The goal of this pilot study was to gather information on differences between intravesical chondroitin sulfate and inactive vehicle control for treatment of interstitial cystitis/painful bladder syndrome (IC/PBS).

This was a prospective, randomized, double-blind, inactive vehicle-controlled, 12-week study (6-week treatment period, followed by a 6-week follow-up period) in patients with IC/PBS. Patients were randomized to weekly intravesical treatment with 2.0% sodium chondroitin sulfate in phosphate-buffered saline or intravesical vehicle control. Primary efficacy analysis compared responders (moderately or markedly improved) according to the 7-point Global Response Assessment. Secondary endpoints include questionnaires focused on symptoms and quality of life.

Sixty-five evaluable patients were randomized. At the primary endpoint analysis (week 7), 22.6% of the vehicle control group were responders compared with 39.4% of the active therapy group (P = .15). There was no statistically significant difference for any of the secondary endpoints. Overall, 76.9% of the patients in the study reported at least 1 adverse event; most were mild or moderate, the majority associated with the vehicle control treatment. Nine nonserious intervention-related adverse events were reported in 3 patients in the vehicle control group compared with 2 in 1 patient in the active treatment group.

The difference in treatment effect in this small underpowered study was not statistically significant, although twice as many patients reported a clinically significant benefit with intravesical chondroitin sulfate treatment compared with vehicle control treatment. This trial provides data required to design a well-powered randomized vehicle-controlled trial to determine the true efficacy of this potentially promising therapy.