Safety and tolerability of DIM-based therapy designed as personalized approach to reverse prostatic intraepithelial neoplasia (PIN)

First results of the double-blind randomized placebo-controlled multicenter clinical trial of DIM-based therapy designed as personalized approach to reverse prostatic intraepithelial neoplasia (PIN)

Background

Targeted pharmacological correction is used extensively in medical practice today. 3,3'-Diindolylmethane (DIM) is known as a substance with various anticancer properties. An interim study of the efficacy of a new drug Infemin on the basis of diindolylmethane (DIM) with improved bioavalability has been conducted.

Methods

The clinical trial had a multicenter, randomized, placebo-controlled, double-blind design and was carried out in two parallel groups. The interim analysis of data included 21 patients diagnosed with a high-grade prostatic intraepithelial neoplasia (PIN). Group 1 (11 patients) received Infemin in a dose of 900 mg of DIM a day, and group 2 (10 patients) received placebo. To assess the efficacy of therapy, the analysis of morphological index (MI) changes based on the results of histological examinations of prostate biopsy specimens was performed, and a proportion of patients with persistent PIN in 12 months after Infemin initiation was calculated. Researchers also evaluated prostate size, urodynamic parameters (Qmax, Qave, Vres), IPSS, and QoL (quality of life) indices and International Index of Erectile Function (IIEF) at 3, 6, 9, and 12 months after the Infemin administration start.

Results

After 12 months of treatment in the Infemin group, MI decreased from 0.50 to 0.08, while in the placebo group, it increased from 0.27 to 0.58; the difference between the groups was statistically significant (p = 0.0003, Mann-Whitney test). In 45.5 % of patients in the Infemin group, a complete regression of PIN was also observed, while in the placebo group, PIN regression was not observed in any patients (p = 0.053, Yates’ corrected chi-square). Study results in the Infemin group show improvement of maximal urinary flow rate Qmax (53.3 % increase compared to the initial value); however, the statistical significance was not reached (p = 0.180, Mann-Whitney test) due to the small sample size. Evaluation of other urodynamic parameters, prostate volume, quality of life, symptoms reflecting urination disorder, and erectile dysfunction symptoms did not reveal significant differences between the Infemin and placebo groups either which is probably due to the small sample size.

Conclusions

The intermediate results of the 21 patients in this multicenter, randomized, placebo-controlled, double-blind study show that Infemin may be a promising drug candidate in patients with  high-grade PIN.

Trial registration

www.chictr.org.cnChiCTR-INR-15007496

Premalignancy in Prostate Cancer: Rethinking What we Know

High-grade prostatic intraepithelial neoplasia (PIN) has been accepted as the main precursor lesion to invasive adenocarcinoma of the prostate, and this is likely to be the case. However, in an unknown number of cases, lesions fulfilling the diagnostic criteria for high-grade PIN may actually represent intra-acinar or intraductal spread of invasive carcinoma. Intriguingly, this possibility would not contradict many of the findings of previous epidemiologic studies linking high-grade PIN to carcinoma or molecular pathologic studies showing similar genomic (e.g., TMPRSS2-ERG gene fusion) as well as epigenomic and molecular phenotypic alterations between high-grade PIN and carcinoma. Also, this possibility would be consistent with previous anatomic studies in prostate specimens linking high-grade PIN and carcinoma in autopsy and other whole prostate specimens. In addition, if some cases meeting morphologic criteria for PIN actually represent intra-acinar spread of invasive carcinoma, this could be an important potential confounder of the interpretation of past clinical trials enrolling patients presumed to be without carcinoma, who are at high risk of invasive carcinoma. Thus, in order to reduce possible bias in future study/trial designs, novel molecular pathology approaches are needed to decipher when an apparent PIN lesion may be intra-acinar/intra-ductal spread of an invasive cancer and when it truly represents a precursor state. Similar approaches are needed for lesions known as intraductal carcinoma to facilitate better classification of them as true intra-ductal/acinar spread on one hand or as precursor high-grade PIN (cribriform type) on the other hand; a number of such molecular approaches (e.g., coevaluating TMPRSS-ERG fusion and PTEN loss) are already showing excellent promise. Cancer Prev Res; 9(8); 648-56. ©2016 AACR.