Efficacy and Safety of Sanjie Analgesic Capsule in Patients with Endometriosis-Associated Pain: A Multicenter, 3:1 Randomized, Double-Blind, Placebo-Controlled Trial.

Objective: To assess the efficacy and safety of Sanjie Analgesic Capsule (SAC) in Chinese patients with endometriosis-associated pain.

Methods: This was a multicenter, randomized, double-blind, placebo-controlled trial conducted at 15 centers between November 2013 and July 2017 in China. Eligible 323 patients with endometriosis were randomized at a 3:1 ratio to the SAC group (241 cases) and placebo group (82 cases) by stratified block randomization. Patients in the SAC or placebo groups were given SAC or placebo 1.6 g 3 times per day, orally, respectively since the first day of menstruation for 3 consecutive menstrual cycles. The primary endpoint was clinical response to dysmenorrhea evaluated using a 10-point Visual Analogue Scale at 3 and 6 months. The secondary endpoint was the pain score evaluated by VAS (chronic pelvic pain, defecation pain, and dyspareunia) at 3 and 6 months, and the pain recurrence rate at 6 months. Adverse events (AEs) were recorded during the study.

Results: A total of 241 women were included in the SAC group, and 82 were in the placebo group. Among these women, 217 (90.0%) and 71 (86.6%) completed the intervention, respectively. At 3 months, overall response rate (ORR) was significantly higher in women administered SAC (80.1%) compared with those who received a placebo (30.5%, P<0.01). Six months after treatment, the ORR for dysmenorrhea was 62.7% in the SAC group and 31.7% in the placebo group (P<0.01). Chronic pelvic pain and defecation pain were significantly improved by SAC compared with placebo (both P<0.05). The incidence rates of total AEs events in the SAC and placebo groups were 6.6% and 9.8%, respectively, and no significant difference was shown between the two groups (P=0.339).

Conclusion: SAC is well-tolerated and may improve dysmenorrhea in women with endometriosis-associated pain. (Trial registration: ClinicalTrials.gov, No. NCT02031523).