Immunostimulation in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS): a one-year prospective, double-blind, placebo-controlled study.

purposeInflammation/immunological dysfunction are discussed etiological causes of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). OM-89 is an orally immunostimulating agent. We performed a phase three multicentre, randomized, double-blind, placebo-controlled, long-term (12 months) study with OM-89 produced with a different lysis process in patients with moderate-to-severe CP/CPPS type III.

methodsPatients were randomized to OM-89 or placebo. Primary efficacy variable was difference of responders at the end of treatment (month 9) in patients receiving OM-89 versus placebo.

resultsTwo hundred and three patients were screened, 185 patients (47.8 ± 8.4 years) (90 % of CP/CPPS type IIIb) were enrolled in 30 centers and included in the safety set. Ninety-four were randomized to OM-89, 91 to placebo. One hundred and seventy-six patients were subjected to the full analysis (FAS), 150 to the per protocol set (PPS). Baseline NIH-CPSI score in FAS was 21.8 ± 3.8 (OM-89) and 23.0 ± 5.6 (placebo). At primary efficacy endpoint (month 9), in the OM-89 group, 67.0 % in FAS (PPS 72.7 %) and in the placebo group, 64.3 % in FAS (PPS 64.4 %) were responders [FAS: OR 1.19, p = 0.59; PPS: p = 0.19]. Mean relative decrease in NIH-CPSI was 40.5 and 44.0 % in the FAS. Treatment-related adverse events were low: 8.5 % with OM-89 and 5.5 % with placebo. Because of small numbers, no conclusion could be drawn regarding the potential benefit of OM-89 in CP/CPPS IIIa.

conclusionsThis placebo-controlled study evaluating OM-89 in patients with CP/CPPS showed a significant and long-lasting (12 months) favorable response with OM-89, but also with placebo. OM-89 was safe and well tolerated. EUDRACT: 2007-004609-85.