Pyrilutamide has undergone several clinical trials for the treatment of androgenic alopecia (AGA) in both males and females.[5] The primary endpoint for most trials was the change from baseline in non-vellus target area hair count (TAHC) compared to placebo after 24 weeks of treatment.[5]
Phase II Trials
Male AGA in China
A phase II trial in China enrolled 120 male patients, randomized into four groups: KX-826 0.25% BID (twice daily), KX-826 0.5% QD (once daily), KX-826 0.5% BID, and placebo. After 24 weeks, the 0.5% BID group showed significant improvement:[5]
Non-vellus target area hair count (TAHC) increased by 22.73 hair counts per cm² from baseline (P<0.001)
TAHC increased by 15.34 hair counts per cm² compared to placebo (P=0.024)
Female AGA in China
A phase II trial for female AGA in China included 160 patients in five groups: KX-826 0.25% QD, 0.25% BID, 0.5% QD, 0.5% BID, and placebo. After 24 weeks:[5]
The 0.5% QD group showed an increase of 11.39 hair counts per cm² compared to placebo (P=0.0087)
Efficacy was observed as early as 12 weeks
Male AGA in the U.S.
A phase II trial in the U.S. enrolled 123 male patients, divided into KX-826 0.25% QD, 0.5% QD, 0.5% BID, and placebo groups. Results after 24 weeks showed:[5]
The 0.5% BID group increased by approximately 10 hair counts per cm² from baseline (P=0.0088)
A dose-response relationship was observed across different dosage groups
Phase III Trials
Male AGA in China
A phase III trial for male AGA in China enrolled 740 patients, randomized into KX-826 0.5% BID and placebo groups. Results announced on November 27, 2023, showed:[5]
KX-826 promoted hair growth compared to baseline with statistical significance (P<0.0001)
Improvement in TAHC at all visit points compared to placebo, though without statistical significance
Ongoing Studies
A long-term safety phase III trial for AGA treatment in China, enrolling 271 male and female patients for a 52-week treatment period, focusing on treatment-emerged adverse events (TEAE).[5]
A phase Ib/III clinical trial of KX-826 in combination with minoxidil for male AGA in China, approved by NMPA on February 1, 2024.[5]
Adverse effects
Pyrilutamide is generally well-tolerated. The most common adverse event is contact dermatitis.[6]
Across all trials, KX-826 demonstrated a favorable safety profile:[5]
No serious adverse events (SAE) or adverse drug reactions (ADR) were reported
Most treatment-emerged adverse events (TEAE) were mild and similar to placebo
Low systemic exposure was observed after topical application
Pharmacology
Plasma concentration of pyrilutamide and metabolite KX-982 in different dose groups in phase Ib clinical trials in China
Pharmacodynamics
Pyrilutamide binds to the androgen receptor with a very high affinity with an IC50 of 0.28 nM.[4] Reference drug bicalutamide had an IC50 of 3.1 nM.[4]
^Saceda-Corralo D, Domínguez-Santas M, Vañó-Galván S, Grimalt R (January 2023). "What's New in Therapy for Male Androgenetic Alopecia?". American Journal of Clinical Dermatology. 24 (1): 15–24. doi:10.1007/s40257-022-00730-y. PMID36169916.
