Japanese multicenter phase II and pharmacokinetic study of rituximab in relapsed or refractory patients with aggressive B-cell lymphoma

Evidence for Therapeutic Drug Monitoring of Targeted Anticancer Therapies

Therapeutic drug monitoring (TDM) provides valuable guidance for dose adjustment of antibiotics, immunosuppressives, antiepileptics, and other drugs, but its use for traditional anticancer therapies has been limited. Perhaps the most important obstacle is the impractical requirement of multiple blood samples to adequately define systemic exposure of drugs that have a short elimination half-life and are given by intermittent intravenous injections. However, the newer targeted anticancer therapies have different pharmacokinetic (PK) and dosing characteristics compared with traditional cytotoxic drugs, making it possible to estimate the steady-state drug exposure with a single trough-level measurement. Recent evidence indicates that certain PK parameters, including trough levels, are correlated with clinical outcomes for many of these agents, including imatinib, sunitinib, rituximab, and cetuximab. Although the current evidence is insufficient to mandate TDM in routine practice, a concerted investigation should be encouraged to determine whether the steady-state trough measurements of targeted agents will have a practical place in the clinical care of patients with cancer.

Everolimus in combination with rituximab induces complete responses in heavily pretreated diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma is an aggressive non-Hodgkin's lymphoma without a standard therapy for patients who relapse after or are not eligible for salvage autologous stem cell transplantation. In vitro analysis of lymphoma cell lines has shown that everolimus can inhibit cell cycle progression in vitro and inhibitors of the mammalian target of rapamycin have already demonstrated single-agent activity in relapsed non-Hodgkin's lymphomas including diffuse large B-cell lymphoma, validating mammalian target of rapamycin as a viable therapeutic target. We performed an open label phase II study of everolimus, an inhibitor of mammalian target of rapamycin, in combination with rituximab to examine efficacy and tolerability in patients with relapsed/refractory diffuse large B-cell lymphoma. Eligible patients were treated with everolimus 10 mg by mouth once daily on days 1-28 of a 28-day cycle with rituximab administered weekly during cycle one and then on day one of subsequent cycles. Patients were treated for a total of 12 cycles or until disease progression. The primary end-point was objective response rate, with secondary end-points being toxicity, progression-free survival, duration of response, and overall survival. Twenty-six patients (24 evaluable) were enrolled and had an overall response rate of 38% [90% CI (21%-56%)] with three complete responses and six partial responses among these 24 patients. The median duration of response among responders was 8.1 months. At a median follow-up of 12 months, the overall survival rate was 37% [90% CI (20%-54%)]. The most common grade 3 to 4 toxicities were neutropenia, anemia, and thrombocytopenia. In conclusion, everolimus in combination with rituximab is well tolerated and demonstrates activity in relapsed diffuse large B-cell lymphoma. Further studies of this combination are warranted.

Model-based design of rituximab dosage optimization in follicular non-Hodgkin's lymphoma

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The concentration-effect relationship of rituximab in follicular lymphoma (FL) was previously described using pharmacokinetic-pharmacodynamic (PK-PD) modelling. The influence of genetic polymorphism of FCGR3A on rituximab efficacy in FL patients was included in this PK-PD model. Previous studies suggest that increasing the dose of rituximab and/or the number of infusions may lead to a better clinical response in FL.

WHAT THIS STUDY ADDS

The previously validated PK-PD model can be used to design an optimized rituximab dose regimen in FL patients. Clinical trial simulation shows the potential clinical benefits of changes in rituximab dose. Optimization of the rituximab dose regimen cannot compensate for the lower response of FCGR3A-158F carriers compared with that of FCGR3A-158VV patients. AIMS Rituximab has dramatically improved the survival of patients with non-Hodgkin's lymphoma (NHL). However, studies have suggested that the dose regimen currently used (i.e. 375 mg m(-2) ) could be optimized. The aims of this study were to quantify the benefits of the new dose regimen for rituximab in follicular NHL (FL) patients using a previously validated PK-PD model and to design clinical trials investigating optimization of rituximab dosage.

METHODS

A PK-PD model was used to predict progression-free survival (PFS) of FL patients treated by rituximab alone in asymptomatic FL, and those treated by rituximab combined with chemotherapy (R-CHOP) in relapsed/resistant FL. This model accounts for the influence of a polymorphism in FCGR3A, the gene encoding the FcγRIIIa receptor, on clinical efficacy. Several induction and maintenance dose regimens using rituximab alone or in combination with conventional chemotherapy (CHOP) were tested. The benefits of rituximab dose adjustment for F carriers were investigated. The numbers of subjects required for the design of two-armed clinical trials were calculated using model-predicted PFS at a power of 80%.

RESULTS

The model predicted a potential benefit of 1500 mg m(-2) maintenance doses of rituximab for both rituximab monotherapy and R-CHOP. The model shows that the PFS of FCGR3A-F carriers remains lower than that of homozygous FCGR3A-VV patients, even with markedly increased rituximab doses.

CONCLUSION

Our results suggest a benefit of increasing doses of rituximab in FL, both during induction and maintenance. These results need to be confirmed in controlled clinical trials.

The role of sex and weight on rituximab clearance and serum elimination half-life in elderly patients with DLBCL

Pharmacokinetics of 8 doses of rituximab (375 mg/m(2)) given in combination with 2-week cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone/prednisolone (CHOP-14) was determined by ELISA in 20 elderly patients with diffuse large B-cell lymphoma (DLBCL) 10 minutes before and after each infusion and 1 week and 1, 2, 3, 6, and 9 months after the last infusion. Population pharmacokinetic modeling was performed with nonlinear mixed-effect modeling software (NONMEM VI). Concentration-time data were fitted into an open 2-compartment model and total clearance, central compartment volume, intercompartment clearance, and volume of distribution at steady-state (Vd(ss)) were investigated. Total clearance was 9.43 mL/h and Vd(ss) was 9.61 l. Rituximab clearance was reduced (8.21 mL/h vs 12.68 mL/h; P = .003) and elimination half-life was prolonged in women compared with men (t(1/2β) = 30.7 vs 24.7 days; P = .003). Body weight also affected Vd(ss) (0.1 l increase of Vd(ss) per kilogram above median of 75 kg). A sex-dependent effect and the higher weight of males contribute to their faster rituximab clearance, which might explain why elderly males benefit less from the addition of rituximab to CHOP than females. This trial was registered on www.clinicaltrials.gov as numbers NCT00052936, EU-20243 (RICOVER-60 Trial), EU-20534, and NCT00726700 (Pegfilgrastim Trial).

Population pharmacokinetics of rituximab in patients with chronic lymphocytic leukemia

This retrospective analysis characterizes rituximab population pharmacokinetics in combination with fludarabine and cyclophosphamide and its effect on fludarabine and cyclophosphamide disposition in chronic lymphocytic leukemia (CLL) patients. Rituximab concentration data were well described by a 2-compartment model comprising a time-varying clearance component related to the target-mediated clearance pathway and a constant clearance component reflecting catabolic elimination pathway. Marked differences were observed compared to pharmacokinetic parameters for non-Hodgkin lymphoma (NHL) obtained previously: in CLL, time-varying clearance at time zero (CL(2)) was faster, volumes of distribution (V(1) and V(2)) were larger, and rate of change (K(des)) from the targetmediated clearance pathway to catabolic elimination was lower than NHL. Fludarabine and cyclophosphamide disposition showed no apparent change when co-administered with rituximab. A positive correlation between pharmacokinetic parameters and clinical response was observed, supporting the use of the higher rituximab dose of 500 mg/m(2) in CLL patients (vs 375 mg/m(2) in NHL) to achieve an effective clinical response.

Rituximab monotherapy with eight weekly infusions for relapsed or refractory patients with indolent B cell non-Hodgkin lymphoma mostly pretreated with rituximab: a multicenter phase II study

Information regarding rituximab monotherapy with eight weekly infusions for relapsed or refractory indolent B cell non-Hodgkin lymphoma (B-NHL), in particular for patients pretreated with rituximab, is limited. To evaluate the efficacy and safety of eight doses of rituximab monotherapy, 52 patients with relapsed or refractory indolent B-NHL were enrolled in the present study. Forty of 45 eligible patients (89%) had follicular lymphoma and 24 (53%) were at intermediate or high risk group according to the Follicular Lymphoma International Prognostic Index. The median number of prior chemotherapy regimens was 1 (range 1-7). At the median follow-up of 12.2 months, the overall response rate (ORR), complete response rate (%CR), and median progression-free survival (PFS) were 69% (95% confidence interval [CI] 53%-82%), 47% (95% CI 32%-62%), and 15.6 months (95% CI 10.6- months), respectively. In the 33 patients pretreated with rituximab, the ORR, %CR, and median PFS were inferior compared with values for the 12 patients who had not received rituximab previously (64%vs 83% for ORR; 39%vs 67% for %CR; and 13.8 vs 17.5 months for median PFS, respectively). All mild-to-moderate infusion-related toxicities were reversible. Grade 3/4 non-hematologic adverse events occurred in six of the 52 patients. Two patients developed Grade 4 late-onset neutropenia and a decrease (>50%) in serum immunoglobulin was observed in six patients. In conclusion, rituximab monotherapy with eight weekly infusions is effective in relapsed patients with indolent B-NHL, with acceptable toxicities, including in patients pretreated with rituximab; however, careful monitoring is recommended for infections associated with late-onset neutropenia and hypogammaglobulinemia. (University Hospital Medical Information Network no. UMIN000002974.)

Rituximab in chronic lymphocytic leukemia

Rituximab (Rituxan; iogen Idec, San Diego, CA, USA) is a human-mouse chimeric monoclonal antibody specific for CD20, a surface glycoprotein expressed on B lymphocytes. Administration of rituximab as a single agent to patients with chronic lymphocytic leukemia (CLL) has limited clinical activity, but generally does not eradicate leukemia from the marrow. However, when administered in combination with chemotherapy, rituximab can improve the survival of patients relative to those treated with chemotherapy alone. As a result of this, the US Food and Drug Administration approved the use of rituximab in previously untreated and previously treated CD20-positive CLL in combination with fludarabine monophosphate and cyclophosphamide. The results of clinical studies evaluating the activity of rituximab when used alone or in combination with other antileukemia agents for the treatment of this disease are reviewed here.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Prevention of hepatitis B virus reactivation under rituximab therapy

Rituximab is a useful drug for the treatment of B-cell non-Hodgkin's lymphoma, and its use has been extended to other diseases such as idiopathic thrombocytopenic purpura and chronic rheumatoid arthritis. One serious complication associated with rituximab use is reactivation of hepatitis B virus, and the search for methods to prevent this occurrence has resulted in a rapid accumulation of knowledge in recent years. In this review, we will discuss case studies from our group, as well as other groups, and outline current knowledge on the topic together with issues that remain to be resolved.

Phase I study of LY2469298, an Fc-engineered humanized anti-CD20 antibody, in patients with relapsed or refractory follicular lymphoma

Patients with follicular lymphoma (FL), where position 158 of FcγR-IIIa is heterozygous valine/phenylalanine or homozygous phenylalanine (F-carriers), have natural killer cells with lower binding affinity to IgG than valine homozygote patients. In addition, F-carriers show less efficacy with rituximab treatment than patients homozygous for valine. LY2469298 is a humanized IgG1 monoclonal antibody targeting CD20, with human germline framework regions, and specific amino acid substitutions engineered into the Fc region to increase effector function in antibody-dependent cell-mediated cytotoxicity. This dose-escalation, phase I study was conducted to assess the safety, pharmacokinetics and preliminary efficacy of LY2469298 in Japanese patients with previously treated, CD20-positive FL who had not relapsed or progressed within 120 days of prior rituximab. LY2469298 was administered by intravenous infusion at 100 or 375 mg/m(2) weekly for 4 weeks. Ten patients were enrolled (median age, 60 years); all had previously been treated with rituximab. Nine patients were F-carriers while one was homozygous for valine at position 158 of FcγRIIIa. No patients developed dose-limiting toxicities, and the most frequent adverse events were lymphopenia, pyrexia, leukopenia, chills and neutropenia. Five (50%) of the ten patients responded to LY2469298 treatment (three complete responses, one unconfirmed complete response and one partial response). Serum LY2469298 was eliminated in a biphasic manner and the pharmacokinetic profiles were not different from those in a preceding study in the United States. In conclusion, LY2469298 was well tolerated and clinical activity was observed in FL patients pretreated with rituximab, mostly consisting of F-carriers. Further investigation of FL is warranted.

An international phase II trial of single-agent lenalidomide for relapsed or refractory aggressive B-cell non-Hodgkin's lymphoma

BACKGROUND

Lenalidomide is an immunomodulatory agent with antitumor activity in B-cell malignancies. This phase II trial aimed to demonstrate the safety and efficacy of lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular grade 3 lymphoma (FL-III), or transformed lymphoma (TL).

METHODS

Patients received oral lenalidomide 25 mg on days 1-21 every 28 days as tolerated or until progression. The primary end point was overall response rate (ORR).

RESULTS

Two hundred and seventeen patients enrolled and received lenalidomide. The ORR was 35% (77/217), with 13% (29/217) complete remission (CR), 22% (48/217) partial remission, and 21% (45/217) with stable disease. The ORR for DLBCL was 28% (30/108), 42% (24/57) for MCL, 42% (8/19) for FL-III, and 45% (15/33) for TL. Median progression-free survival for all 217 patients was 3.7 months [95% confidence interval (CI) 2.7-5.1]. For 77 responders, the median response duration lasted 10.6 months (95% CI 7.0-NR). Median response duration was not reached in 29 patients who achieved a CR and in responding patients with FL-III or MCL. The most common adverse event was myelosuppression with grade 4 neutropenia and thrombocytopenia in 17% and 6%, respectively.

CONCLUSION

Lenalidomide is well tolerated and produces durable responses in patients with relapsed or refractory aggressive non-Hodgkin's lymphoma.

Rituximab pharmacokinetics during the management of acute idiopathic thrombotic thrombocytopenic purpura

BACKGROUND

Increasingly, patients with acute, idiopathic, antibody mediated thrombotic thrombocytopenic purpura (TTP) are being treated with rituximab to achieve a durable remission, however, there is the potential that it is removed by plasma exchange (PEX).

OBJECTIVES

To look at the pharmacokinetics and pharmacodynamics of rituximab in patients with acute idiopathic TTP undergoing PEX.

PATIENTS AND METHODS

Patients who received rituximab for acute idiopathic TTP (group 1, n = 30) and a control group (group 2, n = 3) of TTP patients in remission receiving rituximab electively as maintenance were included. Rituximab levels were measured before/after each infusion, before/after PEX and in follow-up. ADAMTS-13 activity, anti-ADAMTS-13 IgG and CD19% were measured to assess response.

RESULTS

The median number of PEX to remission after rituximab was 10 (range 4-25). In group 1 there was no significant incremental rise in the peak serum rituximab level until dose 4. Trough levels were lower in patients who had had PEX since their last rituximab infusion. In the control group, there was an incremental rise in the peak serum rituximab level and all patients had detectable trough levels. The median fall in rituximab per PEX was 65%. All patients achieved CD19 < 1%. In group 1, the median time to undetectable rituximab was 5 months (range 0-12 months) and to B cell return was 7 months (range 3-24 months). ADAMTS-13 increased and anti-ADAMTS-13 fell after therapy. There were three deaths and two relapses in group 1. Relapse was not temporally related to B cell return.

Pharmacokinetics and pharmacokinetic/pharmacodynamic associations of ofatumumab, a human monoclonal CD20 antibody, in patients with relapsed or refractory chronic lymphocytic leukaemia: a phase 1-2 study

The purpose of this phase 1-2 study was to investigate the association between the pharmacokinetic properties of ofatumumab, a human monoclonal CD20 antibody, and outcomes in 33 patients with relapsed/refractory chronic lymphocytic leukaemia receiving 4 weekly infusions of ofatumumab. The ofatumumab concentration profiles were fitted well by a two-compartment model with different elimination rate constant at first infusion compared to the remaining infusions in line with the observed rapid and sustained B-cell depletion. Exposure to ofatumumab was linked to clinical outcomes: high exposure was associated with higher probability of overall clinical response and longer progression-free survival. This association still remained statistically significant even when adjusting for relevant baseline covariates including tumour burden.

Pharmacokinetics of rituximab associated with CHOP chemotherapy in B-cell non-Hodgkin lymphoma

The pharmacokinetics of rituximab administered alone at a dose of 375 mg/m(2) once a week have been widely studied but few data are available for the administration of rituximab in combination with other agents. We carried out a pilot pharmacokinetic study in 10 patients with B-cell non-Hodgkin lymphoma treated with rituximab associated with chemotherapy on a three-weekly basis. Patients received four courses of rituximab (375 mg/m(2)) associated with CHOP (cyclophosphamide, adriamycin, vincristine and prednisone) at 21-day intervals. Blood samples were collected from each patient at selected times throughout the treatment period and analysed using a validated enzyme-linked immunosorbent assay. The NONMEM software was used to obtain population and post hoc estimates of rituximab pharmacokinetic parameters and to study possible time-dependent variation during treatment. Pharmacokinetic parameters obtained from 10 patients were similar to those described for studies in the absence of chemotherapy. We did not observe any intra-subject variation in pharmacokinetic parameters over the treatment period. Our results suggest that rituximab pharmacokinetics is not affected by combination with CHOP chemotherapy. Nevertheless, the substantial intersubject variability observed in this small sample size highlights the need for further study of the determinants of rituximab pharmacokinetic variability.

Ten years of rituximab in NHL

BACKGROUND

Rituximab, a chimeric mouse/human monoclonal antibody targeting the pan-B-cell antigenic marker CD20, was the first monoclonal antibody licensed for use in the treatment of cancer.

OBJECTIVE

This review focuses on the impact of rituximab in the treatment of patients with B-cell non-Hodgkin lymphoma (NHL).

METHODS

Three key areas related to the use of rituximab in B-cell NHL are discussed: mechanism of action, clinical efficacy in both indolent and aggressive disease, and safety of its use as both monotherapy and in combination with chemotherapy.

RESULTS/CONCLUSIONS

Rituximab has demonstrated significant clinical efficacy in the treatment of NHL, particularly in combination with chemotherapy, and its use has revolutionized the treatment of both indolent and aggressive B-cell NHL over the past decade. Furthermore, consistent toxicity data have been obtained with a safe and tolerable profile in most patients.

Use of rituximab in diffuse large B-cell lymphoma in the salvage setting

The addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy was a milestone in the development of front-line therapy for diffuse large B-cell lymphoma (DLBCL). R-CHOP and equivalent rituximab-containing anthracycline-based regimens are now widely accepted as the standard of care in this setting. However, the optimal treatment for patients with DLBCL relapsing or progressing after front-line therapy is not yet established. This review explores the role of rituximab in the treatment of DLBCL in the salvage setting, as monotherapy, in combination with chemotherapy or novel agents, and in the context of autologous stem cell transplantation (ASCT). Current evidence suggests that rituximab may improve outcomes in several ways: the higher response rates achieved with rituximab-based induction in the salvage setting optimize the number of patients who are able to proceed to high-dose therapy -ASCT; rituximab may improve outcomes following ASCT when used as post-transplantation consolidation/maintenance therapy; and addition of rituximab to salvage regimens may improve outcomes for patients ineligible for transplantation. However, patients refractory to or relapsing after first-line therapy (including rituximab-based regimens) still have a poor prognosis. In conclusion, rituximab in salvage therapy for DLBCL is effective and well tolerated. Ongoing studies will further clarify the optimal use of rituximab in the salvage setting.

Effects of ultrasound on apoptosis induced by anti-CD20 antibody in CD20-positive B lymphoma cells

AIM

The present study was conducted to examine the thermal and non-thermal effects of ultrasound on apoptosis induced by anti-CD20 monoclonal antibody (rituximab).

MATERIALS AND METHODS

SU-DHL-4 cells, a CD20-positive cell line derived from B cell lymphomas with a BCL2 gene rearrangement, were exposed to continuous 1 MHz ultrasound for therapeutic use under an air- or CO(2)-saturated condition to control cavitation. Early apoptosis (EA) and secondary necrosis (SN) were examined by flow cytometry. Cavitation was determined by detecting the hydroxyl radicals derived from pyrolysis of water molecules using electron paramagnetic resonance-spin trapping. To assess thermal effects, cells were treated in a temperature-controlled water bath.

RESULTS

There was a significant additive increase in EA and EA+SN observed in cells treated with rituximab combined with heat at 42 degrees C or non-thermal ultrasound at 0.5 W/cm(2) under an air-saturated condition, where heat or ultrasound induced some cell death. A significant synergistic increase in EA and EA+SN was observed in cells treated with rituximab and ultrasound at 2.5 W/cm(2) under CO(2)-saturated conditions, where inertial cavitations were completely suppressed. No enhancement was observed at a temperature less than 40 degrees C or ultrasound at 0.5 W/cm(2) under CO(2)-saturated conditions.

CONCLUSION

These results suggest that the immuno-therapeutic application of ultrasound at relatively high-intensities combined with rituximab thus produces synergistic effects under conditions where the non-thermal and non-cavitational effects are predominant.

Rituximab in combination with CHOP chemotherapy for the treatment of diffuse large B cell lymphoma in Chinese patients

The objective of this study is to evaluate the long-term efficacy and safety of rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in Chinese patients with newly diagnosed diffuse large B cell lymphoma (DLBCL). The study comprised a retrospective analysis of patients treated at a single center. Patients received four to six infusions of rituximab (375 mg/m(2) per dose) on day 1 of each cycle of CHOP chemotherapy. CHOP was initiated on day 3 of each cycle; cycles were repeated at 21-day intervals. A total of 82 patients with a median age of 45 years (range 18-76 years) was included. The overall response (OR) and complete response (CR) rates were 90.2 and 70.7%, respectively. The estimated 5-year progression-free survival (PFS) and overall survival (OS) rates were 56.4 +/- 8.3% and 74.1 +/- 7.4%, respectively. Patients with International Prognostic Index (IPI) scores < or = 2 had significantly higher OR, CR, PFS, and OS rates (p = 0.01, p = 0.02, p = 0.01, p < 0.001, respectively) compared with patients with IPI scores >2. The hematologic toxicity was mild. Five patients with a history of chronic hepatitis B experienced a reactivation of viral hepatitis. The rituximab-CHOP combination was effective and well tolerated in Chinese patients with newly diagnosed DLBCL.

Outcomes of primary thyroid non-Hodgkin’s Lymphoma

Primary non-Hodgkin's lymphoma (NHL) of the thyroid gland is a rare disease with an incidence of 0.5 per 100,000 population. Stages IE and IIE thyroid NHL have been traditionally treated by surgical resection; however, modern treatment consists of chemotherapy and local radiotherapy, and surgery is often reserved for tissue diagnosis and relief of airway compression. We retrospectively reviewed the management and outcomes of nine consecutive patients with thyroid NHL, eight females and one male (median age 63 yr, range 34-71 yr) treated between 1994 and 1999. Five patients had disease stage IE and 4 stage IIE. Median follow-up was 72 mo. Pathohistology and immunohistochemistry identified two patients with mucosa-associated lymphoid tissue (MALT), three follicular center cell lymphoma (FCC), two patients large B-cell lymphoma (BLCL), one a marginal zone lymphoma (MZL), and one patient a peripheral T-cell lymphoma (PTCL). Total thyroidectomy was performed in three patients and subtotal thyroidectomy in four. One (MALT) patient underwent surgery alone; three patients surgery, radiotherapy, and chemotherapy (two FCC, one PTCL); three patients surgery and chemotherapy (one MALT, one FCC, one LBCL); and two chemotherapy alone (one LBCL, one MZL). Median survival was 79 mo (range 13-124 mo). The PTCL patient, a 34-yr-old man, died from disseminated disease at 13 mo despite secondary chemotherapy, and one LBCL patient with extensively invasive local disease died from stroke 17 mo after diagnosis. The remaining seven patients remain in remission with no local or systemic relapse at a mean of 86 mo. With appropriate therapy primary thyroid NHL has a favorable course; however, prognosis depends on the histology, local spread, and the stage of the disease at presentation, as well as the patient's performance status. Surgery in combination with chemotherapy and/or radiotherapy is still warranted for intermediate and high-grade thyroid NHLs, with over 77% of patients achieving long-term remission. Peripheral T-cell lymphoma carries a poor prognosis.

A phase I/II study of galiximab (an anti-CD80 monoclonal antibody) in combination with rituximab for relapsed or refractory, follicular lymphoma

BACKGROUND

Galiximab is a monoclonal antibody that targets CD80, a costimulatory molecule constitutively expressed on follicular and other lymphomas. Modest single-agent clinical activity and tolerability were demonstrated in a phase I study in relapsed or refractory, follicular non-Hodgkin's lymphoma (NHL). A phase I/II study was conducted to evaluate galiximab in combination with a standard course of rituximab. Safety, pharmacokinetics, and efficacy were evaluated.

PATIENTS AND METHODS

Patients with follicular NHL who had relapsed or failed primary therapy were enrolled. Rituximab-refractory patients (no response or a response with time to progression <6 months) were excluded. Patients received 4 weekly i.v. infusions of galiximab (125, 250, 375, or 500 mg/m(2)) and rituximab (375 mg/m(2)). International Workshop Response Criteria (IWRC) were used to evaluate response.

RESULTS

Seventy-three patients received treatment. All had received at least one prior lymphoma therapy; 40% were rituximab naive. Infusions were delivered in an outpatient setting and were well tolerated. The most common study-related adverse events (AE) were lymphopenia, leukopenia, neutropenia, fatigue, and chills. The overall response rate at the recommended phase II dose of galiximab (500 mg/m(2)) was 66%: 19% complete response, 14% unconfirmed complete response, and 33% partial response. The median progression free survival was 12.1 months. Combination therapy did not appear to alter pharmacokinetics.

CONCLUSION

These results indicate that galiximab can be safely combined with a standard course of rituximab. This doublet biologic approach offers the potential to avoid or delay chemotherapy or to integrate with other lymphoma therapies. A phase III, randomized study evaluating clinical benefit of rituximab versus the combination has been initiated.

Rituximab alone was effective for the treatment of a diffuse large B-cell lymphoma associated with hemophagocytic syndrome

We report here the case of a 63-year-old man who had a diffuse large B-cell lymphoma associated with hemophagocytic syndrome (HPS). The lymphoma involved the spleen, bilateral adrenal glands, and paraaortic lymph nodes of the abdomen. In both the bone marrow and lymph nodes, hemophagocytosis was evident, and the laboratory findings were consistent with HPS. The lymphoma cells showed a CD4+, CD5+, CD10-, CD19+, CD20+, CD25+ and surface immunoglobulin microalpha/kappa+ immunophenotype. The patient was unintentionally treated with rituximab alone, resulting in complete resolution of the lymphomatous lesions as well as the features of HPS in response to the initial two doses of rituximab, although he developed gastric hemorrhage requiring vigorous resuscitation. After the completion of eight doses of rituximab, the patient remains free of disease with an excellent performance status.

Pharmacokinetics of rituximab and its clinical use: thought for the best use?

Rituximab (MabThera, Rituxan) is a chimaeric monoclonal antibody increasingly used in the treatment of B-lymphoproliferative disorders and autoimmune diseases. Rituximab is now associated with chemotherapy for the treatment of non-Hodgkin's lymphoma and should be approved soon in maintenance strategies. During its rapid clinical development, rituximab schedules were dictated more often by logistical rather than by scientific considerations. In addition, early clinical phases have shown that rituximab exposure was variable in patients receiving similar doses and that clinical response was related to rituximab concentrations. There is however limited information on rituximab pharmacokinetics and on factors influencing individual exposure to this monoclonal antibody, although a better understanding of these factors is needed to optimise its dosing regimen. This review focuses on the current knowledge on rituximab pharmacokinetics and on factors influencing individual exposure and suggests ways to improve its clinical use.

Rituximab plus ASHAP for the treatment of patients with relapsed or refractory aggressive non-Hodgkin’s lymphoma: a single-centre study of 20 patients

The anti-CD20 antibody rituximab improves the results of first-line therapy in aggressive non-Hodgkin's lymphoma (NHL) of B cell lineage. The purpose of this retrospective study was to evaluate its efficacy and toxicity in combination with the doxorubicine, methylprednisolone, high-dose cytarabine, cisplatin (ASHAP) protocol, an established treatment regimen for relapsed or refractory aggressive NHL. After a median of four cycles, 9 of 20 patients treated achieved a complete remission and 6 a partial remission, resulting in a total response rate of 75%. Remissions were not only seen in patients with relapsed lymphomas but also in patients with primary refractory or transformed indolent lymphomas. The outcome in cases with an international prognostic index score > or =2 was poor. Five of 15 responders received consolidating high-dose therapy with autologous stem cell transplantation. All of them are in ongoing remission. The main toxicity was myelosuppression, with neutropenias or thrombocytopenias of World Health Organization (WHO) grades III or IV developing in more than 90% of the cycles. There was one therapy-related death due to neutropenic sepsis. Non-hematologic toxicity was generally mild. At the time of analysis, six patients have died. After a median observation time of 17.5 months, the 2-year overall survival rate is 62%. ASHAP plus rituximab is an active and well-tolerated salvage protocol for patients with relapsed or refractory aggressive NHL, which compares favourably with other immuno-chemotherapy regimens, especially in patients with primary refractory or transformed indolent lymphomas.

4. Antibody therapy for malignant lymphoma

Rituximab, a genetically engineered, chimeric anti-CD20 monoclonal antibody, induces the apoptosis of B-lymphoma cells, in addition to the lyses by complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC), as shown in Fig. 1. A Japanese phase I study of rituximab in relapsed or refractory patients with B-cell non-Hodgkin's lymphoma (B-NHL) showed an overall response rate (ORR) of 64% (7/11) with minimal toxicities. Elimination half-life (T(1/2)) of serum rituximab was 445+/-361 hours, and the serum rituximab was detectable at three months. In the subsequent phase II study, 90 relapsed or refractory patients with indolent B-NHL or mantle cell lymphoma (MCL) were treated with rituximab at 375 mg/m2x4 weekly infusions. ORRs in indolent B-NHL and MCL were 61% (37/61) and 46% (6/13), respectively. In this presentation, the results of clinical trials of antibody therapy of malignant lymphoma are summarized, focusing on the two recent Japanese multicenter trials of rituximab and a Japanese feasibility study of anti-CD20 radioimmunotherapy with yttrium-90-lableled ibritumomab tiuxetan.

High-Dose Celecoxib and Metronomic “Low-dose” Cyclophosphamide Is an Effective and Safe Therapy in Patients with Relapsed and Refractory Aggressive Histology Non–Hodgkin's Lymphoma

PURPOSE

Angiogenesis is increased in aggressive histology non-Hodgkin's lymphoma and may be a target with selective cyclooxygenase-2 inhibition and metronomic chemotherapy.

EXPERIMENTAL DESIGN

We assessed response, toxicity, and biomarkers of angiogenesis to low-dose cyclophosphamide (50 mg p.o. o.d.) and high-dose celecoxib (400 mg p.o. b.i.d.) in adult patients with relapsed or refractory aggressive non-Hodgkin's lymphoma in a multicenter phase II prospective study.

RESULTS

Thirty-two of 35 patients (median age, 62 years) are evaluable for response. Patients had primarily relapsed diffuse large B-cell lymphoma (63%) were heavily pretreated (median of three regimens) and high risk (79% international prognostic index, >or=2) and 34% were relapsed after autologous stem cell transplant. With a median follow-up of 8.4 months, the overall best response rate is 37% (2 complete clinical response/complete clinical response unconfirmed and 9 partial response), with 22% achieving stable disease. Median overall and progression-free survivals are 14.4 and 4.7 months, respectively. The median response duration was 8.2 months. The most common toxicity was skin rash (40%); myelosuppression and gastrointestinal side effects were uncommon. Three patients developed deep vein thromboses and two heavily pretreated patients developed treatment-related acute myelogenous leukemia or myelodysplasia after 3.7 and 12 months of therapy. Circulating endothelial cells and their precursors declined and remained low in responders, whereas plasma vascular endothelial growth factor trended to decline in responding patients but increase in nonresponders. Trough celecoxib levels achieved targeted "antiangiogenic" levels.

CONCLUSIONS

Low-dose cyclophosphamide and high-dose celecoxib is well tolerated and active in pretreated aggressive non-Hodgkin's lymphoma. Close surveillance for arterial and venous thrombotic events is recommended. The decline in circulating endothelial cells and their precursors suggests that this combination may be working by inhibiting angiogenesis but should be validated in a larger patient sample.

Pharmacokinetic behavior of rituximab: a study of different schedules of administration for heterogeneous clinical settings

This study was designed to report the pharmacokinetic behavior of Rituximab in patients affected with different diseases and treated with different schedules of administration. A low tumor burden was a common feature of all patients (N=48) included in our study, whereas the timing of Rituximab administration varied from weekly (groups 1, 2, 3) to monthly (group 4). Group 1 included patients with follicular lymphoma treated with 4 weekly doses of Rituximab after first-line chemotherapy with CHOP. At the start of Rituximab, patients were in partial or complete clinical response but showed persistence of disease at molecular level (bcl-2-positive) in bone marrow and/or peripheral blood. Patients in group 2 had autoimmune disorders and Rituximab was given to act on B-cells, interfering with their production of autoantibodies. In patients with amyloidosis (group 3), Rituximab was given to kill progenitor B-cells of the small clone terminating in amyloid-producing plasma cells. In groups 2 and 3, the target of monoclonal antibody was a population of small B cells, which make an intrinsic feature of the diseases. Group 4 included patients with relapsed or refractory follicular and mantle cell lymphoma who underwent a salvage program of immunochemotherapy, purging in vivo and autotransplant: the first of the six planned doses of Rituximab was administered after a debulking phase with a third-generation regimen, such as VACOP-B. An enzyme-linked immunoassay (ELISA) developed and validated in our laboratory was used for the pharmacokinetic study. Rituximab disposition was characterized by a 2-exponential decay, with a long elimination half-life of approximately 3 weeks (range, 248-859 hours). The total systemic clearance ranged between 3.1 and 11.9 mL/hr/m. After 4 weekly infusions, Rituximab concentration was approximately 2.5 microg/mL, which is approximately 85% of the steady-state level. Steady-state plasma concentrations of Rituximab were reached after 6 to 8 weekly infusions. The adopted pharmacokinetic model (2-compartment open model) seems to provide the best fit of Rituximab disposition both during and after treatment, even when different schedules of drug administration are used. Because several studies reported an association between response and serum Rituximab concentrations, a treatment based on a pharmacokinetic model may be useful for predicting the desired drug concentration.

Reactivation of hepatitis B virus with rituximab

Rituximab has become a useful drug for the treatment of non-Hodgkin's lymphoma (NHL) and such autoimmune diseases as idiopathic thrombocytopenic purpura and rheumatoid arthritis. When combined with cytotoxic agents, rituximab showed synergistic effects for the treatment of NHL. In such treatment, hepatitis B virus (HBV) reactivation is a crucial complication when patients are treated with immunosuppressive or chemotherapeutic agents. Despite its treatment efficacy, several studies have pointed out unusual viral infections after its administration that resulted in fatal hepatitis due to HBV reactivation. In the cases at the authors' institute, the authors analysed the kinetics of HBV antibodies, HBV-reactivation timing, and the prophylactic efficacy of lamivudine. The authors reviewed their cases and the previous literature to clarify the characteristics of HBV-reactivated patients who were administered rituximab.

Improved therapeutic outcomes of DLBCL after introduction of rituximab in Korean patients

The addition of rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been shown to improve the outcome in all age groups with newly diagnosed diffuse large B-cell lymphoma (DLBCL). We conducted a retrospective analysis to evaluate the impact of this combination therapy on DLBCL outcomes in Korea. From October 2001 to June 2004, newly diagnosed DLBCL patients in nine Korean institutes were included. All of these 81 patients were treated with three or more cycles of rituximab plus CHOP (R-CHOP) combination chemotherapy (R group), and followed for a minimum of 12 months. For comparison, a historical cohort of patients was used and analyzed for "Clinicopathologic characteristics of Korean non-Hodgkin's lymphomas (NHLs) based on Revised American Lymphoma (REAL) classification" in 1999. Among the 1,098 NHL patients, the data of 214 DLBCL patients, who were treated with CHOP chemotherapy in first-line, were analyzed (C group). We compared outcomes between the C group and the R group. A total of 295 patients were evaluated (C group, 214; R group, 81). The complete response (CR) rate was higher in R group (73 vs 91%, p=0.001). The 2-year event-free survival (EFS) rate was significantly higher in R group (78 vs 85%, p=0.0194). This survival benefit was maintained in high-risk patients according to the international prognostic index (IPI) (p=0.0039), regardless of age. However, there was no significant difference in low-risk patients. The addition of rituximab to CHOP combination chemotherapy for DLBCLs showed improved outcomes, particularly in high-risk group according to the IPI. Long-term follow-up results will be needed to confirm these results.

Clinical trials for malignant lymphoma in Japan

The results of the clinical trials by the Lymphoma Study Group of the Japan Clinical Oncology Group (JCOG-LSG) and those of the industry-supported trials mainly conducted by the members of JCOG-LSG are summarized. In the treatment of advanced aggressive non-Hodgkin's lymphoma (NHL), we investigated the efficacy of granulocyte colony-stimulating factor (G-CSF)-supported, dose-intensified strategies. Based on the results of a randomized phase II study (JCOG9505), we conducted a phase III study, JCOG9809, comparing CHOP and biweekly CHOP. However, JCOG9809 was terminated early based on the results of a planned interim analysis, because it was deemed highly unlikely that biweekly CHOP would be superior to standard CHOP. For aggressive ATL, a G-CSF-supported, dose-intensified, multi-agent regimen (JCOG9303; LSG15) showed superior efficacy to our historical controls. To establish a new standard for ATL, we conducted a phase III study, JCOG9801, comparing LSG15 and biweekly CHOP. To develop new agents for lymphoid malignancies, we focused on irinotecan hydrochloride, interferon-alpha, cladribine and oral fludarabine. Among them, cladribine and oral fludarabine are promising for indolent B-cell malignancies. The Japanese phase I and II studies of rituximab, a chimeric anti-CD20 monoclonal antibody, in relapsed indolent and aggressive B-NHL showed high efficacy with minimal toxicities, which led us to conduct combination studies with chemotherapy for B-NHL. In addition, a phase I study of a radiolabeled anti-CD20 antibody (ibritumomab tiuxetan) was completed in 2003, and a phase II study for indolent B-NHL will be initiated. The multicenter trials by the JCOG-LSG and industry-supported new agent studies will contribute to further improvement in the treatment of malignant lymphoma.