In a proof-of-concept study performed in primates, frozen immature testicular tissue has been successfully used for the conception and birth of a baby monkey. Although human trials are needed before the technique can be approved for people, the study’s results point to potential options for preserving fertility among prepubescent boys being treated for cancer. "Showing that something works in nonhuman primates is the last and critical step to demonstrate safety and feasibility,” said Kyle Orwig, Ph.D., of the University of Pittsburgh School of Medicine, who led the study. "This is now a very mature technology, and I believe it's ready to go into human trials." Early human studies would take some years to implement fully, but such clinical trials now appear feasible, explained David R. Freyer, D.O, MS, director of the Survivorship and Supportive Care Program at Children's Hospital Los Angeles, who was not involved in the study. “This is exciting and opens up the possibility of fertility preservation to a new subset of males, namely those who are prepubertal,” Dr. Freyer said.