Phase III study of pentosanpolysulfate (PPS) in treatment of gastrointestinal tract sequelae of radiotherapy

OBJECTIVES: To evaluate the effectiveness of pentosanpolysulfate (PPS) in the treatment of gastrointestinal tract sequelae of radiotherapy. METHODS: Eligible patients were those with grade 1 to 3 radiation related proctitis, diarrhea and/or melena. At least 4 weeks had to elapse since the completion of the radiotherapy course. Patients with bleeding diathesis or ulcers, and patients receiving anticoagulants or chemotherapy were excluded. Stratification criteria included the type of sequelae (proctitis, diarrhea, melena), the severity grade and the onset (<3 months post-RT, >3 months post-RT). Patients were randomized to one of the following arms: 100 mg PPS 3 times per day (300 mg/day), 200 mg PPS 3 times per day (600 mg/day), or placebo 3 times per day. If there was no improvement in symptoms after 2 months, the protocol treatment was discontinued. If the symptoms improved or resolved, the protocol treatment was continued for additional 4 months. Patients under treatment were evaluated monthly, than every 2 to 3 months for the next 18 months. A symptom assessment questionnaire was used to measure quality of life endpoints. RESULTS: From June 1999 to March 2001 180 patients were accessioned from 34 institutions. A total of 168 were analyzable. Neither the best observed response within 3 months for the entire population, nor the response rate within sequelae category or the quality of life measures differed significantly between the 3 arms of the study. CONCLUSION: Administration of PPS has not been associated with an improvement in the clinical course of radiation related morbidity of the gastrointestinal tract.