Category Archives: Topical Antiandrogen


Due to the numerous news items, conferences and other hair loss research related developments in recent months, I have had to delay covering an important product until today. This product, as evident from the title of this post, is CB-03-01 (Edit: now known as Breezula). It is a topical anti-androgen type molecule that is as yet not approved for sale and is still undergoing clinical trials.


CB-03-01 is manufactured by Italy-based Cassiopea (Edit: acquired by Cosmo Pharmaceuticals in 2021), a company that is primarily focused on treating Inflammatory Bowel Diseases (IBD) and colon cancer. Strangely enough, the company has also been active in the seemingly entirely unrelated skin disorders area.

Cosmo licensed the CB-03-01 product to Medicis (US) in early 2012, but Valeant (Canada) then purchased Medicis later in the same year. Per some reports, Valeant still seems to be interested in the product, although it has an option for right of refusal in case of Cosmo re-licensing.

The CB-03-01 product will supposedly cure (or improve?) acne, hirsutism and male pattern baldness (MPB). This very useful January 2013 Cosmo Presentation has a number of pages on CB-03-01 for both acne and hair loss applications. My favorite is the diagram on page 48. It shows that while Finasteride and Dutasteride work on preventing the conversion from Testosterone to DHT, CB-03-01 does not mess with that perhaps important hormonal mechanism, but rather, acts at the receptor site (in their own words on page 51: “antagonize the DHT/T interaction at these receptors”).

The one discouraging aspect of the above presentation’s page 48 diagram is that it seems to compare CB-03-01’s mechanism of action with that of Cyproterone Acetate and Flutamide, neither of which have turned out to be of any major help for most people when it comes to hair regrowth (and mixed testimonials when it comes for hair maintenance). Luckily, while those two drugs are taken orally, CB-03-01 will be applied topically and most likely result in far fewer side effects. Note that CB-03-01 is technically known as Cortexolone 17α-propionate according to this source.

Key Events Affecting CB-03-01 (parts of below directly pasted from their site with my modifications in some places)

  • IND granted in Q1 2012 for acne treatment.
  • Phase II dose escalating clinical trials for acne treatment completed in H1 2014.
  • An FDA meeting for discussion of the phase III acne trial design is expected at the end of 2014 or beginning of 2015.
  • The first patient in for a “proof of concept” phase II trial for alopecia is expected in October 2014.
  • Patents have been granted in the US and expire in 2023 and 2030.

Cosmo’s half-year 2014 report has more recent updates, including a useful clinical trial and schedule of release diagram for all its key products on page 14.

I will probably have more on CB-03-01 in coming posts, as there is a lot of discussion about this on the forums and I have not had much time to process most of it, especially Desmond’s recent thread.