Treatment with ibritumomab tiuxetan radioimmunotherapy in patients with rituximab-refractory follicular non-Hodgkin's lymphoma

An open-label expanded-access trial of bendamustine in patients with rituximab-refractory indolent non-Hodgkin lymphoma or previously untreated chronic lymphocytic leukemia: BEND-ACT

BACKGROUND

Bendamustine is a bifunctional alkylating agent with unique properties that distinguish it from other agents in its class. Bendamustine is used as monotherapy or in combination with other agents to treat patients with non-Hodgkin lymphoma (nhl) and chronic lymphocytic leukemia (cll).

METHODS

The prospective interventional open-label bend-act trial evaluated bendamustine in patients with rituximab-refractory indolent nhl (inhl) and previously untreated cll. Study objectives were to assess the safety and tolerability of bendamustine monotherapy and to provide patients with access to bendamustine before Health Canada approval. The study aimed to enrol up to 100 patients. All patients with inhl received an intravenous dose of bendamustine 120 mg/m(2) over 60 minutes on days 1 and 2 for up to eight 21- or 28-day treatment cycles. All patients with cll received an intravenous dose of bendamustine 100 mg/m(2) over 30 minutes on days 1 and 2 for up to six 28-day treatment cycles.

RESULTS

Of 90 patients treated on study (16 with cll and 74 with inhl), 35 completed the study (4 with cll and 31 with inhl). The most common treatment-emergent adverse events (teaes) were nausea (70%), fatigue (57%), vomiting (40%), and diarrhea (33%)-mostly grades 1 and 2. Ondansetron was the most common supportive medication used in the patients (63.5% of those with inhl and 68.8% of those with cll). Neutropenia (32%), anemia (23%), and thrombocytopenia (21%) were the most frequent hematologic teaes, with neutropenia being the most common grade 3 or 4 teae leading to dose modification. Dose delays occurred in 28 patients (31.3%) because of grade 3 or 4 teaes, with a higher incidence of dose delays being observed in inhl patients on the 21-day treatment cycle than in those on the 28-day treatment cycle (50.0% vs. 24.1%). During the study, 33 patients (36.7%) experienced at least 1 serious adverse event, and 4 deaths were reported (all in patients with inhl).

CONCLUSIONS

The type and frequency of the teaes reported accorded with observations in earlier clinical trials and post-marketing experiences, thus confirming the acceptable and manageable safety profile of bendamustine.

Radioimmunotherapy ((90) Y-Ibritumomab Tiuxetan) for Posttransplant Lymphoproliferative Disorders After Prior Exposure to Rituximab

Posttransplantation lymphoproliferative disorders (PTLDs) are life-threatening complications after solid organ and hematopoietic stem cell transplantation. Only half of CD20-positive PTLDs respond to rituximab monotherapy, and outcomes remain poor for patients with relapsed/refractory disease, especially those who do not qualify for an anthracycline containing regimen due to frailty or comorbidities. Radioimmunotherapy (RIT) might be an option in this particular setting. We report a panel of eight patients with rituximab refractory/relapsed CD20-positive PTLDs including three ineligible for subsequent CHOP-like chemotherapy who received (90) Y-Ibritumomab tiuxetan as a single agent (n = 7) or combined to chemotherapy (n = 1). Five out of eight patients were kidney transplant recipients, while 2/8 had a liver transplant and 1/8 had a heart transplant. Patients received a median of two previous therapies. Overall response rate was 62.5%. Importantly, all responders achieved complete response. At a median follow-up of 37 months [5; 84], complete response was ongoing in four patients. Toxicity was predominantly hematological and easily manageable. No graft rejection was noticed concomitantly or following RIT administration despite immunosuppression reduction after diagnosis of PTLDs. This report emphasizes the potential efficiency of salvage RIT for early rituximab refractory PTLDs without any unexpected toxicity.

Targeted Cancer Therapy with a Novel Anti-CD37 Beta-Particle Emitting Radioimmunoconjugate for Treatment of Non-Hodgkin Lymphoma

177Lu-DOTA-HH1 (177Lu-HH1) is a novel anti-CD37 radioimmunoconjugate developed to treat non-Hodgkin lymphoma. Mice with subcutaneous Ramos xenografts were treated with different activities of 177Lu-HH1, 177Lu-DOTA-rituximab (177Lu-rituximab) and non-specific 177Lu-DOTA-IgG1 (177Lu-IgG1) and therapeutic effect and toxicity of the treatment were monitored. Significant tumor growth delay and increased survival of mice were observed in mice treated with 530 MBq/kg 177Lu-HH1 as compared with mice treated with similar activities of 177Lu-rituximab or non-specific 177Lu-IgG1, 0.9% NaCl or unlabeled HH1. All mice injected with 530 MBq/kg of 177Lu-HH1 tolerated the treatment well. In contrast, 6 out of 10 mice treated with 530 MBq/kg 177Lu-rituximab experienced severe radiation toxicity. The retention of 177Lu-rituximab in organs of the mononuclear phagocyte system was longer than for 177Lu-HH1, which explains the higher toxicity observed in mice treated with 177Lu-rituximab. In vitro internalization studies showed that 177Lu-HH1 internalizes faster and to a higher extent than 177Lu-rituximab which might be the reason for the better therapeutic effect of 177Lu-HH1.

Radioimmunotherapy of human tumours

The eradication of cancer remains a vexing problem despite recent advances in our understanding of the molecular basis of neoplasia. One therapeutic approach that has demonstrated potential involves the selective targeting of radionuclides to cancer-associated cell surface antigens using monoclonal antibodies. Such radioimmunotherapy (RIT) permits the delivery of a high dose of therapeutic radiation to cancer cells, while minimizing the exposure of normal cells. Although this approach has been investigated for several decades, the cumulative advances in cancer biology, antibody engineering and radiochemistry in the past decade have markedly enhanced the ability of RIT to produce durable remissions of multiple cancer types.

The use of Yttrium-90 Ibritumomab Tiuxetan ((90)Y-IT) as a consolidation therapy in high-risk patients with diffuse large B-cell lymphoma ineligible for autologous stem-cell transplantation

Aim of the study

To evaluate the efficacy and safety of Yttrium-90 Ibritumomab Tiuxetan (⁹⁰Y-IT) as a consolidation therapy in the management of DLBCL.

Material and methods

Patients with primary refractory or high-risk DLBCL (n = 18), ineligible for autologous stem-cell transplantation, were included in a retrospective study performed at three centers by the Polish Lymphoma Research Group (PLRG). All patients (mean age 61, range 35–82) either didn't achieve a complete response or didn't complete the scheduled therapy due to its complications. Response rates (CR, PR, SD, PD) according to Cheson criteria, overall survival (OS), progression-free survival (PFS) and adverse effects of radioimmunotherapy were analyzed.

Results

Consolidation radioimmunotherapy increased the CR rate from 38% (n = 7) to 82% (n = 15). One patient remained in PR, one patient remained in SD, while one patient remained in PD. During a median follow-up of five years, 11 patients (62%) were alive with no recurrence, 4 patients (22%) were alive with relapse while 3 patients (16%) died. There was no statistically significant difference in PFS between those in CR and those in PR before ⁹⁰Y-IT.

Conclusions

Radioimmunotherapy is an effective consolidation therapy for high risk/refractory DLBCL patients and worthy of further investigation in prospective trials.

Beyond peptides and mAbs--current status and future perspectives for biotherapeutics with novel constructs

Biotherapeutics are attractive anti-cancer agents due to their high specificity and limited toxicity compared to conventional small molecules. Antibodies are widely used in cancer therapy, either directly or conjugated to a cytotoxic payload. Peptide therapies, though not as prevalent, have been utilized in hormonal therapy and imaging. The limitations associated with unmodified forms of both types of biotherapeutics have led to the design and development of novel structures, which incorporate key features and structures that have improved the molecules' abilities to bind to tumor targets, avoid degradation, and exhibit favorable pharmacokinetics. In this review, we highlight the current status of monoclonal antibodies and peptides, and provide a perspective on the future of biotherapeutics using novel constructs.

Treatment of follicular lymphoma

Follicular lymphoma (FL) is the most common subtype of indolent lymphomas. Several lines of evidence suggest that the prognosis of patients with FL has improved since the introduction of rituximab, although cure cannot be achieved. Although the treatment paradigm for FL has changed over the past decade with the introduction of rituximab and other agents, there is still no standard therapy to fit all patients. Instead, treatment decisions are made taking into consideration disease status (stage, tumor burden, and presence of symptoms) and patient factors including patient preferences. Rituximab-containing chemotherapy such as R-CHOP, R-CVP, and bendamustine plus rituximab is usually recommended for symptomatic patients. However, optimal rituximab-containing chemotherapy has not been established. Rituximab maintenance is one of the post-induction options for patients responding to first-line chemoimmunotherapy. For patients without symptoms and low-tumor burden, both expectant management (watchful waiting) and rituximab monotherapy are reasonable options. A very limited proportion of patients with FL are diagnosed at stage I with rigorous staging using bone marrow biopsy and whole-body imaging with computed tomography (CT) and/or positron emission tomography/CT. Although local radiotherapy has been the standard approach for these patients, its role is being questioned. Patients with FL who achieve remission eventually relapse and require salvage therapy. The salvage regimen should be chosen taking into account previous treatment and its response duration. Moreover, the presence of histological transformation should be assessed.

Astatine-211 conjugated to an anti-CD20 monoclonal antibody eradicates disseminated B-cell lymphoma in a mouse model

α-Emitting radionuclides deposit a large amount of energy within a few cell diameters and may be particularly effective for radioimmunotherapy targeting minimal residual disease (MRD). To evaluate this hypothesis, (211)At-labeled 1F5 monoclonal antibody (mAb) (anti-CD20) was studied in both bulky lymphoma tumor xenograft and MRD animal models. Superior treatment responses to (211)At-labeled 1F5 mAb were evident in the MRD setting. Lymphoma xenograft tumor-bearing animals treated with doses of up to 48 µCi of (211)At-labeled anti-CD20 mAb ([(211)At]1F5-B10) experienced modest responses (0% cures but two- to threefold prolongation of survival compared with negative controls). In contrast, 70% of animals in the MRD lymphoma model demonstrated complete eradication of disease when treated with (211)At-B10-1F5 at a radiation dose that was less than one-third (15 µCi) of the highest dose given to xenograft animals. Tumor progression among untreated control animals in both models was uniformly lethal. After 130 days, no significant renal or hepatic toxicity was observed in the cured animals receiving 15 µCi of [(211)At]1F5-B10. These findings suggest that α-emitters are highly efficacious in MRD settings, where isolated cells and small tumor clusters prevail.

90Y-ibritumomab tiuxetan radiotherapy as first-line therapy for early stage low-grade B-cell lymphomas, including bulky disease

(90) Y-ibritumomab-tiuxetan ((90) YIT) was used as a first-line therapy for patients with early-stage follicular lymphoma (FL) or marginal zone B-cell lymphoma (MZL). Thirty-one patients were treated, with an overall 3-month response rate of 100% (68% complete response, 29% unconfirmed complete response and 3% partial response). At a median follow-up of 56 months, ten patients (32%) had disease relapse or progression. The progression-free rates at 3 and 5 years were lower in males, patients with FL, stage II disease and non-bulky disease, although they did not reach statistical significance. Grade 3-4 neutropenia, thrombocytopenia and anaemia were 61%, 35%, and 3%, respectively. (90) YIT was well tolerated, including in those patients over 60 years old, and achieved high response rates in patients with early-stage low-grade B-cell lymphomas. Bulky disease did not adversely affect tumour response.

The development of immunoconjugates for targeted cancer therapy

Immunoconjugates are specific, highly effective, minimally toxic anticancer therapies that are beginning to show promise in the clinic. Immunoconjugates consist of three separate components: an antibody that binds to a cancer cell antigen with high specificity, an effector molecule that has a high capacity to kill the cancer cell, and a linker that will ensure the effector does not separate from the antibody during transit and will reliably release the effector to the cancer cell or tumour stroma. The high affinity antibody-antigen interaction allows specific and selective delivery of a range of effectors, including pharmacologic agents, radioisotopes, and toxins, to cancer cells. Some anticancer molecules are not well tolerated when administered systemically owing to unacceptable toxicity to the host. However, this limitation can be overcome through the linking of such cytotoxins to specific antibodies, which mask the toxic effects of the drug until it reaches its target. Conversely, many unconjugated antibodies are highly specific for a cancer target, but have low therapeutic potential and can be repurposed as delivery vehicles for highly potent effectors. In this Review, we summarize the successes and shortcomings of immunoconjugates, and discuss the future potential for the development of these therapies.

Does tumoral (111)In-ibritumomab accumulation correlate with therapeutic effect and outcome in relapsed or refractory low-grade B-cell lymphoma patients undergoing (90)Y-ibritumomab radioimmunotherapy?

OBJECTIVES

The aim of this study was to determine whether tumoral (111)In-ibritumomab accumulation on pre-treatment imaging correlates with therapeutic responses and progression-free survival (PFS) in patients with non-Hodgkin's lymphoma (NHL) undergoing (90)Y-ibritumomab radioimmunotherapy (RIT).

METHODS

This was a retrospective study of 39 patients with low-grade B-cell NHL treated with RIT. We classified the patients into positive and negative groups according to the presence or absence of tumoral (111)In-ibritumomab accumulation on pre-treatment (111)In-ibritumomab examinations. We then determined the correlation between the (111)In-ibritumomab imaging findings and the patients' therapeutic responses and PFS.

RESULTS

Tumoral (111)In-ibritumomab accumulation was positive in 64.1% and negative in 35.9% of the patients. The (111)In-positive patients had a significantly higher overall response rate (ORR) compared to the (111)In-negative patients (100.0% vs. 78.6%, p = 0.02). The (111)In-negative patients with advanced disease (stages III/IV) had a significantly lower ORR (40%) and a significantly higher rate of progressive disease (40.0%) compared to those of the (111)In-negative patients with limited disease (stages I/II) (100% and 0%, p = 0.009 each). However, these two groups had similar 2-year PFS rates (65.0% vs. 50.0%, p = 0.80).

CONCLUSIONS

(111)In-ibritumomab imaging findings seem to correlate with ORR and the progressive disease rate after RIT, but not with PFS.

KEY POINTS

All 39 NHL patients had tumoral accumulation on pretreatment FDG-PET/CT. 64.1% of NHL patients had tumoral accumulation on a pretreatment (111) In-ibritumomab examination. (90) Y-ibritumomab RIT resulted in high overall response and complete remission rates. (111) In-ibritumomab avidity of lymphoma lesions could predict a strong therapeutic effect. (111) In-ibritumomab imaging findings did not correlate with progression-free survival.

Autologous transplant for relapsed follicular lymphoma: impact of pre-transplant rituximab sensitivity

Patients with rituximab-refractory follicular lymphoma (FL) have limited options. Before the rituximab era, autologous stem cell transplant (ASCT) was shown to improve outcomes in chemotherapy-sensitive, relapsed FL, but the impact of rituximab-sensitivity on these results is unknown. We analyzed 194 consecutive relapsed patients with FL who underwent ASCT at out center and categorized them as rituximab-sensitive (RS, n = 35), rituximab-refractory (RR, n = 65) or no rituximab (NoR, n = 94) if transplanted before rituximab was used. Progression-free survival at 3 years was 85% in RS and 35% in RR patients (p = 0.0004). Only rituximab-sensitivity was significant on multivariate analysis with improved overall survival (OS) (hazard ratio [HR] 0.24, p = 0.01) and progression-free survival (PFS) (HR 0.35, p = 0.006) in RS patients and increased relapse in RR patients (HR 2.11, p = 0.01). Pre-transplant rituximab-sensitivity is a strong independent predictor of post-transplant outcomes in relapsed FL, although one-third of RR patients achieved a PFS of over 3 years with ASCT.

Myeloablative anti-CD20 radioimmunotherapy +/- high-dose chemotherapy followed by autologous stem cell support for relapsed/refractory B-cell lymphoma results in excellent long-term survival

Background

Radioimmunotherapy (RIT) has been used to treat relapsed/refractory CD20+ Non-Hodgkin lymphoma (NHL). Myeloablative anti-CD20 RIT followed by autologous stem cell infusion (ASCT) enables high radiation doses to lymphoma sites. We performed a phase I/II trial to assess feasibility and survival.

Methods

Twenty-three patients with relapsed/refractory NHL without complete remission (CR) to salvage chemotherapy were enrolled to evaluate RIT with Iodine-131 labelled rituximab (¹³¹I-rituximab) in a myeloablative setting. Biodistribution and dosimetric studies were performed to determine ¹³¹I activity required to induce a total body dose of 21-27Gy to critical organs. In 6/23 patients RIT was combined with high-dose chemotherapy. 8/23 patients received a sequential high-dose chemotherapy with a second ASCT. The median follow-up is 9.5 years.

Results

6.956-19.425GBq of ¹³¹I was delivered to achieve the limiting organ dose to lungs or kidneys. No grade III/IV non-hematologic toxicity was seen with RIT alone. Significant grade III/IV toxicity (mucositis, fever, infection, one therapy related death) was observed in patients treated with RIT combined with high-dose chemotherapy. The overall response rate was 87% (64% CR). The median progression-free (PFS) and overall survival (OS) is 47.5 and 101.5 months. An international prognostic index score >1 was predictive for OS.

Conclusion

Myeloablative RIT with ¹³¹I-rituximab followed by ASCT is feasible, well-tolerated and effective in high risk CD20+ NHL. Combination of RIT and high-dose chemotherapy increased toxicity significantly. Long-term results for PFS and OS are encouraging.

The optimal management of follicular lymphoma: an evolving field

Follicular lymphoma consists of a heterogeneous group of diseases that can vary dramatically in clinical course. As with other indolent lymphomas, follicular lymphoma is felt to be highly treatable, but ultimately incurable. The appropriate management of this disease ranges from close observation to chemoimmunotherapy based on presenting symptoms and comorbidities. In this article, we focus on the optimal management of follicular lymphoma, including prognostication, indications for treatment, and current treatment options. While a number of front-line chemoimmunotherapy options exist, R-CHOP (rituximab, cyclophosphamide, vincristine, prednisone) and BR (bendamustine, rituximab) tend to be favored due to efficacy and tolerability. Post-induction options include maintenance rituximab and radioimmunotherapy, but neither has demonstrated an overall survival benefit. In relapsed disease, patients can receive an alternative chemoimmunotherapy regimen or radioimmunotherapy, or participate in a clinical trial. There are a number of new biologic targeted therapies with promising activity in follicular lymphoma that have the potential to change our approach to this disease.

Theranostic applications of antibodies in oncology

Targeted therapies, including antibodies, are becoming increasingly important in cancer therapy. Important limitations, however, are that not every patient benefits from a specific antibody therapy and that responses could be short-lived due to acquired resistance. In addition, targeted therapies are quite expensive and are not completely devoid of side-effects. This urges the need for accurate patient selection and response monitoring. An important step towards personalizing antibody treatment could be the implementation of theranostics. Antibody theranostics combine the diagnostic and therapeutic potential of an antibody, thereby selecting those patients who are most likely to benefit from antibody treatment. This review focuses on the clinical application of theranostic antibodies in oncology. It provides detailed information concerning the suitability of antibodies for theranostics, the different types of theranostic tests available and summarizes the efficacy of theranostic antibodies used in current clinical practice. Advanced theranostic applications, including radiolabeled antibodies for non-invasive functional imagining, are also addressed. Finally, we discuss the importance of theranostics in the emerging field of personalized medicine and critically evaluate recent data to determine the best way to apply antibody theranostics in the future.

PI3Kδ inhibition by idelalisib in patients with relapsed indolent lymphoma

BACKGROUND

Phosphatidylinositol-3-kinase delta (PI3Kδ) mediates B-cell receptor signaling and microenvironmental support signals that promote the growth and survival of malignant B lymphocytes. In a phase 1 study, idelalisib, an orally active selective PI3Kδ inhibitor, showed antitumor activity in patients with previously treated indolent non-Hodgkin's lymphomas.

METHODS

In this single-group, open-label, phase 2 study, 125 patients with indolent non-Hodgkin's lymphomas who had not had a response to rituximab and an alkylating agent or had had a relapse within 6 months after receipt of those therapies were administered idelalisib, 150 mg twice daily, until the disease progressed or the patient withdrew from the study. The primary end point was the overall rate of response; secondary end points included the duration of response, progression-free survival, and safety.

RESULTS

The median age of the patients was 64 years (range, 33 to 87); patients had received a median of four prior therapies (range, 2 to 12). Subtypes of indolent non-Hodgkin's lymphoma included follicular lymphoma (72 patients), small lymphocytic lymphoma (28), marginal-zone lymphoma (15), and lymphoplasmacytic lymphoma with or without Waldenström's macroglobulinemia (10). The response rate was 57% (71 of 125 patients), with 6% meeting the criteria for a complete response. The median time to a response was 1.9 months, the median duration of response was 12.5 months, and the median progression-free survival was 11 months. Similar response rates were observed across all subtypes of indolent non-Hodgkin's lymphoma, though the numbers were small for some categories. The most common adverse events of grade 3 or higher were neutropenia (in 27% of the patients), elevations in aminotransferase levels (in 13%), diarrhea (in 13%), and pneumonia (in 7%).

CONCLUSIONS

In this single-group study, idelalisib showed antitumor activity with an acceptable safety profile in patients with indolent non-Hodgkin's lymphoma who had received extensive prior treatment. (Funded by Gilead Sciences and others; ClinicalTrials.gov number, NCT01282424.).

Advances in the treatment of hematologic malignancies using immunoconjugates

Monoclonal antibody therapy has revolutionized cancer treatment by significantly improving patient survival both in solid tumors and hematologic malignancies. Recent technological advances have increased the effectiveness of immunotherapy leading to its broader application in diverse treatment settings. Immunoconjugates (ICs) consist of a cytotoxic effector covalently linked to a monoclonal antibody that enables the targeted delivery of its therapeutic payload to tumors based on cell-surface receptor recognition. ICs are classified into 3 groups based on their effector type: immunotoxins (protein toxin), radioimmunoconjugates (radionuclide), and antibody drug conjugates (small-molecule drug). Optimization of each individual component of an IC (antibody, linker, and effector) is essential for therapeutic efficacy. Clinical trials have been conducted to investigate the effectiveness of ICs in hematologic malignancies both as monotherapy and in multiagent regimens in relapsed/refractory disease as well as frontline settings. These studies have yielded encouraging results particularly in lymphoma. ICs comprise an exciting group of therapeutics that promise to play an increasingly important role in the management of hematologic malignancies.

Targeted alpha-therapy using [Bi-213]anti-CD20 as novel treatment option for radio- and chemoresistant non-Hodgkin lymphoma cells

Radioimmunotherapy (RIT) is an emerging treatment option for non-Hodgkin lymphoma (NHL) producing higher overall response and complete remission rates compared with unlabelled antibodies. However, the majority of patients treated with conventional or myeloablative doses of radiolabelled antibodies relapse. The development of RIT with alpha-emitters is attractive for a variety of cancers because of the high linear energy transfer (LET) and short path length of alpha-radiation in human tissue, allowing higher tumour cell kill and lower toxicity to healthy tissues. In this study, we investigated the molecular effects of the alpha-emitter Bi-213 labelled to anti-CD20 antibodies ([Bi-213]anti-CD20) on cell cycle and cell death in sensitive and radio-/chemoresistant NHL cells. [Bi-213]anti-CD20 induced apoptosis, activated caspase-3, caspase-2 and caspase-9 and cleaved PARP specifically in CD20-expressing sensitive as well as in chemoresistant, beta-radiation resistant and gamma-radiation resistant NHL cells. CD20 negative cells were not affected by [Bi-213]anti-CD20 and unspecific antibodies labelled with Bi-213 could not kill NHL cells. Breaking radio-/chemoresistance in NHL cells using [Bi-213]anti-CD20 depends on caspase activation as demonstrated by complete inhibition of [Bi-213]anti-CD20-induced apoptosis with zVAD.fmk, a specific inhibitor of caspases activation. This suggests that deficient activation of caspases was reversed in radioresistant NHL cells using [Bi-213]anti-CD20. Activation of mitochondria, resulting in caspase-9 activation was restored and downregulation of Bcl-x_L and XIAP, death-inhibiting proteins, was found after [Bi-213]anti-CD20 treatment in radio-/chemosensitive and radio-/chemoresistant NHL cells. [Bi-213]anti-CD20 seems to be a promising radioimmunoconjugate to improve therapeutic success by breaking radio- and chemoresistance selectively in CD20-expressing NHL cells via re-activating apoptotic pathways through reversing deficient activation of caspases and the mitochondrial pathway and downregulation of XIAP and Bcl-x_L.

Development of anthropomorphic hand phantoms for personal dosimetry in 90Y-Zevalin preparation and patient delivering

Anthropomorphic tissue-equivalent hand phantoms were achieved to measure the extremity dose involved in Zevalin (90)Y-labelling and patient delivering procedure for radioimmunotherapy treatment of non-Hodgkin lymphoma. The extremity doses to hands and wrists of operators were measured by using thermoluminescent detectors mounted on the developed phantoms. Measurements of chest- and lens-equivalent doses performed on a Rando phantom are also reported.

Molecular imaging and carbonic anhydrase IX-targeted radioimmunotherapy in clear cell renal cell carcinoma

Conventional imaging is suboptimal at evaluating disease status in renal cell carcinoma (RCC) because of poor sensitivity. Furthermore, there is an unmet need for the treatment of metastatic RCC, both in terms of improvement of progression-free survival and limitation of toxicity. For this reason, radionuclide imaging and radionuclide therapy are extensively investigated. This review provides an overview of the current progress in molecular imaging and radionuclide therapy in clear cell RCC and will focus on promising detection and therapy strategies targeting the carbonic anhydrase IX antigen, which is expressed in clear cell RCC.

The current status and future impact of targeted therapies in non-Hodgkin lymphoma

A number of new, biologic targeted therapies have been developed for the treatment of lymphoid malignancies. These include anti-CD20 monoclonal antibodies designed with greater binding affinities and different mechanisms of action profiles compared with rituximab. Other extracellular antigens on B cells and T cells are also being targeted. Monoclonal antibodies have been conjugated to radioisotopes and cellular toxins. In addition, several exciting new small-molecule kinase inhibitors are in development that target intracellular pathways that contribute to the pathogenesis of these diseases. Drugs that affect the tumor microenvironment are also under investigation. The advantage of these targeted agents compared with standard chemotherapy is greater tumor specificity, a more favorable toxicity profile, and, when combined with scientific rationale, and in the appropriate setting, perhaps a better long-term outcome.

Treatment challenges in the management of relapsed or refractory non-Hodgkin's lymphoma - novel and emerging therapies

Over the last few decades, advances in immunochemotherapy have led to dramatic improvement in the prognosis of non-Hodgkin's lymphoma (NHL). Despite these advances, relapsed and refractory disease represents a major treatment challenge. For both aggressive and indolent subtypes of NHL, there is no standard of care for salvage regimens, with prognosis after relapse remaining relatively poor. Nevertheless, there are multiple emerging classes of targeted therapies for relapsed/refractory disease, including monoclonal antibodies, antibody- drug conjugates, radioimmunotherapy, small-molecule inhibitors of cell-growth pathways, and novel chemotherapy agents. This review will discuss treatment challenges of NHL, current available salvage regimens for relapsed/refractory NHL, and the safety and efficacy of novel emerging therapies.

Development of an imaging-guided CEA-pretargeted radionuclide treatment of advanced colorectal cancer: first clinical results

Background:

Radiolabelled antibody targeting of cancer is limited by slow blood clearance. Pretargeting with a non-radiolabelled bispecific monoclonal antibody (bsMAb) followed by a rapidly clearing radiolabelled hapten peptide improves tumour localisation. The primary goals of this first pretargeting study in patients with the anti-CEACAM5 × anti-hapten (HSG) bsMAb, TF2, and the radiolabelled hapten-peptide, IMP288, were to assess optimal pretargeting conditions and safety in patients with metastatic colorectal cancer (CRC).

Methods:

Different dose schedules were studied in four cohorts of five patients: (1) shortening the interval between the bsMAb and peptide administration (5 days vs 1 day), (2) escalating the TF2 dose (from 75 to 150 mg), and (3) reducing the peptide dose (from 100 to 25 μg). After confirmation of tumour targeting by ¹¹¹In-IMP288, patients were treated with a bsMAb/¹⁷⁷Lu-IMP288 cycle.

Results:

Rapid and selective tumour targeting of the radiolabelled peptide was visualised within 1 h, with high tumour-to-tissue ratios (>20 at 24 h). Improved tumour targeting was achieved with a 1-day interval between the administration of the bsMAb and the peptide and with the 25-μg peptide dose. High ¹⁷⁷Lu-IMP288 doses (2.5–7.4 GBq) were well tolerated, with some manageable TF2 infusion reactions, and transient grades 3–4 thrombocytopaenia in 10% of the patients who received ¹⁷⁷Lu-IMP288.

Conclusion:

This phase I study demonstrates for the first time that pretargeting with bsMAb TF2 and radiolabelled IMP288 in patients with CEA-expressing CRC is feasible and safe. With this pretargeting method, tumours are specifically and rapidly targeted.

Radioimmunotherapy of B-Cell Non-Hodgkin's Lymphoma

This manuscript reviews current advances in the use of radioimmunotherapy (RIT) for the treatment of B-cell non-Hodgkin's lymphoma (NHL). RIT has been in use for more than 20 years and has progressed significantly with the discovery of new molecular targets, the development of new stable chelates, the humanization of monoclonal antibodies (MAbs), and the use of pretargeting techniques. Today, two products targeting the CD20 antigen are approved: (131)I-tositumomab (Bexxar(®)), and (90)Y-ibritumomab tiuxetan (Zevalin(®)). (131)I-tositumomab is available in the United States, and (90)Y-ibritumumab tiuxetan in Europe, the United States, Asia, and Africa. RIT can be integrated in clinical practice using non-ablative activities for treatment of patients with relapsed or refractory follicular lymphoma (FL) or as consolidation after induction chemotherapy in front-line treatment in FL patients. Despite the lack of phase III studies to clearly define the efficacy of RIT in the management of B lymphoma in the era of rituximab-based therapy, RIT efficacy in NHL has been demonstrated. In relapsing refractory FL and transformed NHL, RIT as a monotherapy induces around 30% complete response with a possibility of durable remissions. RIT consolidation after induction therapy significantly improves the quality of the response. Dose-limiting toxicity of RIT is hematological, depending on bone marrow involvement and prior treatment. Non-hematological toxicity is generally low. Different studies have been published assessing innovative protocols of RIT or new indications, in particular treatment in patients with aggressive lymphomas. High-dose treatment, RIT as consolidation after different therapeutic induction modalities, RIT in first-line treatment or fractionated RIT showed promising results. New MAbs, in particular humanized MAbs, or combinations of naked and radiolabeled MAbs, also appear promising. Personalized dosimetry protocols should be developed to determine injected activity.

A phase I trial of immunostimulatory CpG 7909 oligodeoxynucleotide and 90 yttrium ibritumomab tiuxetan radioimmunotherapy for relapsed B-cell non-Hodgkin lymphoma

Radioimmunotherapy (RIT) for relapsed indolent non-Hodgkin lymphoma produces overall response rates (ORR) of 80% with mostly partial remissions. Synthetic CpG oligonucleotides change the phenotype of malignant B-cells, are immunostimulatory, and can produce responses when injected intratumorally and combined with conventional radiation. In this phase I trial, we tested systemic administration of both CpG and RIT. Eligible patients had biopsy-proven previously treated CD20+ B-cell NHL and met criteria for RIT. Patients received rituximab 250 mg/m(2) days 1,8, and 15; (111) In-ibritumomab tiuxetan days 1, 8; CpG 7909 days 6, 13, 20, 27; and 0.4 mCi/kg of (90) Y-ibritumomab tiuxetan day 15. The doses of CpG 7909 tested were 0.08, 0.16, 0.32 (six patients each) and 0.48 mg/kg (12 patients) IV over 2 hr without dose limiting toxicity. The ORR was 93% (28/30) with 63% (19/30) complete remission (CR); median progression free survival of 42.7 months (95% CI 18-NR); and median duration of response (DR) of 35 months (4.6-76+). Correlative studies demonstrated a decrease in IL10 and TNFα, and an increase in IL1β, in response to therapy. CpG 7909 at a dose of 0.48 mg/kg is safe with standard RIT and produces a high CR rate and long DR; these results warrant confirmation.

90Yttrium-Ibritumomab Tiuxetan Consolidation of First Remission in Advanced-Stage Follicular Non-Hodgkin Lymphoma: Updated Results After a Median Follow-Up of 7.3 Years From the International, Randomized, Phase III First-Line Indolent Trial

Purpose

Updated results are presented after a median follow-up of 7.3 years from the phase III First-Line Indolent Trial of yttrium-90 (90Y) –ibritumomab tiuxetan in advanced-stage follicular lymphoma (FL) in first remission.

Patients and Methods

Patients with CD20+stage III or IV FL with complete response (CR), unconfirmed CR (CRu), or partial response (PR) after first-line induction treatment were randomly assigned to90Y-ibritumomab consolidation therapy (rituximab 250 mg/m2days −7 and 0, then90Y-ibritumomab 14.8 MBq/kg day 0; maximum 1,184 MBq) or no further treatment (control). Primary end point was progression-free survival (PFS) from date of random assignment.

Results

For 409 patients available for analysis (90Y-ibritumomab, n = 207; control, n = 202), estimated 8-year overall PFS was 41% with90Y-ibritumomab versus 22% for control (hazard ratio [HR], 0.47; P < .001). For patients in CR/CRu after induction, 8-year PFS with90Y-ibritumomab was 48% versus 32% for control (HR, 0.61; P = .008), and for PR patients, it was 33% versus 10% (HR, 0.38; P < .001). For90Y-ibritumomab consolidation, median PFS was 4.1 years (v 1.1 years for control; P < .001). Median time to next treatment (TTNT) was 8.1 years for90Y-ibritumomab versus 3.0 years for control (P < .001) with approximately 80% response rates to second-line therapy in either arm, including autologous stem-cell transplantation. No unexpected toxicities emerged during long-term follow-up. Estimated between-group 8-year overall survival rates were similar. Annualized incidence rate of myelodysplastic syndrome/acute myeloblastic leukemia was 0.50% versus 0.07% in90Y-ibritumomab and control groups, respectively (P = .042).

Conclusion

90Y-ibritumomab consolidation after achieving PR or CR/CRu to induction confers 3-year benefit in median PFS with durable 19% PFS advantage at 8 years and improves TTNT by 5.1 years for patients with advanced FL.

An update on radioimmunotherapy for lymphoma

SUMMARY Radioimmunotherapy is a promising treatment for B-cell lymphoma. 90Y-ibritumomab tiuxetan (Zevalin®) and 131I-tositumomab (Bexxar®) combine the potent antilymphoma effect of radiation with the specificity of antibody targeting. They have shown efficacy in follicular lymphoma in the setting of relapsed or refractory disease as consolidation regimens after first-line therapy, and in the front-line setting as single agents. Given their tolerability, they are actively being investigated as therapies or adjuncts for elderly patients with relapsed or high-risk diffuse large B-cell lymphoma. They have been added to autologous and allogeneic stem cell transplant preparatory regimens in early clinical trials with acceptable safety and efficacy. Early concerns over excess rates of treatment-related myelodysplastic syndrome and acute myelogenous leukemia have not come to fruition, but these questions remain to be fully answered. Ultimately, these are promising treatments for a variety of B-cell lymphomas. They are also models for the development of new radioimmunotherapies.

Phase I study of a modified regimen of ⁹⁰Yttrium-ibritumomab tiuxetan for relapsed or refractory follicular or transformed CD20+ non-Hodgkin lymphoma

Radioimmunotherapy capitalizes on the radiosensitivity of non-Hodgkin lymphoma (NHL) and the targeted nature of monoclonal antibodies. In an attempt to reverse bone marrow infiltration with B-cells and optimize the biodistribution of Yttrium-90 (⁹⁰Y)-ibritumomab tiuxetan, we conducted a phase I study combining a single course of ⁹⁰Y-ibritumomab tiuxetan after a 4-weekly course of rituximab in relapsed or refractory low-grade or transformed CD20+ B-cell NHLs with <25% marrow involvement. The 0.4 mCi/kg dose was associated with 80% grade-4 cytopenias. Dose escalation was held, and 6 patients were enrolled at a 0.3 mCi/kg cohort. As the 0.3 mCi/kg dose was well tolerated, the 0.4 mCi/kg cohort was expanded to 6 additional patients. In the expansion cohort, grade-4 cytopenia developed in 33%. Further dose escalation was held, and the maximum tolerated dose was determined at 0.4 mCi/kg. With this regimen, marrow involvement decreased in all patients with complete clearance in 50%. The overall response rate was 82%. With a median follow-up of 31.7 months, the median progression-free survival and time to next treatment were 12.3 and 10.9 months, respectively. Although this regimen was associated with a high response rate, the hematologic toxicity was higher than with the standard ⁹⁰Y-ibritumomab tiuxetan regimen.

Prognostic significance of pretreatment ¹⁸F-FDG PET/CT in patients with relapsed/refractory B-cell non-Hodgkin's lymphoma treated by radioimmunotherapy using ¹³¹I-rituximab

AIMS

It was the aim of this paper to identify prognostic factors in patients with relapsed or refractory B-cell non-Hodgkin's lymphomas, treated by radioimmunotherapy (RIT) with radioiodinated human/murine chimeric anti-CD20 monoclonal antibody rituximab (¹³¹I-rituximab).

METHODS

Twenty-four patients were enrolled prospectively and were treated with unlabeled rituximab 70 mg and a therapeutic activity (median 7.3 GBq) of ¹³¹I-rituximab. Contrast-enhanced ¹⁸F-FDG PET/CT scans were performed before and after 1 month of RIT. Tumor sizes and maximum standardized uptake values (SUVmax) of scans were measured.

RESULTS

Four of the 24 patients survived. High SUVmax in a pretreatment scan was found to be related to poorer overall survival (OS) and progression-free survival (p = 0.04 and 0.02, respectively). Furthermore, a large tumor size in a pretreatment scan was associated with poorer OS but not with progression-free survival (p < 0.01 and p = 0.07, respectively). By multivariate analyses, a high SUVmax, a large tumor size in a pretreatment scan and diffuse large B-cell lymphoma histology were significantly associated with poorer OS [p = 0.04/hazard ratio (HR) = 3.54, p < 0.01/HR = 5.52, and p = 0.02/HR = 3.38, respectively).

CONCLUSION

SUVmax and tumor size determined by a pretreatment ¹⁸F-FDG PET/CT result as significant predictors of OS in patients with relapsed or refractory B-cell non-Hodgkin's lymphoma treated by RIT.

RadNuc: a graphical user interface to deliver dose rate patterns encountered in nuclear medicine with a 137Cs irradiator

The temporal variations in absorbed dose rates to organs and tissues in the body are very large in diagnostic and therapeutic nuclear medicine. The response of biological endpoints of relevance to radiation safety and therapeutic efficacy is generally modulated by dose rate. Therefore, it is important to understand how the complex dose rate patterns encountered in nuclear medicine impact relevant biological responses. Accordingly, a graphical user interface (GUI) was created to control a cesium-137 irradiator to deliver such dose rate patterns.

METHODS

Visual Basic 6.0 was used to create a user-friendly GUI to control the dose rate by varying the thickness of a mercury attenuator. The GUI facilitates the delivery of a number of dose rate patterns including constant, exponential increase or decrease, and multi-component exponential. Extensive visual feedback is provided by the GUI during both the planning and delivery stages.

RESULTS

The GUI controlled irradiator can achieve a maximum dose rate of 40 cGy/h and a minimum dose rate of 0.01 cGy/h. Addition of machined lead blocks can be used to further reduce the minimum dose rate to 0.0001 cGy/h. Measured dose rate patterns differed from programmed dose rate patterns in total dose by 3.2% to 8.4%.

CONCLUSION

The GUI controlled irradiator is able to accurately create dose rate patterns encountered in nuclear medicine and other related fields. This makes it an invaluable tool for studying the effects of chronic constant and variable low dose rates on biological tissues in the contexts of both radiation protection and clinical administration of internal radionuclides.

Targeted drug delivery for cancer therapy: the other side of antibodies

Therapeutic monoclonal antibody (TMA) based therapies for cancer have advanced significantly over the past two decades both in their molecular sophistication and clinical efficacy. Initial development efforts focused mainly on humanizing the antibody protein to overcome problems of immunogenicity and on expanding of the target antigen repertoire. In parallel to naked TMAs, antibody-drug conjugates (ADCs) have been developed for targeted delivery of potent anti-cancer drugs with the aim of bypassing the morbidity common to conventional chemotherapy. This paper first presents a review of TMAs and ADCs approved for clinical use by the FDA and those in development, focusing on hematological malignancies. Despite advances in these areas, both TMAs and ADCs still carry limitations and we highlight the more important ones including cancer cell specificity, conjugation chemistry, tumor penetration, product heterogeneity and manufacturing issues. In view of the recognized importance of targeted drug delivery strategies for cancer therapy, we discuss the advantages of alternative drug carriers and where these should be applied, focusing on peptide-drug conjugates (PDCs), particularly those discovered through combinatorial peptide libraries. By defining the advantages and disadvantages of naked TMAs, ADCs and PDCs it should be possible to develop a more rational approach to the application of targeted drug delivery strategies in different situations and ultimately, to a broader basket of more effective therapies for cancer patients.

Radioimmunotherapy for B-cell non-hodgkin lymphomas

BACKGROUND

Radioimmunotherapy (RIT) is a safe and effective therapeutic option for patients with indolent B-cell non-Hodgkin lymphomas (NHL), in both up-front and relapsed/refractory settings. Two approved agents (90Y-ibritumomab tiuxetan and 131I-tositumomab) are available in the United States. Both target CD20 with similar clinical outcomes but with unique clinical considerations and radiation precautions due to the use of varying radioisotopes.

METHODS

This paper reviews the available evidence for these approved RIT agents and examines the recently published and ongoing clinical trials of potential novel indications for aggressive B-cell NHL.

RESULTS

A pretreatment biodistribution evaluation required before administering the 90Y-ibritumomab tiuxetan therapeutic dose has been removed, which once limited its usage. The potential clinical applications of RIT include relapsed/refractory indolent B-cell NHL, diffuse large B-cell lymphoma, indolent lymphoma in the front-line setting, and mantle cell lymphoma. Multiple novel RIT agents are in preclinical and clinical development, and the addition of radiosensitizers or external-beam radiotherapy may act in synergy with RIT for both indolent and aggressive lymphomas. The risk of treatment-related myelodysplastic syndrome does not appear to be higher in patients treated with RIT over those receiving chemotherapy alone.

CONCLUSIONS

RIT is a safe, effective, and significantly underutilized therapy for patients with B-cell NHL, and many studies have demonstrated the efficacy of 90Y-ibritumomab tiuxetan and 131I-tositumomab for relapsed/refractory indolent B-cell lymphomas. Continued research to establish its efficacy for other lymphoma subtypes is warranted.

Iodine-131 rituximab radioimmunotherapy with BEAM conditioning and autologous stem cell transplant salvage therapy for relapsed/refractory aggressive non-Hodgkin lymphoma

A standard salvage therapy of relapsed/refractory aggressive non-Hodgkin lymphoma (NHL) comprises autologous stem cell transplantation (ASCT) after chemotherapy conditioning with carmustine, etoposide, cytarabine, and melphalan (BEAM) regimen. However, the achievement of long-term disease-free survival remains challenging. We have introduced concomitant (131)I-rituximab radioimmunotherapy (RIT) in an attempt to effect the elimination of lymphoma cells. Our phase II physician-sponsored study of 16 consecutive patients with relapsed, refractory, aggressive B-cell NHL reports a median 44 month follow-up after (131)I-rituximab-BEAM conditioning therapy and ASCT. Prospective personalized dosimetry performed in each patient limited the whole body radiation absorbed dose to 0.75 Gy. RIT (131)I-rituximab was administered on an outpatient basis on day -15 before ASCT. The BEAM conditioning regimen was commenced on day -6. Evaluable engraftment data are available for 15 patients who had 16 ASCTs. Engraftment was achieved in all patients, 15 out of 16 ASCTs achieved a complete response, and 1 out of 15 ASCTs achieved a partial response. Twelve out of sixteen patients remained alive and disease free at a median of 44 months (range 4-108 months) post-ASCT. This study suggests that the addition of (131)I-rituximab RIT to BEAM conditioning, before ASCT, for relapsed or primary refractory B-cell NHL improves disease eradication, compared with BEAM conditioning alone, without significant additional toxicity. In particular, there is an impression of improved disease control in the subset of patients with transformed follicular and mantle cell lymphomas.

Concepts, consequences, and implications of theranosis

Although the term has been coined recently, the concepts underlying theranosis have been applied in patient care for more than one-half century. However, advanced technologies are used now. Theranosis describes processes used to tailor therapy for a patient. It is the use of diagnostic tests to identify those patients better-suited for a drug (or drugs) or to determine how well a drug is working. (131)I-iodide for imaging and for therapy of hyperthyroidism and thyroid cancer is an excellent example of personalized theranosis and has withstood challenge for more than 50 years. Radioimmunotherapy for non-Hodgkin lymphoma is a more recent example of theranosis. Either of 2 anti-CD20 monoclonal antibodies, one labeled with indium for imaging or (90)Y for radiotherapy or a second labeled with (131)I for both imaging and radiotherapy, is used for salvage and first-line therapy of multifocal non-Hodgkin lymphoma. The efficacy of these drugs is greater than that of alternative therapies. To mimic the molecular specificity and cell selectivity of a monoclonal antibody, smaller molecules that also bind to proteins upregulated by malignant cells can be used to transport cytotoxic agents to the malignant cells. Smaller carrier molecules like peptides, aptamers, affibodies, and selective, high-affinity ligands facilitate intensification of therapy because of their size. Personalized genomics, proteomics, and molecular imaging are among technologies currently used for theranosis. Molecular emission tomographic imaging with radiolabeled drugs has been used to examine the pharmacology of anticancer therapies and their effectiveness. Increased glycolysis, a molecular phenotype of many malignancies, can be imaged using (18)F-fluoro-2-deoxyglucose (FDG). Tomographic imaging using FDG allows stratification of patients into those responding and likely to respond to the therapy and those better treated in another manner. Prediction of therapeutic response avoids useless therapy so that FDG imaging is included in official response evaluation criteria. Although a fixed approach to therapy may be more practical, an individualized approach is more likely to ensure that each patient receives an effective drug and drug dose that has acceptable and definable tissue effects. Drugs that work in one individual may be ineffective or cause adverse events in others.

Follicular lymphoma - treatment and prognostic factors

Follicular lymphoma is the second most frequent non-Hodgkin lymphoma accounting for about 10-20% of all lymphomas in western countries. The median age at diagnosis is 60 years old. The clinical presentation is usually characterized by asymptomatic peripheral adenopathy in cervical, axillary, inguinal and femoral regions. Treatment options for patients with naïve or recurrent follicular lymphoma are still controversial, ranging from a "watch and wait" policy to hematopoietic stem cell transplantation. More recently, the availability of rituximab has substantially changed follicular lymphoma therapeutic approaches to such an extent that R-Chemo is now the standard induction first-line treatment. This review provides a general overview of the state of the art in the management of follicular lymphoma and also, a brief description regarding the current prognostic tools available for treatment decisions.

RIT with Y90-Ibritumomab Tiuxetan in Follicular Non-Hodgkin Lymphoma: Evaluation of Recent Outcomes in a Single Institution

Background. Based on historical data we reviewed our hospital clinical database to analyse our updated information and therapy outcomes of follicular non-Hodgkin lymphoma (F-NHL) patients treated with ⁹⁰Y-Ibritumomab tiuxetan. Patients and Methods. Between 2005 and 2011, 56 F-NHL patients were included in a clinical protocol conducted by a multidisciplinary team and treated in the same centre. All patients received 0.3 or 0.4 mCi/kg IV (88%) of ⁹⁰Y-IT; response evaluation was performed 12 weeks after. Results. M/F 44.6%/55.4%, mean age 61.45 years (30–85); ECOG 0-1 96.9%. According to FLIPI score, distribution were good: 58.5%, intermediate: 29.2%, and poor: 12.3%. Previous therapies: >2: 40% (26). ORR was 94.6% (53/56). CR: 85.7%; CR according to previous disease: relapsed disease: 90% (27/30), refractory disease: 42.85% (3/7), consolidation with CR: 92.85% (13/14), and consolidation with PR: 100% (5/5). Global PR and NR were 8.9% (5) and 5.3% (3), respectively. Mean OS 63.86 months with a mean follow-up time of 57 months (2–73). Mean TTP: 52.65 months (95% CI: 43.83–61.48). Median OS and TTP were not achieved. No hospital submissions or deaths were registered. Conclusions. This study confirms the safety and high efficacy of ⁹⁰Y-IT in F-NHL patients, RIT in early stage of disease could improve outcomes.

Second-line 90Yttrium-ibritumomab tiuxetan (Zevalin) in a patient with conjunctival mucosa-associated lymphoid tissue lymphoma refractory to rituximab

Lymphoma of mucosa-associated lymphoid tissue (MALT) is the most common variety of lymphoma seen in the ocular adnexae. The authors present the case of a patient with MALT lymphoma refractory to treatment with rituximab. Subsequent treatment with 90Yttrium-Ibritumomab tiuxetan yielded a complete response.

Efficacy and safety of yttrium-90 ibritumomab tiuxetan in Japanese patients with non-Hodgkin lymphoma

PURPOSE

The aim of this study was to evaluate the efficacy and side effects of radioimmunotherapies with Zevalin(®) (RIT-Z) in Japanese patients with low-grade B-cell non-Hodgkin lymphoma (NHL).

MATERIALS AND METHODS

Sixty-two patients with NHL were enrolled. Based on histology, 49 of the patients had follicular lymphoma and 23 had other lesions. The response was assessed at 8-12 weeks after RIT-Z injection with PET/CT.

RESULTS

The overall response rate was 85 %. Thirty-seven (60 %) patients achieved complete remission, 16 (26 %) had partial remission, 4 (6 %) had stable disease, and 5 (8 %) had progressive disease. There was a significant correlation between the response to RIT-Z, frequency of chemotherapy, and history of prior treatment with fludarabine. There was no significant difference in efficacy according to lymphoma type, years since last chemotherapy, patient age, or disease stage at RIT-Z. Thrombocytopenia of grade 4 was significantly correlated with disease stage at RIT-Z and history of prior treatment with fludarabine. There was also no significant correlation between hematotoxicity and lymphoma type, frequency of chemotherapy, years since last chemotherapy, patient age, or history of bone marrow transplant. Anemia was significantly correlated with frequency of chemotherapy, history of bone marrow transplant, and history of prior treatment with fludarabine.

CONCLUSIONS

The response rate was high, and we were able to decrease the hematologic side effects by using RIT-Z earlier.