The European Commission has approved Roche and Genentech’s MabThera to treat rheumatoid arthritis and as a maintenance therapy for patients with relapsed or refractory follicular non-Hodgkin's lymphoma.

The approval in arthritis is of particular significance for MabThera (rituximab), according to analysts, because it opens up a market that could potentially add more than a billion dollars to its annual turnover, even though it has been cleared for use only as a second-line treatment after current biologics.

Biologic therapy with anti tumor necrosis factor drugs currently accounts for around $4.6 billion of the total $5.5 billion rheumatoid arthritis market, but it is estimated that 30%-40% of patients do not respond to these drugs.

Rituximab was approved for the same indication earlier this year in the USA, where it is sold as Rituxan. Roche reported MabThera sales of 1.15 billion Swiss francs ($921m) in the first quarter of this year, while Genentech said it booked $477 million from Rituxan in the same period.

Meanwhile, approval in maintenance therapy means that rituximab’s position at the cornerstone of NHL therapy will be consolidated, according to Roche. In trials, maintenance therapy with the drug reduced the risk of death by almost half (48%) for patients with this form of NHL, compared to standard disease management.

NHL is one of the fastest growing cancers and has grown in incidence by 80% since the early 1970s. If the number of cases continues to increase at current rates, NHL will have an incidence similar to that of breast, colon, lung and skin cancer by the year 2025. Indolent NHL is a slow developing cancer and patients may live many years with the disease but standard treatments cannot cure it.