Good question. Not sure, but it seems like she’s dropped this line of research. Maybe she determined that it was likely to take too much tweaking of the culture to turn enough of the hair inductive genes on.
The JAK inhibitors actually look a lot more promising. A few things we know about JAK inhibitors from previous work:
Taken orally (pill form) they are known to often regrow all lost hair in people with Alopecia Areata. But when people with Alopecia Areata who also have some MPB regrow their hair this way, they only regrow the hair lost due to the Areata, not the MPB.
Dr. Christiano says that if it’s turned into a topical, that would greatly increase the local absorption in the skin, which would increase the concentration around balding follicles. She believes this would regrow hair lost due to MPB. (She believes that the reason the pills don’t help people with MPB is that the concentration in the skin when taken in oral form isn’t high enough.) I don’t know how she knows this but maybe they have some limited insight from human testing (although, as we know, clinical trials for hair loss have not begun yet.)
What we know about JAK inhibitors chemically is that the molecules have a very short half-life in the human body. So, taking them in pill form, most of the molecule would be broken down before it could build up to sufficiently high concentrations in the skin where the hair follicles are located.
Probably this indicates the best means of delivery will be a topical cream or lotion, and it may mean that you’d have to apply it twice a day like Minoxidil to keep scalp concentration high enough. You’d also start losing hair again if you stopped using it and also stopped any other maintenance drugs.
Good news is that JAK inhibitors are thought to be safe.