After posting positive late-stage results for its rare blood disease drug, Sanofi has been handed a priority review from the FDA for sutimlimab.
The French Big Pharma is hoping that its complement C1s inhibitor will get a green light for use in cold agglutinin disease (CAD), a rare condition in which the immune system turns on the patient’s red blood cells.
By inhibiting C1s, Sanofi thinks sutimlimab can prevent the activation of a mechanism that destroys red blood cells, thereby sparing patients from the anemia, fatigue and other symptoms that characterize CAD.
The FDA will speed through its application for the drug, with a decision expected by Nov. 13 this year (pandemic chaos pending).
“People living with cold agglutinin disease currently have no approved treatment option and experience chronic anemia and profound fatigue, which have a persistent and serious impact on their lives,” said John Reed, M.D., Ph.D., global head of research and development at Sanofi.
“Results from our 26-week pivotal Phase 3 study clearly demonstrated that sutimlimab had a clinically meaningful effect on complement-mediated hemolysis, which is the cause of anemia and fatigue. If approved, sutimlimab will be the first and only FDA-approved treatment to uniquely address C1-activated hemolysis and help alleviate the chronic disease burden for people with CAD,” Reed said.
At the American Society of Hematology annual meeting late last year, Sanofi revealed the phase 3 trial generated data for the FDA. After receiving weekly infusions of the study drug for 26 weeks, 13 of the 24 people in the study had met the primary endpoint, a composite assessment that looked at hemoglobin and freedom from transfusions.
Close to two-thirds of participants met the hemoglobin part of the endpoint, indicating they either experienced a 2 g/dL increase from baseline or ended the study with 12 g/dL or higher, a level that is at the bottom of the normal range for women and just below it for men. More than two-thirds of the subjects were free from transfusions from week five onward.
Sanofi, echoing the findings of an earlier study, showed sutimlimab starts working quickly. The participants experienced a mean increase in hemoglobin of more than 1 g/dL by the end of the first week, rising to more than 2 g/dL by the third week. Hemoglobin levels stayed above 11 g/dL, having begun below 9 g/dL, for the rest of the trial.
The trial also linked sutimlimab to fast-onset effects against other endpoints. Bilirubin, a biomarker for red blood cell destruction, fell in the first week and normalized by week three. Participants also reported improved scores on a fatigue scale from week one onward, suggesting reduced destruction of red blood cells translates into improved quality of life for patients.
Winning approval for sutimlimab would give Sanofi a chance to start recouping some more of the $11.6 billion (€10.5 billion) it spent to acquire Bioverativ last year. Bioverativ acquired sutimlimab the year before being bought by Sanofi, paying $400 million upfront for True North Therapeutics. At the time of Sanofi’s takeover of Bioverativ, Citi analyst Peter Verdult saw sutimlimab as “the most promising pipeline asset” at the acquired company.
The interest in sutimlimab is, in part, a reflection of its potential in indications beyond CAD. Sanofi is running an early phase trial in immune thrombocytopenic purpura.
May 15, 2020