OrBIT: Percutaneous Tibial Nerve Stimulation Versus Extended-Release Tolterodine
OrBIT was a multicenter, open-label randomized trial of 12 weekly sessions of percutaneous tibial nerve stimulation (PTNS) versus extended-release tolterodine initially 4 mg daily in 100 adults with overactive bladder, with the change in voiding frequency at 12 weeks as the primary comparison.[1] Voiding-diary measures improved similarly in both groups, and 35/44 (79.5%) evaluated PTNS subjects versus 23/42 (54.8%) evaluated tolterodine subjects rated themselves cured or improved at 12 weeks (P = 0.01).[1][2]
- Design and population
- Multicenter, open-label noninferiority randomized trial. 100 adults with overactive bladder and urinary frequency (94 women), mean age about 58 years, at United States centers.
- Arms
- Percutaneous tibial nerve stimulation (Urgent PC) weekly for 12 weeks versus extended-release tolterodine 4 mg daily for 12 weeks
- Report and follow-up
- 2009 · 12 weeks of treatment
| Endpoint | Results | Effect | Finding |
|---|---|---|---|
| Mean (SD) change in voids per day from baseline to 12 weeks | -2.4 (SD 4.0) vs -2.5 (SD 3.9) | P 0.44 | Not met |
| Share of subjects reporting cure or improvement at 12 weeks | 35/44 (79.5%) vs 23/42 (54.8%) | P 0.01 |
Harms: Serious adverse events: 0/50 vs 0/50
Design
The trial enrolled 100 adults with overactive bladder and urinary frequency at United States centers (94 women, 6 men; mean age 57.5 years in the PTNS group and 58.2 years in the tolterodine group).[1] Eligibility required a voiding frequency of at least 8 times per day. Exclusions included overactive bladder pharmacotherapy within the previous month, a primary complaint of stress incontinence, a pacemaker or implantable defibrillator, a history of heart problems, nerve damage or neuropathy, and gastric or urinary retention.[1][2]
Participants were randomized 1:1 (50 per group) to weekly PTNS with the Urgent PC system (Uroplasty) for 12 weeks or to extended-release tolterodine starting at 4 mg daily for 12 weeks; two reduced to 2 mg daily for intolerance.[1] The trial was sponsored by Uroplasty, the manufacturer of the stimulator. The registered primary outcome was the change in voids per day from baseline to 12 weeks, with the hypothesis that PTNS was noninferior to tolterodine; secondary outcomes were urgency incontinence episodes, voided volume, overactive bladder quality of life and known side effects.[2]
Subjects completed voiding diaries and an overactive bladder questionnaire at baseline and at the end of therapy. At 12 weeks, subjects and investigators each completed a global response assessment (GRA) of symptoms compared with baseline.[1]
Results
Mean voids per day fell by 2.4 (SD 4.0) with PTNS and 2.5 (SD 3.9) with tolterodine (P = 0.44), and urgency incontinence episodes per day fell by 1.0 (SD 2.2) and 1.7 (SD 3.8).[3] The authors report that reductions in urinary frequency, urgency incontinence episodes, urge severity and nighttime voids, and the increase in voided volume, were similar in the two groups.[1]
On the subject GRA at 12 weeks, 35/44 evaluated PTNS subjects (79.5%) reported cure or improvement versus 23/42 evaluated tolterodine subjects (54.8%; P = 0.01). Investigator assessments were similar to the subjects' but did not reach statistical significance (P = 0.05).[1]
12-month extension
After 12 weeks, PTNS responders were offered 9 more months of treatment. Thirty-three responders continued, and 32 and 25 completed 6 and 12 months of therapy. They received a mean of 12.1 treatments over an average of 263 days, with a mean of 21 days (median 17) between treatments. Sustained improvement on the subject GRA was reported by 30/32 continuing responders (94%) at 6 months and 24/25 (96%) at 12 months. Among 25 PTNS extension completers at 12 months, voiding frequency was 2.8 voids per day lower than at baseline (P < 0.001), urgency incontinence 1.6 episodes per day lower (P < 0.001), nocturia 0.8 voids lower (P < 0.05) and voided volume 39 mL higher (P < 0.05).[4]
Surgery and treatment delivery
PTNS was delivered weekly with the Urgent PC system, which applies percutaneous electrical stimulation to the tibial nerve.[1][2] Of 50 subjects randomized to each group, 41 PTNS and 43 tolterodine subjects completed the 12-week phase.[2] In the 12-month extension, responders received a mean of 21 days between treatments.[4]
Adverse events
No serious adverse events or device malfunctions occurred.[1] The registry lists one or more non-serious adverse events in 6 of 50 PTNS subjects (needle-site pressure or discomfort in 3, leg cramp in 2, and bruising, needle-site redness, a vasovagal response to needle placement and a leg jolt during treatment in 1 each) and in 4 of 50 tolterodine subjects (blurred vision, headache, constipation, increased urgency or frequency and severe dizziness, 1 each).[2] No serious adverse events were reported during the 12-month extension.[4]
Limitations
Treatment was open-label, and the GRA, the endpoint on which the groups differed, is patient-reported. The comparison lasted 12 weeks; 6 of 50 PTNS and 7 of 50 tolterodine subjects did not complete treatment, and two tolterodine subjects reduced the extended-release dose from 4 mg to 2 mg daily for intolerance.[1] The extension followed only PTNS responders with no comparison arm, and 25 of 33 completed 12 months.[4][2]
In conversation
- Extended by SUmiT (2010). Tested the same Urgent PC therapy against sham stimulation rather than against extended-release tolterodine.
- Parallel to SUmiT (2010). Same Urgent PC device and lead investigator; SUmiT compared PTNS with sham stimulation rather than tolterodine.
- Parallel to Burgio 1998 (1998). Both compared a nondrug overactive bladder treatment with an antimuscarinic; ORBIT used tibial nerve stimulation against tolterodine.
Same setting OASIS (Revi) (2024)
OrBIT compared PTNS with an active drug, and its GRA counted cure or improvement. SUmiT compared PTNS with sham stimulation and defined response at 13 weeks as moderately or markedly improved on the GRA; 55% of PTNS participants met that definition versus 21% of the sham group.[3][7]
Guidelines and approvals
- AUA/SUFU 2024 overactive bladder guideline. Clinicians should offer sacral neuromodulation, tibial nerve stimulation and/or intradetrusor botulinum toxin injection to patients with OAB who have an inadequate response to, or intolerable side effects from, pharmacotherapy or behavioral therapy . The guideline's discussion describes OrBIT as an RCT published before its systematic-review period in which PTNS and tolterodine produced comparable reductions in voids per day and urgency incontinence episodes.[3]
- EAU 2026 non-neurogenic female LUTS guideline. Offer posterior tibial nerve stimulation as an option for symptomatic improvement of OAB/UUI . Its evidence summary cites OrBIT among the studies showing significant, sustained symptom improvement with PTNS, similar to tolterodine.[5]
- FDA. Uroplasty's Urgent PC Neuromodulation System, the stimulator used in OrBIT, has a 510(k) decision date of October 17, 2005 (K052025).[6]
Report history
| Published | Report | Cutoff | Headline results | Citation |
|---|---|---|---|---|
| 2009-07-18 | 12-week randomized report · primary | — | Mean (SD) change in voids per day from baseline to 12 weeks: -2.4 (SD 4.0) vs -2.5 (SD 3.9); P 0.44 Not met Mean (SD) change in episodes per day from baseline to 12 weeks: -1.0 (SD 2.2) vs -1.7 (SD 3.8); — Share of subjects reporting cure or improvement at 12 weeks: 35/44 (79.5%) vs 23/42 (54.8%); P 0.01 Investigator assessment of cure or improvement at 12 weeks: The abstract describes investigator assessments as similar to the subject assessments but not statistically significant; percentages are not given.; P 0.05 | Peters KM, MacDiarmid SA, Wooldridge LS, et al. Randomized trial of percutaneous tibial nerve stimulation versus extended-release tolterodine: results from the overactive bladder innovative therapy trial. *J Urol.* 2009;182(3):1055-1061. DOI |
| 2010 | 12-month PTNS extension · updated | — | Share of initial PTNS responders reporting sustained improvement from baseline at 6 and 12 months: 30/32 (94%) at 6 months; 24/25 (96%) at 12 months; — Descriptive Mean improvement from baseline at 12 months among 25 extension completers: 2.8 voids per day; P <0.001 Descriptive Mean improvement from baseline at 12 months among 25 extension completers: 1.6 episodes per day; P <0.001 Descriptive Mean improvement from baseline at 12 months among 25 extension completers: 0.8 voids; P <0.05 Descriptive Mean improvement from baseline at 12 months among 25 extension completers: 39 mL; P <0.05 Descriptive | MacDiarmid SA, Peters KM, Shobeiri SA, et al. Long-term durability of percutaneous tibial nerve stimulation for the treatment of overactive bladder. *J Urol.* 2010;183(1):234-240. DOI |
References
1. Peters KM, MacDiarmid SA, Wooldridge LS, et al. "Randomized trial of percutaneous tibial nerve stimulation versus extended-release tolterodine: results from the overactive bladder innovative therapy trial." J Urol. 2009;182(3):1055-1061. doi:10.1016/j.juro.2009.05.045
2. ClinicalTrials.gov. "Overactive Bladder Innovative Therapy Trial (OrBIT)." Identifier NCT00448175.
3. Cameron AP, Chung DE, Dielubanza EJ, et al. The AUA/SUFU Guideline on the Diagnosis and Treatment of Idiopathic Overactive Bladder. American Urological Association; 2024. Statement 25 and discussion of PTNS.
4. MacDiarmid SA, Peters KM, Shobeiri SA, et al. "Long-term durability of percutaneous tibial nerve stimulation for the treatment of overactive bladder." J Urol. 2010;183(1):234-240. doi:10.1016/j.juro.2009.08.160
5. Harding CK, Lapitan MC, Arlandis S, et al. EAU Guidelines on Management of Non-Neurogenic Female Lower Urinary Tract Symptoms (LUTS). Arnhem: EAU Guidelines Office; limited update March 2026. Section 4.1.4.a.5.
6. U.S. Food and Drug Administration. "Urgent PC Neuromodulation System, 510(k) K052025." FDA 510(k) database
7. Peters KM, Carrico DJ, Perez-Marrero RA, et al. "Randomized trial of percutaneous tibial nerve stimulation versus sham efficacy in the treatment of overactive bladder syndrome: results from the SUmiT trial." J Urol. 2010;183(4):1438-1443. doi:10.1016/j.juro.2009.12.036