Recently a company called Eirion Therapeutics came out with a press release that they had found a breakthrough treatment for hair loss. This treatment was named ET-02. However as many of you will know, novel treatments for hair loss are very common so what makes ET-02 different?

The mechanism of action for ET-02 in hair growth is not completely clear. However, it appears to be related to ET-02’s ability to inhibit PAI-1, a protein involved in blood clotting. 

Elevated levels of PAI-1 may play a role in the development of obesity, tumor formation, cancer, and cell aging (cell senescence). Blocking PAI-1 may have anti-aging effects that could restore a more youthful hair growth pattern.

One rodent study provided some insight into the link between PAI-1 and hair growth. Mice given the human PAI-1 gene using gene editing produced high levels of human PAI-1 in their blood and subsequently failed to grow hair. This suggests that increasing PAI-1 can cause hair loss and, conversely, that lowering PAI-1 levels or blocking PAI-1 could induce hair growth.

Because of all this theoretical work Eirion Therapeutics decided to investigate how ET-02, a PAI-1 inhibitor, would help treat hair loss. Accordingly, ET-02 at a 5% concentration leads to a 6 FOLD INCREASE in non-vellus hair count compared to the placebo group. This outperformed the results of Minoxidil after 4 months – within one month. 

HOWEVER, people in the know in the hairloss community were justifiably skeptical of this article. The reason being the company only reported a 6 fold increase in hair growth but didn’t report the actual number – meaning this could just be a sensationalist report whereby the haircount in the area was 1 and then after treatment was 6.

To investigate further I looked into the clinical studies on Minoxidil to figure out how much hair exactly was grown. The press release refers to a 4 month duration period, and “(N=180)” which for those who don’t know represents the number of patients at this measurement point. After reviewing many papers I found one titled “A multicenter, randomized, placebo-controlled, double-blind clinical trial of a novel formulation of 5% minoxidil topical foam versus placebo in the treatment of androgenetic alopecia in men” which met this criteria.

Here we can see that ; after 16 weeks on 5% minoxidil topical foam (MTF), there was a mean increase in non-vellus hair count of 20.9 compared to baseline. In comparison, the placebo group had a mean increase of 4.7 non-vellus hairs. Which means there was a placebo-adjusted increase of 16.2 for the 180 patients in this minoxidil trial.

Logic would dictate that at the bare minimum, ET-02 lead to an improvement in hair count from 2.7 to 16.2 when adjusted for placebo. That is still some of the best results we’ve ever seen.

Clearly, from everything we know about ET-02 it is efficacious, as well as assuring reports of it being safe and well tolerated. However Eirion incorrectly states, “ET-02 has the potential to be significantly more effective than existing treatments since it directly addresses what Eirion believes is the fundamental cause of androgenic alopecia”. As you know Androgenetic Alopecia, the most common type of alopecia, is caused by androgens (specifically DHT) binding to the androgen receptor and signaling the eventual death of the hair follicle.

As far as we can tell ET-02 hair growth promoting pathways are completely distinct to the hormonal pathways which are actually causing hair loss in men to begin with. This is not necessarily a bad thing either, because we already have Finasteride/Dutasteride which are capable of addressing this hormonal pathway, so using a more efficacious hair growth stimulant which works through a separate pathway may help improve the results of guys trying to treat their hair loss.

Additionally, since it has such a distinct pathway it could be stacked on top of existing treatments such as Minoxidil, 5 Alpha Reductase Inhibitors, and topical antiandrogens.

Overall the study is high quality, the results are some of the most promising ive ever seen, but this is only a phase 1 clinical trial I believe so we need to wait and see how it unfolds. 

Link to reading the full article:

https://www.prnewswire.com/news-releases/eirion-therapeutics-announces-potential-breakthrough-treatment-for-hair-loss-based-on-first-in-man-clinical-trial-results-302344730.html

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Eren M, Gleaves LA, Atkinson JB, King LE, Declerck PJ, Vaughan DE. Reactive site-dependent phenotypic alterations in plasminogen activator inhibitor-1 transgenic mice. J Thromb Haemost. 2007 Jul;5(7):1500-8. doi: 10.1111/j.1538-7836.2007.02587.x. Epub 2007 Apr 16. PMID: 17439629.

Olsen EA, Whiting D, Bergfeld W, Miller J, Hordinsky M, Wanser R, Zhang P, Kohut B. A multicenter, randomized, placebo-controlled, double-blind clinical trial of a novel formulation of 5% minoxidil topical foam versus placebo in the treatment of androgenetic alopecia in men. J Am Acad Dermatol. 2007 Nov;57(5):767-74. doi: 10.1016/j.jaad.2007.04.012. Epub 2007 Aug 29. PMID: 17761356.