Amgen released new Phase 3 data Wednesday for its rare disease drug Uplizna in an autoimmune condition, bringing it potentially closer to another FDA approval.
The results may put additional pressure on other companies working in similar spaces, such as Immunovant and argenx, both of which faced recent setbacks. Immunovant postponed readouts last week for two of its immune-mediated disease programs, while an injectable form of argenx’s approved drug failed a Phase 3 study in a platelet disease called primary immune thrombocytopenia last November.
Uplizna’s success came in a study looking at patients with IgG4-related disease. The drug hit its primary endpoint, Amgen said, reducing the risk of a disease-caused flare by 87% after one year compared to placebo. It also achieved all of the study’s secondary endpoints.
Vikram KarnaniVikram Karnani, Amgen’s head of rare diseases, told Endpoints News the drug can help patients reduce the “unpredictability” of flare-ups that affect their day-to-day lives. There is currently no FDA-approved treatment for IgG4-related disease, he said.
“When those flares show up, it completely changes the quality of life of the patient,” Karnani said. “The ongoing management of disease is key to flare prevention, and more importantly, potential future organ damage.”
The company is still figuring out when it will file for FDA approval, Karnani added. “It would be a bit premature to start to speculate on that right now,” he said.
Yaron WerberTD Cowen analyst Yaron Werber said in a note to investors that the readout was a best-case scenario for Amgen. Not only does it emphasize Uplizna as an “underappreciated” drug with the potential for several autoimmune disease approvals, it also boosts confidence for a trial in myasthenia gravis expected to read out before the end of this year.
Peak sales in IgG4-related disease, for which Werber estimates a market between 7,000 to 14,000 patients, could reach up to $3 billion, Werber said.
Though Immunovant and argenx are not currently testing their drugs in IgG4-related disease specifically, Wednesday’s readout could have implications in myasthenia gravis. Both formulations of argenx’s Vyvgart are approved to treat the condition, while Immunovant’s batoclimab will see a Phase 3 readout in the first quarter of 2025 — delayed from the second half of 2024.
Immunovant is also testing an early-stage program, IMVT-1402, in autoimmune diseases more broadly. The argenx and Immunovant programs are all FcRn inhibitors, while Uplizna targets CD19-expressing B cells.
Other companies developing drugs that reduce IgG levels include Johnson & Johnson, whose nipocalimab read out a positive Phase 3 myasthenia gravis study and two Phase 2 studies in rare diseases in February, and Biohaven, whose early-stage candidate BHV-1300 disappointed investors in a healthy volunteer study last month.
Uplizna came to Amgen via the company’s $27.8 billion acquisition of Horizon last year. The drug was previously approved to treat neuromyelitis optica spectrum disorder in June 2020, a decision won by Viela Bio, which itself was spun out from AstraZeneca. Horizon acquired Viela for $3 billion in February 2021.