Targeted antibody therapy MabThera (rituximab) halves the risk of disease progression in previously untreated patients with follicular lymphoma, the most common type of indolent (slow-growing) non-Hodgkin lymphoma (NHL), compared to those who received no maintenance therapy.
This new data, to be presented at the American Society of Clinical Oncology (ASCO) annual meeting in June, also demonstrate that when treated with rituximab alone for a two-year period (known as ‘maintenance therapy’) following initial treatment with rituximab plus chemotherapy, 82 per cent of patients with previously untreated advanced follicular lymphoma were able to live without their disease progressing, compared to 66 per cent of those who did not receive maintenance therapy.
“Dr Robert Marcus, Consultant Haematologist at King’s College Hospital, London, commented: “The PRIMA study results show a significant improvement in progression-free survival in those patients who received rituximab maintenance, therapy compared to those who did not. These data could change both our practice and our perspective on what is, in the majority of patients, a condition that should be controllable with intermittent and relatively non-toxic therapy.”
Rituximab is the world’s first monoclonal antibody licensed for cancer treatment and is the first treatment to be licensed for NHL maintenance therapy, through its initial indication in patients with relapsed/refractory (difficult to treat) disease. The new data from the phase III PRIMA trial have been submitted to EU health authorities with a view to extending the current maintenance licence in 2010, to include previously untreated patients.
Dr Premini Mahendra, Consultant Haematologist at the Queen Elizabeth Hospital, Birmingham said: “These results are extremely encouraging and reaffirm rituximab’s ability to suppress and control this complex cancer. While not considered curable, advances in treatment, in particular maintenance therapy, mean follicular lymphoma is now a condition that can be managed chronically. The aim for treatment is to prolong the time that patients are in remission, when their cancer is under good control, and rituximab maintenance therapy has been shown to do this very successfully in relapsed follicular lymphoma. These findings have potential to change the way this condition is managed in the first-line setting.”
Maintenance therapy is designed to prolong the effects of the primary treatment and delay relapse for as long as possible. Traditionally, therapy is stopped once the cancer is in remission and is only resumed when the patient relapses or the cancer progresses. Targeted therapies such as rituximab can be taken for longer time periods than treatments such as chemotherapy, as they are better tolerated and have fewer side effects.
Sally Penrose, Chief Executive, Lymphoma Association, commented: “A key goal for anyone with follicular lymphoma is to stay in remission for as long as possible so that they are able to return to work and undertake everyday tasks. Coming to terms with the uncertainty of living with this incurable cancer can be very difficult both for patients and their families. However, advances in therapy that prolong remission make it easier for those affected to return to their normal life.”
Rituximab works by targeting B-cells, white blood cells that are vital to the body’s immune system. Most non-Hodgkin lymphomas affect the B-cells, which is why rituximab is particularly effective at tackling a number of conditions that disrupt the normal function of these cells. 12 years on from its launch, rituximab is now licensed to treat both indolent and aggressive forms of NHL, rheumatoid arthritis and chronic lymphocytic leukaemia.
Safety data from the PRIMA study are consistent with that seen in previous trials, with no new or unexpected findings. The most common adverse events in the PRIMA study were infections, with grade 3 – 4 (serious) adverse events including neutropenia and infections. In each case, the incidence was only moderately higher in the maintenance group compared to patients who did not receive maintenance.