Phase 2a Randomized, Double‑Blind, Placebo‑Controlled Study of LY4005130 in Adults with Severe Alopecia Areata

The primary objective is to assess the efficacy of LY4005130 compared with placebo in adult participants with severe alopecia areata, using validated hair‑regrowth severity indices to determine clinical benefit. Secondary assessments will evaluate safety parameters, characterize the drug’s pharmacokinetic profile, and explore relevant pharmacodynamic markers to inform exposure‑response relationships.

The trial enrolled 51 participants diagnosed with Alopecia Areata meeting criteria for severe disease. Both male and female adults were eligible; specific age limits were not disclosed. Eligible individuals exhibited hair loss covering 50 % to 90 % of the scalp as measured by the Severity of Alopecia Tool (SALT) score, with the current episode lasting at least six months but no more than four years, and no notable spontaneous regrowth for a minimum of six months. Participants were required to refrain from using any concomitant AA treatments throughout the study. General health status beyond the alopecia condition was not detailed, and no lifestyle restrictions such as diet or physical activity were specified. Selection was based on the outlined inclusion criteria, and no additional exclusion criteria were provided.

The study (J5D-MC-FPAC) is a Phase 2a, multicenter, randomized, double-blind, placebo-controlled proof‑of‑concept trial evaluating the efficacy and safety of the intravenous investigational product LY4005130 compared with placebo in adult participants with severe Alopecia Areata. Eligible individuals must have a Severity of Alopecia Tool (SALT) score indicating 50‑90 % scalp hair loss for at least 6 months but not longer than 4 years, and must refrain from using other AA therapies. After an initial screening visit to confirm eligibility, participants are randomized at the baseline visit to receive either LY4005130 or placebo. Subsequent scheduled follow‑up visits assess safety, tolerability, and the primary efficacy outcome, defined as the percentage of participants achieving a SALT score ≤20. The trial enrolment period spans from 31 May 2026 to 27 July 2026, and participant involvement continues from screening through the final end‑of‑study visit.

The investigational product LY4005130 is supplied as a sterile solution for injection intended for intravenous administration. Each dose consists of 0 mg of the active substance in a volume appropriate for infusion. The medication is administered as a single intravenous infusion on Day 1 of the study, with no subsequent dosing planned during the double‑blind treatment period.

The comparator arm receives a matching placebo (product code SUB12581MIG) formulated to appear identical to the active solution. The placebo is also delivered as an intravenous infusion on Day 1, following the same administration procedure as the investigational product.

All infusions are performed under clinical supervision in a controlled setting. Participants are observed for a minimum of two hours post‑infusion to monitor immediate safety parameters. Compliance with the single‑dose regimen is confirmed by documented infusion records and verification of study drug accountability. No additional dosing or dosing adjustments are required during the trial.

Efficacy will be evaluated by the proportion of participants who achieve an absolute Severity of Alopecia Tool (SALT) score of 20 or less. This primary efficacy parameter reflects the degree of hair regrowth and is expressed as a percentage of the study population meeting the predefined threshold.

The SALT score will be determined using the validated SALT assessment methodology applied by trained investigators. Participants’ scores will be compared to baseline values to ascertain achievement of the ≤20 criterion, and the resulting percentages will be analyzed to compare the investigational product with placebo.