A small pilot study shows that gene therapy might help men with erectile
dysfunction.
The gene in question
is dubbed hSlo (for the human slowpoke gene), which encodes a protein that
relaxes smooth muscle and allows blood flow into the penis, researchers report
in the medical journal Human Gene Therapy. In order for the gene to be
administered to patients, it is incorporated into a packet of DNA called a
plasmid.
The results of the
early-stage trial, lead investigator Dr. Arnold Melman told Reuters Health,
“suggest that the technology worked. We have shown that we could give a safe
vector, naked DNA, and the hSlo gene and obtain an expected physiological
response without transfer-related side effects.”
Melman, at
Montefiore Medical Center and Albert Einstein College of Medicine, the Bronx,
New York and colleagues studied 11 patients with erectile dysfunction, which was
associated with diabetes or cardiovascular disease in about half of the cases.
The subjects were given a single injection ranging from 500 to 7500 micrograms
of the hSlo plasmid into the corpus cavernosum of the penis and monitored for 24
weeks.
No serious adverse
effects were seen, and patients given the two highest doses had sustained
improvements in erectile function. One patient at each of these dosing levels
reported improvements that were highly clinically significant and were
maintained over the whole study period.
The researchers note that the goal of the study was to establish the
safety of the procedure and no conclusions about efficacy can be drawn, although
the results are highly encouraging. The “final proof will be obtained in the
larger placebo-controlled trials to follow,” Melman said.