A single intrapenile injection of fat-derived stem cells harvested through abdominal liposuction can restore erectile function to a degree sufficient for intercourse, according to a first-in-human study.
And the effects were durable. The men, all of whom experienced erectile dysfunction after radical prostatectomy, reported intercourse when assessed 6 and 12 months after the injection.
"We conclude that stem cells can significantly improve erectile function in continent men," said Martha Haahr, MD, from Odense University Hospital in Denmark.
"Stem cells represent a novel intervention therapy for radical prostatectomy," she said here at the European Association of Urology 2017 Congress.
The primary goal of the uncontrolled study was safety, not efficacy, however, and it remains to be seen whether the results will hold up in larger, randomized studies, Dr Haahr acknowledged.
Conventional Therapies Failed
Dr Haahr and her colleagues assessed 21 men who underwent radical prostatectomy at their center and were then unable to have satisfactory erections despite treatment with either a phosphodiesterase-5 (PDE-5) inhibitor, such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra), or a prostaglandin E1 analog (alprostadil).
The investigators harvested adipose tissue using water-jet-assisted liposuction, and extracted 5 mL of adipose-derived regenerative cells. They delivered freshly harvested cells to the corpus cavernosum in a single 4 mL injection; they reserved the remaining 1 mL for cell characterization.
Erectile function was assessed with the five-item International Index of Erectile Function and the Erection Hardness Score during follow-up visits 1, 3, 6, and 12 months after injection.
The treatment was not effective for the six men with urinary incontinence at the time of study enrollment. For the other 15 men, eight (53%) recovered erectile function and could start sexual intercourse 6 months after injection, and the effect lasted up to 12 months.
Incontinent men might be more likely to have severe nerve damage than men who retain urinary control, Dr Haahr explained. And they might have had more pressing concerns than erectile function.
"The damage is greater in incontinent men, and their focus is the incontinence. They don't feel sexy, they don't feel attractive. It's like incontinence is a heavier burden than the erectile dysfunction," she told Medscape Medical News. "Some of the men were not even able to have any sexual thoughts because their incontinence was so severe."
Overall, mean erectile function score 1 month after injection was 6.95, indicating severe erectile dysfunction, and was unchanged from baseline. However, at 6 months, mean score increased to 11.71, indicating moderate dysfunction (P = .0003), and that was sustained at 12 months, when the mean score was 11.52 (P = .0003).
For the 15 continent men, the mean score was 7.60 at 1 month, indicating severe erectile dysfunction, and was unchanged from baseline. This increased to a mean of 14.30 at 6 months (P < .0001) and was sustained at 12.13 at 12 months (P = .001). Both the 6- and 12-month scores indicate mild to moderate erectile dysfunction.
The procedure was generally safe, and no serious adverse events were reported. The eight minor events that occurred were all related to liposuction (hematoma and abdominal skin sensitivity).
The kit used to separate the stem cells from the fat costs approximately €500 (US$545), and the liposuction kit costs in the range of €200 to €300 (US$217 to US$326), Dr Haahr reported.
Feasible, But Does it Work?
This is "feasible to the extent that there were no considerable side effects, and it's certainly a situation — erectile dysfunction after radical prostatectomy — where we need new treatment," said session comoderator Mikkel Fode, MD, PhD, from Herlev Hospital in Denmark.
"But the study doesn't have a control group, and there is regeneration of erectile function after prostatectomy even without treatment, so we really need more studies with control groups to know if this is working," he told Medscape Medical News. "The study shows that we can do it but, unfortunately, does not show us yet if it works."
This study was funded by Odense University Hospital, the Danish Centre for Regenerative Medicine, and the Danish Cancer Society. Dr Haahr and Dr Fode have disclosed no relevant financial relationships.
European Association of Urology (EAU) 2017 Congress: Abstract 368. Presented March 25, 2017.