Amgen Scores Uplizna Expansion Into Generalized Myasthenia Gravis

 

Generalized myasthenia gravis is Uplizna’s second new indication this year, after the FDA cleared the anti-CD19 antibody for IgG4-related disease in April.

On Thursday, the FDA approved a key expansion for Amgen’s autoimmune therapy Uplizna, allowing its use in patients with a certain type of generalized myasthenia gravis.

Specifically, the regulatory agency cleared Uplizna for adults positive for autoantibodies against the anti-acetylcholine receptor (AChR) and anti-muscle specific tyrosine kinase (MuSK). Uplizna is the first CD19-targeted B cell therapy approved for this indication, Amgen said in its press release, and allows long-term disease control with just two doses per year.

Data from the Phase III MINT study supported the regulatory verdict. A September 2024 readout showed significant improvements in activities of daily living at 26 weeks, as measured by the Myasthenia Gravis Activities of Daily Living (MG-ADL) scale, as compared with placebo. Uplizna’s benefit remained clinically meaningful and statistically significant in both AchR-positive and MuSK-positive subgroups.

In March, Amgen released follow-up data showing that Uplizna not only maintains but also deepens treatment response at 1 year. Placebo-adjusted improvement in MG-ADL was 2.8 points at one year, as compared with 1.8 points at 26 weeks. Scores on the Quantitative Myasthenia Gravis scale, which assesses functional performance, improved by 4.3 points at one year from a 2.5-point average improvement at 26 weeks.

Reacting to this 52-week readout, analysts at William Blair said in a March 12 note that these data “solidify a meaningful role for Uplizna in the treatment of myasthenia gravis” and support its “blockbuster potential.” The analysts also noted that the therapy’s “infrequent every-six-month dosing interval” will give it an edge over “weekly, monthly, or every-other-month dosing regimens with other therapies.”

Uplizna is an IgG1 monoclonal antibody that works by targeting CD19 on immature and mature B cells. Its specific mechanism of action in myasthenia gravis isn’t yet completely understood, though Uplizna could act by depleting B cells, which are key drivers of the disease’s pathology. Patients with myasthenia gravis suffer from muscle weakness, breathing problems and difficulty in swallowing and speech.

The FDA first approved Uplizna in 2020 for neuromyelitis optica spectrum disorder, a rare autoimmune and neuroinflammatory disease of the optic nerve, spinal cord and brain stem. The drug secured a label expansion in April this year for IgG4-related disease.

https://www.biospace.com/fda/amgen-scores-uplizna-expansion-into-generalized-myasthenia-gravis