LAD603
LAD603 is in Phase 2 for alopecia areata, developed by Almirall.
Almirall's subcutaneous candidate in severe alopecia areata, dose-finding across three levels since December 2025, mechanism not stated under this code.
- Developed by
- Almirall
- Current phase
- Phase 2
- Mechanism
- Undisclosed
- Indications
- Alopecia areata
- Also known as
- LAD-603
- Last public activity
- May 2026
- Copy last reviewed
- September 2026
- Record confidence
- Low
Tests whether it works, at what dose, in a few hundred people.
The sponsor has not said how it is supposed to work.
A research record, not medical advice: being listed here says nothing about whether a treatment works or whether it is right for you. Talk to a dermatologist about your own case.
Why it matters
The Phase 2 is a randomised, placebo-controlled, double-blind dose-finding study of three subcutaneous dose levels over 28 weeks in about 136 adults with severe to very severe disease, registered in the EU as well as the US, after a Phase 1 in 92 healthy volunteers that started in December 2023. Almirall licensed SIM0278, an IL-2 mutein Fc fusion protein that expands regulatory T cells, from Simcere in September 2022 and announced its Phase 1 under the code ALM223 that same December, which would put it in the same class as rezpegaldesleukin. Nothing public says LAD603 is that molecule, so the mechanism stays undisclosed here until Almirall connects the two.
Development history
- Phase 2
First Phase 2 trial on record: NCT07311564 — A Study of LAD603 in Adults With Alopecia Areata
ClinicalTrials.gov ↗
Registered trials
Pulled automatically from ClinicalTrials.gov. Matching is by name and development code, so occasional gaps are possible — tell us if you spot one.
A Study of LAD603 in Adults With Alopecia Areata
Almirall, S.A. · n=136 · December 2025
Listing a trial is not a recommendation to join one. Eligibility, risks and costs vary enormously — discuss any trial with your own doctor first.
Sources
- A Study of LAD603 in Adults With Alopecia Areata — ClinicalTrials.gov
- Dose-finding study of LAD603 in adults with alopecia areata — EU Clinical Trials Register
- A Single and Multiple Ascending Dose Study of LAD603 in Healthy Subjects — ClinicalTrials.gov
- Almirall announces initiation of Phase I study of SIM0278 (overseas code ALM223) — Company release, December 2023
- Simcere and Almirall enter into a licensing agreement for IL-2 mu-Fc — Company release, September 2022
Related programmes
Other programmes in the register with the same approach.
Cite this page
Hair Pipeline, "LAD603 — development record", hairpipeline.com/pipeline/lad603