Immunocytoma: a retrospective analysis from St Bartholomew's Hospital-1972 to 1996

A phase II study of bendamustine in combination with rituximab as initial treatment for patients with indolent non-follicular non-Hodgkin lymphoma

The purpose of this phase 2 study was to determine the activity and safety of six cycles of bendamustine and eight rituximab (RB) as first-line treatment of adult patients with advanced stage non-follicular indolent non-Hodgkin lymphomas (INFL). The primary end-point was the complete response rate (CRR) with expected CRR of 75%. Sixty-nine patients were enrolled; median age was 65 years (45-75), 65% were male, 93% of patients had stage IV disease. Complete and overall response rates were 48% (95% CI = 35.6-60.2) and 86% (CI = 75.0-92.8). The most common grade 3/4 adverse events were neutropenia (43%), thrombocytopenia (7%) and anemia (4%); whereas the rate of febrile neutropenia was very low (3%). At a median follow-up of 22 months (1-43 months), 2-year progression-free survival was 89% (CI = 79-95) and 2-year overall survival was 96% (CI = 87-99). RB combination is active and well tolerated in patients with advanced stage previously untreated INFL.

Fludarabine, cyclophosphamide, and rituximab in patients with advanced, untreated, indolent B-cell nonfollicular lymphomas: phase 2 study of the Italian Lymphoma Foundation

BACKGROUND

Indolent nonfollicular non-Hodgkin B-cell lymphomas (INFLs) are clonal mature B-cell proliferations for which treatment has not been defined to date.

METHODS

In this phase 2 study of patients with advanced INFL, the authors evaluated the efficacy and safety of first-line rituximab, fludarabine, and cyclophosphamide (FCR) as induction immunochemotherapy (rituximab 375 mg/m(2) intravenously on day 1 of each cycle and on days 1 and 14 of cycles 4 and 5; fludarabine 25 mg/m(2) intravenously on days 2-4, cyclophosphamide 250 mg/m(2) intravenously on Days 2-4) every 28 days for 6 cycles followed by a maintenance phase with 4 infusions of rituximab (375 mg/m(2) intravenously on day 1) every 2 months for responders.

RESULTS

Forty-seven patients were enrolled. Among 46 evaluable patients (28 men; median age, 59 years), 19 were diagnosed with lymphoplasmacytic lymphoma, 21 were diagnosed with small lymphocytic lymphoma, and 6 were diagnosed with nodal marginal zone lymphoma. The overall response rate after maintenance was 89.1% with a 67.4% complete remission (CR) rate (CR/unconfirmed CR) and a 21.7% partial response rate. After a median follow-up of 40.9 months, the failure-free survival and progression-free survival rates both were 90.1%, and the overall survival rate was 97.4%. The main toxicity was hematologic, and related grade 3 and 4 neutropenia was observed in 55.3% of patients.

CONCLUSIONS

FCR induction therapy followed by a short maintenance phase is a highly effective regimen with acceptable toxicity.

Clinical features and treatment outcomes of lymphoplasmacytic lymphoma: a single center experience in Korea

Lymphoplasmacytic lymphoma (LPL) constitutes less than 5% of all non-Hodgkin lymphomas, and little is known about clinical features and treatment outcomes for patients with LPL in East Asia. In this study, we summarize our experiences managing patients diagnosed with LPL in Korea. A retrospective analysis was performed using data for 22 patients with LPL diagnosed at Samsung Medical Center. LPL was more common among males (77.3%), with a median age of diagnosis of 63 years (range 26-86). The most common presenting symptom was fatigue related to anemia (59.1%), and the bone marrow was commonly involved at diagnosis (90.9%). IgM paraproteinemia was found in 15 patients, and only one patient had anti-hepatitis C virus. Although some patients could be observed without treatment, the majority of patients required systemic treatment. Chlorambucil alone and cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) or CHOP-like combination chemotherapy was frequently used as a first-line treatment, and a fludarabine-based regimen was commonly used as salvage therapy. However, responses to those treatments were not satisfactory. Even patients who could be monitored without therapy became refractory to salvage therapies once their disease progressed. Eight patients died due to disease progression, and the median overall survival was 70.8 months (95% CI: 31.4-109.2 months). This study describes the clinical features and treatment outcome of LPL in Korea. The treatment approach was too heterogeneous to draw firm conclusions, however, and treatment recommendations in the future should utilize a uniform treatment strategy.

The addition of rituximab to front-line therapy with CHOP (R-CHOP) results in a higher response rate and longer time to treatment failure in patients with lymphoplasmacytic lymphoma: results of a randomized trial of the German Low-Grade Lymphoma Study Group (GLSG)

Lymphoplasmacytic lymphoma (LPL) is an indolent lymphoma with moderate sensitivity to conventional chemotherapy. This study investigated whether the addition of rituximab to standard chemotherapy improves treatment outcome in LPL and the subgroup of LPL patients fulfilling the criteria of Waldenstroem's macroglobulinemia (WM). A total of 69 patients with previously untreated LPL were enrolled into the trial; 64 patients were evaluable for treatment outcome. In all, 48 of the 64 LPL patients fulfilled the criteria of WM. Patients were randomly assigned to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone, n=34) or CHOP (n=30). R-CHOP resulted in significantly higher overall response (OR) rate (94 vs 67%, P=0.0085) in the LPL patients and in the WM subgroup (91 vs 60%, P=0.0188). With a median observation time of 42 months, R-CHOP induced a significantly longer time to treatment failure (TTF) with a median of 63 months for R-CHOP vs 22 months in the CHOP arm in the LPL patients (P=0.0033) and in the WM subgroup (P=0.0241). There was no major difference of treatment-associated toxicity between both treatment groups. These data indicate that the addition of rituximab to front-line chemotherapy improves treatment outcome in patients with LPL or WM.

Molecular Characterization of Waldenstrom's Macroglobulinemia Reveals Frequent Occurrence of Two B-Cell Clones Having Distinct IgH VDJ Sequences

PURPOSE

Malignant B lineage cells in Waldenstrom's macroglobulinemia (WM) express a unique clonotypic IgM VDJ. The occurrence of biclonal B cells and their clonal relationships were characterized.

EXPERIMENTAL DESIGN

Bone marrow and blood from 20 WM patients were analyzed for clonotypic VDJ sequences, clonal B-cell frequencies, and the complementary determining region 3 profile.

RESULTS

Two different clonotypic VDJ sequences were identified in 4 of 20 WM. In two cases, partner clones had different VDJ rearrangements, with one clonotypic signature in bone marrow and a second in blood. For both cases, the bone marrow clone was hypermutated, whereas the blood clone was germ line or minimally mutated. In two other cases, partner clones shared a common VDJ rearrangement but had different patterns of somatic mutations. They lacked intraclonal diversity and were more abundant in bone marrow than in blood. VDJ mutation profiles suggested they arose from a common IgM progenitor. Single-cell analysis in one case indicated the partner clones were reciprocally expressed, following rules of allelic exclusion.

CONCLUSIONS

The existence of two B-cell clones having distinct VDJ sequences is common in WM, suggesting that frequent transformation events may occur. In two cases, the partner clones had distinct tissue distributions in either blood or bone marrow, were of different immunoglobulin isotypes, and in one case exhibited differential response to therapy. The contributions of each clone are unknown. Their presence suggests that WM may involve a background of molecular and cellular events leading to emergence of one or more malignant clones.

Lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia derives from an extensively hypermutated B cell that lacks ongoing somatic hypermutation

Lymphoplasmacytic lymphoma (LPL) is a rare lymphoma thought to originate from a B cell stimulated to differentiate to a plasma cell, and which is usually accompanied by clonal IgM secretion, defining the diagnosis of Waldenstrom's macroglobulinemia (WM). However, the immunoglobulin variable heavy chain (VH) gene usage and the somatic hypermutation status have not been widely investigated in LPL. LPL biopsies (CD19+/CD20+/CD22+/CD5-/CD10-/CD23-/kappa+) from 14 patients were included most of whom had a serum IgM component of variable magnitude (two cases with IgG). Highly mutated VH genes (mean mutation rate 8%) were revealed in 13 of 14 LPLs, whereas one case displayed a germline VH gene configuration. Cloning of the VH gene rearrangements in nine cases showed homogeneous sequences without intraclonal heterogeneity. Furthermore, no bias in the VH gene usage was shown, with VH3, VH4, and VH1 gene family members represented. These data confirm that the LPL precursor cell has been exposed to the germinal centre environment, as indicated by extensive hypermutation, but also that the transformation event occurred after affinity maturation, since there was a lack of intraclonal variation. Additionally, the VH gene repertoire was not skewed in LPL/WM as has been demonstrated in other B cell malignancies.

Plasmacellular differentiation in extranodal marginal zone B cell lymphomas of the ocular adnexa: an analysis of the neoplastic plasma cell phenotype and its prognostic significance in 136 cases

AIM

To determine (a) the expression of plasma cell related antigens in extranodal marginal zone B cell lymphomas (EMZL) of the ocular adnexa; and (b) the prognostic value of plasmacellular differentiation in these tumours.

METHODS

A consecutive case series of 136 ocular adnexal EMZL obtained from three ocular pathology centres over 20 years was analysed retrospectively. An extensive immunohistochemical panel, including the plasma cell related antigens VS38c, CD38, CD138, multiple myeloma oncogene-1-protein (MUM1/IRF4), and CREB binding protein (CBP) was performed. EMZL were defined as "plasmacellular differentiated" on the basis of morphological features, evidence of cytoplasmic immunoglobulin, negativity for BSAP/PAX5, and expression of at least one of the investigated plasma cell related antigens. Controls included normal or hyperplastic lymphatic tissues. Detailed clinical data were collected for most patients, and compared with the results of immunohistochemistry. The end points considered for statistical analysis were development of local tumour recurrence, development of systemic disease, and lymphoma related death.

RESULTS

57 (42%) of the 136 ocular adnexal EMZL showed a plasmacellular differentiation; 45 of these plasmacytoid cases were primary tumours. In contrast with most admixed normal plasma cells, which displayed co-expression of MUM1/IRF4, Vs38c, CD38, CD138, and CBP, the plasmacellular differentiated EMZL tumour cells demonstrated co-expression of all five plasma cell related antigens in only six of 57 (11%) plasmacellular differentiated ocular adnexal EMZL. The most commonly expressed plasma cell related antigen was MUM1/IRF4, immunoreactivity being seen in 56/57 (98%) plasmacellular differentiated EMZL examined. Although the association of plasmacellular differentiation in primary ocular adnexal EMZL and disseminated disease was statistically significant on univariate analysis (p = 0.042), this was weaker on multivariate analysis.

CONCLUSION

Plasmacellular differentiated tumour cells in EMZL demonstrate an aberrant immune profile for plasma cell related antigens when compared with normal plasma cells. On multivariate analysis, plasmacellular differentiation in ocular adnexal EMZL was not significantly associated with local recurrence, the development of systemic disease, or with lymphoma related death.

Phase III Study of Chlorambucil Versus Fludarabine as Initial Therapy for Waldenström's Macroglobulinemia and Related Disorders

The WM1 study is a prospective randomized open-label study that includes patients with previously untreated Waldenstrom's macroglobulinemia (WM), splenic lymphoma with villous lymphocytes (SLVL), and nonimmunoglobulin (Ig) M lymphoplasmacytic lymphoma (LPL) who have an indication for treatment. At registration, patients are categorized as having WM, SLVL, or LPL, and these cohorts are to be analyzed separately. The aim of the study is to compare the efficacy of oral chlorambucil at a dose of 8 mg/m(2) (6 mg/m(2) for those > 75 years of age) for 10 days every 28 days to a maximum of 12 cycles with oral or intravenous (I.V.) fludarabine at a dose of 40 mg/m(2) orally or 25 mg/m(2) I.V. (30 mg/m(2)orally or 20 mg/m(2)I.V. for those > 75 years of age) for 5 days every 28 days to a maximum of 6 cycles. Primary endpoints are response to therapy and duration of response; secondary endpoints are improvement in hematologic parameters, toxicity of therapy, quality of life, and survival. To detect a difference in response rate of patients with WM of 15%, assuming that the overall response rates will be 50% to chlorambucil and 65% to fludarabine, with a power of 80%, requires the sample size of each group to be 183, indicating the need for collaboration among a number of national investigator groups. As of February 2005, accrual to the study stands at 143. Registration, randomization, and data collection are entirely Internet-based (www.waldenstroms.org), and the study is organized by an international collaboration, with a planned interim analysis and an external data monitoring committee.

Pan B-cell markers are not redundant in analysis of chronic lymphocytic leukemia (CLL)

BACKGROUND

The classic immunophenotype for chronic lymphocytic leukemia (CLL) is CD19(+), restricted dim surface expression of kappa or lambda light chain, CD5(+), CD23(+), dim CD20(+), negative FMC7, and negative CD79b. However, the necessity of assaying for all 3 pan B-cell markers (CD20, FMC7, and CD79b) by flow cytometry has not been definitively documented for CLL.

METHODS

Qualitative patterns and semi-quantitative assessment of staining intensity for CD20, FMC7 and CD79b were performed in 70 cases with a current or prior diagnosis of CLL or CLL with increased prolymphocytes leukemia (CLL/PL). The concurrent morphology in 66 of 70 specimens was classified as typical CLL in 53 cases, CLL/PL in 10 cases, and large cell lymphoma in 3 cases.

RESULTS

Forty percent of the cases varied from the characteristic immunophenotype by having moderate or bright staining of CD20 (36%), FMC7 (7%), and/or CD79b (18%). Discrepant qualitative staining patterns were found between FMC7 and CD20 (21%), CD20 and CD79b (15%), and CD79b and FMC7 (10%). Semiquantitative measurement of staining intensity showed little correlation between CD79b and CD20 or FMC7. Moderate correlation was seen between CD20 and FMC7. No correlation was observed between morphology and intensity of marker expression.

CONCLUSIONS

Variable patterns and intensity of staining were seen for FMC7, CD20, and CD79b in this cohort of CLL samples. Dim or negative staining was most consistently seen for FMC7 (93% of specimens). Although FMC7 staining intensity was moderately correlated with CD20, CD79b intensity was poorly correlated with either CD20 or FMC7, and thus, may provide some independent information.

Clonotypic IgM V/D/J sequence analysis in Waldenstrom macroglobulinemia suggests an unusual B-cell origin and an expansion of polyclonal B cells in peripheral blood

Analysis of clonotypic immunoglobulin M (IgM) from 15 patients with Waldenstrom macroglobulinemia (WM) showed a strong preferential use of the VH3/JH4 gene families. Identification of the WM IgM V/D/J was validated using single-cell analysis, confirming its presence in most B cells. Despite the extensive hypermutated VH genes in 13 of 15 patients, statistical analysis of framework/complementary-determining region (FR/CDR) mutation patterns suggests that they might have escaped antigenic selection. Neither intraclonal diversity nor isotype switching was detectable. Membranous and secreted forms of clonotypic IgM transcripts were present in bone marrow and blood. Single-cell analysis showed that clonotypic B cells coexpress CD20, surface IgM (sIgM), and sIgD but that they lack CD138. Most B cells lacked memory marker CD27 despite their hypermutated variable regions otherwise suggestive of memory status. At diagnosis, circulating B cells in WM are largely clonotypic. However, when monoclonal IgM levels are decreased, clonotypic frequencies are substantially reduced despite elevated CD20+ cells, shown to be polyclonal by DNA sequencing and CDR3 fragment analysis. Thus, WM includes the expansion of circulating, polyclonal B cells. Overall, this work suggests that WM may originate from a largely VH3-restricted, somatically mutated, predominantly CD27(-)IgM(+)IgD+ population that cannot undergo class switching, suggestive of B cells that might have bypassed the germinal center.

Treatment of indolent B-Cell nonfollicular lymphomas: final results of the LL01 randomized trial of the Gruppo Italiano per lo Studio dei Linfomi

PURPOSE

To evaluate the effect of epirubicin on therapeutic response and survival in patients with indolent nonfollicular B-cell lymphomas (INFL) treated with pulsed high-dose chlorambucil.

PATIENTS AND METHODS

A total of 170 untreated patients with advanced/active INFL were randomly assigned to receive either eight cycles of high-dose chlorambucil (15 mg/m2/d) plus prednisone (100 mg/d) for 5 days (HD-CHL-P; arm A) or eight cycles of HD-CHL-P plus epirubicin 60 mg/m2 intravenous on day 1 (arm B). The responding patients were randomly assigned to either maintenance therapy with interferon alfa (IFNalpha-2a; 3 MU, three times weekly) for 12 months or observation.

RESULTS

There were 160 assessable patients (82 males, 78 females; median age, 63 years; range, 33 to 77 years); 77 patients were assigned to arm A, and 83 were assigned to arm B. Induction therapy led to 47 complete responses (CRs; 29.4%) and 68 partial responses (PRs; 42.5%), with no significant difference between the two arms (60 CR + PR in arm A [77.9%] and 55 CR + PR in arm B [66.3%]; P =.07). After a median follow-up of 38 months (range, 2 to 103 months), there was no between-group difference in overall survival (OS; P =.45), failure-free survival (P =.07), or progression-free survival (PFS; P =.5). Eighty-eight patients were randomly assigned to either IFNalpha-2a (n = 43) or observation (n = 45), without any difference in 3-year PFS (44% and 42%, respectively). Univariate analysis showed that OS was influenced by age, anemia, serum lactate dehydrogenase levels, and International Prognostic Index distribution; multivariate analysis identified age and anemia as having influence on OS.

CONCLUSION

HD-CHL-P treatment outcome in INFL patients was good (50% 3-year PFS, minimal toxicity, and low costs); epirubicin did not add any advantage. One-year IFNalpha maintenance treatment did not prolong response duration.

Developing diagnostic criteria in Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia (WM) is a poorly characterized B-cell lymphoproliferative disorder. There are a relatively limited number of detailed clinicopathological assessments, while the majority of clinical trials have been nonrandomized, single-institution phase II studies. Unfortunately progress in this disorder has been hindered by a lack of universally accepted diagnostic criteria. It is clear that criteria incorporating clinical, morphological, immunophenotypic, and, ultimately, genotypic parameters are needed for future clinical trails. Following a detailed clinicopathological assessment of 111 patients and a review of the published literature the following diagnostic criteria were proposed for WM: IgM monoclonal gammopathy of any concentration, bone marrow infiltration by small lymphocytes, plasmacytoid cells and plasma cells in a diffuse, interstitial or nodular pattern, and a surface Ig(+)CD19(+)CD20(+)CD5(-)CD10(-)CD23(-) immunophenotype.

Clinicopathological definition of Waldenstrom's macroglobulinemia: consensus panel recommendations from the Second International Workshop on Waldenstrom's Macroglobulinemia

This presentation represents consensus recommendations for the clinicopathological definition of Waldenstrom's macroglobulinemia (WM), which were prepared in conjunction with the Second International Workshop held in Athens, Greece during September 2002. WM is an uncommon lymphoproliferative disorder characterized primarily by bone marrow infiltration and IgM monoclonal gammopathy. It should be considered a distinct clinicopathological entity rather than a clinical syndrome secondary to IgM secretion. The underlying pathological diagnosis in WM is lymphoplasmacytic lymphoma as defined by the World Health Organization (WHO) and Revised European-American Lymphoma (REAL) classification criteria. The concentration of monoclonal IgM can vary widely in WM and it is not possible to define a concentration that reliably distinguishes WM from monoclonal gammopathy of undetermined significance (MGUS) and other lymphoproliferative disorders. A diagnosis of WM can therefore be made irrespective of IgM concentration if there is evidence on a bone marrow trephine biopsy of bone marrow infiltration by lymphoplasmacytic lymphoma with predominantly an intertrabecular pattern, supported by appropriate immunophenotypic studies. Simple criteria to distinguish patients with symptomatic WM who require therapy from those with asymptomatic WM and MGUS were also proposed. Patients with clinical features attributable to IgM monoclonal gammopathy but no overt evidence of lymphoma are considered to constitute a distinct clinical group and the term "IgM-related disorders" is proposed.

Patterns of clinical presentation, treatment, and outcome in patients with Waldenstrom's macroglobulinemia: a two-institution study

Waldenstrom's macroglobulinemia (WM) is in the World Health Organization (WHO) classification considered to be a clinical syndrome rather than a specific pathologic diagnosis. The clinical manifestations associated with WM relate to direct tumor infiltration, hyperviscosity, and deposition of IgM in various tissues. The indications for and choice of treatment vary considerably and no generally accepted prognostic models exist. The clinical features, treatment, and prognosis of 72 patients with WM seen at one British (n = 36) and one Swedish (n = 36) academic center were therefore compared. Significantly more patients presented with a low albumin concentration (< v > 40 g/L, P <.001), anemia (hemoglobin < v > 120 g/L; P <.001), thrombocytopenia (< v > 150 x 10(9)/L; P <.05), hepatomegaly (P <.001), splenomegaly (P <.01), and lymphadenopathy (P <.01), at St Bartholomew's Hospital (SBH) in comparison to the Karolinska Hospital (KH). Fifty-six percent of SBH patients received chemotherapy immediately following diagnosis as compared to 14% at KH. The median overall survival of all patients was 6.3 years; 4.2 years and 11.0 years at SBH and KH, respectively (P <.001). In univariate analysis, anemia (hemoglobin < 120 g/L) and albumin < 35 g/L (but not <40 g/L) at diagnosis predicted a worse overall survival. The presence of hepatomegaly and/or splenomegaly and/or lymphadenopathy was significantly associated with anemia (P <.001) and hypoalbuminaemia (P <.001). The mean Morel score (including age, albumin, and cytopenias) of patients treated at SBH (2.6) was significantly higher than that of KH patients (1.6; P <.001). These findings illustrate the clinical heterogeneity of WM, most probably explained by differences in referral patterns, and in addition, indicate the need for establishing standard criteria for diagnosis, response to treatment, and prognostic features.

Waldenström macroglobulinemia. Development of diagnostic criteria and identification of prognostic factors

To establish whether a combination of morphologic and immunophenotypic criteria could be developed to more precisely define Waldenström macroglobulinemia (WM) and prognostic factors, we retrospectively assessed the clinical and laboratory features of 111 cases of WM. Bone marrow infiltration by small lymphocytes was documented in each case; and diffuse, interstitial, nodular, and paratrabecular patterns of infiltration were documented in 58%, 32%, 6%, and 4% of cases, respectively. Ninety percent were characterized by a surface immunoglobulin-positive, CD19+CD20+CD5-CD10-CD23- immunophenotype. The median overall survival from diagnosis was 60 months; univariate analysis revealed the following adverse prognostic factors: older than 60 years, performance status more than 1, platelet count less than 100 x 10(3)/microL (< 100 x 10(9)/L), pancytopenia, and diffuse bone marrow infiltration. Associated median survival was 40, 38, 46, 28, and 59 months, respectively. Multivariate analysis revealed age, performance status, and platelet count as prognostically significant, but stratification of patients according to the International Prognostic Index had limited value. We suggest defining WM by the following criteria: IgM monoclonal gammopathy; bone marrow infiltration by small lymphocytes, plasmacytoid cells, and plasma cells in a diffuse, interstitial, or nodular pattern; and a surface immunoglobulin-positive, CD19+CD20+CD5-CD10-CD23- immunophenotype.

Clinicopathological correlates of IgM paraproteinemias

IgM paraproteinemia is considered to be the major defining feature of Waldenström's macroglobulinemia (WM), but it may also occur in other B-cell lymphoproliferative disorders. In this study we have reviewed the final pathological diagnosis of 106 patients with IgM paraproteinemia investigated in our laboratories between April 1993 and May 1999. In 22 of the 106 patients (20.8%), there was no clinical or laboratory evidence of an underlying lymphoproliferative disorder, and a diagnosis of monoclonal gammopathy of undetermined significance (MGUS) was therefore made. In 60 cases (56.6%), a diagnosis of WM was made, while in the remaining 24 patients, the final diagnosis was chronic lymphocytic leukemia (n = 10), diffuse large B-cell lymphoma (n = 5), extranodal marginal-zone lymphoma (n = 3), follicular lymphoma (n = 3), and mantle-cell lymphoma (n = 3). The median paraprotein concentration in patients with WM, MGUS, and "other" lymphoproliferative disorders was 13 g/L (range, 2-54), 6 g/L (range, 3-30), and 4.5 g/L (range, 3-61), respectively. It is clear that IgM paraproteins are demonstrable in all subtypes of peripheral B-cell disorders and, although paraprotein concentrations are generally higher in WM, there is considerable overlap. Immunophenotypic criteria are therefore essential for the accurate diagnosis of WM.

European phase II study of rituximab (chimeric anti-CD20 monoclonal antibody) for patients with newly diagnosed mantle-cell lymphoma and previously treated mantle-cell lymphoma, immunocytoma, and small B-cell lymphocytic lymphoma

PURPOSE

Mantle-cell lymphoma (MCL), immunocytoma (IMC), and small B-cell lymphocytic lymphoma (SLL) are B-cell malignancies that express CD20 and are incurable with standard therapy. A multicenter phase II study was conducted to assess the toxicity and the overall response rates (RR) and complete response (CR) rates to rituximab (chimeric anti-CD20 monoclonal antibody).

PATIENTS AND METHODS

Between January 1997 and January 1998, 131 patients with newly diagnosed MCL (MCL1; n = 34) and previously treated MCL (MCL2; n = 40), IMC (n = 28), and SLL (n = 29) received rituximab 375 mg/m(2)/wk for 4 weeks via intravenous infusion. Restaging studies were performed 1 and 2 months after treatment. An analysis of the duration of response was conducted in December 1998.

RESULTS

Eleven patients were unassessable, including one who died of splenic rupture after the first infusion. The RR among the 120 assessable patients was 30% (36 of 120 patients). The RR by histology was as follows: MCL1, 38%; MCL2, 37%; IMC, 28%; and SLL, 14%. Ten patients, all with MCL, achieved CR. The median duration of response in MCL was 1.2 years. Immediate side effects were common and usually responded to adjustments in the infusion rate. There were 31 episodes of infection after treatment; most cases were mild. Cardiac arrhythmia and ophthalmologic side effects occurred in 10 and nine patients, respectively, including one case of severe loss of visual acuity.

CONCLUSION

Single-agent rituximab has moderate activity in MCL and IMC but only limited activity in SLL. The duration of response in MCL was similar to that previously reported in follicular lymphoma. Its use in combination with cytotoxic chemotherapy to increase the CR rate is warranted in MCL and IMC.