The Interstitial Cystitis Clinical Trials Group (ICCTG) RCT1 was a pilot clinical trial using a 2x2 factorial study design with double masked drug treatment to evaluate the feasibility of oral pentosan polysulfate (PPS) and oral hydroxyzine in patients with interstitial cystitis (IC). IC is a bladder syndrome characterized as painful, debilitating and chronic, with no widely accepted effective treatment. Characteristic symptoms include pain with bladder filling, and marked urinary frequency (to relieve pain). The presentation of symptoms can be quite variable among patients, suggesting that IC is a multi-factorial syndrome with several proposed etiologies, some of which may be interrelated. Subjects with IC were randomized over 18 months and followed for 24 weeks. The primary endpoint was a patient reported global response assessment (GRA) of overall symptoms. Secondary endpoints included symptom indexes and patient reports of urinary pain, urgency and frequency. The low global response rates for PPS and hydroxyzine suggest that neither provided benefit for the majority of patients with IC.

The ICCTG RCT1 study was pilot designed to evaluate the feasibility of a multicenter, randomized, clinical trial in interstitial cystitis (IC). Secondary objectives were to evaluate the safety and efficacy of oral pentosan polysulfate (PPS), hydroxyzine and a combination of both to consider their use in a larger randomized clinical trial.

The primary end point was a participant reported global response assessment (GRA) at 24 weeks relative to overall baseline symptoms. A 7-point centered scale was used to define response and subjects who withdrew from the study for any reason before the 24-week end point examination were considered non-responders. A number of secondary outcomes (including the O’Leary-Sant IC Symptom and Problem Index, the University of Wisconsin Symptom Score, patient reported symptoms of pain/discomfort and urgency and results of a 24-hour voiding diary) were used to supplement the primary analysis.

Eligible participants had to be at least 18 years old and receive a diagnosis of IC, confirmed by cystoscopy and hydrodistention, following National Institutes of Health-National Institute of Diabetes and Digestive and Kidney Diseases criteria. All patients were required to have moderate symptoms of urinary frequency (at least 11 times daily) and pain/discomfort (at least 4 on a 0 to 9 Likert scale) for at least 24 weeks before to study entry. All participants provided written informed consent.

The low global response rates for oral pentosan polysulfate and hydroxyzine suggest that neither provided benefit for the majority of patients with IC. This pilot trial demonstrated the feasibility of conducting a multicenter randomized clinical trial in IC using uniform procedures and outcomes. Slow recruitment underscored the difficulties of evaluating commonly available IC drugs.