Erectile Dysfunction Treatment May Be Safe With Maxi-K Gene

Maxi-K gene therapy may be a safe and effective future treatment for men whose erectile dysfunction (ED) is not treatable with oral therapy. Two studies presented today at the 103rd Annual Scientific Meeting of the American Urological Association (AUA) may give hope to these individuals. Researchers presented their findings to reporters in a special press conference on May 20, 2008 at 10 a.m.
Maxi-K therapy is a unique, locally administrated gene-transfer technology to treat erectile dysfunction (ED). The safety and the restorative effects of the treatment have been shown by data from participants in a phase I trial. In some men, the effect lasted up to six months. The gene therapy appears safe as no transfer-related adverse events were reported more than two years after the transfer in some subjects. Unlike conventional oral therapies for men with erectile dysfunction, Maxi-K therapy does not require prior planning, fosters sexual spontaneity and can be used by men taking heart medication.
Researchers not only provided follow-up to previous studies on Maxi-K therapy in men, but also explored whether increased erectile function enhanced other areas of sexual behavior. Male cynomulgus monkeys with erectile dysfunction were observed during their injection period and while in the presence of estrogen-implanted females. Researchers observed and measured the monkeys’ number of ejaculations, time to ejaculation, number of mounts, time to first mount, number of thrusts, number of sexual invitations by the female and number of erections achieved. Researchers observed dramatic changes after gene transfer, including increases in the number of partial and full erections and a two-fold increase in erection duration. An increase in intimacy was also seen. The data imply that increased erectile function per se may lead to increased sexual function.
“This study gives hope to men who experience erectile dysfunction but have not responded to oral therapies,” said Arnold Melman, M.D., one of the study’s authors. The importance of these observations in clinical and pre-clinical trials is that it appears that gene transfer with the Maxi-K channel enhances both erectile capacity as well as other important measures of sexual behavior.”
Researchers also presented updated data reaffirming that human patients being treated with hMaxi-K therapy for erectile dysfunction were not adversely affected. The trial, conducted with 11 men between the ages of 18 and 65 with moderate to severe erectile dysfunction who received previous unsuccessful treatment, concluded that direct, organ-targeted, naked DNA gene transfer with hMax-K produced no treatment-related adverse events and the treatment is not associated other diseases or conditions. These results open the door to further testing involving Maxi-K gene transfer and could lead to its effective use in providing erectile dysfunction treatment for human population.

Post-Prostatectomy Rehabilitation Improves Men's Natural Sexual Function

Men's Natural Sexual Function
This year doctors will diagnose nearly 219,000 men with prostate cancer. Many will undergo radical prostatectomy surgery. While radical prostatectomy provides an excellent cure, impotence (erectile dysfunction) is a common side effect. However early, postoperative penile rehabilitation can speed prostatectomy patients' healing, achieve natural erectile function and improve their quality of life.
Studies show that even 24 months after prostate cancer treatment sexual dysfunction was the most important quality of life issue. "Increasingly doctors are finding quality of life issues important in the overall treatment of any disease, including erectile dysfunction," said Dr. Skip Freedman, executive medical director for AllMed Healthcare Management.
Treating erectile dysfunction has changed over the last several years, and can offer men a confusing number of treatment choices. Today treatments can range from vacuum erectile devices, oral drugs and injection therapies to penile prostheses.
Working with postoperative patients, a doctor may choose either single or combined therapies based on a patient's rehabilitation need and lifestyle. "Starting penile rehabilitation early after a prostatectomy prevents tissue damage, or fibrosis, by oxygenating the cavernosa or erectile tissue," said Dr. Freedman.
Doctors commonly prescribe single oral therapies such as 5PDEI, or sildenafil (trade name Viagra). Studies of these drugs show early treatment with 50 to 100 milligrams a day (or every other day) improves sexual function and that higher doses produce better results. There's also a health benefit. Using sildenafil early preserves the smooth muscles in the penis. At 100 milligrams a day, 5PDEI increases the smooth muscle content of the cavernosa. With oral therapies, patients often will accept a lower degree of sexual satisfaction.
After post-radical prostatectomy, vacuum erectile devices (VEDs) or vacuum constriction devices (VCDs) aid earlier recurring erections while preserving the penile length and girth that heightens sexual satisfaction for men and their spouses.
Injecting vaso-active substances, such as alprostadil (Prostaglandin E1, or PGE1), increases blood flow and expands blood tissue vessels. Studies on intracavernous injections of PGE1 show it can prevent long-term postoperative damage by periodically increasing oxygenation of the spongy cavernosa tissue. Intraurethral PGE1 (MUSE, or Medicated Urethral Suppository for Erections) can promote the earlier return of spontaneous erections and sexual activity.
Intracavernous PGE1 or VCDs are best used during the first postoperative months, because they allow sexual activity to begin earlier and facilitate long-term healing. However, because of the postoperative nerve damage (neuropraxia), 5PDE1 medications are rarely successful in producing erections. In time, their efficacy improves, however.
Tri-mix, or Triple P, is a combined injection therapy using varying concentrations of PGE1, phentolamine and papaverine. It allows patients to inject lower doses of each and with less pain. Early low-dose Triple P can produce more effective erections than early low-dose PGE1.
Combining oral and injection therapies, such as using oral 5PDEI and intracavernous PGE1 can increase early sexual activity and improve natural erections. The oral addition of sildenafil with the injections allows a lower dose of PGE1 and decreases the patient's pain.
Today there are many treatment choices for men with postsurgical impotence. "Health insurers and re-insurers should consider their plan language, as well as the individual's need to decide on the medical necessity of penile rehabilitation therapy," said Dr. Freedman. "Insurers covering treatment for erectile dysfunction should also cover early penile rehabilitation, because after radical prostatectomy, all patients exhibit impotence."