Aug. 16, 2012 -- The promise of a safe and effective birth control pill for men has long eluded scientists, but a new approach could change that.
Researchers have identified a small molecule compound that inhibits sperm production, and they say it could lead to the first non-hormonal, easily reversible male contraceptive since the introduction of the condom centuries ago.
So far, it's only been tested in mice. In early studies, mice treated with the molecule had lower sperm counts than untreated mice, and their sperm were slower swimmers.
The treatment effectively rendered the mice infertile without affecting their desire to mate, says researcher James Bradner, MD, of the Dana-Farber Cancer Institute.
And sperm counts rebounded quickly once the treatment was stopped.
The next step, Bradner says, is to develop a more selective version of the molecule that could be safely used in human males.
“It will take some creative chemistry to make this happen, but I think we are up to the challenge,” Bradner says.
Research to develop a birth control pill for men has largely focused on manipulating male sex hormones, but this approach has proven challenging, says William J. Bremner, MD, PhD, of the University of Washington School of Medicine.
One major challenge has been the presence of a sperm-testis barrier, which prevents larger molecules from reaching the site where sperm production occurs.
The small molecule compound developed in the Dana-Farber lab, known as JQ1, easily crosses this barrier.
JQ1 targets a testes-specific protein called BRDT that is critical for sperm production.
‘Non-Hormonal Male Pill Years Away’
The compound was developed as a potential new treatment for cancer. Besides BRDT, it also targets another protein associated with tumor growth.
Trials in cancer patients will soon be under way, and Bradner says they could provide some early clues about whether or not the approach will work as a male contraceptive.