Remibrutinib in chronic spontaneous urticaria patients: phase 3b extension trial: Marcus Maurer, EAACI 2023

Phase 2 results of remibrutinib for chronic spontaneous urticaria (CSU) show a fast and sustained response to treatment. While the phase 3b trial is ongoing, touchIMMUNOLOGY were delighted to speak with Prof. Marcus Maurer (Professor of Dermatology and Allergy, Charité – Universitätsmedizin Berlin) about the rationale for studying remibrutinib in relation to CSU and the ongoing Phase 3b extension trial.

The abstract ‘Efficacy, safety, and tolerability of remibrutinib (LOU064) in CSU patients: Study design of Phase 3b extension trial‘ was presented at the European Association of Allergy & Immunology (EAACI) conference, 09-11 June 2023.

Questions:

1. What is the mechanism of action of remibrutinib and the rationale for its study in chronic spontaneous urticaria (CSU)?
2. What clinical data already supports the use of remibrutinib for the treatment of CSU?
3. Please could you describe the study design of the phase 3b extension trial?

Disclosures: Marcus Maurer is or recently was a speaker and/or advisor for and/or has received research funding from Allakos, Alvotech, Amgen, Aquestive, Aralez, AstraZeneca, Astria, Bayer, BioCryst, Blueprint, Celldex, Celltrion, Centogene, CSL Behring, Evoemmune, GSK, Ipsen, Kalvista, Kyowa Kirin, Leo Pharma, Lilly, Menarini, Mitsubishi Tanabe Pharma, Moxie, Noucor, Novartis, Orion Biotechnoloy, Pharvaris, Resonance Medicine, Sanofi/Regeneron, Septerna, Takeda, Teva, Trial Form Support International AB, Third HarmonicBio, Valenza Bio, Yuhan Corporation, Zurabio.

Support: Interview and filming supported by Touch Medical Media Ltd. Interview conducted by Victoria Jones.

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Transcript

What is the mechanism of action of remibrutinib and the rationale for its study in chronic spontaneous urticaria (CSU)? (00:21)

Remibrutinib is a BTK inhibitor, and BTK is downstream of the high affinity IgE receptor on mast cells on basophils. We know that mast cells and basophils are involved in the pathogenesis of chronic spontaneous urticaria. In fact, mast cells are the key drivers, and their activation via IgE and the IgE receptor is a major mechanism. So that’s one of the mechanisms of action, how remibrutinib stops mast cell activation, and therefore, the development of signs and symptoms of chronic spontaneous urticaria, but there’s a second mechanism that is in the B-cell domain, because BTK is also downstream of autoantibody-producing B-cells and can therefore stop the production or reduce the production of autoantibodies that contribute to mast cell activation in chronic spontaneous urticaria.

What clinical data already supports the use of remibrutinib for the treatment of CSU? (01:24)

Well, we have a lot of data from the phase 2 study. The phase 3 study is ongoing, hopefully will finish very soon, so that we will know by the end of the year a lot more. But we know that remibrutinib across all the doses that were tested in the phase 2 study was effective. There was a dose response. The response was fast and sustained. We have subgroup analyses that teaches us a little bit about differences in patient populations, and most importantly, maybe, we have a very clean safety profile as of now.

Please could you describe the study design of the phase 3b extension trial? (02:04)

So the phase 2 was a straightforward parallel group designed study and the phase 3 study is the same. We’re using the doses that came from the phase 2, they are obviously placebo-controlled, and we’ll have a long term follow-up with open label. All in all, a study that is designed like chronic spontaneous urticaria studies should be, sufficient size, all the important patient reported outcome measures are in there, the gold standard of measuring disease activity and improvement, Urticaria Activity Score. So a study that will lead to very robust and reliable results.

Subtitles and transcript are autogenerated