Double-blind randomized placebo-controlled multicenter clinical trial (phase IIa) on diindolylmethane’s efficacy and safety in the treatment of CIN: implications for cervical cancer prevention

BACKGROUND: The article presents the results of a clinical trial on the efficacy and safety of a novel pharmaceutical composition in the form of vaginal suppositories containing diindolylmethane in the course of cervical intraepithelial neoplasia (CIN) I–II conservative treatment. It offers an attractive drug therapy for more personalized prevention of cervical cancer. METHODS: A total of 78 women of reproductive age were included. This was a multicenter, randomized, placebo-controlled, double-blind, parallel-group trial with efficacy determined by histological evaluation of cervical biopsies. The efficacy of active drug treatment (100 and 200 mg/day) in both treatment groups was significantly higher in comparison with the placebo group, according to the primary efficacy end point (proportion of patients with complete CIN regression after 90–180 days of the study drug treatment). RESULTS: The efficacies were 100.0 % (confidence interval (CI) 95 %: 82.35–100.00 %), 90.5 % (CI 95 %: 69.62–98.83 %), and 61.1 % (CI 95 %: 35.75–82.70 %), for the high dose, low does, and placebo, respectively. Adverse events in the placebo group were reported in 22 % of patients (CI 95 %: 7.5–43.7 %); in the first treatment group (100 mg/day), adverse events were reported in 40.0 % of patients (CI 95 %: 21.1–61.3 %); in the second treatment group (200 mg/day), adverse events were reported in 42.0 % of patients (CI 95 %: 22.1–63.4 %). The differences in side effects between treatment groups treated with the active drug and placebo were statistically significant. No serious adverse events were reported in any of the groups. CONCLUSIONS: Thus, the use of diindolylmethane in the form of intravaginal suppositories can be effective in patients with CIN I–II and is not accompanied by clinically significant side effects. This approach could be a better option for young women with CIN I–II as it takes in attention their reproductive plans. TRIAL REGISTRATION: ID: ChiCTR-INR-15007497 (2 December 2015)