Alexion's Ultomiris notches myasthenia gravis win amid quest for 3rd Soliris use

In the quest to match its predecessor Soliris, Alexion's Ultomiris just notched a win in the autoimmune disorder myasthenia gravis. 

Alexion is trumpeting data showing Ultomiris met its primary endpoint in its rare disease phase 3 study, which evaluated changes in generalized myasthenia gravis (gMG) symptoms using a standard patient assessment. Armed with the results, which Alexion says could position the drug as "the new standard of care for gMG," the company plans regulatory filings in late 2021 or early 2022.

Generalized myasthenia gravis crops up in about 107 to 278 people per million, Alexion said, and most commonly occurs in women before the age of 40 or in men above 60 years old. The neuromuscular disorder causes inflammation that damages the connection between nerve cells and the muscles they control, which can lead to loss of muscle function and "severe" weakness.

Alexion's blockbuster Soliris won its gMG green light back in 2017. The drug has continued its ascent since its 2007 debut, generating about $4.06 billion in 2020 sales, Alexion said in its annual report. Alexion is in the process of selling itself to AstraZeneca in a major M&A move for the industry.

RELATED: Alexion's pricey Ultomiris wins backing from England's cost watchdogs thanks to confidential discount

Meanwhile, Soliris' successor Ultomiris, which scored approval at the end of 2018 to treat adult paroxysmal nocturnal hemoglobinuria (PNH), has spent the past few years chasing its forerunner's rare disease green lights. 

Alexion's 26-week phase 3 trial for Ultomiris looked at 175 gMG patients across the U.S., Europe, the Asia-Pacific region and Japan who hadn't received prior treatment with a complement inhibitor. At the end of the trial, patients on Ultomiris scored better on the Myasthenia Gravis-Activities of Daily Living Profile (MG-ADL) assessment than those on placebo. 

Ultomiris also won out on secondary endpoints using the Quantitative Myasthenia Gravis (QMG) test, which is given by physicians to measure the disease's clinical severity. 

For the 75 patients taking part in Alexion's ongoing extension study, Ultomiris continued to help after 56 weeks. 

But the drug came up short in certain quality of life metrics, including the Revised 15-Component Myasthenia Gravis Quality of Life test and Neuro-QOL Fatigue assessment. 

Ultomiris' safety was on par with placebo, Alexion said. There were four Ultomoris patient deaths at the 52-week mark, but three of them were caused by COVID-19 and none are thought to be related to Alexion's therapy. 

RELATED: After discount, U.K. price watchdog gives a nod to Alexion's Ultomiris for a second rare blood disorder

Upon its approval, Soliris was the first new treatment for myasthenia gravis in more than 60 years, John Orloff, M.D., EVP and head of research & development at Alexion, said in a statement. The latest Ultomiris data suggest the drug could "help a broader range of patients" than those studied in Soliris' phase 3 study, including patients with milder symptoms or earlier-stage disease, he said. 

For its part, Ultomiris broke the blockbuster barrier in 2020 with about $1.08 billion in sales, a big leap over the $338.9 million it ginned up in 2019. The drug bagged a priority review for its second Soliris indication in atypical hemolytic uremic syndrome (aHUS) in June 2019 and scored that approval a few months later.

Overall, Alexion has had a pretty good week. Its proposed $39 billion sale to AstraZeneca won the blessing of the U.K.’s Competition and Markets Authority earlier this week, clearing the final antitrust hurdle after OKs from the European Union and the U.S. The companies expect the deal to close next week.