The cure for baldness may be already here — for some people at least.

Columbia University Medical Center (CUMC) researchers published the results of a promising pilot trial in the Journal of Clinical Investigation/Insight this September. Twelve patients with moderate to severe baldness caused by alopecia areata (AA), an autoimmune disorder where the person’s own cells attack their hair follicles, were given the JAK inhibitor ruxolitinib. As with earlier animal and small human studies, the drug proved to be almost miraculous in its hair-raising powers. Seventy-five percent of patients gained more than 90 percent of their lost hair back during the 3 to 6 months of treatment with the drug.

“Although our study was small, it provides crucial evidence that JAK inhibitors may constitute the first effective treatment for people with alopecia areata,” said the study's lead author Dr. Julian Mackay-Wiggan, an associate professor and director of the clinical research unit in dermatology at CUMC as well as a dermatologist at New York-Presbyterian/Columbia, in a statement. “This is encouraging news for patients who are coping with the physical and emotional effects of this disfiguring autoimmune disease.”

Encouraging as the results are, there are several substantial caveats to make clear. For one, the “cure” was often temporary. Once people went off the drug, a third began to lose hair again, though not to the same degree as before. In a related study of another JAK inhibitor, tofacitinib, also published in the Journal of Clinical Investigation/Insight this month, the drug was less successful both during and after the trial. Out of 66 subjects with various degrees of AA, including some who lost all hair along their bodies, 32 percent experienced 50 percent or greater improvement from the disease during treatment. But after 8.5 weeks off the drug, everyone had begun to lose some hair.

“Our findings suggest that initial treatment induces a high rate of disease remissions in patients with moderate to severe alopecia areata but maintenance therapy may be needed,” Mackay-Wiggan said.

And while both drugs were tolerated safely by patients with no severe side-effects, they did come with some milder ones. Namely, they weakened the immune system and made people more likely to become sick.

Unfortunately, the biggest sticking point to these treatments is that they may not do anything for the majority of hair loss sufferers. As mentioned earlier, AA is an autoimmune disorder, which means the mechanism that causes baldness happens in these people is different than what causes the most common kind of baldness — androgenic alopecia, or male and female pattern baldness. Despite the risk of hair loss post-treatment, though, it would certainly be a great boon to the approximately four million people in America currently suffering from AA.

Along with finding ways to identify early on who will or won’t respond to the treatment, Mackay-Wiggan and her colleagues do plan to test out JAX inhibitors against androgenic alopecia as well as other hair loss conditions in the near future.

“We expect JAK inhibitors to have widespread utility across many forms of hair loss based on their mechanism of action in both the hair follicle and immune cells,” said co-author Dr .Angela M. Christiano, a professor of genetics and development and dermatology at Columbia.

A relatively new class of drugs, JAK inhibitors have already been approved to treat bone marrow cancers and rheumatoid arthritis. Time will tell if they may also someday lead to the end of hair loss.

Source: Mackay-Wiggan J, Jabbari A, Nguyen N, et al. Oral ruxolitinib induces hair regrowth in patients with moderate-to-severe alopecia areata. Journal of Clinical Investigation/Insight. 2016.