Protein gel offers hope to childless

A pre-intercourse gel derived from a protein found in sperm could prove the key to fertility for thousands of childless couples.

A $6 million collaborative research agreement between Adelaide University's Reproductive Medicine Unit, growth factor company GroPep (ASX: GRO) and OSI Pharmaceuticals in the United States is working on an infertility treatment for women whose bodies reject sperm as foreign.

It is estimated about 25 per cent of all infertility is caused because the female partner's immune system shuns the protein in sperm.

But research leader and NHMRC fellow Dr Sarah Robertson has discovered that a protein called transforming growth factor beta moderates that immune response.

"In fertile couples, this protein helps induce tolerance naturally at insemination, but disruption in this response seems likely to account for a significant proportion of human infertility and pregnancy problems such as recurrent miscarriage," Robertson said.

"Our findings have substantial ramifications in fertility treatment and diagnosis in humans, as well as in animal husbandry."

She said her group was currently finalising the pre-clinical trial results and hoped to commence Phase I tests in early 2003 on women who had suffered recurrent miscarriage.

Robertson said that while the clinical studies would initially focus on recurrent miscarriage patients, the treatment was also expected to be useful for other forms of infertility and in women who had suffered or were at risk of pre-eclampsia.

She said that as well as assisting natural intercourse, the new treatment could also help the 50 per cent of couples for whom IVF failed when embryos failed to implant.

"We have got a lot of animal data to show it works and we are just beginning to work in humans," she said.

While the phase I trial would focus on safety, Robertson said the next step would be to show that using the gel in the cervix could cause changes in the immune system associated with better reproductive rates.

She then hoped to show implantation rates could also be improved with the treatment.

"This form of new therapy is going to be the front-runner of a whole new way of treating infertility with an immunological approach," Robertson said. "It is likely to be the vanguard of a whole series of new products."

The recombinant protein for the trial will be sourced from OSI Pharmaceuticals, which has granted GroPep the global rights to use transforming growth factor beta as a drug for use in infertility.

Robertson said it was hoped a product would be on the market in four to five years.