Amgen’s CD19-directed antibody Uplizna in a late-stage study showed it can suppress the risk of flares by nearly 90% in patients with IgG4-related disease, the company announced Wednesday.
Amgen on Wednesday announced that its anti-CD19 antibody Uplizna (inebilizumab-cdon) met its primary and key secondary efficacy endpoints in the Phase III MITIGATE trial, demonstrating a significant and substantial reduction in flares in patients with IgG4-related disease.
Topline data from the pivotal study showed that Uplizna cut the risk of flares in IgG4-related disease (IgG4-RD) patients by 87% versus placebo. This effect was highly statistically significant, with a p-value less than 0.0001, according to Amgen.
Uplizna also aced all key secondary endpoints including annualized flare rate, flare-free, corticosteroid-free complete remission, as well as flare-free, treatment-free complete remission.
In terms of safety, MITIGATE found no new signals of concern. Uplizna’s adverse event profile in the trial was consistent with what had been established in prior studies. Amgen will provide full data and analyses from MITIGATE at an upcoming medical congress, the company said.
Amgen CSO Jay Bradner in a statement called Wednesday’s readout “an important advance in the treatment of patients with IgG4-RD,” adding that Uplizna could be a promising treatment option for this rare disease “that currently has no approved therapy.” Amgen is gearing up for a regulatory filing for Uplizna in IgG4-RD later this year.
IgG4-RD is a chronic, systemic, progressive and immune-mediated disease characterized by tissue fibrosis and the formation of lesions in affected organs. The disease can cause irreversible organ damage without manifesting symptoms and is characterized by alternating periods of remission and unpredictable flares.
A central pathologic pathway in IgG4-RD involves CD19-positive B cells, which drive inflammatory and fibrotic cascades and activate other cells that are involved in disease activity. Uplizna addresses this underlying disease process by binding to the CD19 surface protein and triggering the destruction of B cells.
This mechanism of action also gives Uplizna its therapeutic efficacy for the rare neuroinflammatory disease neuromyelitis optica spectrum disorder (NMOSD), for which the FDA granted the antibody approval in June 2020.
In a note to investors, William Blair analyst Matt Phipps said that Wednesday’s positive readout could open a “meaningful expansion opportunity” for Amgen, particularly given the “estimated addressable market for IgG4-RD roughly double that of NMOSD as well as straightforward registrational path given the high unmet need and first-mover advantage for Uplizna.”
Beyond IgG4-RD, Amgen is also trialing Uplizna in myasthenia gravis, for which the company is running a Phase III study with a readout expected later this year.
Tristan Manalac is an independent science writer based in Metro Manila, Philippines. Reach out to him on LinkedIn or email him at tristan@tristanmanalac.com or tristan.manalac@biospace.com.
