On July 25, Sandoz announced that the Food and Drug Administration has accepted its 351(k) application for the first biosimilar in the multiple sclerosis category.
Developed by its partner Poland-based Polpharma Biologics, PB006 is a natalizumab biosimilar (reference product, Biogen’s Tysabri®). The agent is an integrin-receptor antagonist that has been prescribed since 2004. Sales revenues in the U.S. for Tysabri were $1.1 billion in 2021. The drug is infused intravenously in adults with highly active, relapsing-remitting multiple sclerosis (RRMS).
The filing is supported by a phase 3, randomized, double-blind trial, in which 256 patients with RRMS were given 300-mg infusions of either PB006 or Tysabri every 4 weeks for a total of 12 doses. Researchers monitored the development of combined unique active lesions on imaging. At week 24, the mean number of lesions for the biosimilar group was 1.4, compared with 1.9 for those taking the reference product. The results of the study demonstrated the noninferiority of the biosimilar compared with the reference product in terms of efficacy and safety.
Based on the submission date, an FDA decision may be expected as early as Q2 2023. Sandoz noted in its announcement that the drug was submitted for European Medicines Agency approval in mid-July.
As reported earlier, natalizumab is an unusual target for biosimilars, in that it is not the dominant pharmaceutical prescribed for its class. In fact, Tysabri’s marketshare is less than 10% of all patients with MS. However, Biogen manufacturers several other drugs in the MS class, and receives royalties on the sales of best-selling drug Ocrevus®. Prestige Pharma of Singapore, is also involved in preclinical research of a natalizumab biosimilar, but it stated that it is targeting natalizumab’s Crohn’s disease indication only.