Inroads in the Therapy of Indolent Lymphomas: Exploiting Biological Insights

Progress and promise in the treatment of indolent lymphomas

In the era of conventional alkylating agent-based chemotherapy, advanced stage indolent lymphoma has been considered incurable. The failure of our traditional therapies to cure these patients, coupled with the indolent course of the disease and the elderly population affected, has fostered a nihilistic attitude about the treatment of these diseases. Twenty years ago, in the absence of interesting alternatives to alkylating agents, judicious use and reuse of alkylators was perhaps the best we could do. There are now many reasons for optimism and excitement in the treatment of these diseases, including the availability of promising agents such as interferon-alpha, the nucleoside analogues, and rituximab. Radioimmunotherapy will also likely play a role in future therapy programs. Allogeneic stem cell transplantation is a high-risk approach that is not an option for all patients, but it has the potential to cure patients, even in the setting of relapse. Mini-allogeneic transplantation may permit an approach to allogeneic transplantation that is better tolerated than standard transplant strategies. In addition to these therapy options, biological insights have provided new options for monitoring patients. Molecular monitoring (polymerase chain reaction for bcl-2) is a stringent measure of short-term treatment efficacy, and one that correlates with durability of remission, i.e., it is a surrogate marker by which to judge treatment efficacy. There used to be a limited number of conventional treatment approaches, which consistently failed. The pendulum has swung. There are now many promising new options. It is time to plan and conduct trials that are geared for success.

Treatment of follicular and other indolent lymphomas

The understanding of specific lymphoma entities continues to evolve. This is perhaps most clearly illustrated by developments concerning gastric lymphomas of mucosa-associated lymphoid tissue (MALT) origin, ranging from further evidence of the role played by Helicobacter pylori, to new information about the role of an apoptotic regulatory gene, bcl-10. Another area of productive research is the study of the mechanism of immune recognition and death signaling in follicular lymphomas. This should lead to refinements and improvements in an already very promising array of immunotherapeutic approaches, which currently ranges from vaccine development to allogeneic transplant strategies designed to induce a graft-versus-lymphoma effect. The clinical success of the chimeric anti-CD20 antibody, rituximab, leaves no doubt that biologic insights can lead to therapeutic advances. Researchers appear to be breaking free of the notion that alkylating agent therapy is the best option and the only viable treatment strategy for the indolent lymphomas. The current challenge is to apply new insights wisely.