The U.S. Food and Drug Administration (FDA) has extended its review of Novartis' ofatumumab for the treatment of multiple sclerosis (MS), delaying the decision until September. Ofatumumab, a repurposed cancer drug, offers the potential for a monthly self-administered therapy targeting the overactive B-cells that contribute to nerve damage in MS patients.
Originally developed by Genmab, ofatumumab was first approved by the FDA in 2009 for chronic lymphocytic leukemia under the brand name Arzerra. Novartis gained rights to the drug through an asset swap deal with GlaxoSmithKline in 2015. The drug targets the CD20 receptor on B-cells, which are believed to activate the body's nervous system in multiple sclerosis.
According to Novartis, ofatumumab's selective mechanism of action allows precise delivery to the lymph nodes, where B-cell depletion is needed in MS. Preclinical studies suggest that the drug may also preserve B-cells in the spleen, while the monthly dosing allows for fast repletion of B-cells. Novartis has not provided specific details regarding the reason for the FDA's extended review period but indicated that additional regulatory filings are in progress. Regulatory approval in Europe is expected by the second quarter of 2021.
Competition in the MS Market
While the MS market is substantial, projected to reach $32.9 billion by 2028, ofatumumab faces competition from Roche's Ocrevus (ocrelizumab). Ocrevus has demonstrated strong results in reducing relapses in MS and achieved blockbuster status shortly after its U.S. approval in 2017.
Mechanism of Action
Ofatumumab targets the CD20 receptor on B-cells, which are implicated in the autoimmune response that drives MS. Novartis suggests the drug's mechanism allows targeted B-cell depletion in the lymph nodes, potentially preserving B-cells in the spleen and allowing for rapid B-cell repletion due to monthly dosing.
