Keypoints

Relapsed non-Hodgkin's lymphoma

Monoclonal antibodies, such as rituximab monotherapy, are used in the treatment of non-Hodgkin's lymphoma that has relapsed after treatment. Initial treatment for indolent non-Hodgkin's lymphoma usually produces a remission, which may last for a number of years. However, almost all of these patients have a relapse, and the lymphoma recurs.

There is now a lot of evidence that monoclonal antibody therapies are useful in treating non-Hodgkin's lymphoma that has relapsed

Around half of patients with a relapsed indolent non-Hodgkin's lymphoma will have a further remission with rituximab monotherapy. The average length of remission is then about 13 months, which is longer than the average length of remission in those whose treatment does not include rituximab. Some patients respond a second and even a third time to rituximab.

Rituximab may be given by itself in the treatment of relapsed indolent non-Hodgkin's lymphoma. However, it may also be given in combination with chemotherapy.

When it is used with chemotherapy, similar to the previously untreated patients, it is usually given at the beginning of each treatment cycle, just before the chemotherapy. Combining rituximab with chemotherapy has been shown to increase the length of remission. The side effects of rituximab generally occur only when the drug is being given and decrease with later doses, and giving it with chemotherapy does not cause any significant increase in the side effects experienced by patients

There is also increasing evidence that rituximab may be useful, in combination with chemotherapy, in treating aggressive non-Hodgkin's lymphoma that has relapsed following successful chemotherapy. Sometimes it is used as part of the preparation for peripheral blood transplantation or bone marrow transplant.

Maintenance therapy is given to patients who are well after successful treatment for their non-Hodgkin's lymphoma - in other words, patients who are in complete or partial remission. The idea is that regular therapy may increase the duration of the remission. This has been an approved indication since July 2006 in the European Union

Evidence for monoclonal antibody therapy

There is now a lot of evidence that monoclonal antibodies, in particular rituximab, are useful in treating non-Hodgkin's lymphoma that has relapsed.

For example, in indolent non-Hodgkin's lymphoma that has relapsed, rituximab monotherapy was shown to produce a complete or partial remission in almost half of patients and was well tolerated. In patients relapsing after the first course of rituximab, patients responding to a second course experienced a second remission that was at least as long, if not longer, than the first one.

This is different than with chemotherapy alone, where the tendency for the second remission is to be shorter than the first one. Some patients go on to respond a second and even a third time to rituximab.

Likewise, clinical trials in patients with aggressive non-Hodgkin's lymphoma have shown that adding rituximab to chemotherapy increases the effectiveness of the treatment.