ORLANDOThe activity of rituxi-mab (Rituxan) in lymphocyte-predominant Hodgkin’s disease (LPHD) warrants additional investigation, according to a presentation at the 38th Annual Meeting of the American Society of Clinical Oncology (abstract 1052).
"Rituximab appears to have some activity in patients with LPHD, but the duration of response is quite short, and two cases transformed to large-cell non-Hodgkin’s lymphoma, so there is some debate about whether it is an appropriate therapy," lead author Bradley C. Ekstrand, MD, PhD, senior oncology fellow, Stanford University Medical Center, told ONI in an interview. "It will require a lot more investigation."
Lymphocyte-predominant Hodgkin’s disease is rare, constituting only 5% of all Hodgkin’s disease cases, and misdiagnosis is common because pathologic features may be similar to those of other types of Hodgkin’s disease. Although LPHD is typically relatively indolent and limited to the lymph nodes, it represents a therapeutic challenge.
"With the standard therapy of radiation therapy and chemotherapy, 96% of patients have a complete response, but they tend to relapse over time, with relapses continuing up to 20 years after remission," Dr. Ekstrand said. "Significant late effects of therapy include secondary cancers."
The rationale for using the anti-CD20 antibody rituximab(Drug information on rituximab) is that the malignant cells of LPHD are CD20 positive, and therefore rituximab may have activity with fewer adverse late effects than conventional chemotherapy.
In this phase II trial, 22 patients with either untreated or relapsed CD20-positive LPHD and measurable disease on CT scans received four consecutive weekly doses of rituximab at 375 mg/m2. Patients who had previously received rituximab were excluded, and steroid treatment during the study period was prohibited.
Median age at treatment was 45 years (range, 18 to 61 years). Of 10 previously treated patients, six were in their first relapse, three in their second relapse, and one in fourth relapse. Three had relapsed after chemotherapy alone, three after radiotherapy alone, and four after combined modality treatment. Median duration of remission before receiving rituximab was 9 years. Of 12 patients with untreated disease, 6 were stage I or II, and 6 were stage III.