Eli Lilly's BTK Inhibitor Enters the Autoimmune Disease Therapeutic Field

On September 11th, the official website of the Drug Clinical Trial Registration and Information Disclosure Platform showed that Eli Lilly has registered a Phase I/II, dose-finding study (CTR20253341) in China, which aims to evaluate the safety and efficacy of pitobrutinib in adult patients with immune thrombocytopenia. According to DXY Insight Database, this is the first autoimmune disease clinical study initiated by pirtobrutinib.

Pirtobrutinib is a highly selective, non-covalent (reversible) BTK inhibitor. Initially developed by Redx Pharma, it was acquired by Loxo Oncology in July 2017. In January 2019, Eli Lilly purchased Loxo Oncology for $8 billion, bringing Pirtobrutinib into its portfolio. In December 2024, Innovent Biologics in-licensed the rights to import, market, promote and distribute Pirtobrutinib in mainland China.

Pirtobrutinib received its first global approval in January 2023. Currently, it has been approved for 2 oncology indications, including relapsed or refractory mantle cell lymphoma (MCL) and relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). In 2024, Pirtobrutinib generated $337 million in revenue, and it achieved $215 million in revenue in the first half of this year.

Autoimmune diseases represent the next battlefield for BTK inhibitors, and major pharmaceutical companies including Eli Lilly are actively making strategic layouts in this area.

According to DXY Insight Database, there are currently 55 BTK inhibitors (only active ones included in the statistics) worldwide under research for autoimmune diseases. The companies conducting the research include not only pharmaceutical giants such as AbbVie, Sanofi, Novartis, Eli Lilly, AstraZeneca, Roche, and Gilead Sciences, but also a number of domestic leading pharmaceutical enterprises like BeiGene, InnoCare Pharma, CHIATAI TIANQING, Hengrui Pharmaceutical, Humanwell Healthcare, and Hansoh Pharma.

Sanofi's Rilzabrutinib was just approved for marketing by the FDA on August 29th this year for the treatment of immune thrombocytopenia. It is the first BTK inhibitor specifically approved for autoimmune diseases, representing a major breakthrough for BTK in the field of autoimmune diseases.

In addition, there are more than 30 autoimmune-focused BTK inhibitors that have reached the clinical trial approval stage or beyond. These drugs cover two main types: traditional small-molecule inhibitors and PROTACs. From the perspective of indication distribution, the top 4 indications with the fiercest competition are multiple sclerosis, rheumatoid arthritis, chronic spontaneous urticaria, and systemic lupus erythematosus, each corresponding to more than 10 BTK drug pipelines.

Source: DXY Insight Database