Roche announced that a Phase III study investigating MabThera (rituximab) in combination with chemotherapy has shown a significant improvement in progression free survival in patients with relapsed or refractory Chronic Lymphocytic Leukaemia (CLL), the most common form of adult leukaemia.

The pivotal REACH trial successfully met its primary endpoint by showing that patients treated with MabThera in combination with the current standard chemotherapy were able to significantly extend the amount of time they lived without their disease progressing, compared to patients treated with chemotherapy alone. Preliminary analysis of the safety data is in line with previous trials.

Full results of the REACH study will be submitted at an upcoming medical meeting, a Roche release said.

"The positive results of the REACH study are very encouraging news for patients suffering from a disease that remains life-threatening and incurable ," said William M. Burns, CEO Pharmaceuticals Division of Roche. "The outcome of this trial, together with the positive findings of the pivotal CLL8 trial in first-line CLL patients, clearly demonstrate the important role MabThera will have in the treatment of this devastating disease."

Chronic Lymphocytic Leukaemia (CLL) is the most common type of leukaemia in adults, accounting for approximately 25-30 per cent of all forms of leukaemia. Incidence of CLL in Western countries is around 2-4 per 100,000, and is twice as common in men compared to women. Ninety five per cent of patients diagnosed are aged over 55 years. While CLL is generally considered a disease that is slow to progress, a significant proportion of patients have rapidly progressing forms of the disease.

The REACH study is a randomized international study that included 552 patients with CLL. It was conducted at 90 study sites across 18 countries. The study was set up to investigate whether treatment of patients with relapsed or refractory CLL with MabThera in combination with chemotherapy (fludarabine and cyclophosphamide) was more beneficial than treatment with chemotherapy alone. The primary endpoint of the study was to show an increase in terms of median progression-free survival.

The data will be used for applying for approval for the use of MabThera in relapsed or refractory CLL with the relevant health authorities.

MabThera is a therapeutic antibody that binds to a particular protein - the CD20 antigen - on the surface of malignant cells as well as on normal B-cells. It then recruits the body's natural defences to attack and kill the marked B-cells. Stem cells (B-cell progenitors) in bone marrow lack the CD20 antigen, allowing healthy B-cells to regenerate after treatment and return to normal levels within several months.

MabThera is indicated for the treatment of previously untreated patients with stage III-IV follicular lymphoma in combination with chemotherapy.

MabThera maintenance therapy is indicated for patients with relapsed/refractory follicular lymphoma responding to induction therapy with chemotherapy with or without MabThera.

MabThera monotherapy is indicated for the treatment of patients with stage III-IV follicular lymphoma who are chemoresistant or are in their second or subsequent relapse after chemotherapy.

MabThera is indicated for the treatment of patients with CD20 positive diffuse large B cell non-Hodgkin's lymphoma in combination with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone) chemotherapy.

MabThera in combination with methotrexate is indicated for the treatment of adult patients with severe active rheumatoid arthritis who have had an inadequate response or intolerance to other disease-modifying anti-rheumatic drugs (DMARD) including one or more tumour necrosis factor (TNF) inhibitor therapies. MabThera is known as Rituxan in the United States, Japan and Canada.

To date, patients have received more than 1.5 million treatments with MabThera worldwide.

Genentech and Biogen Idec co-market MabThera in the United States, and Roche markets MabThera in the rest of the world, except Japan, where MabThera is co-marketed by Chugai and Zenyaku Kogyo Co. Ltd.