Optilume drug-coated balloon for anterior urethral stricture: 2-year results of the ROBUST III trial

Objective: The aim of this study is to report the updated 2-year results of the intervention arm of the ROBUST III randomized trial evaluating the safety and efficacy of the Optilume drug-coated balloon (DCB) versus standard endoscopic management of recurrent male anterior urethral stricture.

Materials and methods: Eligible patients included men with recurrent anterior urethral stricture ≤3 cm in length and ≤12Fr in diameter, International Prostate Symptom Score (IPSS) ≥11 and peak flow rate (Qmax) <15 mL/s. Patients were randomized to treatment with the Optilume DCB or standard-of-care endoscopic management. Primary efficacy endpoints measured at 2 years included freedom from re-intervention and changes in IPSS, Qmax and post-void residual (PVR). Secondary endpoint was impact on sexual function using the International Index of Erectile Function (IIEF). Primary safety endpoint was freedom from serious procedure- or device-related adverse events (AEs).

Results: A total of 127 patients enrolled at 22 sites in the United States and Canada (48 randomized to standard-of-care dilation and 79 to DCB dilation). Seventy-five patients in the DCB arm entered the open-label phase after 6 months. Participants averaged 3.2 prior endoscopic interventions (range 2-10); most (89.9%) had bulbar strictures with an average stricture length of 1.63 cm (SD 0.76). Significant improvements in IPSS, average Qmax and PVR were maintained at 2 years. Freedom from repeat intervention was significantly higher in the Optilume DCB arm at 2 years versus the Control arm at 1 year (77.8% vs. 23.6%, p < 0.001). During the follow-up period, there were 15 treatment failures and two non-study-related deaths. Treatment-related AEs were rare and generally self-limited (haematuria, dysuria and urinary tract infection).

Conclusion: The Optilume DCB shows sustained improvement in both objective and subjective voiding parameters at 2-year follow-up. Optilume appears to provide a safe and effective endoscopic treatment alternative for short recurrent anterior urethral strictures among men who wish to avoid or delay formal urethroplasty.