Preliminary results published in Hematology/Oncology Today that were also presented at the 2002 annual meeting of the American Society of Clinical Oncology indicated that the combination of Rituxan® (rituximab) plus epratuzumab appears to produce high anti-cancer responses in patients with relapsed non-Hodgkin’s lymphoma.
Non-Hodgkin’s lymphoma (NHL) is a cancer that begins in the cells of the lymph (immune) system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a very specific function in aiding the body to fight infection. NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. While NHL is categorized by the type of lymphocyte it involves, it is also further defined by the rate at which the cancer grows, based on the appearance of the cells under a microscope. High-grade or aggressive NHL is the fastest growing and low-grade is the slowest growing.
Treatment for NHL varies, according to the type of NHL as well as the stage, or extent. Researchers have been evaluating biologic therapy in the treatment of NHL with two monoclonal antibodies, Rituxan® and Zevalin®, approved by the FDA for treatment of various stages and types of NHL. Epratuzumab is another monoclonal antibody entering the last phases of clinical trials for the treatment of NHL. Monoclonal antibodies are proteins that are made through laboratory processes and are designed to bind to specific portions on specific cells. Rituxan® is designed to bind to the CD20 antigen, or small protein sequence located on the surface of B-lymphocytes. Epratuzumab is designed to bind to the CD22 antigen, also found on B-lymphocytes. Once the antibody is bound to the cell, the immune system recognizes the cell as foreign and attacks the cell. Researchers speculate there are also other mechanisms in which the monoclonal antibodies produce their anti-cancer effects.
Researchers from the Weill Cornell Medical College and New York-Presbyterian Hospital’s Weill Cornell Medical Center recently conducted a small clinical trial to evaluate Rituxan® plus epratuzumab in patients with B-cell NHL. This trial involved 16 patients with low-grade (indolent) NHL and 4 patients with aggressive NHL. All patients had received at least two prior treatment regimens. Of the patients with indolent NHL, 63% achieved an anti-cancer response, with 56% achieving a complete disappearance of cancer (remission). Of the 4 patients with aggressive NHL, three patients achieved an anti-cancer response, with two experiencing a complete remission. Treatment was very well tolerated with very mild transfusion-related effects.
These researchers indicate that although these are preliminary results and the trial sample was small, the anti-cancer activity with this treatment combination appears very promising for both indolent and aggressive recurrent NHL. Future trials with a larger number of patients to evaluate epratuzumab plus Rituxan® are warranted. Patients with recurrent B-cell NHL may wish to speak with their physician about the risks and benefits of participating in a clinical trial further evaluating epratuzumab plus Rituxan® or other novel therapeutic approaches. Two sources of information regarding ongoing clinical trials include the National Cancer Institute ( cancer.gov) and www.eCancerTrials.com. eCancerTrials.com also provides personalized clinical trial searches on behalf of patients.
1.Hematology/Oncology Today. Combination targeted therapy yields 63% response rate in indolent NHL. 2002;3:8-9.
2.Leonard J, Coleman M, Matthews J, et al. Epratuzumab (anti-CD22) and rituximab (anti-CD20) combination immunotherapy for non-Hodgkin’s lymphoma: preliminary response rate. Proceedings from the 38th Annual Meeting of the American Society of Clinical Oncology. 2002;21: abstract 1060.