ROBUST I: Optilume maintains durable efficacy, safety for urethral strictures

Treatment with the Optilume drug-coated balloon was associated with durable efficacy and safety in patients with short, recurrent bulbar urethral strictures, according to 5-year data from the ROBUST I clinical trial (NCT03014726), which were recently published in the Journal of Urology.¹

These results are in-line with previous findings, as well as data from the ROBUST III trial.

Optilume was approved by the FDA in December 2021 for the treatment of men with urethral strictures based on data from the ROBUST I and ROBUST III clinical trials.²

"Optilume [drug-coated balloon] is a transformative addition to the treatment algorithm for stricture patients," said Allen F. Morey, MD, FACS, in a news release on the data.³ "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."

Overall, data from the trial showed that 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-year follow-up. Four participants did not achieve an IPSS improvement of at least 50%.

According to the authors, “The functional success rate was not significantly different when a threshold of [at least] 30% improvement in IPSS was utilized (63%; 27/43).”

Data also showed an improvement in average Qmax values following treatment with Optilume, with an increase of 5.0 mL/s at baseline to 19.9 mL/s at 5 years (P < .01). Average post-void residual (PVR) also improved, with a decrease from 141.4 mL at baseline to 59.5 mL at 5 years (P < .01). There was also an improvement in average IPSS from 25.2 at baseline to 7.2 at 5 years (P < .0001).

The authors noted, “These outcomes were not significantly different when utilizing the failure carried forward methodology for missing data, with an IPSS of 9.9, Qmax of 15.7 mL/s, and PVR of 69.9 mL at 5 years.”

Data also showed that the estimated freedom from repeat intervention was 71.7% at the 5-year timepoint, with most failures occurring within the first 12 months of treatment, per Kaplan-Meier analysis.

The investigators also observed differences in treatment outcomes when assessing patients based on drug-coated balloon diameter. In total, 25 patients received treatment with the 24F balloon, and 28 received treatment with the 30F balloon.

“Baseline stricture length and stricture diameter were similar between these groups,” the authors noted.

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. Patients in the 30F group also experienced greater improvements in average Qmax and PVR from baseline to 5 years.

Regarding safety, no serious treatment-related adverse events (AEs) were reported. There were 93 mild to moderate AEs, of which 15 were considered treatment- or device-related. Additionally, there were 6 reported serious AEs, none of which were determined to be related to the treatment or the device.

Data also showed no effect of treatment on erectile function, as measured using the International Index of Erectile Function (IIEF) questionnaire. IIEF scores among patients who were sexually active within the month prior were 25.9 at baseline and 26.8 at 5-year follow-up.

According to the authors, “The 5-year data are in line with previous reports from years 1 to 3, showing sustained response in patient-reported outcomes, as well as freedom from repeat intervention.”

In total, the prospective, multicenter, single-arm, open-label trial enrolled 53 men across 4 clinical trial sites in Latin America. 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. The mean age of participants was 50.7 years.

The authors also noted, “Results are in line with the ROBUST III randomized controlled trial that will continue follow-up through 5 years.”

Four-year interim results from the ROBUST III trial were shared at the 2024 American Urological Association Annual Meeting in San Antonio, Texas.⁴ Overall, results showed that treatment with the Optilume balloon was associated with excellent long-term freedom from reintervention rates in patients with recurrent anterior urethral strictures. Patients treated with Optilume also demonstrated significant improvements in symptoms and Qmax at 4-year follow-up.

References

1. DeLong J, Virasoro R, Pichardo M, et al. Long-term outcomes of recurrent bulbar urethral stricture treatment with the Optilume drug-coated balloon: Five-year results from the ROBUST I Study. J Urol. 2025 Jan;213(1):90-98. doi:10.1097/JU.0000000000004229

2. FDA approves Optilume Urethral Drug Coated Balloon, a breakthrough treatment for urethral strictures. Published online December 13, 2021. Accessed January 20, 2025. https://www.biospace.com/fda-approves-optilume-urethral-drug-coated-balloon-a-breakthrough-treatment-for-urethral-strictures?s=74

3. Optilume drug-coated balloon shows long-term efficacy for urethral strictures: Five-year data published in the Journal of Urology. News release. Laborie Medical Technologies. January 17, 2025. Accessed January 20, 2025. https://www.laborie.com/blog/2025/01/17/optilume-drug-coated-balloon-shows-long-term-efficacy-for-urethral-strictures-five-year-data-published-in-the-journal-of-urology/

4. Elliott S, Virasoro R, DeLong J, et al. The Optilume Drug Coated Balloon for recurrent anterior urethral strictures: ROBUST III study 4-year interim results. Presented at: 2024 American Urological Association Annual Meeting. May 3-6, San Antonio, Texas. MP06-15