Company: HMDCF
Filing Date: 2025-03-19
Form Type: 20-F
Source: 0001410578-25-000377
Chunk: 198

Company: HUTCHMED (China) Ltd
Filing Date: 2025-03-19
Form: 20-F
Item: Item 1
Chunk 198
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Sovleplenib

There has been extensive research on oral small-molecule Syk inhibitors due to the major unmet medical need in inflammation and oncology. However, many Syk inhibitors have failed in the development stage due to their off-target toxicity as a result of lower kinase selectivity and possibly poor pharmacokinetic properties. The only small molecule drug candidate targeting Syk specifically that has been approved to date is Tavalisse for the treatment of chronic immune thrombocytopenia. Lanraplenib (GS-9876) is a Syk inhibitor that has been studied for autoimmune diseases, but not currently in active development for autoimmune diseases. Syk inhibitors currently in clinical studies for hematological cancers include lanraplenib and cerdulatinib (for the treatment of lymphoma).

Table of Contents

The threshold of safety for a Syk inhibitor in chronic disease is extremely high, with no room for material toxicity. The failure of Tavalisse in a global Phase III registration study in rheumatoid arthritis provided important insights for us in the area of toxicity. While Tavalisse clearly showed patient benefit in rheumatoid arthritis, a critical proof-of-concept for Syk modulation, it also caused high levels of hypertension which is widely believed to be due to the high levels of off-target kinase insert domain receptor inhibition. In addition, Tavalisse has also been shown to strongly inhibit the Ret kinase, and in pre-clinical trials it was demonstrated that inhibition of the Ret kinase was associated with developmental and reproductive toxicities.

The requirement for Syk kinase activity in inflammatory responses was first evaluated with Tavalisse, which was co-developed by AstraZeneca/Rigel Pharmaceuticals, Inc. In 2013, AstraZeneca announced results from pivotal Phase III clinical trials that Tavalisse statistically significantly improved ACR20 (a 20% improvement from baseline based on the study criteria) response rates of patients inadequately responding to conventional disease-modifying anti-rheumatic drugs and a single anti-TNFα (a key pro-inflammatory cytokine involved in rheumatoid arthritis pathogenesis) antagonist at 24 weeks, but failed to demonstrate statistical significance in comparison to placebo at 24 weeks. As a result, AstraZeneca decided not to proceed. Rigel Pharmaceuticals subsequently chose to develop Tavalisse for immune thrombocytopenia instead, for which it was approved by the FDA in 2018 and the EMA in 2020.

Tavalisse was also in trials for