RU58841 (or RU-58841) has been originally synthesized in the early 90’s by Battman et al. They showed in their research paper that RU58841 was topically active in a rat model. Their research suggested that the compound was a candidate of choice for androgen dependent skin related disorders such as acne, androgenetic alopecia and hirsutism.
This was mainly due to the compound showing exceptional high topical activity combined with the unprecedented activity regarding systemic effects. This research led to RU58841 being investigated in more research papers by different researchers in animal models.
Eventually a company called Prostrakan picked up the compound rights and renamed RU58841 to PSK-3841 and investigated it for therapeutic value for androgenetic alopecia and acne in humans. They ran both phase 1 and phase 2 human clinical trials. The first clinical trial consisted of a 5% topical solution administered twice daily over 4 weeks to a total of 30 people. This led to a phase 2 trial which consisted of a 5% and a 2.5% topical solution being administered once a day over a time period of 6 months in 120 people. After that trial Proskelia had put out the following comment;
“PSK 3841 ProSkelia partnering opportunity, Worldwide Partners are sought by ProSkelia for the development of PSK 3841, Neil Brown, Vice President of Licensing and Acquisitions at ProSkelia, announced during a presentation at BioSquare PSK 3841, a nonsteroidal antiandrogen, has completed phase IIa trials for the treatment of androgenetic alopecia and a clinical proof-of-concept study to reduce sebum flow and secretion in patients with acne. Six months of treatment with PSK 3481 demonstrated equivalent or better net hair growth compared with finasteride”
Especially the latest sentence is interesting where they mention that RU58841 demonstrated similar or better hair growth compared with finasteride. Morgan-Stanely also analysed, reported about RU58841 and had the following to say;
““ProStrakan’s topical androgen receptor antagonist has completed a Phase IIa proof-of-concept study for alopecia. In this trial, which was not powered for efficacy, there was an observed increase in both new and existing hair growth and the data compared well with historical data for finasteride (marked by Merck as Propecia). We believe the market for this agent is resonably modest – US $100 – 200 million – but that could be of interest to a specialty dermatology company. With partnering discussions ongoing we believe that a deal could be announced next year”
Ultimately however that deal never got announced and the development of RU58841 stopped.
- BATTMAN T, BONFILS A, BRANCHE C et al.: RU-58841, a new specific topical antiandrogen: a candidate of choice for the treatment of acne, androgenetic alopecia and hirsutism.
J. Steroid Biochem. Mol. Biol. (1994) 48:55-60.