Targeting the SHIP1 Pathway Fails to Show Treatment Benefit in Interstitial Cystitis/Bladder Pain Syndrome: Lessons Learned from Evaluating Potentially Effective Therapies in This Enigmatic Syndrome

Abstract

Purpose: In this 12-week, randomized, double-blind, placebo controlled, multicenter, 3-arm, parallel group, phase 3 trial we assessed the effects of a novel SHIP1 activator on bladder pain and urinary symptoms in patients with interstitial cystitis/bladder pain syndrome.

Materials and methods: Subjects with interstitial cystitis/bladder pain syndrome and a mean pain score of 5 or greater on an 11-point scale despite treatment were randomized to 100 or 200 mg of an oral SHIP1 activator or placebo once daily for 12 weeks. Maximum pain scores and urinary frequency were recorded in an e-diary. The ICSI (O'Leary-Sant Interstitial Cystitis Symptom Index) and BPIC-SS (Bladder Pain Interstitial Cystitis Symptom Score) questionnaires were administered. Safety was monitored through 12 weeks of treatment.

Results: A total of 298 female subjects with moderate to severe symptoms of interstitial cystitis/bladder pain syndrome were treated with 100 or 200 mg SHIP1 activator orally once daily for 12 weeks. Treatment demonstrated no difference in maximum daily bladder pain compared to placebo. There was no treatment benefit over that of placebo in the secondary end points of urinary voiding frequency, the BPIC-SS, the ICSI and a global response assessment. Exploratory analysis in 87 male subjects yielded a similar result, that is no difference from placebo. Treatment was generally well tolerated at both doses.

Conclusions: SHIP1 activation is a safe but ineffective therapeutic approach to interstitial cystitis/bladder pain syndrome. Although this was a negative trial, the important lessons learned from this study in respect to inflammatory phenotype differentiation, including the potential importance of cystoscopy based classification, will improve current treatment in patients with interstitial cystitis/bladder pain syndrome and allow for better future trial design in those with this difficult urological chronic pain syndrome.

Keywords: cystitis; interstitial; negative results; patient reported outcome measures; pelvic pain; urinary bladder.