Amgen's Uplizna approved for second rare immune disorder, US filing imminent

Amgen announced on Wednesday that it has achieved positive results from the pivotal Phase III MITIGATE trial, which assesses the efficacy of its CD19-directed antibody Uplizna (inebilizumab-cdon) as a treatment for immunoglobulin G4-related disease (IgG4-RD). Following these promising results, Amgen intends to seek US approval for this new indication and pursue regulatory approvals in other markets as well. Jay Bradner, the head of Amgen's research and development, described MITIGATE as a "landmark study" that signifies a crucial advancement in treating a debilitating and rare disease that currently lacks any approved therapies.

The MITIGATE trial involved 135 patients and successfully met its primary endpoint. Participants who were administered intravenous Uplizna experienced a significant 87% reduction in the risk of IgG4-RD flares compared to those given a placebo over the 52-week control period. In addition to the primary endpoint, all key secondary endpoints were achieved. These included measures such as the annualized flare rate, flare-free and treatment-free complete remission, and flare-free, corticosteroid-free complete remission. Amgen reported that the safety profile of Uplizna in this trial was consistent with its known safety characteristics. Detailed data from the study are expected to be presented at an upcoming medical conference.

IgG4-RD is a chronic immune-mediated fibroinflammatory condition that can affect almost any organ system, often impacting multiple organs simultaneously and leading to irreversible organ damage. Patients eligible for the MITIGATE study had a history of multi-organ disease and were undergoing treatment with glucocorticoids at the time of screening. Amgen highlighted that the "steroid-sparing" design of the MITIGATE trial points toward a treatment approach that reduces toxicity.

Uplizna is already approved for treating neuromyelitis optica spectrum disorder (NMOSD) in the US, Europe, and other markets. Originally developed by Viela Bio, the drug's rights were acquired by Horizon Therapeutics in 2021. Horizon Therapeutics then merged with Amgen last year in a transaction valued at $27.8 billion.

The promising results of the MITIGATE trial represent a significant step forward in addressing IgG4-RD, offering new hope for patients suffering from this rare and severe disease. With plans to seek regulatory approvals, Amgen is poised to potentially bring the first approved therapy for IgG4-RD to the market, marking an important milestone in the treatment landscape for this condition.