Fulranumab vs. Placebo for the Treatment of IC/PBS
Wang, H., Russell, L. J., Kelly, K. M., Wang, S., & Thipphawong, J. (2017). Fulranumab in patients with interstitial cystitis/bladder pain syndrome: observations from a randomized, double-blind, placebo-controlled study. BMC Urology, 17, 2.
Elmiron (pentosan polysulfate sodium) is currently the only FDA-approved oral medication for the treatment of interstitial cystitis/painful bladder syndrome (IC/PBS) in the United States. Other medications are used off-label, but none have received FDA approval due to their failure to demonstrate consistent statistical significance in studies. In the search to find alternatives for bladder pain management and bladder analgesic effects, one study attempted to look at the use of fulranumab, a human monoclonal antibody for nerve growth factor. Fulranumab has previously demonstrated clinical efficacy in the treatment of bladder pain in animal studies, as well as treatment of pain in humans with osteoarthritis and diabetic peripheral neuropathy. Initial studies involving the use of fulranumab in the treatment of IC/PBS showed promise, but subsequent studies have not been able to replicate those positive results. Unfortunately, this study was conducted during a period of time in which there was concern that anti-nerve growth antibodies like fulranumab could worsen osteoarthritis and osteonecrosis. Therefore, this study was ended early, and not enough subjects completed the study to determine a potential significance in the treatment of IC/PBS with fulranumab versus a placebo. Only ten patients received all three doses of fulranumab, while 15 patients received all three doses of the placebo. Patients demonstrated no statistically significant difference in pain control or analgesic effect. However, there was some perceived improvement on the global assessment scale among the group treated with fulranumab, indicating overall improvement. Patients in the fulranumab group also reported less disease duration and lower daytime frequency. Common side effects were diarrhea, carpal tunnel syndrome, and urinary tract infections, which were determined to be either not related or doubtfully related to the use of fulranumab. The study continued to follow patients for 26 months following the last dose.
In 2015, the FDA allowed for the further development and study of anti-nerve growth antibodies to resume. Anti-nerve growth antibodies are currently being studied in the treatment of osteoarthritis and low back pain. Further studies are needed to determine the safety and potential effectiveness of these drugs for the treatment of IC/PBS.
—By Christina Hicks
Christina Hicks, MS, APRN, WHNP-BC, is a women’s health nurse practitioner in urogynecology with a special interest in interstitial cystitis, chronic pelvic pain, and women’s sexual health. She lives in Dallas, Texas.