Prolactin Receptor Inhibition for Hair Loss: A New Frontier in Hair Regrowth
Clinical Summary
Prolactin Receptor Inhibition: An Emerging Approach for Hair Regrowth
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Prolactin receptor (PRLR) inhibition, hair loss: Hair follicles express prolactin receptors; blocking this pathway may convert non-growing hairs into growing hairs. An AI-developed prolactin receptor–blocking therapy showed hair growth in rodent studies and subsequently in macaque monkeys with male- and female-pattern hair loss.
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Clinical development: Human studies are ongoing in Australia and planned in the United States. The treatment is administered by injection, with a proposed regimen of approximately 3–4 injections, potentially providing benefit across a scalp growth cycle lasting about 1 year.
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Safety and future applications: Reported safety findings to date have been favorable, with inhibition of lactation noted as an expected effect. The therapy may eventually be used alongside emerging approaches such as exosomes and extended-release oral minoxidil, with potential applications in androgenetic alopecia and possibly alopecia areata.
Reviewed by Jessica Garlewicz, Managing Digital Editor of Immunology Group
Dr David Goldberg discusses emerging prolactin receptor–targeted therapies for androgenetic alopecia and other hair disorders. Learn how blocking prolactin signaling may stimulate hair growth through a novel mechanism distinct from minoxidil and antiandrogens, and explore early data on efficacy, durability, safety, and the future role of PRLR inhibition in hair restoration.
Transcript
I'm Dr David Goldberg. I am the director of Clinical Research and Cosmetic Dermatology for the national private equity-based dermatology group, Schweiger Dermatology Group. I am also a clinical professor of dermatology at the Icahn School of Medicine at Mount Sinai in New York.
What is the role of prolactin and its receptor in the hair cycle, and how does inhibiting this pathway differ from current hair loss treatments?
Dr Goldberg: So the notion that prolactin plays any role in hair is mind-boggling. You know, prolactin is the hormone of lactation. It's what women need to breastfeed. Well, it turns out that there are prolactin receptors on hair follicles. And so if you can block those receptors, you may be able to convert non-growing hairs into growing hairs. And so there's a technology which is based on artificial intelligence that developed this block for the prolactin receptor on hair.
The initial studies were done in rodents, and the rodents grew hair. Then the macaque monkeys were the next study. People know the macaque monkeys because of punch. That's the macaque monkey in Japan. And they have hair loss patterns both in males and females just like humans. They were then given this drug. They all grew hair. Current studies are now being done in humans in Australia and soon in the United States. And it turns out they're growing hair.
And the great thing about this particular treatment is it's kind of like the GLP-1s; it's done by injection, but not as commonly as GLP-1s. GLP-1s, people inject themselves every week. This will be a series of 3-4 injections. And then the growth cycle in the scalp could be a year. And so they're not going to need them very often.
And then looking at side effect profile, it is true. You can't lactate when you're on this particular medication because it's going to inhibit prolactin. Otherwise, everything else has been perfectly safe. So this is an exciting new area. It's not available yet. Studies are going on, but watch out.
Based on emerging data, what potential advantages does prolactin receptor inhibition offer in terms of efficacy, durability, or mechanism compared to existing therapies like minoxidil or antiandrogens?
Dr Goldberg: So the hair improvement market is expanding and probably going to expand with multiple different agents. What we've learned over the last several years is that topically applied exosomes can lead to hair growth. We are currently involved in the FDA trials for an extended release, higher dosage of oral minoxidil. That seems to be leading to improvement. Again, it's not available yet.
And then there's now this prolactin antibody, receptor antibody. I think they're all going to be used together. And what's going to happen is people with either male or female hair who want to grow hair are going to be able to grow hair. You can be like me. I mean, I seem to get away with this buzz cut. But not everybody wants that. Certainly younger people don't want that.
And then we're also going to be looking at other forms of hair loss, alopecia areata. What roles do these play? But one thing is clear. You're going to see over the next two to three years that treatments for hair loss are going to be expanding.
What should clinicians know today about the safety profile and future clinical applications of PRLR-targeted therapies for patients with androgenetic alopecia or other hair disorders?
Dr Goldberg: So you never know for sure what's going to happen at the end of an FDA trial. So, you know, we're early on. But thus far, the safety profile of this drug has been fantastic. And so if it works as well in humans as it did in the monkeys, and monkeys are different than us but not that different, then we've got a great drug ahead of us.
