Pelage's PP405 Demonstrates Efficacy in Phase 2a Trial for Androgenetic Alopecia

Dermoscopic image of androgenetic alopecia in a male patient | Image Credit: © DermNet

Positive results have been announced from a phase 2a clinical trial evaluating the safety, pharmacokinetics and efficacy of PP405 for the treatment of androgenetic alopecia in adult patients, Pelage Pharmaceuticals announced in a release.¹ The company said it plans to initiate phase 3 studies in 2026 to further evaluate the therapy.

Results from the trial (NCT06393452) showed that PP405 met its primary safety endpoint of percentage of patients with treatment related adverse events and serious treatment related adverse events. The therapy also met its primary secondary pharmacokinetic endpoint of concentration in blood plasma.

“Despite affecting millions, hair loss has seen remarkably little progress in clinical research,” Arash Mostaghimi, MD, MPH, FAAD, vice chair of Clinical Trials and Innovation at Brigham and Women’s Hospital, said in a release.¹ “What’s compelling about PP405 is that it brings scientific rigor to a space that’s needed it for decades. A well-tolerated, topically delivered therapy that shows measurable biological activity this early is rare. This could reshape how we think about clinical progress in hair growth.”

PP405 takes a different approach from current hair loss treatments, which mostly focus on secondary causes like hormones. Instead, it targets the primary biological pathway that controls the natural hair growth cycle. By acting on hair follicle stem cells—which remain present even in balding areas—PP405 offers a promising option for people often left out by existing therapies.

The study was a randomized, multicenter, double-blind, vehicle-controlled phase 2a trial that evaluated the safety, pharmacokinetics and efficacy of PP405 for the treatment of androgenetic alopecia in adult patients. The study cohort included 78 patients aged 18 to 55 years. Exclusion criteria for the study included having an additional diagnosis of other forms of alopecia, using other hair loss treatments, or using certain medications or having certain medical conditions.

Patients received either 0.05% PP405 topical gel or placebo comparator topical gel vehicle. Patients applied the therapy or placebo once per day for 4 weeks and were followed for up to 12 weeks. After the randomized portion of the study, patients were eligible to enroll in an open-label extension study for 3 months to assess the long term safety of PP405.

The study found that 31% of men with a higher degree of hair loss who received PP405 had a greater than 20% increase in hair density at 8 weeks, compared to 0% in the placebo group. The study also showed PP405 induced new hair growth where there was previously no hair, suggesting the therapy has the potential for regeneration. Additionally, PP405 was seen to be well tolerated with no systemic absorption detected in blood plasma.

“These early clinical results reinforce the potential of our approach to go beyond slowing the hair loss process and directly drive hair follicle regeneration,” Christina Weng, MD, chief medical officer of Pelage, said in a release.¹ “We see this as a milestone that expands the possibilities of regenerative medicine. As we advance into the next stage of clinical development, our focus remains on delivering a science-driven solution that works for everyone.”

References

1. Pelage Pharmaceuticals announces positive phase 2a clinical trial results for PP405 in regenerative hair loss therapy. News release. Pelage Pharmaceuticals. June 17, 2025. Accessed June 17, 2025. https://www.businesswire.com/news/home/20250617338859/en/Pelage-Pharmaceuticals-Announces-Positive-Phase-2a-Clinical-Trial-Results-for-PP405-in-Regenerative-Hair-Loss-Therapy

[This article was originally published by our sister publication, Drug Topics.]