On February 10, 2025, Hansoh Pharmaceutical Group Co., Ltd. (Hansoh Pharma, 03692.HK) , a leading innovation-driven pharmaceutical company in China, today announces that based on the positive results from the global pivotal Phase 3 MITIGATE trial on XINYUE (昕越^®) (Inebilizumab Injection) , the new indication of the treatment of immunoglobulin G4-related disease (IgG4-RD) has been included in the Priority Review and Approval Procedure by the National Medical Products Administration (“NMPA”).

MITIGATE Study and its key findings in IgG4-related disease (IgG4-RD)

MITIGATE (NCT04540497) was conducted at 80 sites in 22 countries including Chinese sites. It is the first randomized, double-blind, placebo-controlled study ever conducted in IgG4-RD, and establishes the safety and efficacy of CD19+ B cell depletion with inebilizumab in IgG4-RD.

Key findings include*:

·A clinically meaningful and statistically significant 87% reduction in the risk of IgG4-RD flare compared to placebo (Hazard Ratio 0.13, p<0.001) during the 52-week placebo-controlled period; seven of 68 participants receiving inebilizumab experienced a flare compared to 40 of 67 participants receiving placebo.

·A reduction in annualized flare rate for treated and adjudication committee-determined flares during the placebo-controlled period; 0.10 for participants receiving inebilizumab compared to 0.71 for participants receiving placebo (p<0.001).

·57.4% (39 of 68) of participants receiving inebilizumab achieved flare-free, treatment-free, complete remission at Week 52 compared to 22.4% (15 of 67) participants receiving placebo (p<0.001).

·58.8% (40 of 68) of participants receiving inebilizumab achieved flare-free, corticosteroid-free, complete remission at Week 52 compared to 22.4% (15 of 67) participants receiving placebo (p<0.001).

·Confirmation of the unique mechanism of action of inebilizumab to deliver rapid and sustained depletion of peripheral B cells leading to lowered levels of disease biomarkers.

Notably, 89.7% (61 of 68) of inebilizumab-treated patients required no glucocorticoid treatment for disease control during the placebo-controlled period, compared to 37.3% (25 of 67) of patients on placebo. After Week 8, inebilizumab-treated patients experienced a ten-fold reduction in total glucocorticoid use relative to placebo.

The safety results in the placebo-controlled period were consistent with the established safety profile of inebilizumab. The most common treatment-emergent adverse events included COVID-19, lymphopenia, urinary tract infection, and headache.

The data were published in The New England Journal of Medicine in November 2024. In August 2024, the U.S. Food and Drug Administration granted Breakthrough Therapy Designation for inebilizumab in IgG4-RD based on data from the MITIGATE study, and regulatory filing activities for the IgG4-RD indication are currently underway.

*All p-values follow the New England Journal of Medicine reporting guidelines; values smaller than 0.001 are presented as 0.001.

*The trial was conducted with the support of Hansoh Pharma and other partners. Hansoh Pharma is the exclusive licensee, local regulatory and commercial agent for XINYUE (inebilizumab) in China's mainland, Hong Kong, and Macau.

About Immunoglobulin G4-related disease (IgG4-RD)

Immunoglobulin G4-related disease (IgG4-RD) is a chronic, systemic, immune-mediated, fibroinflammatory disease which can affect numerous and generally multiple organs of the body. It is a progressive disease affecting new organs over time either consecutively or simultaneously and is characterized by periods of remission and unpredictable disease flares. IgG4-RD can cause irreversible organ damage with or without the presence of symptoms. Awareness of how organ damage manifests is critically important to inform the timely diagnosis of IgG4-RD. B cells are central to the pathogenesis of IgG4-RD. In IgG4-RD, CD19-expressing (CD19+) B cells are thought to drive inflammatory and fibrotic processes and interact with other immune cells that contribute to disease activity.

The incidence is estimated at 1-5 in 100,000 although the number of IgG4-RD patients is difficult to determine based on limited epidemiology data. The typical age of onset of IgG4-RD is between 50 and 70 years old and, unlike many other immune-mediated diseases, IgG4-RD is more likely to occur in men than women.

About XINYUE (inebilizumab)

XINYUE (inebilizumab) is a targeted CD19 B cell-depleting antibody.On May 24, 2019, Hansoh Pharma entered into a license agreement with Viela Bio, and has been granted an exclusive license to develop and commercialize the Product in Chinese mainland, Hong Kong and Macao(Viela Bio was acquired by Horizon Therapeutics in 2021, which was acquired by Amgen in 2023).

Inebilizumab was approved for marketing by the US FDA, the Ministry of Health, Labour and Welfare of Japan, and the European Commission in June 2020, March 2021 and April 2022, respectively.On March 14, 2022,XINYUE was approved to be launched in China by NMPA for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positive. In January 2023, inebilizumab was included in the National Reimbursement Drug List4 (NDRL)for the first time, and this inclusion was successfully renewed in November 2024.