Sanofi, Regeneron rack up Humira-topping data for delayed RA therapy sarilumab

Regeneron had hoped to roll out its Sanofi-partnered biologic sarilumab for rheumatoid arthritis this year, but the FDA rejected it on manufacturing concerns.

Sanofi and Regeneron’s wannabe blockbuster sarilumab may be delayed, but once it hits the market, it will have to take on AbbVie’s behemoth Humira. Good thing it's posted new data that could help arm it for the fight.

In a study of 369 adults with active rheumatoid arthritis, Sanofi and Regeneron’s prospect topped the AbbVie megablockbuster at decreasing disease activity. Sarilumab sent DAS28-ESR—a disease-activity metric that evaluates joint swelling and inflammation—down from baseline by 3.28 points, compared with the 2.20 decrease Humira posted. The DAS28 scale ranges from 0 to 9.4.

Those data will be important for the duo as it sets out to steal share from the world’s best-selling drug and other blockbusters in the anti-TNF class. The drugmakers will be vying for the 30% of RA patients who receive biologic monotherapy instead of methotrexate, usually because of a methotrexate intolerance.

Sanofi and Regeneron’s reps won’t get to tout the results for awhile, though. Last month, the FDA handed the tandem a complete response letter for the candidate med, flagging “manufacturing deficiencies” at a Sanofi fill-finish facility.

And that wasn’t the only bad news the partners have faced recently. Last week, Sanofi and Regeneron announced that their PCSK9 contender Praluent couldn’t capitalize on an opportunity to nab the lead in the PCSK9 sales race. Instead of stopping early, a key cardiovascular outcomes trial will go ahead as planned, they said, which will delay any marketing boost some early positive data could have promised.

Meanwhile, sarilumab is just one contender lining up to challenge Humira, a popular target among biosimilars makers. Amgen’s copycat version of the drug, which already boasts an FDA green light, is first in line to take on AbbVie’s superstar. When it’ll actually get that chance depends on how Humira's patents hold up to legal challenges.