Geron made medical history last October, when it treated subject number one in the first-ever trial of a human embryonic stem cell (hESC) therapy, for spinal cord injury.
Now, the second and third hESC trials have been launched. On July 12, in an operating room at the University of California, Los Angeles, the first subject in each of the trials — one for a rare form of blindness that usually begins in childhood, the other for a common cause of blindness in the elderly — was treated with retinal pigment epithelial (RPE) cells derived from hESCs. Details are available in this press release from the sponsoring company, Advanced Cell Technology, based in Santa Monica.
The surgery was performed by Steven Schwartz, the study’s principal investigator and retina division chief at UCLA’s Jules Stein Eye Institute, who is pictured above in the process of transplanting the cells into one of the patients on Tuesday.
The trials, each of which aims to enroll 12 patients, will assess over the course of one year the safety and tolerability of ascending dosages of the cells. The first two patients received what are considered small doses — 50,000 cells each — transplanted into the tissue directly under their retinas.
“Early indications are that the patients tolerated the surgical procedures well,” Schwartz said in the press release.
The company’s therapy uses hESCs to recreate RPE cells, which support the photoreceptors needed for vision. It has shown promise in rat and mouse models of degenerative disease of the macula, a three-to five millimeter area that is responsible for central (as opposed to peripheral) vision. It also contains the fovea, the high-acuity hot spot of the retina. Abstracts of the relevant papers are here and here.
One of the conditions being treated, Stargardt’s Macular Dystrophy, it is a degenerative disease of the retina that affects roughly 1 in 10,000 US youngsters. The other, a closely related cause of blindness, Age-related Macular Degeneration (AMD), affects millions of Americans. (The trial therapy is attacking “dry” AMD, which account for about 90% of all AMD.)
To date, the US Food and Drug Administration has approved only these three hESC trials. For a profile of the first subject in the Geron trial, an Alabama man in his early twenties, see this article from The Washington Post.