A pilot study of rituximab in patients with recurrent, classic Hodgkin disease

To explore the potential role of infiltrating benign B cells in classic Hodgkin disease (HD) lesions in supporting the survival of malignant Hodgkin and Reed–Sternberg (H/RS) cells, the authors initiated a pilot study of rituximab. Rituximab is used to primarily deplete normal B cells from HD lesions. Patients with recurrent, classic HD who had received a minimum of two prior treatment regimens, regardless of whether H/RS cells expressed CD20, were treated with 6 weekly doses of 375 mg/m² rituximab to selectively deplete infiltrating benign B cells. Objective tumor response was determined 3 weeks after completion of the last dose of rituximab and every 3 months thereafter. Serum samples were collected from patients before they started rituximab therapy and 3 weeks after the final course of rituximab. Serum cytokine levels of interleukin 6 (IL-6), IL-10, IL-12, IL-13, and interferon γ were determined using commercially available enzyme-linked immunosorbent assay kits. Twenty-two patients with nodular sclerosis histology were evaluable for treatment response. Five patients (22%) achieved partial or complete remission that lasted for a median of 7.8 months (range, 3.3–14.9 months). Remissions were observed in patients only at lymph node and splenic sites, but not at extranodal sites, and were irrespective of CD20 expression by H/RS cells. Furthermore, systemic (B) symptoms resolved in six of seven patients after therapy. In two patients, partial remissions were associated with a decline in serum IL-6 levels. The current data suggest that rituximab therapy in patients with recurrent, classic HD can alter serum IL-6 cytokine levels, can improve B symptoms, and may result in clinical remissions. Cancer 2003;98:310–4. © 2003 American Cancer Society. DOI 10.1002/cncr.11511