What’s Next for ET-02? CEO of Eirion, Jon Edelson, MD, Shares Phase 2 Plans

Eirion Therapeutics recently announced its pharmaceutical, small molecule topical ET-02 will be advancing to a phase 2 study for androgenic alopecia after its successful first-in-man clinical trial. The 5% dosage showed a 6-fold increase in non-vellus hair count after just 5 weeks.

CEO and President of Eirion, Jon Edelson, MD, spoke with Dermatology Times and discussed how the treatment showed significant promise in reactivating hair follicle stem cells and stimulating normal, non-vellus hair growth as they transition to extended phase 2 applications.

Edelson: I'm Jon Edelson. I'm the chairman, CEO, and President of Eirion Therapeutics and its founder.

Dermatology Times: What specific proof of mechanism was demonstrated in phase 1? How do these findings support the progression to phase 2?

Edelson: As we looked at the target and the mechanism of action, we actually did extensive preclinical studies that demonstrated we were able to address the issue in the stem cell biology, and we were able to take inactivated hair follicle stem cells and reactivate them to normal function. We further demonstrated this in a study we did with human scalp graphs that were implanted in mice that could accept these graphs. Once they were implanted, we could actually treat the mice, and hence the scalp graphs, to see what would happen. And we had a control arm in the study, and we studied it topically, and what we saw was that there was a remarkable amount of hair growth in the group that got the 5% ET-02 versus the control group. But more than just hair growth, when we looked at the type of hair being grown, it was, again, the normal non-vellus type that was important to people who have hair loss. And we also saw that when we looked at this histologically, at a molecular level, all the abnormalities that are present in androgenic alopecia and were observed in the control group had actually been corrected. And so, all of the hair that was being grown was the normal sort of hair that you want to see. And we also saw that at a molecular level, markers for things like cellular growth, Ki-67 to be technical,were actually elevated, as you would like them to be, in normally growing hair, but depressed in the control group, which you actually see in androgenic alopecia. So we believe there's actually quite a bit of data that suggests we've engaged the target and are getting the response. The phase 1 study was really all about trying to confirm what we already saw in the human scalp tissue from the people in that graph study. And so, these people who donated their graphs are the exact same people, or type of people, you'd have in our human first-in-man study. And so we wanted to just see; could we demonstrate this sort of hair growth and good hair growth, non-vellus hair growth that we saw there? And I'm very pleased to say that in what is, I think, a very brief study in the field of androgenic alopecia, we were able to demonstrate that. Typical studies for androgenic alopecia last for 4 months, many usually up to 6 months. And so, for us to see this type of response in just 1 month of treatment was extraordinary. And now we're, of course, very excited to take this to the next level, to a phase 2 study where we will actually study this for 6 months. And again, based on the pre-clinical studies where we treated for 4 months, we saw continued growth over the entire 4 months, and in fact, it was on a trajectory to continue to grow at the end of this study. So we believe, as good as we saw results in 1 month, we think we'll see even more remarkable results over the 6 months of treatment.

Dermatology Times: What might be some anticipated challenges or limitations in phase 2 evaluations? How do you plan to address or overcome these?

Edelson: I'm very happy to say that based on the first-in-man study, we don't really see challenges in the phase 2. I mean, the 2 things one thinks about are signals for safety and signals for efficacy. The signals we saw in this study are very strong and so, we expect and hope that they'll be validated in the phase 2 study. I would say the things that are on our mind, less than challenges per se, are strategic decisions about how to study this promising opportunity further. One of the things that we certainly want to do is look at the potential efficacy of this in women. We had only men in this study, and we believe, based on the mechanism of action, that this could be very effective in women. But of course, we need to demonstrate that. So one of the strategic questions is, do we include women in this next study, or do we have a separate study dedicated to their treatment? The other thing that's on our mind strategically is thinking about the potential treatment of hair graying. And while this study was focused on hair loss and androgenic alopecia, we believe that there's a very similar mechanism of aging involved in why people develop gray hair. Instead of the hair follicle stem cell, we believe it's the melanocyte stem cell that's involved. That's the one that creates color in the hair, and we believe that there's the potential to correct the stem cell biology for that using the drug. So we hope in the future to actually have a separate study looking at the safety and efficacy of treating graying hair, and again, based on the mechanism of action, we think there's the potential. And of course, we look forward to our future studies and hopefully some exciting further clinical news for dermatologists everywhere.

[Transcript has been edited for clarity.]