Swiss drug maker, Roche, said on Tuesday that the European Commission had approved its drug MabThera, a cancer-drug, to treat lymphoma patients with arthritis. Analysts believe the push into arthritis will bring in billions of dollars worth of additional revenue since the illness affects 21 million people worldwide.

According to Roche, MabThera when used in combination with methotrexate has been approved for adult patients with rheumatoid arthritis. It also said most of these patients were intolerant to other modes of treatment.

The Food and Drug Administration approved MabThera for rheumatoid arthritis earlier this year. The drug is alternatively referred to as rituxan.

The drug specifically targets B-cells known to drive the arthritic disease process.

Currently, patients with arthritis first take anti-inflammatory drugs before moving onto anti-TNF therapies that are biological drugs. Those who do not respond to both of these procedures may opt for rituxan.