Amgen's Uplizna likely to gain new indication after myasthenia gravis trial success

Amgen's neurological disorder treatment, Uplizna, is on track to receive two new indications following successful trial results. Three months after Amgen announced that Uplizna had successfully passed a phase 3 trial for immunoglobulin G4-related disease (IgG4), the company revealed that the anti-CD-19 antibody has also shown promising results in a study for another neurological condition.

In the ongoing phase 3 MINT study, patients with myasthenia gravis (MG) showed a median improvement of 4.2 points on the 24-point activities of daily living scale (MG-ADL) after 26 weeks of treatment. This is compared to a 2.3-point improvement for those on a placebo. The study observed patients who received Uplizna being dosed twice, 15 days apart at the start, followed by doses every six months. According to Amgen, the results presented a “clinically meaningful and statistically significant benefit.”

Myasthenia gravis is a rare autoimmune disorder where antibodies interrupt communication between nerves and muscles, leading to muscle weakness, especially in the eyes, mouth, throat, and limbs. Although Amgen did not issue a press release, the results were disclosed during a webcast, which also included some less impressive outcomes from a trial of its eczema treatment, rocatinlimab.

Amgen is moving forward with regulatory filing activities to secure approval for Uplizna to treat MG. The competition in this space includes Argenx, which received FDA approval for its injected treatment Vyvgart Hytrulo for MG last year, and AstraZeneca’s approved treatment, Soliris.

Vikram Karnani, Amgen’s chief of rare diseases, highlighted during the webcast that Uplizna offers a unique and differentiated profile, making it a significant treatment option for MG patients. Karnani noted that Uplizna functions “upstream” of other approved treatments and comes with a favorable dosing schedule, which adds convenience for patients dealing with a chronic disease.

Uplizna also maintained its effectiveness as patients in the trial reduced their steroid use toward a goal of 5 mg per day by week 24. Karnani emphasized that while steroids are commonly used to manage myasthenia gravis, long-term high-dose steroid use can lead to harmful effects. He added that the competitors' trials also permitted patients to continue background therapy, including steroids.

Initially approved in 2020 for neuromyelitis optica spectrum disorder (NMOSD), Uplizna could soon gain two additional indications. In a June trial involving IgG4 patients, Uplizna demonstrated that a 300 mg intravenous dose reduced the risk of flare-ups by 87% compared to placebo over 52 weeks. According to William Blair analyst Matt Phipps, this represents a “meaningful expansion opportunity,” as an approval for IgG4 would double the treatable patient population compared to NMOSD.

Uplizna generated $92 million in sales during the second quarter, an increase from $80 million in the previous period. The drug was one of the significant assets acquired from Amgen's $27.8 billion acquisition of Horizon Therapeutics, completed in October of the previous year.