Efficacy of RestoreX Penile Traction Therapy In Preserving Erectile Function Post-Prostatectomy

Background and Preliminary Data

The treatment of prostate cancer results in several known sexual dysfunctions/risks, including erectile dysfunction, orgasmic dysfunction, ejaculatory dysfunction, penile curvature (Peyronie's disease), and reduced penile length. Although all forms of prostate cancer treatment are associated with many of these changes, prostatectomy currently has the most data available on sexual function outcomes. Among the dysfunctions, erectile dysfunction has remained a very challenging adverse effect without effective preventative therapies. Specifically, prior randomized controlled trials evaluating the efficacy of PDE5 inhibitors (vardenafil and tadalafil) have failed to demonstrate improved erectile function preservation post-operatively.

Recently, out team conducted a single-center randomized, controlled trial evaluating the efficacy of a novel penile traction therapy (PTT) device, RestoreX at preventing penile length loss post-prostatectomy. In addition to meeting the primary outcome of achieving improved penile length compared to controls, the study unexpectedly demonstrated improvements in erectile function in the treatment group compared to controls. Results were also consistent with two other prior randomized, controlled trials, one of which demonstrated improved erectile function in men with Peyronie's Disease and the other in men with diabetes mellitus (unpublished).

As these findings represent the first known therapy which resulted in preserved erectile function post-prostatectomy, we sought to perform a larger, multi-center study in an attempt to confirm or refute findings.

Investigational Device

RestoreX is a PTT device developed by PathRight Medical using technology licensed from the Mayo Clinic. The device is classified as class I (orthotic) and does not require clinical trials to prove safety or efficacy. Mayo Clinic has previously performed 3 randomized controlled trials which have confirmed the safety of the device as well as efficacy in improving erectile function and penile length in various cohorts of men.

The device has two functional aspects. The first is the ability to provide direct traction on the penis. The second is the ability to provide counter-bending forces, to treat conditions such as Peyronie's disease (bent penis). In the current study, only the direct traction aspects of the device will be utilized.

Study Rationale

PTT with Restorex has been shown to improve erectile function in several clinical scenarios, including in men with Peyronie's disease, men with diabetes mellitus (unpublished), and post-prostatectomy. As no therapy has ever been shown to improve erectile function or prevent loss of erectile function post-prostatectomy, we felt that there was significant clinical value in performing a large, multi-center, randomized, controlled trial to affirm or refute the efficacy of Restorex PTT in preserving erectile function post-prostatectomy.

Potential Benefits

There are several anticipated benefits to using PTT following prostatectomy. As loss of penile length results in several issues including loss of sexual function, cosmetic concerns, and difficulty in maintaining hygiene (incontinence resulting in yeast infections), the ability to maintain or restore length post-prostatectomy may mitigate these issues. Our team has previously demonstrated that Restorex PTT significantly improved penile length post-prostatectomy. Although this is an anticipated beneficial effect of therapy, we will not be specifically evaluating this outcome in the current study.

In addition to improved penile length, our prior investigations have demonstrated preserved erectile function in men who received PTT with Restorex post-prostatectomy compared to controls. And among all patients in the three prior randomized, controlled trials evaluating Restorex, no significant or long-term adverse events were reported, highlighting the safety of the therapy.

Anticipated Duration of the Clinical Investigation

The overall study will be scheduled for 3 years, to permit adequate time for enrollment and follow-up. The intervention phase will include 5 months of randomized treatment (for the treatment arm), and 3 months of open label treatment (for all arms).

Inclusion criteria

• Undergoing bilateral nerve-sparing prostatectomy
• >18 years old
• Have a regular sexual partner for at least 6 months prior to study enrollment

Exclusion criteria

• Requiring adjuvant radiation therapy or androgen deprivation / androgen blockade post-operatively (by the time of enrollment)
• Baseline severe erectile dysfunction as measured by the IIEF-EFD
• Urethral complications from prostatectomy at the time of baseline visit including contrast extravasation, anastomotic dehiscence of vesicourethral anastomosis, need for re-doing of vesicourethral anastomosis intra-operatively