With success in myasthenia gravis trial, Amgen's Uplizna looks set up to add new indication

Three months after Amgen revealed that Uplizna had aced a phase 3 trial in immunoglobulin G4-related disease (IgG4), the company said the anti-CD-19 antibody has excelled in a study against another neurologic disorder.

In the ongoing phase 3 MINT study, patients with the rare autoimmune condition myasthenia gravis (MG) experienced a median improvement of 4.2 points on the 24-point activities of daily living scale (MG-ADL), compared to a 2.3-point improvement for those on placebo after 26 weeks of treatment, Amgen said Tuesday.

In the study, those on Uplizna were dosed twice 15 days apart at the start of the trial, followed by doses every six months. The results showed a “clinically meaningful and statistically significant benefit,” Amgen said in a presentation (PDF).

MG is a condition in which antibodies destroy the communication between nerves and muscle, weakening the muscles of the body, particularly those that control the eyes, mouth, throat and limbs.

Amgen did not post the results in a press release. It revealed the result during a webcast on Tuesday afternoon, in which it also reported successful but underwhelming results from a trial of its investigational eczema treatment rocatinlimab.

As for Uplizna, Amgen said that it is initiating regulatory filing activities to set it up for approval to treat MG. Last year, Argenx gained an FDA for its injected treatment Vyvgart Hytrulo for MG. AstraZeneca’s Soliris also is approved in the indication.

“Uplizna has a unique and differentiated product profile which makes it a very meaningful treatment option for MG patients,” Vikram Karnani, Amgen’s rare disease chief, said during the webcast.

Karnani pointed out that Uplizna works “upstream” of other approved treatments and has an advantageous dosing schedule, which is “important for a chronic disease, especially from a point of convenience for these patients.”

Uplizna also retained its efficacy as patients in the trial tapered their steroid use toward a goal of 5 mg per day by week 24.

“Steroids are often used to treat myasthenia gravis patients but prolonged high-dose steroid use can have pretty harmful effects,” Karnani added. “All of our competitor trials allowed patients to remain on background therapy including steroids.”

Uplizna, which was initially approved in 2020 for neuromyelitis optica spectrum disorder (NMOSD), could add two indications in short order. In June, in a trial of patients with IgG4, the company reported that a 300 mg intravenous dose of Uplizna reduced the risk of flare by 87% compared to placebo over 52 weeks.

William Blair analyst Matt Phipps called it a “meaningful expansion opportunity” as a nod in IgG4 would add a treatable patient population double the size of that for NMOSD.

Uplizna generated sales of $92 million in the second quarter, which was up from $80 million in the previous period. Uplizna was one of the key drugs acquired from the company’s $27.8 billion acquisition of Horizon Therapeutics, which was completed in October of last year.