JOHN HAINSWORTH, MD: The median survival of patients with low-grade lymphomas is about eight years. So a lot of patients do well, but they're never free of the lymphoma.
ANNOUNCER: Never being free of low-grade, or indolent, lymphoma means the disease is likely to recur, requiring additional rounds of treatment.
JOHN LEONARD, MD: Standard options for patients who have relapsed indolent lymphoma include many of the same chemotherapy regimens that we use as initial treatment. The challenge is that they tend to be less effective the second, third, fourth time around than they are the first time around.
ANNOUNCER: In 1997, a different type of drug, called a monoclonal antibody, was approved as an alternative treatment for recurrent, indolent lymphoma.
SANDRA J. HORNING, MD: There was a lot of enthusiasm about the advent of a treatment that was effective and was safe. The major difference with rituximab compared to conventional chemotherapy is twofold. One, it's a different form of therapy. It attacks cells in a different way, so that patients who were no longer responsive to chemotherapy could still respond to rituximab. And perhaps even more importantly, it had very little toxicity, so the treatment could be a respite for patients with recurrent disease, from the toxicities associated with treatment, particularly with chemotherapy.
ANNOUNCER: The initial studies, on older patients with NHL, showed similar results as for patients treated with a second round of chemotherapy.
JOHN LEONARD, MD: Those results showed that about 50 to 60 percent of patients with relapsed indolent lymphoma had response or tumor shrinkage of their disease to a treatment of four doses of rituximab. And, in general, those responses lasted in the range of about a year.