Roche has been informed by the European Organisation for Research and Treatment of Cancer (EORTC) that a phase III study1 in relapsed indolent non-Hodgkin's lymphoma (NHL) evaluating the use of MabThera (rituximab) as maintenance treatment has shown positive results earlier than expected. MabThera maintenance therapy is administered over two years and aims to prevent disease recurrence.

"Our study confirms that MabThera maintenance therapy is beneficial for patients that have already received MabThera as part of their initial therapy. The full results of the trial will be presented as an oral presentation at this year's annual conference of the American Society of Hematology (ASH) in Atlanta," said lead investigator, Professor Marinus van Oers M.D., from the academic medical center of the University of Amsterdam.

According to a company release the international cooperative group phase III trial was conducted in 18 countries and recruited 465 patients with relapsed indolent NHL. Patients were randomised to receive either six cycles of MabThera in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy, or CHOP chemotherapy alone. Patients who responded to initial treatment were then randomised to MabThera maintenance therapy (one infusion every three months for two years) or no further treatment.

A pre-planned analysis in early 2004 showed that induction treatment with MabThera plus CHOP was significantly superior to CHOP alone and that two years of MabThera maintenance therapy substantially improved progression-free survival compared to observation. Therefore, the trial was suspended as it had reached both primary endpoints. At that time the results were not mature enough to determine if MabThera maintenance therapy also prolongs progression-free survival for the subgroup of patients who already had received MabThera plus CHOP as initial treatment. The EORTC therefore originally decided to amend the study to evaluate this outstanding question

Non-Hodgkin's lymphoma affects 1.5 million people worldwide. Indolent NHL, representing about 45% of NHL patients, is a slow developing but serious cancer of the lymphatic system.

MabThera is a therapeutic antibody that binds to a particular protein, the CD20 antigen, on the surface of normal and malignant 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.

Roche is currently preparing an application to the European Authorities to request a label extension for maintenance therapy, expected to be submitted in the fourth quarter 2005, making this treatment option available to all patients.