NEW ORLEANSRituximab (Rituxan) is more effective in indolent
B-cell non-Hodgkins Lymphoma (NHL) than in mantle cell lymphoma
(MCL), according to a study evaluating factors affecting toxicity,
response, and time to progression presented at the 36th Annual
Meeting of the American Society of Clinical Oncology (ASCO).
Ninety patients with CD20-positive B-cell NHL (group 1) or mantle
cell lymphoma (group 2) were treated with rituximab at 375 mg/m²
for 4 weekly infusions. To prevent adverse drug reactions, patients
were premedicated with ibuprofen (200 mg) and d-chlorphen-iramine
maleate (2 mg) 30 minutes before each infusion.
Included patients had relapsed or refractory B-cell NHL with
measurable lesions (2 cm or larger if one lesion), age between 15 and
74 years, ECOG performance status (PS) 0 to 2, and adequate organ
function, said lead investigator Michinori Ogura, MD, of the
IDEC-C2B8 Study Group, Japan.
Follicular lymphoma accounted for 59 patients and mantle cell
lymphoma for 17. Excluded were patients with positive human
antichimeric antibody (HACA) with a history of mouse monoclonal
antibody treatment; B cells in peripheral blood greater than
5,000/mL; CNS involvement; or positive HBs antigen, HBV antibody, or
Fifteen patients were judged ineligible due to pathology or positive
HBV serology, leaving 61 eligible in group 1 and 13 in group 2.
Plasma rituximab concentrations were assayed by ELISA.
Dr. Ogura said that overall response rates in indolent B-NHL and
mantle cell lymphoma were 61% (37/61) and 46% (6/13), respectively.
The median time to progression was 245 days for NHL (range, 19 to 539
days) and 111 days for mantle cell lymphoma (range, 20 to 266 days).
Response rates in indolent B-cell NHL were affected by performance
status (PS 0 vs 1-2, P = .011); B symptoms (+ vs -, P =
.012); and number of prior chemotherapies (1 vs 2 vs 3, P =
Dr. Ogura stated that in a subgroup of 26 patients for whom rituximab
concentrations were available, there was a significant increase in
time to progression for patients showing high plasma concentration
both at day 14 (more than 70 mg/mL) and at 3 months (more than 10
mg/mL), compared with those having lower concentrations (P =
Plasma concentrations at limited time points may become a
predictive surrogate marker for prediction of time to
progression, he said.
By univariate analysis, hematologic toxicities (grade 3-4) were more
frequent in female than in male patients (P = .028).
Leukopenia and thrombocytopenia were more frequent in patients with
high LDH (serum lactic dehydrogenase) (P = .020 and P =
Nonhematologic toxicities (grade 2-3) were more frequent in patients
with high LDH, more than two extranodal sites, or bone marrow
involvement, Dr. Ogura said. He pointed out that toxicities were seen
mostly during the first infusion.