic neuralgia.
Researchers of a multicenter, randomized, double-blinded, placebo-controlled, parallel-group trial (ClinicalTrials.gov Identifier: NCT05140863) determined the safety and efficacy of crisugabalin vs placebo in patients with postherpetic neuralgia.
Part 1 of the trial included a 2-week screening period followed by a 7-day run-in, and a 12-week treatment period. Part 2 was a 14-week open-label extension period.
Eligible study participants had postherpetic neuralgia, and average pain scores of at least 40 mm on the visual analog scale (VAS) of the Short-Form McGill Pain Questionnaire (SF-MPQ) and at least 4 on the Numeric Pain Rating Scale (NPRS) in the preceding week. Average daily pain score (ADPS) was used to measure pain and sleep.
Persistent postherpetic neuralgia was defined as persistent neuropathic pain occurring more than 1 month after disappearance of acute herpetic rash.
In part 1, patients were randomly assigned 1:1:1 to receive 20 mg twice-daily crisugabalin (40 mg/d), 40 mg twice-daily crisugabalin (80 mg/d), or placebo for 12 weeks.
The primary efficacy endpoint was change in ADPS score at week 12. Secondary efficacy endpoints were responder rate, weekly changes in ADPS and SF-MPQ VAS scores, changes in the SF-MPQ Pain Rating Index, Present Pain Intensity (PPI) scores, and health-related quality of life (HRQOL).
Between 2021 and 2023, a total of 366 patients (mean age, 60.5; 52.7% men) were enrolled in the study, of whom 121 received 40 mg/day crisugabalin, 121 received 80 mg/day crisugabalin, and 124 received placebo.
From weeks 1 to 12, both groups receiving crisugabalin vs placebo had lower ADPS scores. The least-square mean (LSM) change in ADPS at 12 weeks for 40 mg/day crisugabalin, 80 mg/day crisugabalin, and placebo were -2.2, -2.6, and -1.1, respectively, with an LSM difference of -1.1 and -1.5 for the crisugabalin groups, respectively.
At week 12, a higher percentage of patients who received 40 or 80 mg/day crisugabalin vs placebo achieved at least a 30% reduction in ADPS (61.2%, 54.5%, and 35.5%, respectively; P <.001). Similarly, a higher percentage of patients who received 40 or 80 mg/day crisugabalin vs placebo achieved at least a 50% reduction in ADPS (37.2%, 38.0%, and 20.2%, respectively; P =.002 and P <.001).
Patients who received 40 or 80 mg/day crisugabalin vs placebo were 3-fold more likely to achieve at least a 30% (odds ratios [ORs], 3.58 and 2.93, respectively) or 50% (ORs, 3.03 and 3.84, respectively) reduction in ADPS.
The researchers noted a decrease in SF-MPQ VAS scores after week 4, as well as greater LSM changes at week 12, in patients who received crisugabalin vs placebo. In addition, SF-MPQ PPI scores also decreased until week 12, with a greater reduction in the crisugabalin vs placebo groups. Compared with placebo, crisugabalin also improved HRQOL, such as mobility, daily activities, pain/discomfort, and anxiety and depression.
In part 1 of the trial, 65% and 76.2% of patients who received 40 and 80 mg/day crisugabalin vs 63.7% of patients who received placebo had any-grade treatment-emergent adverse events (TEAEs), with serious TEAEs occurring in 4 patients in each group. In part 2, any-grade TEAEs occurred in 68.9% of patients. During the study, no deaths occurred due to TEAEs.
Limitations of the analysis were the lack of a control group; not a reflection of current standards of care in the US or Europe; the lack of generalizability to populations other than Chinese; and the lack of applicability to all subsets of patients with postherpetic neuralgia.
“Taken together, crisugabalin can be flexibly selected depending on individual patient response and tolerability at 40 mg/d or 80 mg/d,” the researchers concluded.
This research was supported by Haisco Pharmaceutical Group Co Ltd. Multiple study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the authors’ disclosures.
