Amgen preps Uplizna filing for a second indication

Amgen has moved closer to a second indication for its B cell-depleting therapy Uplizna, acquired as part of its $27.8 billion takeover of Horizon Therapeutics last year, after positive results in a phase 3 trial.

The drugmaker said that based on the positive results with CD19-directed Uplizna (inebilizumab) in immunoglobulin G4-related disease (IgG4-RD), it plans to file for FDA approval in the US and other world markets. The drug was cleared for its first indication, rare eye disease neuromyelitis optica spectrum disorder (NMOSD), in 2020.

IgG4-RD is an immune-mediated disease that leads to inflammation and scarring (fibrosis) in multiple organs of the body and is characterised by unpredictable flares in which the disease progresses and can lead to organ failure, followed by periods of remission. It affects roughly 1-5 out of every 100,000 people, typically striking between the ages of 50 and 70, and is more common in men.

In the 135-subject MITIGATE study, treatment with Uplizna led to an 87% reduction in the risk of flares compared to placebo over 52 weeks of follow-up, which Amgen chief scientific officer Jay Bradner said was a “landmark” for IgG4-RD, which has no approved therapies.

Uplizna also hit the target on a number of secondary measures, including: annualised flare rate; flare-free, treatment-free complete remission; and flare-free, corticosteroid-free complete remission. Amgen will present the full dataset at a future medical meeting.

The drug was acquired by Horizon from its earlier developer Viela Bio in 2021 and was one of three products the company had on the market before the Amgen merger, along with Tepezza (teprotumumab) for thyroid eye disease (TED) and chronic refractory gout treatment Krystexxa (pegloticase).

Amgen reported sales of $65 million for the drug in NMOSD in the last quarter of 2023 – though that only includes the period after it completed the Horizon deal on 6th October – rising to $80 million in the first quarter of this year.

The new data in IgG4-RD comes at a welcome time for Amgen, as Uplizna is now facing stiffer competition in NMOSD. AstraZeneca’s long-acting complement C5 inhibitor Ultomiris (ravulizumab) was cleared for that indication by the FDA in March, joining its older C5 drug Soliris (eculizumab), while Roche is also in the mix with its Enspryng (satralizumab).

Amgen, meanwhile, is also developing Uplizna for generalised myasthenia gravis (gMG) in a phase 3 trial that could also read out this year.