Roche and Biogen Idec’s blockbuster Rituxan has received yet another approval from regulators in the USA, this time for the most common form of adult leukaemia.

The US Food and Drug Administration has approved Rituxan (rituximab) in combination with the chemotherapy regime fludarabine and cyclophosphamide (FC) for people with previously untreated as well as treated CD20-positive chronic lymphocytic leukaemia. According to the American Cancer Society, there are nearly 90,000 people in the USA living with CLL, accounting for one-third of all leukemia cases, and last year, more than 15,000 new cases were expected to be diagnosed in the country.

The green light is based on data from two Phase III studies, CLL8 and REACH. In the first, previously untreated patients who received Rituxan plus chemotherapy lived a median of 39.8 months without the disease worsening compared to 31.5 months for thosewho received FC alone. In REACH, previously treated patients who received Rituxan plus FC lived for 26.7 months compared to 21.7 months in the other arm.

Hal Barron, Roche’s chief medical officer, said Rituxan with chemotherapy can delay the need for additional treatment “because it significantly extends the time people with CLL live without the disease worsening”. Greg Reyes, head of oncology R&D at Biogen added that this latest approval reinforces the importance of the antibody in heamatologic cancers, noting that Rituxan, either alone or in combination, “has now achieved its fifth approval for the most common forms of non-Hodgkin's lymphoma and adult leukaemia”.

Rituxan, which is sold as MabThera in Europe and is also indicated for rheumatoid arthritis, had sales of almost $6 billion last year and this latest approval can only swell that figure.