OvaScience, a Cambridge, Mass., company co-founded by Tilly in April 2011, will begin clinical trials this year of a treatment designed to increase the success rate of in vitro fertilization.
That treatment builds on Tilly’s patented discovery of egg stem cells in the ovary, which OvaScience has licensed as EggPCs. It involves extracting mitochondria—the biological material that powers cell functions—from an IVF candidate’s egg stem cells, and then injecting the mitochondria into her eggs during IVF to give the eggs a robust energy boost.
Tilly, who serves on OvaScience’s scientific advisory board, says there is strong research evidence that “bioenergetic potential” is an important factor in egg fertility and that this potential diminishes as eggs age.
The OvaScience approach builds on the outcome of a clinical trial conducted by a private IVF center some 14 years ago—a promising result that was derailed by ethical concerns.
The trial involved 28 couples who had experienced repeated in vitro failures. Each of the women underwent another round of IVF, but with a crucial addition: a minuscule amount of cell material taken from an egg donated by a young woman was injected into an older woman’s eggs.
Twelve of those couples—43 percent—had a successful pregnancy, says Tilly. But there was a hitch. That cell material in the donor eggs contained mitochondrial DNA—genetic coding from a nonparent introduced into a human egg at fertilization. The Food and Drug Administration decided that the treatment would open the door to genetic manipulation and placed a regulatory straitjacket on the procedure.
But, as Tilly notes, OvaScience would not run afoul of that ruling because the company would be using mitochondrial material taken from a mother’s own egg stem cells.
OvaScience, a publicly traded firm led by co-founder and CEO Michelle Dipp, has two other fertility treatments in its pipeline growing out of Tilly’s ongoing work.
One is designed to boost a woman’s egg reserve using her own egg stem cells, which, if successful, could also extend ovary life and theoretically delay menopause. The other seeks to create mature fertilizable eggs from a woman’s egg stem cells without the need for hormone injections.
All three treatments could also have an impact on genetic conditions that are highly correlated with aging eggs, such as Down syndrome.
“The hard work is over,” says Tilly. “We hope to have more answers over the next year or two but so far, so good. We haven’t hit a hurdle or roadblock yet that has changed our viewpoint on being able to deal with the fundamental issues of egg quantity and quality.”