Christian Kramme

Christian Kramme’s first project when he started at a Harvard Medical School lab in 2018 was definitely way out there: using genetic engineering to turn skin cells into human eggs. But functional human eggs are hard to make–no one has done it yet. And, he worried, lab-made eggs might be too controversial to ever use.

So Kramme, 29, pivoted to making other cells in the ovarian follicle, the kind that support the egg maturation by releasing hormones. These cells were easier to produce, and today Kramme is chief scientific officer at Gameto, a spin-out from Harvard racing forward to develop new applications of these cells.

Its first idea is to help IVF patients. Gameto is already testing a product in which a patient’s own eggs are matured, or ripened, by putting them inside an “artificial ovary”–in reality, just a droplet of water where the eggs come into contact with the lab-made ovary cells, which help orchestrate the eggs’ development. Fully maturing eggs in the lab, rather than a person’s body, means the IVF process requires fewer shots of hormones, and less stress for the patient.  

Kramme has a next product in mind. This year Gameto won $10 million from a US women’s health program to try to use its lab-made ovary cells to treat menopause. The goal is to create a biocompatible implant containing tens of millions of the cells. Once placed under a person’s skin, this artificial ovary would churn out hormones like estradiol and progesterone for years, creating a long-lasting alternative to hormone replacement therapy.

The first IVF birth using Gameto’s technique occurred in December 2024, in Peru, and since then the company has won a green light to perform a large-scale study in US fertility clinics, which started this summer. “Seeing a woman take my treatment for the first time, get pregnant, and have a baby... That was the coolest thing I have ever done,” says Kramme.