A Male Pill, Maybe

Some developments on the male birth control pill R&D front:

A Norwegian company seeking to develop a male birth control pill has signed a licensing agreement with the University of Massachusetts Medical School covering research that could lead to a drug to block sperm's ability to swim and fertilize an egg.

The method that led to the long-term deal announced Monday could expand the decades-long search for a male pill by targeting a protein found only in sperm cells.

Researchers at the University of Massachusetts in Worcester and elsewhere say that approach carries far less risk of side effects than manipulating a man's hormones, the avenue that has attracted the most research aimed at finding alternatives to condoms and vasectomies.

...

Such a drug potentially could take the form of a pill, implant, patch or gel, and take as long as a decade to develop, [Dr.] De Paolo said.

Here's some background on the type of research mentioned in the article:

In studies on mice, disrupting a gene that contains a putative calcium-permeable ion channel - identified in earlier research as CatSper2 - did not change normal sperm cell production or basic sperm motility, or movement. It did, however, prevent the appearance of a stimulated form of sperm motility, called hyperactivation, normally seen near the time of fertilization. Sperm cells were, thus, incapable of generating the power needed to penetrate an egg cell's extracellular matrix, or outer shell, which is necessary for fertilization.

"Basically this protein or ion channel plays a critical role in sperm cell hyperactivation, which is essential for fertilization," said Dr. Timothy Quill.... "The same protein exists in human sperm cells, so it is likely that disruption of CatSper2 would result in infertility in men as well. If a contraceptive drug could be designed that would bind to the protein and block its function, then those sperm cells would be rendered ineffective or infertile."

Such an ion channel-blocking contraceptive would likely be fast acting, Dr. Quill said. It also could have fewer side effects than other available contraceptives, as it would target a protein found only in sperm cells.

"Blocking the protein's activity would not cause defects in the development of the sperm cell, but only prevent hyperactivation," he said. "This discovery could serve as one of the next steps in the process of creating a new type of contraceptive that would offer less risk and perform faster."