Category Archives: George Cotsarelis

FGF-9, George Cotsarelis, PGD2

Dr. George Cotsarelis Updates Us

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Recently, one of the blog readers sent me an e-mail stating that Dr. George Cotsarelis replied to him. I then decided to resend Dr. Cotsarelis an old e-mail to which I previously got no response. My e-mail was fairly generic and I asked him about updates on various key areas of hair loss research that he might still be doing.

George Cotsarelis Responds

The below is his reply from yesterday, which might just be a generic response that he sends to everyone (since the above mentioned blog reader also received a similar response):

Thank you for your interest in my research. Rest assured that we are continuing our work on hair follicle stem cells and hair follicle regeneration in the hopes of better understanding hair growth and developing treatments for hair loss.

Re PGD2R antagonists, Kythera, recently bought by Allergan, will be working on commercialization of these compounds for treatment of male pattern baldness.

Re FGF9, a small biotech company has licensed that IP and will be pursuing its commercialization.

My lab continues to work on developing novel treatments. The largest barrier is funding.

Sincerely,
George Cotsarelis, M.D.

Note that “PGD2R antagonist” is sometimes referred to as “PGD2 antagonist”, but these two phrases are not the same thing as the “R” stands for receptor. Thanks to the commenter who corrected my initial sentence.

FGF-9 is an important growth factor with hair growth benefits. I have made several posts in the past on various other fibroblast growth factors such as FGF-2, FGF-5 and FGF-7. Also see this interesting recent study on FGF-9 and wounding.

The PGD2 treatment route is far more interesting than the FGF-9 treatment route. My conclusion from reading Dr. Cotsarelis’ e-mail is that its best we focus on Allergen (Kythera)’s future announcements. We should avoid contacting the busy Dr. Cotsarelis regularly for any new information.

Kythera Biopharmaceuticals, George Cotsarelis, Luis Garza, PGD2, Setipiprant

Setipiprant Global Rights Purchased by Kythera

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Update: October 2021 — Unfortunately, the clinical trials of Setipiprant for androgenetic alopecia saw no hair growth benefits. The trials were conducted by AbbVie (US), which purchased Allergan in 2020.

Kythera audio interview with founder and CEO Keith Leonard regarding Setipiprant. Plus the company’s recent history of hair loss research is now out. Excellent stuff.

Setipiprant Rights Purchased by Kythera (now Allergan)

A thus far barren February when it comes to significant hair loss research developments suddenly changed drastically today. It was announced that Kythera Biopharmaceuticals (US) has purchased global rights to Setipiprant, a clinical-stage oral antagonist to the prostaglandin D2 (PGD2) receptor.

The shareholder presentation on this is a must read. Rights were purchased via licensing agreements with Actelion Pharmaceuticals (Switzerland) and the University of Pennsylvania. A good summary is here, with a very encouraging quote from Kythera’s Chief Medical Officer:

Setipiprant is believed to directly affect this hair loss pathway, and our own preclinical and in vitro human hair models confirmed this effect. It is a well-characterized molecule with a large safety database and we believe we can quickly initiate a development program to study it in hair loss.

Setipiprant Trials

According to the investor presentation, Setipiprant has already undergone 8 clinical trials, including:

  • A Phase III study in seasonal allergic rhinitis patients.
  • A Phase IIB proof of concept study in asthma patients.
  • A safety database of over 1,000 subjects.

One other item in the investor presentation that I found shocking (in a very good way) was that Actelion owns 45 patents that were granted for molecules that inhibit PGD2. So Setipiprant is just one molecule of perhaps dozens or even hundreds that can inhibit PGD2.

There must be other companies that also have patents to proprietary PGD2 antagonist molecules. I wonder if they can introduce their products into the hair loss market in future if they do not have licensing agreements with the University of Pennsylvania?

PGD2

PGD2 has been in the news a lot in the hair loss world during the past several years. This is in large part due to Dr. Luis Garza’s work and excellent publicly available 2014 paper on the subject. And also due to the past work of Dr. George Cotsarelis and his team at the University of Pennsylvania.

Both Cotsarelis and Garza were part of a large group of authors of an important 2012 paper which concluded that PGD2 inhibits hair growth and was elevated on the scalps of balding men. Together, these two men are also considered to be co-inventors/co-founders of this PGD2-receptor pathway that inhibits hair growth. The patent for this technology is owned by the University of Pennsylvania, hence their involvement in this current transaction.

It seems like the PGD2-GPR44 pathway (PGD2 binds to the GPR44 receptor) is responsible for hair growth inhibition, and any drug to regrow hair will target GPR44. More significantly, PGD2 is also involved in asthma, allergies and related medical disorders. In fact a number of drugs targeting PGD2 are already in advanced clinical trials or even on the market, so there should already be a good deal of safety information on this type of product.

I found seven studies on Setipiprant on Pubmed as of today. Also, some popular media articles from 2012 on PGD2 and a hair loss cure are worth a reread: Dailymail,  The Telegraph and NY Times. Unfortunately we are still not close to getting a topical lotion cure, since Setipiprant is an oral medication.

For the neglected female readers of this blog, it seems like there is a very good chance that this same drug could also cure female pattern hair loss. PGD2 appears to curtail hair growth in both men and women.

Finally, a bit about Los Angeles area based publicly traded Kythera from their website. Where else would one expect a biopharma company to focus on eliminating double chins?

Our product candidate, ATX-101, is a potential first-in-class, injectable drug currently in late-stage clinical development for the reduction of submental fat, which commonly presents as an undesirable “double chin.” We maintain an active research interest in hair and fat biology, pigmentation modulation and facial contouring.