“We are excited about this treatment, because we think this has the potential to slow the disease progression,” said Steve Rose, chief research officer of the Foundation Fighting Blindness, a nonprofit that invested about $2 million in early animal testing of the treatment, but is no longer directly involved. “This company has had their ups and downs, and I am really happy to see they got into the clinic. We’ve had our fingers crossed.”
During a recent visit to Advanced Cell’s laboratories, a research technician adjusted a microscope to show off the company’s lead product: cube-shaped retinal pigment epithelial cells growing in a petri dish. Some were translucent, while others already had the brownish coloring of a mature cell. (The pigment absorbs stray light in the eye, acting as a kind of glare shield.)
These retinal cells are the type that are killed off in macular degeneration, eventually leading to the death of photoreceptors, and the gradual loss of central vision. Advanced Cell believes that injecting new, lab-grown cells into the eye may cure the condition.
Embryonic stem cells can grow into any other type of human tissue. That’s why they have been touted as a potential cure for everything from Alzheimer’s disease to alopecia. But the reality is that applications are likely to be far more limited, at least in the near term, Lanza believes.
It’s no accident, for instance, that both early studies of embryonic stem-cell therapies—those of Geron and Advanced Cell—involved cells of the nervous system. The reason is that embryonic stem cells naturally want to make neuroectoderm, a cell lineage in the embryo that forms the nervous system.
“Embryonic stem cells have a mind of their own, and they want to do certain things,” says Lanza. Efforts to produce other cell types, such as liver cells, have proved far more difficult, he says.
Another obstacle not always fully considered is immune rejection. Many have suggested that embryonic stem cells could cure type 1 diabetes if researchers could transplant lab-grown islet cells. But such a treatment could require powerful immune suppressing drugs whose side effects, such as infection and cancer, can be as bad as the disease they are meant to treat, or worse.
Lanza says that is why all the early embryonic stem-cell trials are targeting body areas such as the spine, brain, and parts of the eye, where the body’s defenses against invaders are blocked, at least partially, in a phenomenon known as immune privilege. “Nature has got to cooperate,” says Lanza. “That is why a lot of companies went out of business, and we didn’t.”