Pyrilutamide

Pyrilutamide (developmental code name KX-826) is a nonsteroidal antiandrogen (NSAA) – specifically, a selective high-affinity silent antagonist of the androgen receptor (AR) – which is under development by Suzhou Kintor Pharmaceuticals, inc., a subsidiary of Kintor Pharmaceutical Limited, for the potential treatment of androgenic alopecia (androgen-dependent scalp hair loss)  As of October 2022, it is in phase 3 clinical trials for androgenic alopecia and phase 2 trials for acne.

Development
The primary endpoint is the change from baseline in non-vellus target area hair count (TAHC) at the end of week 24. The drug will be dosed at 10 mg (0.5% BID) per patient per day in the trial.

Adverse effects
Pyrilutamide is generally well-tolerated. The most common adverse event is contact dermatitis.

Pharmacodynamics
Pyrilutamide binds to the androgen receptor with a very high affinity with an IC50 of 0.28 nM. Reference drug bicalutamide had an IC50 of 3.1 nM.