Five-year data from the ROBUST I clinical trial indicates that the Optilume drug-coated balloon (DCB) maintains durable efficacy and safety in patients with short, recurrent bulbar urethral strictures. The findings, published in the Journal of Urology, reinforce Optilume's potential as a transformative treatment option.
The ROBUST I trial (NCT03014726) evaluated 53 men with recurrent bulbar strictures. The results showed that 71.7% of patients did not require repeat intervention over the five-year follow-up period. Functional success, defined as at least a 50% improvement in International Prostate Symptom Score (IPSS), was achieved in 58% of patients (25 of 43) at 5 years.
Significant Improvements in Urological Parameters
Data from the trial demonstrated notable improvements in several key urological parameters:
- IPSS: Average IPSS improved from 25.2 at baseline to 7.2 at 5 years (P < .0001).
- Qmax: Maximum urinary flow rate (Qmax) increased from 5.0 mL/s at baseline to 19.9 mL/s at 5 years (P < .01).
- Post-Void Residual (PVR): Average PVR decreased from 141.4 mL at baseline to 59.5 mL at 5 years (P < .01).
"Optilume [drug-coated balloon] is a transformative addition to the treatment algorithm for stricture patients," said Allen F. Morey, MD, FACS. "With the robust 5-year clinical data, we now see its ability to provide durable, long-term relief. It remains an excellent option for elderly patients or those with comorbidities who are suboptimal candidates for open surgery and for enhancing outcomes in complex stricture management."
Safety and Tolerability
The study reported no serious treatment-related adverse events (AEs). There were 93 mild to moderate AEs, with 15 considered treatment- or device-related. Erectile function, as measured by the International Index of Erectile Function (IIEF) questionnaire, was not affected by the treatment. IIEF scores among sexually active patients were 25.9 at baseline and 26.8 at 5-year follow-up.
Drug-Coated Balloon Diameter Impact
The investigators observed differences in treatment outcomes based on the drug-coated balloon diameter. Patients treated with the 30F balloon experienced greater improvements in average Qmax and PVR from baseline to 5 years compared to those treated with the 24F balloon. At 5-year follow-up, functional success was achieved among 38% (8 of 21) of patients in the 24F group and 77% (17 of 22) of patients in the 30F group.
Mechanism of Action and Clinical Context
The Optilume DCB combines mechanical dilation with the localized delivery of paclitaxel, which inhibits tissue regrowth, directly to the urethral tissue. This dual-action approach aims to limit scar tissue formation and reduce stricture recurrence. The ROBUST I data is consistent with the ROBUST III randomized controlled trial, which also demonstrated favorable outcomes with Optilume for recurrent anterior urethral strictures.
Study Design and Patient Population
The ROBUST I trial was a prospective, multicenter, single-arm, open-label study conducted across 4 clinical trial sites in Latin America. It enrolled 53 men with a mean age of 50.7 years. Of these, 41 patients completed all follow-up through either an end point event or to 5 years, and 29 completed follow-up to 5 years without the need for re-treatment.
