Roche announced data from the phase III PRIMA study. The data showed that continuing MabThera (rituximab) for two years in patients who responded to initial treatment with MabThera plus chemotherapy, doubled the likelihood of them living without their disease worsening, known as progression-free survival (PFS), compared to those who did not receive maintenance. The study enrolled patients with previously untreated advanced follicular lymphoma. No new safety signals were observed in this study and the safety profile was consistent with previous experience with MabThera.

The data were featured during an American Society of Clinical Oncology (ASCO) presscast. The organization’s 46th Annual Meeting will take place from June 4 – 8, 2010 in Chicago, with more detailed PRIMA results presented on Saturday, June 5.

“Follicular lymphoma is an incurable cancer that may return many times during a person's life and require additional therapy,” said Hal Barron, M.D., executive vice president, Global Development and chief medical officer, Roche. “The study is important because in those people who continued MabThera, the risk of the cancer progressing was cut in half compared to those who did not receive maintenance MabThera.”

Results of the PRIMA study showed MabThera, when used as maintenance, doubled the likelihood of people with follicular lymphoma living without their disease worsening compared to those who stopped treatment (based on a hazard ratio of 0.50, 95% CI, 0.39; 0.64; p=<0.0001). After two-years of follow-up, 82 per cent of patients who received MabThera maintenance were in remission compared to 66 per cent of patients who did not.

Roche and Genentech recently submitted an extension of the MabThera Marketing Authorization Application to the European Medicines Agency (EMEA) and a sBLA (supplemental Biologics License Application) for Rituxan to the US Food and Drug Administration (FDA) based on the PRIMA study data.

“These findings provide hope for the way we manage follicular lymphoma. MabThera maintenance therapy is likely to become a new standard of care for these patients,” said Prof. Gilles Salles, Centre Hospitalier Lyon Sud, France and principal investigator for the PRIMA trial.

Follicular lymphoma is a common type of non-Hodgkin’s lymphoma (NHL), accounting for about one in five of all cases. It can occur at any time during adulthood, though people are typically diagnosed during their sixties, and affects as many men as it does women. It is a low-grade lymphoma, which means that it usually develops slowly. Approximately 286’000 people worldwide are diagnosed with non-Hodgkin lymphoma each year.

PRIMA abstract will be presented at the 46th Annual Meeting of the American Society of Clinical Oncology (ASCO) in Chicago: PRIMA: Rituximab Maintenance For Two Years Significantly Improves the Outcome of Patients With Untreated High Tumor Burden Follicular Lymphoma After Response to Immunochemotherapy: Results of the PRIMA Study (Abstract #8004) – Saturday, June 5, 2010, 1:00 p.m. – 1:15 p.m. CST, Room E354a

Sponsored by the Group d’Etudes de Lymphomes de L’Adulte (GELA), PRIMA is an international, multicenter, randomized, Phase III clinical study that enrolled 1’217 patients with previously untreated advanced follicular lymphoma. The study evaluated the efficacy and safety profile of maintenance MabThera in patients who responded to initial treatment with MabThera plus chemotherapy (induction treatment).

In the study, MabThera plus either CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone), CVP (cyclophosphamide, vincristine, prednisone) or FCM (fludarabine, cyclophosphamide, mitoxantrone) chemotherapy was used as initial treatment. Patients who responded (1,018/1,217) were randomized to receive MabThera alone, given once every two months for two years (maintenance), or observation alone.

The safety profile was consistent with those previously reported in pivotal studies of MabThera alone or in combination with chemotherapy. Serious adverse events (Grade 3 or 4) were reported in 23 per cent of patients who received MabThera maintenance compared to 16 per cent who did not, including low white blood cell (neutrophil) counts (4 per cent vs. 1 per cent) and infections (4 per cent vs. 1 per cent).

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.

Genentech and Biogen Idec co-market Rituxan 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.