A UK multicentre phase II study of rituximab (chimaeric anti-CD20 monoclonal antibody) in patients with follicular lymphoma, with PCR monitoring of molecular response

Follicular lymphoma (FL) cells express CD20 and are associated in most cases with the t(14;18) chromosomal translocation. A multicentre study was undertaken between January 1997 and January 1998 to assess the complete response rate (CR) and overall response rate (RR) to rituximab, a chimaeric anti-CD20 monoclonal antibody. Seventy patients with previously treated FL received rituximab (375 mg/m2/week x4, by intravenous infusion). Restaging studies were performed 1 and 2 months after therapy. Molecular monitoring for the presence of cells harbouring the Bcl-2/JH gene rearrangement in the peripheral blood (PB) and bone marrow (BM) was performed before and after treatment using a two-step semi-nested polymerase chain reaction (PCR) assay. The overall RR was 32/70 (46%), being highest in patients who had received only one previous treatment (12/15, 80%). However, only two patients achieved a CR. The median duration of response was 11 months. Thirteen of 21 evaluable 'PCR-positive' patients (62%) became 'PCR-negative' in PB and/or BM samples 1 month after rituximab, although this did not correlate with clinical response. Treatment was generally well tolerated, although one patient developed Stevens-Johnson syndrome. Rituximab was shown to be active in FL, and in some cases PB and/or BM became PCR negative. Studies in combination with cytotoxic chemotherapy to increase the CR rate are warranted.     

Treatment of relapsed idiopathic thrombocytopenic purpura with the anti-CD20 monoclonal antibody rituximab: a pilot study

We performed a prospective pilot study on 12 patients to evaluate the efficacy of the anti-CD20 monoclonal antibody rituximab in relapsed idiopathic thrombocytopenic purpura (ITP). Inclusion criteria were relapse of ITP with a thrombocyte count <20 000 micro L-1 and unsuccessful corticosteroid treatment. Eleven patients had a previous splenectomy, five patients had unsuccessful cytotoxic treatment, and six patients were refractory to intravenous immunoglobulins before rituximab therapy. Response criteria were as follows. Complete remission (CR): normalization of thrombocyte count for at least 30 d. Partial remission (PR): an increase of thrombocytes to above 30 000 microL(-1) for at least 30 d. Minor response (MR): any increase above 30 000 microL(-1) for less than 30 d but more than 10 d. No response (NR): failure to achieve any of the above responses. Treatment plan: We administered 375 mg m(-2) of rituximab once weekly on up to four consecutive weeks, unless there was early CR. Five patients (41%) achieved CR, two patients (17%) PR, and two patients MR (overall response rate 75%, median follow-up of responders 320 d). Four CR patients are ongoing; one CR patient relapsed after 6 months. Adverse events included excessive thrombocytosis in one patient as well as minor infusion-related (grade I) toxicities in four patients. We conclude that rituximab is a promising agent in the treatment of relapsed ITP.     

Elevation of activated platelet-dependent chemokines in patients with anti-CD20 monoclonal antibody (rituximab)-treated non-Hodgkin's lymphoma.

This study measured and compared levels of some chemokines in patients with rituximab-treated non-Hodgkin lymphoma because they may participate in the mechanism of efficacy of rituximab in non-Hodgkin lymphoma patients. Monocytic chemotactant protein-1, RANTES (regulated on activation, normally T-cell expressed and secreted), eotaxin, interleukin-8, neutrophil-activating protein-78, stromal cell-derived factor-1, and growth-regulating oncogene-alpha in patients with rituximab-treated non-Hodgkin lymphoma were measured by enzyme-linked immunosorbent assay. Levels of RANTES were higher in non-Hodgkin lymphoma patients than in controls. Levels of monocytic chemotactant protein-1, RANTES, and neutrophil-activating protein-78 were significantly elevated before and after chemotherapy with rituximab treatment. However, the level of stromal cell-derived factor-1 did not exhibit a significant change. Before to after chemotherapy without rituximab treatment, all chemokine levels did not exhibit significant changes. These findings suggest that activated platelet-dependent chemokines such as RANTES and neutrophil-activating protein-78 may modulate the efficacy of rituximab in antibody-dependent cellular cytotoxity.     

Subcutaneous injections of low-dose veltuzumab (humanized anti-CD20 antibody) are safe and active in patients with indolent non-Hodgkin's lymphoma

Background

Subcutaneous injections of anti-CD20 antibodies may offer benefits to both patients and the healthcare system for treatment of B-cell malignancies.

Design and Methods

A pilot study was undertaken to evaluate the potential for subcutaneous dosing with 2^nd generation anti-CD20 antibody veltuzumab in patients with CD20⁺ indolent non-Hodgkin’s lymphoma. Patients with previously untreated or relapsed disease received 4 doses of 80, 160, or 320 mg veltuzumab injected subcutaneously every two weeks. Responses were assessed by computed tomography scans, with other evaluations including adverse events, safety laboratories, B-cell blood levels, serum veltuzumab levels, and human anti-veltuzumab antibody (HAHA) titers.

Results

Seventeen patients (14 follicular lymphoma; 13 stage III or IV disease; 5 treatment-naive) completed treatment with only occasional, mild-moderate, transient injection reactions and no other safety issues. Subcutaneous veltuzumab demonstrated a slow release pattern over several days, achieving a mean Cmax of 19, 25 and 63 μg/mL at 80, 160, and 320 mg doses for a total of 4 administrations, respectively. Depletion of circulating B cells occurred after the first injection. The objective response rate (partial responses plus complete responses plus complete responses unconfirmed) was 47% (8/17) with a complete response/complete response unconfirmed rate of 24% (4/17); 4 of 8 objective responses continued for 60 weeks or more. All serum samples evaluated for human anti-veltuzumab antibody were negative.

Conclusions

Subcutaneous injections of low-dose veltuzumab are convenient, well tolerated, and capable of achieving sustained serum levels, B-cell depletion, and durable objective responses in indolent non-Hodgkin’s lymphoma. (Clinicaltrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT00546793","term_id":"NCT00546793"}}NCT00546793)     

Phase I clinical trial using escalating single-dose infusion of chimeric anti-CD20 monoclonal antibody (IDEC-C2B8) in patients with recurrent B-cell lymphoma

The B-cell antigen CD20 is expressed on normal B cells and by nearly all B-cell lymphomas. This nonmodulating antigen provides an excellent target for antibody-directed therapies. A chimeric anti-CD20 antibody (IDEC-C2B8), consisting of human IgG1-kappa constant regions and variable regions from the murine monoclonal anti-CD20 antibody IDEC- 2B8, has been produced for clinical trials. It lyses CD20+ cells in vitro via complement and antibody-dependent cell-mediated lysis. Preclinical studies have shown that the chimeric antibody selectively depletes B cells in blood and lymph nodes in macaque monkeys. In this phase I clinical trial, 15 patients (3 per dose level) with relapsed low-grade B-cell lymphoma were treated with a single dose (10, 50, 100, 250, or 500 mg/m2) of antibody administered intravenously. Treatment- related symptoms correlated with the number of circulating CD20 cells and grade II events consisted of fever (5 patients); nausea (2), rigor (2), orthostatic hypotension (2), bronchospasm (1), and thrombocytopenia (1). No significant toxicities were observed during the 3 months of follow-up. Serum C3, IgG, and IgM levels, neutrophils, and T cells were largely unchanged. At the three higher dose levels, pharmacokinetics of the free antibody showed a serum half-life of 4.4 days (range, 1.6 to 10.5). Levels greater than 10 micrograms/mL persisted in 6 of 9 patients for more than 14 days. No quantifiable immune responses to the infused antibody have been detected. CD20+ B cells were rapidly and specifically depleted in the peripheral blood at 24 to 72 hours and remained depleted for at least 2 to 3 months in most patients. Two-week postinfusion tumor biopsies showed the chimeric antibody bound to tumor cells and a decrease in the percentage of B cells. Tumor regressions occurred in 6 of 15 patients (2 partial and 4 minor responses). The results of this single-dose trial have been used to design a multiple-dose phase I/II study.     

Rapid tumor lysis in a patient with B-cell chronic lymphocytic leukemia and lymphocytosis treated with an anti-CD20 monoclonal antibody (IDEC-C2B8, rituximab)

Summary In this report we present a patient with B-cell chronic lymphocytic leukemia who developed an acute tumor lysis syndrome after administration of the human anti-CD20 antibody IDEC-C2B8 (RITUXIMAB) in standard dose of 375 mg/m². IDEC-C2B8 has been demonstrated to have only mild and tolerable side effects in patients with follicular lymphoma. In these trials patients with lymphocytosis >5000/μl were excluded. Physicians must be aware of this hitherto unreported phenomenon in patients with high CD20-positive blood counts. Received: July 9, 1998 / Accepted: July 20, 1998     

Effect of anti-CD20 (rituximab) on resistant thrombocytopenia in autoimmune lymphoproliferative syndrome

Fas (CD95) plays an important role in apoptosis. Patients with defects in Fas have an autoimmune lymphoproliferative syndrome (ALPS) characterized by lymphadenopathy, autoimmune cytopenias and an increased incidence of lymphomas. There are approximately 70 known cases described worldwide. The autoimmune cytopenias are difficult to treat in this group. We describe a patient with a defect in the death domain of the FAS molecule who had autoimmune thrombocytopenia resistant to conventional therapy but which responded to a combination of rituximab and vincristine.     

Combination immunotherapy with rituximab and interleukin 2 in patients with relapsed or refractory follicular non-Hodgkin's lymphoma

Rituximab has significant activity as a single agent in the treatment of follicular non-Hodgkin's lymphoma (NHL). Interleukin 2 (IL-2) is a lymphokine that increases effector cell number. In an effort to augment antibody-dependent cell-mediated cytotoxicity (ADCC) associated with rituximab therapy, low-dose IL-2 was added to a standard rituximab regimen and patients were evaluated for safety and efficacy. Twenty patients with relapsed or refractory follicular NHL were treated with IL-2 (1.2 MIU/m(2)/d for 56 d subcutaneously) as outpatients. Rituximab (375 mg/m(2)) was given on d 15, 22, 29 and 36. The regimen was well tolerated and only three patients required dose adjustments in IL-2. Infusional toxicity associated with rituximab was not exacerbated by IL-2. Peripheral blood immunophenotyping demonstrated significant increases in circulating CD8+ and CD56+ lymphocytes in all evaluable patients (P = 0.0002). Increases in total eosinophil number were observed in all patients. Eleven patients responded to therapy, for an overall response rate of 55%. Four additional patients had stable disease. For these 15 patients, the median time to progression exceeded 13 months. We conclude concomitant cytokine therapy to enhance ADCC with monoclonal antibody therapy was well tolerated and did not exacerbate antibody-related infusional toxicity. Further studies of this rational combination are warranted and ongoing.     

In vitro evaluation of the efficacy of idarubicin in human tumour cells from patients with low-grade non-Hodgkin's lymphoma

Evaluating the potential benefit of the new anthracycline, idarubicin (Ida), in lymphoma, 58 tumour samples from patients suffering from low-grade non-Hodgkin's lymphoma (L-NHL), were analysed in vitro for their sensitivity to 0.5 microg/ml Ida. This was compared with the sensitivity to other anthracyclines (0.5 microg/ml), using the fluorometric microculture cytotoxicity assay. A total of 132 samples from patients with acute leukaemia and a cell-line panel representing different resistance mechanisms was included for comparison. The median cell survival of L-NHL cells did not differ after exposing the cells to Ida or daunorubicin (Dnr), whereas epirubicin, doxorubicin (Dox) and mitoxantrone (Mitox) were significantly less cytotoxic than Ida (P < 0.001). The median cell survival in L-NHL cells did not differ from that of acute leukaemia cells after exposure to 0.5 microg/ml Ida, Dnr, Dox and Mitox. Cells from previously treated patients with L-NHL had a higher median survival than cells from untreated patients after exposure to all drugs, except for Ida. In samples from previously untreated patients, Spearman rank correlations were high (Rho = 0.81-0.90) between cell survival after exposure to Ida and the other anthracyclines. The same pattern was observed in the cell-line panel (Rho = 0.78-0.91) (P < 0.05). In contrast, low correlations (Rho = 0.24-0.42) were observed among samples from previously treated patients. Our results indicate a potential benefit of Ida in previously drug-treated patients with L-NHL.     

Translocation (14; 18) and (8; 22) in three patients with acute leukemia/lymphoma following centrocytic/centroblastic non-Hodgkin's lymphoma

Summary Three patients with centrocytic/centroblastic lymphoma developed a rapidly fatal leukemic transformation of the disease after a transient remission. At the time of transformation, cytogenetic analysis revealed in all patients abnormal karyotypes with coexistence of t (14; 18) and t (8; 22). Molecular analysis in one patient showed rearrangement of the BCL2 oncogene and c-myc m-RNA expression. These findings imply that translocation t (14; 18) was present during the first phase of the disease and that acquisition of translocation t (8; 22) was accompanied by leukemic transformation.This study was supported by theHamburger Krebsgesellschaft and by grants Fi 389/2-2 and Fo 91/11-3 from theDeutsche Forschungsgemeinschaft     

IDEC-C2B8 (Rituximab) anti-CD20 antibody treatment in relapsed advanced-stage follicular lymphomas: results of a phase-II study of the German Low-Grade Lymphoma Study Group

The current study was initiated to assess the clinical efficacy and side effects of rituximab in patients with relapsed advanced stage follicular lymphoma. Patients and methods: The study was performed as an open-label non-randomized multicenter phase-II trial and included patients older than 18 years of age with relapsed advanced-stage follicular lymphomas (FL) grades I and II, according to the REAL classification, or with centroblastic/centrocytic (CB/CC lymphomas according to the Kiel classification. Four weekly doses of 375 mg/m² rituximab were applied. Results: 38 patients from eight centers were included between January 1997 and January 1998 and were evaluable for response and toxicity on an intention to treat basis. The median age was 55 years (range 26–75 years). Thirteen patients (35%) were in first relapse, 11 patients (30%) in second, and 13 patients (35%) in third relapse. The median time between primary diagnosis and study entry was 4.6 years (range 0.9–14.7 years). Twenty-three patients tolerated the application of rituximab without adverse events; in 13 cases the infusion rate had to be reduced because of side effects; in two patients the application was stopped because of pharyngeal edema and anaphylactoid reaction. The most frequent side effects were fever (13 patients) and rigor (13 patients); 65% of the side effects were observed after the first infusion. Twenty grade-III/IV side effects were considered to be related to treatment: lymphocytopenia (3), granalocytopenia (1), thrombocytopenia (2), fever (1), hyperglycermia (1), venous thrombosis (1), syncope (1), plasmatic coagulation disorder (1), shortness of breath (2), photosensitivity (1), cardiac failure (1), chills (1), sepsis (1), tumor lysis (1), anemia (1), and pharyngeal edema (1). Eight patients were not eligible for assessment of response because of non-follicular subtypes of low-grade lymphomas (n=6) or early termination of therapy at the first infusion because of severe side effects (n=2). From the 30 evaluable cases with follicular lymphomas, five patients achieved a complete remission (CR) (17%), nine patients a partial remission (PR) (30%), and two patients a minor response (MR) (7%). The overall response rate was 47%. The median time to treatment progression (TTP) was 201 days (range 64–293 days), with five patients experiencing long-lasting remissions of 214–293 days duration. In three patients, the rituximab-induced remission exceeded the preceding progression-free interval substantially. Bulky disease (P=0.058) and/or bone-marrow involvement (P=0.046) were associated with poor response. Conclusion: This study confirms the moderate treatment-related toxicity and the high antilymphoma activity of rituximab in patients with relapsed follicular lymphoma. Further studies are needed to determine the role of rituximab in the first-line treatment of these disorders and its combination with conventional chemotherapy. Received: 29 September 1999 / Accepted: 23 December 1999     

Loss of CD20 expression following treatment with rituximab (chimaeric monoclonal anti-CD20): a retrospective cohort analysis

A retrospective analysis of CD20 expression following rituximab for B-cell non-Hodgkin's lymphoma demonstrated a significant change in immunophenotype in 6/25 (24%) patients with persistent bone marrow (BM) infiltration. In three out of six patients, the B cells were uniformly CD20-/CD79alpha+, consistent with frank loss of CD20 expression. In the remaining three cases, the BM infiltrate was predominantly (> 80%) CD20-/CD79alpha+. Two of the former but none of the latter three cases achieved a clinical response. In three further cases, the post-treatment BM infiltrate was composed entirely of benign or reactive CD3+ T cells. Frank loss of CD20 was not seen in 25 post-treatment lymph node biopsies. Immunophenotyping is therefore an important adjunct in the diagnosis of BM infiltration following rituximab.     

High response rates with short infusional 2-chlorodeoxyadenosine in de novo and relapsed low-grade lymphoma

Thirty-five patients (eight de novo , 27 relapsed disease) with low-grade non-Hodgkin's lymphoma (diffuse small lymphocytic, follicular small cleaved cell, follicular mixed cell, and lymphoplasmacytoid) were treated with 2-chlorodeoxyadenosine (2CdA) at a daily dose of 0.14 mg/kg for 5 d (2 h infusion) for an average of three cycles. Minor treatment delays, generally due to haematological toxicities, occurred in nine of 105 cycles. Major toxicities were lymphopenia, neutropenia and thrombocytopenia. Opportunistic infections occurred in seven patients.   Overall response rate was 69% (five complete, 19 partial) reaching 88% for de novo patients (two complete, five partial). Elevated β₂-microglobulin level was negatively predictive of response ( P  = 0.0014). Eight of 24 responders relapsed, with a median follow-up of 13 months.   2CdA administered as an intermittent infusion shows considerable single-agent activity in low-grade lymphomas achieving high response rates of prolonged duration. Consideration of schedules where 2CdA is alternatively administered with combination chemotherapy appears warranted.     

Evaluation of purine and pyrimidine analogues in human tumor cells from patients with low-grade lymphoproliferative disorders using the FMCA.

The purine analogues fludarabine and cladribine (CdA) have recently become established to be effective treatment for low-grade non-Hodgkin's lymphoma (NHL). The pyrimidine nucleoside analogue cytarabine (AraC) has an important place in the treatment of acute leukemia, and gemcitabine is a new pyrimidin antimetabolite which has shown clinical activity against solid tumors. We have used the semiautomated fluorometric microculture cytotoxicity assay (FMCA), based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA), to study these drugs. Eighty samples from 60 patients with low-grade NHL were studied. Fifty samples from patients with acute lymphoid leukemia (ALL) and 118 samples from patients with acute myeloid leukemia (AML) were included for comparison. The results indicate that the purine- and pyrimidine nucleoside analogues tested may be as active against low-grade NHL as against acute leukemia. In low-grade NHL, AraC seems to be even more active in comparison to CdA (p=<0.0001) and fludarabine (p=0.001). Untreated patients were more drug sensitive than previously treated patients. Gemcitabine showed the highest correlation with AraC (0.90) whereas CdA showed the highest correlation with fludarabine (0.84). Based on these results we propose that AraC and gemcitabine may have a role in the treatment of low-grade NHL.     

Comparison of the in vitro effects of the anti-CD20 antibodies rituximab and GA101 on chronic lymphocytic leukaemia cells

The effects of two CD20 antibodies, namely rituximab, the current standard for treatment of chronic lymphocytic leukaemia (CLL) in combination with chemotherapy, and GA101, a glyco-engineered type II antibody were compared on CLL cells ex vivo. Antibody-induced phosphatidylserine exposure was examined in isolated CLL cells. For a more comprehensive assessment of antibody-mediated cell killing including Fc-mediated mechanisms, B cell depletion from whole blood samples was monitored. Treatment with rituximab or GA101 reduced the average viability of isolated CLL cells by 6% or 11%, and the ratio of B to T cells in whole blood samples by 12% or 33%, respectively. Combination with GA101 enhanced the cytotoxicity of the chemotherapeutic agent chlorambucil on isolated CLL cells. CD20 surface expression on CLL cells correlated with GA101-induced B cell depletion, but not with direct cell death induction. Treatment of whole blood samples from CLL patients with a CpG-containing oligonucleotide increased CD20 expression on CLL cells and GA101-dependent B cell depletion. Despite the variable responses of individual CLL samples, the CLL cell depletion from whole blood by GA101 was consistently much stronger than by rituximab, which argues for clinical investigation of GA101 in CLL patients.     

Peripheral T-cell non-Hodgkin's lymphomas of low malignancy: prospective study of 25 patients with pleomorphic small cell lymphoma,lymphoepitheloid cell (Lennert's) lymphoma and T-zone lymphoma

Peripheral T-cell lymphomas comprise a heterogenous group of low- and high-grade malignancies differing in their histopathological appearance and also in clinical and prognostic aspects. We prospectively studied 25 patients with low-grade peripheral T-cell lymphomas: pleomorphic, small cell lymphoma (PSC) (n = 9), lymphoepitheloid (Lennert's) lymphoma (LEL) (n= 12) and T-zone lymphoma (TZL) (n= 4). The median patient age was 55 years (range 19-75 years); the male to female ratio was 1.5. 13 patients (52%) had limited stages (I + II), 12 patients (48%) had advanced disease (stage III + IV). 21 patients received the COPBLAM/IMVP-16 regimen. Two patients received more intensive treatments; two received less intensive therapy. Complete remissions were achieved in 16/25 patients (64%). The median observation time of surviving patients was 30 months (range 5-72 months). The actuarial overall survival and event-free survival at 2 years of 21 patients receiving COPBLAM/IMVP-16 were 69% and 35%, respectively. Intensive chemotherapy led to complete remissions in about 60% of the patients and to long-term disease-free survival for one-third. The observed clinical courses illustrate the aggressive nature of PSC, LEL and TZL.     

Tumor lysis syndrome occurring after the administration of rituximab in lymphoproliferative disorders: high-grade non-Hodgkin's lymphoma and chronic lymphocytic leukemia

Rituximab, an anti-CD20 antibody, has been recently approved for the treatment of low-grade or follicular non-Hodgkin's lymphoma (NHL). Because of its relatively benign side effect profile, it has been considered a nontoxic alternative to chemotherapy. Recently, however, tumor lysis syndrome (TLS) resulting from rituximab has been reported in a patient with chronic lymphocytic leukemia (CLL). We herein present two cases of rituximab-induced TLS. The first case occurred in a patient with high-grade NHL, while the second case occurred in a patient with CLL. We also present a summary of the literature regarding TLS induced by immunotherapies.     

Incidence and nature of CD20-negative relapses following rituximab therapy in aggressive B-cell non-Hodgkin's lymphoma: a retrospective review

Re-treatment with rituximab for B-cell non-Hodgkin's lymphoma (NHL) relapsing after previous rituximab therapy has recently been shown to be clinically efficacious. Although the mechanism of resistance to rituximab re-treatment in non-responding patients is unknown, it is possible that loss of CD20 expression in the relapsed NHL could be important in some patients. We examined the incidence and nature of CD20 negative relapses following rituximab therapy in aggressive B-cell NHL treated at our institution. Of a total of 18 patients who received rituximab, 13 have relapsed, with 10 patients subsequently undergoing repeat tissue biopsy. Six of these 10 patients (60%) were shown to have lost CD20 expression by either immunohistochemistry and/or flow cytometry. Furthermore, three of the six patients who relapsed with CD20-negative NHL also suffered relapses at unusual anatomical sites. We conclude that loss of CD20 expression in aggressive B-cell NHL relapsing post-rituximab therapy is common. As such, repeat tissue biopsy should be undertaken to document CD20 expression by both flow cytometry and immunohistochemistry prior to considering repeated courses of rituximab in relapsed aggressive lymphomas.