Even though urethroplasty is the gold standard for recurrent anterior urethral stricture disease, repeat endoscopic intervention is commonly pursued. Many urologists do not perform urethroplasty and there is associated morbidity with the procedure that may be a deterrent for patients. The ROBUST III study is a prospective, randomized controlled trial comparing the Optilume® Drug Coated Balloon (DCB) against standard of care (SOC) direct visual internal urethrotomy (DVIU) or dilation in patients with prior failed endoscopic treatment. The Optilume® DCB is a urethral dilating balloon with a paclitaxel coating that combines mechanical dilation for immediate symptomatic relief with local drug delivery to reduce scarring and maintain urethral patency. Outcomes after 3-year follow-up are presented here.

In this prospective, multicenter, single blind, randomized controlled trial subjects were randomized 2:1 Optilume® DCB to standard of care (SOC) at 23 sites. Seventy-nine patients were treated with the DCB and 48 were treated with SOC DVIU or dilation. Follow-up past 1 year was limited to those treated with the DCB. Eligibility criteria included adult males with an anterior stricture with ≥2 prior endoscopic treatments, stricture length ≤3cm and urethral lumen ≤12F. Patients with prior urethroplasty, hypospadias, lichen sclerosus or unresolved confounding pathologies were excluded. Long-term endpoints included freedom from repeat treatment, International Prostate Symptom Score (IPSS), and peak urinary flow rate (Qmax). Predilation was performed in all patients receiving the Optilume® DCB. Patients were followed post-procedure at foley removal (2-5 days), 30 days, 3 months, 6 months, and yearly thereafter.
Efficacy and safety analyses were performed for all patients undergoing DCB.  Various subgroup analyses were performed, and statistical significance was set at 0.05.

127 patients met inclusion criteria and were included in the study. Subjects randomized to receive the DCB had an average of 3.2 prior treatments and average stricture length of 1.6cm (46% ≥2cm), with 8/79 (10.1%) having penile strictures and 9/79 (11.4%) having prior pelvic radiation. In the DCB group, IPSS significantly improved from 22.0 at baseline to 11.3 at 3 years, which was similar to the one-year (9.0) and two-year (10.1) results. At one-year post-procedure, Qmax was nearly double that in the control group, and showed sustained improvement from a baseline of 7.7 mL/sec to 12.0 mL/sec at the three-year follow up. In contrast, in the SOC control group, IPSS and Qmax deteriorated sharply by the 3 month follow up and had returned to near baseline levels at one year.  Freedom from repeat intervention for DCB subjects was estimated to be 72% at 3 years. No late-onset treatment related adverse events were observed.

The three-year results of the ROBUST III trial continue to show that the Optilume® DCB is a safe and effective endoscopic treatment for men with short, recurrent anterior urethral strictures. Multiple measures of success were followed, and all showed consistent improvement over the study period.  IPSS and Qmax showed sustained, clinically significant improvement at 3 years. Similarly, freedom from repeat intervention was approximately three times higher than in the control group, and this remained consistent at the one, two and three-year follow up points. No mid-term treatment related adverse events were noted, indicating an excellent safety profile.

The Optilume® DCB continues to achieve significant improvements in symptoms, flow, and reintervention rates through 3 years post-treatment. It is a viable less-invasive option for appropriately selected men who wish to avoid urethroplasty.

Continence 7S1 (2023) 100726
DOI: 10.1016/j.cont.2023.100726