Phase I trial of iodine-131 tositumomab with high-dose chemotherapy and autologous stem-cell transplantation for relapsed non-Hodgkin's lymphoma

Anti-CD25 radioimmunotherapy with BEAM autologous hematopoietic cell transplantation conditioning in Hodgkin lymphoma

High-risk relapsed or refractory (R/R) classical Hodgkin lymphoma (HL) is associated with poor outcomes after conventional salvage therapy and autologous hematopoietic cell transplantation (AHCT). Post-AHCT consolidation with brentuximab vedotin (BV) improves progression-free survival (PFS), but with increasing use of BV early in the treatment course, the utility of consolidation is unclear. CD25 is often expressed on Reed-Sternberg cells and in the tumor microenvironment in HL, and we hypothesized that the addition of 90Y-antiCD25 (aTac) to carmustine, etoposide, cytarabine, melphalan (BEAM) AHCT would be safe and result in a transplantation platform that is agnostic to prior HL-directed therapy. Twenty-five patients with high-risk R/R HL were enrolled in this phase 1 dose-escalation trial of aTac-BEAM. Following an imaging dose of 111In-antiCD25, 2 patients had altered biodistribution, and a third developed an unrelated catheter-associated bacteremia; therefore, 22 patients ultimately received therapeutic 90Y-aTac-BEAM AHCT. No dose-limiting toxicities were observed, and 0.6 mCi/kg was deemed the recommended phase 2 dose, the dose at which the heart wall would not receive >2500 cGy. Toxicities and time to engraftment were similar to those observed with standard AHCT, though 95% of patients developed stomatitis (all grade 1-2 per Bearman toxicity scale). Seven relapses (32%) were observed, most commonly in patients with ≥3 risk factors. The estimated 5-year PFS and overall survival probabilities among 22 evaluable patients were 68% and 95%, respectively, and non-relapse mortality was 0%. aTac-BEAM AHCT was tolerable in patients with high-risk R/R HL, and we are further evaluating the efficacy of this approach in a phase 2 trial. This trial was registered at www.clinicaltrials.gov as #NCT01476839.

Evidence Base for the Use of PRRT

The development of peptide receptor radionuclide therapy (PRRT) in disseminated neuroendocrine tumors (NETs) has been a long and protracted process. The idea was born within nuclear medicine academia but its translation to clinical practice has been marked by misunderstanding of the rigors of the processes used in drug registration. There were several false starts and some of the required basic science did not occur until after first in man studies. The standard process of preclinical, phase 1, 2 and 3 clinical trials were sometimes blurred and the required data including the assurances that patients were studied on protocol was missing from subsequent publications. Despite this there was a growing conviction and increasing evidence that the use of PRRT had a positive benefit in both survival and symptom relief in about 80% of treated patients. After a decade and a half of false starts and incomplete data a formal randomized controlled trial was conducted comparing PRRT with high dose somatostatin which clearly proved that PRRT was both safe, effective and the treatment of choice in hormone refractory NETs.

Strategies to improve outcomes of autologous hematopoietic cell transplant in lymphoma

High-dose chemotherapy and autologous hematopoietic cell transplantation (HDT-AHCT) remains an effective therapy in lymphoma. Over the past several decades, HDT with BEAM (carmustine, etoposide, cytarabine, and melphalan) and CBV (cyclophosphamide, carmustine, and etoposide) have been the most frequently used preparatory regimens for AHCT in Hodgkin (HL) and non-Hodgkin lymphoma (NHL). This article reviews alternative combination conditioning regimens, as well as novel transplant strategies that have been developed, to reduce transplant-related toxicity while maintaining or improving efficacy. These data demonstrate that incorporation of maintenance therapy posttransplant might be the best way to improve outcomes.

Radioimmunotherapy-based conditioning regimen prior to autologous stem cell transplantation in non-Hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) is the most common hematologic malignancy and the sixth cause of death from cancer in the USA. Autologous stem cell transplantation (ASCT) is a potentially curative therapeutic option for many NHL patients. Choosing the most effective conditioning regimen prior to ASCT can lead to longer survival in these patients, and, as in many cases of high risk NHL, the only potentially curative option is stem cell transplantation. Radioimmunotherapy (RIT) is based on using radiolabeled monoclonal antibodies against tumoral antigens. Since lymphoma cells are sensitive to radiation, RIT has become a potential approach in treating NHL. In this review, we have discussed the efficacy and safety of RIT as an alternative conditioning regimen prior to ASCT.

Y90 -Ibritumomab tiuxetan (Y90 -IT) and high-dose melphalan as conditioning regimen before autologous stem cell transplantation for elderly patients with lymphoma in relapse or resistant to chemotherapy: a feasibility trial (SAKK 37/05)

Standard conditioning regimens for autologous stem cell transplantation (ASCT) are often not tolerated by elderly patients, on one hand. Single high-dose melphalan, on the other hand, has been shown to be safe and active as a pretransplant preparative regimen in elderly patients. Y⁹⁰ -Ibritumomab tiuxetan (Y⁹⁰ -IT) is well tolerated and feasible in the transplantation setting. We therefore investigated the combination of high-dose melphalan and Y⁹⁰ -IT as a conditioning regimen for patients ≥65 years of age. Patients with relapsed or resistant CD20-positive lymphoma in remission after salvage chemotherapy could be enrolled. High-dose therapy consisted of standard dose Y⁹⁰ -IT (0.4-mCi/kg body weight) followed by melphalan at escalating doses (100, 140, 170 and 200 mg/m² ) and ASCT. The primary objective was to identify the maximum tolerated dose; secondary end points were complete response (CR) rate 100 days after transplantation and toxicity. Twenty patients (median age 72 years) were included. No DLT occurred at any dose level. Thirteen patients completed the treatment, 11 were evaluable for response. Seven patients did not complete treatment because of mobilization failure (n = 3), progressive disease (n = 2), worsening of cardiac function (n = 1), and grade 3 dyspnea (n = 1). Seven patients achieved a CR/complete remission/unconfirmed (CRu) and 2 had stable disease. Five out of 7 responding patients were still alive more than 3 years after transplantation. The 2 patients with SD had a long-term survival of 3 and 5 years, respectively. Nonhematological grade 3 or higher treatment related adverse events (AEs) were infection (n = 6), including 2 cases of febrile neutropenia, diarrhea (n = 3), mucositis, anorexia, viral hepatitis, hypokalemia, dehydration, and multiorgan failure (n = 1 for each). The combination of Y⁹⁰ -IT and high-dose melphalan is feasible before ASCT for elderly patients, with promising activity and manageable toxicity.

Targeted Cancer Therapy Using Radiolabeled Monoclonal Antibodies

Radioimmunotherapy (RIT) combines the advantages of targeted radiation therapy and specific immunotherapy using monoclonal antibodies. RIT can be used either to target tumor cells or to specifically suppress immunocompetent host cells in the setting of allogeneic transplantation. The choice of radionuclide used for RIT depends on its distinct radiation characteristics and the type of malignancy or cells targeted. Beta-emitters with their lower energy and longer path length are more suitable to target bulky, solid tumors whereas α-emitters with their high linear energy transfer and short path length are better suited to target hematopoietic cells (normal or malignant). Different approaches of RIT such as the use of stable radioimmunoconjugates or of pretargeting strategies are available. Encouraging results have been obtained with RIT in patients with hematologic malignancies. The results in solid tumors are somewhat less favorable but new strategies for patients with minimal residual disease using adjuvant and locoregional treatment are evolving. This report outlines basic principles of RIT, gives an overview of available radionuclides and radioimmunoconjugates, and discusses clinical results with special emphasis on their use in hematologic malignancies including use in conditioning regimens for bone marrow transplantation.

Impact of conditioning regimen on outcomes for patients with lymphoma undergoing high-dose therapy with autologous hematopoietic cell transplantation

There are limited data to guide the choice of high-dose therapy (HDT) regimen before autologous hematopoietic cell transplantation (AHCT) for patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). We studied 4917 patients (NHL, n = 3905; HL, n = 1012) who underwent AHCT from 1995 to 2008 using the most common HDT platforms: carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) (n = 1730); cyclophosphamide, BCNU, and etoposide (CBV) (n = 1853); busulfan and cyclophosphamide (BuCy) (n = 789); and total body irradiation (TBI)-containing treatment (n = 545). CBV was divided into CBV(high) and CBV(low) based on BCNU dose. We analyzed the impact of regimen on development of idiopathic pulmonary syndrome (IPS), transplantation-related mortality (TRM), and progression-free and overall survival. The 1-year incidence of IPS was 3% to 6% and was highest in recipients of CBV(high) (hazard ratio [HR], 1.9) and TBI (HR, 2.0) compared with BEAM. One-year TRM was 4% to 8%, respectively, and was similar between regimens. Among patients with NHL, there was a significant interaction between histology, HDT regimen, and outcome. Compared with BEAM, CBV(low) (HR, .63) was associated with lower mortality in follicular lymphoma (P < .001), and CBV(high) (HR, 1.44) was associated with higher mortality in diffuse large B cell lymphoma (P = .001). For patients with HL, CBV(high) (HR, 1.54), CBV(low) (HR, 1.53), BuCy (HR, 1.77), and TBI (HR, 3.39) were associated with higher mortality compared with BEAM (P < .001). The impact of specific AHCT regimen on post-transplantation survival is different depending on histology; therefore, further studies are required to define the best regimen for specific diseases.

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.

Autologous hematopoietic cell transplantation: an update for clinicians

High-dose chemotherapy followed by transplantation of autologous hematopoietic progenitor cells has a proven track record of safety and efficacy in hematological malignancies and select solid tumors. The near-universal use of peripheral blood stem cells as source for autografts, routine growth factor support, and antimicrobial prophylaxis post transplantation has improved the safety of this procedure. However, the advent of highly active novel therapies in the last few years warrants reappraisal of the role of autologous transplantation in the therapeutic armamentarium of malignant disorder. This review summarizes the current role of autologous transplantation for hematological malignancies, discusses modern standards for patient selection, and highlights long-term care issues of transplant survivors from an internist's perspective. Role of tumor purging in autologous transplantation, novel transplant conditioning regimens, and post-transplant therapies to prevent disease relapse are reviewed.

Hematopoietic stem cell transplantation for follicular lymphoma: optimal timing and indication

The definitive management of advanced follicular lymphoma (FL) remains controversial due to various treatment options, including watchful waiting, single-agent or combination chemotherapy, monoclonal antibody, and radioimmunotherapy. These options can provide prolonged progression-free survival. However, they cannot cure advanced FL. Allogeneic hematopoietic stem cell transplantation (allo-SCT) remains the sole curative therapy for FL. Allo-SCT has had a major impact with the use of reduced-intensity conditioning regimens because of its lower associated nonrelapse mortality compared with myeloablative regimens. Autologous SCT (auto-SCT) shows high response rates and extends progression-free survival in patients with chemosensitive relapse. In the rituximab era, however, associated comorbidities, risk of secondary cancers, and presence of refractory disease have become problematic in the auto-SCT population. On the basis of results from large-scale randomized trials, upfront auto-SCT is not recommended. Novel conditioning regimens including radioimmunotherapy followed by either auto-SCT or allo-SCT are likely to show efficacy even in chemorefractory disease. Consequently, the optimal timing for SCT remains a matter of opinion, except for patients in first remission. However, the outcomes of allo-SCT and auto-SCT keep on improving. Physicians should note that there is no therapy with a track record equivalent to that of SCT for relapsed or refractory FL.

Conditioning regimens for hematopoietic cell transplantation: one size does not fit all

An essential component of allogeneic and autologous hematopoietic cell transplantation (HCT) is the conditioning regimen administered before the hematopoietic cell infusion. Early regimens relied on dose intensity, assuming that high-dose chemoradiotherapy would eliminate malignant disease and reinfusion of the graft would then restore hematopoiesis. However, as the contribution of graft-versus-tumor effects to the success of allogeneic HCT was recognized over time, in an effort to exploit these, many investigators lowered the dose of radiation and chemotherapeutic agents in the preparative regimen. This resulted in a major paradigm shift, and consequently, the pool of eligible patients underwent a remarkable expansion. In this article, we provide a review of the definition of high-dose, reduced-intensity, and nonmyeloablative conditioning regimens, the most commonly used agents and combinations, and the evolution of some early regimens. We also provide a brief review of the toxicities associated with these regimens.

Novel conditioning regimens for Hodgkin’s and non-Hodgkin’s lymphoma

SUMMARY Autologous stem cell transplantation (ASCT), in chemosensitive relapsed patients with Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL), is associated with superior event-free survival (EFS) compared with salvage chemotherapy alone. BEAM is one of the most commonly used regimens in both HL and NHL because of its acceptable toxicity and high effectiveness. The nonrelapsed mortality (NRM) ranges from 7 to 10% in historical studies. More recent investigations have demonstrated a lower NRM, probably due to various factors such as the use of peripheral blood precursor cells and better support therapy. Recently, in order to reduce the toxicity of carmustine and increase antilymphoma activity, several groups have introduced conditioning regimens similar to BEAM. The incorporation of newer drugs (anti-CD20 monoclonal antibodies ± radiolabeled) to ‘classic’ BEAM, or the substitution of carmustine with other drugs (thiotepa, bendamustine and fotemustine) may be a valuable strategy in this patient setting. In this review, we will discuss the data available on HDC followed by ASCT in lymphoma using new conditioning regimens, namely second-generation BEAM.

Risk of second cancers after radiotherapy for cervical cancer

Radiotherapy for cervical cancer has both beneficial and detrimental effects: improvement of patient survival and potential induction of a second cancer among long-term survivors. Large epidemiological studies have demonstrated small, but significant, increases of second cancers with radiotherapy compared with the general population. The risk of second cancer has been characterized by organ sites, dose, time since radiotherapy and age at the time of radiotherapy. Analyses of genetic susceptibility and molecular carcinogenesis can be used to develop more appropriate strategies for radiation therapy for cervical cancers.

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.

Monoclonal antibodies in conditioning regimens for hematopoietic cell transplantation

Monoclonal antibodies are increasingly being incorporated in conditioning regimens for autologous or allogeneic hematopoietic cell transplantation (HCT). The benefit of adding rituximab to autologous HCT regimens is purportedly related to in vivo purging of clonal B cells. Randomized trials comparing the addition (or not) of rituximab to high-dose therapy regimens are lacking. No benefit of standard-dose radioimmunotherapy-based regimens for autografting in aggressive lymphomas was seen in a randomized controlled study. The incorporation of rituximab into allogeneic HCT regimens aims to improve responses while reducing nonrelapse mortality resulting from acute graft-versus-host disease. The optimal dose and administration schedule of rituximab in this setting are unknown, and potentially serious complications from increased infections owing to prolonged (and profound) cytopenias or persistent hypogammaglobulinemia are of concern. Radioimmunotherapy-based conditioning for allografting holds promise as a modality to optimize tumor control and synergize adoptive immunotherapy effects, but it remains experimental at this time. The addition of alemtuzumab to allogeneic HCT regimens is associated with prolonged lymphopenia and impaired immune reconstitution, high relapse rates, and serious infections. The optimal dose and schedule of alemtuzumab to avoid prolonged immune paresis remain elusive. It is anticipated that additional monoclonal antibodies will soon become available that can be incorporated into HCT regimens after safety and clinical efficacy are demonstrated.

Autotransplantation for mantle cell lymphoma

Mantle cell lymphoma (MCL) represents about 5% to 9% of all non-Hodgkin lymphomas according to the World Health Organization. The clinical presentation typically consists of diffuse lymphadenopathy and frequent extranodal involvement of the gastrointestinal tract, blood, and bone marrow, as well as frequent splenomegaly. The median survival with standard immunochemotherapy is approximately 3 to 5 years. High-dose chemotherapy and autologous stem cell transplantation (ASCT) have been used either in first partial or complete remission or at the time of relapse in an attempt to prolong the survival for patients with MCL. Autologous SCT has had disappointing results in patients with relapsed MCL with the expected progression-free survival approximately 20% to 40% in most trials. Therefore, most centers now consider ASCT for eligible MCL patients during first remission. If a complete remission can be obtained with the induction chemotherapy, the clinical results following ASCT in complete remission 1 are improved to 60% to 80% progression-free survival greater than 5 years. However, the median age of patients with MCL is older than 60 years, which does not allow ASCT to be used in all patients with MCL. Research is now focused on reducing the relapse rate after transplantation.

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 III randomized study of rituximab/carmustine, etoposide, cytarabine, and melphalan (BEAM) compared with iodine-131 tositumomab/BEAM with autologous hematopoietic cell transplantation for relapsed diffuse large B-cell lymphoma: results from the BMT CTN 0401 trial

PURPOSE

This clinical trial evaluated standard-dose radioimmunotherapy with a chemotherapy-based transplantation regimen followed by autologous hematopoietic cell transplantation versus rituximab with the same regimen in patients with relapsed diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

Patients with chemotherapy-sensitive persistent or relapsed DLBCL were randomly assigned to receive iodine-131 tositumomab (dosimetric dose of 5 mCi on day -19 and therapeutic dose of 0.75 Gy on day -12), carmustine 300 mg/m(2) (day -6), etoposide 100 mg/m(2) twice daily (days -5 to -2), cytarabine 100 mg/m(2) twice daily (days -5 to -2), and melphalan 140 mg/m(2) (day -1; B-BEAM) or rituximab 375 mg/m(2) on days -19 and -12 and the same chemotherapy regimen (R-BEAM).

RESULTS

Two hundred twenty-four patients were enrolled, with 113 patients randomly assigned to R-BEAM and 111 patients assigned to B-BEAM. Two-year progression-free survival (PFS) rates, the primary end point, were 48.6% (95% CI, 38.6% to 57.8%) for R-BEAM and 47.9% (95% CI, 38.2% to 57%; P = .94) for B-BEAM, and the 2-year overall survival (OS) rates were 65.6% (95% CI, 55.3% to 74.1%) for R-BEAM and 61% (95% CI, 50.9% to 69.9%; P = .38) for B-BEAM. The 100-day treatment-related mortality rates were 4.1% (95% CI, 0.2% to 8.0%) for R-BEAM and 4.9% (95% CI, 0.8% to 9.0%; P = .97) for B-BEAM. The maximum mucositis score was higher in the B-BEAM arm (0.72) compared with the R-BEAM arm (0.31; P < .001).

CONCLUSION

The B-BEAM and R-BEAM regimens produced similar 2-year PFS and OS rates for patients with chemotherapy-sensitive relapsed DLBCL. No differences in toxicities other than mucositis were noted.

Changing role of stem cell transplantation in follicular lymphoma

Patients with advanced follicular lymphoma (FL) have numerous treatment options, including observation, radiotherapy, single-agent or combination chemotherapy, mAbs, and radioimmunoconjugates. These therapies can extend progression-free survival but none can provide a cure. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains the only curable therapy for FL, with the field shifting more toward the use of reduced-intensity conditioning regimens because of the lower associated nonrelapse mortality compared with myeloablative regimens. However, GVHD and infection are still problematic in the allo-HSCT population. Autologous HSCT (auto-HSCT) confers high response rates and prolongs progression-free survival in relapsed patients who are chemosensitive, and an increasing amount of data suggest that auto-HSCT may be curative if offered to relapsed patients who are not heavily pretreated. Auto-HSCT has no role as consolidation therapy for patients in first remission based on the results from 3 large randomized trials. Novel conditioning regimens with radioimmunoconjugates have been used in both auto-HSCT and allo-HSCT regimens and results have shown efficacy even in chemorefractory patients. Therefore, with the exception of patients in first remission, the optimal timing for HSCT remains controversial. However, the outcomes seen after auto-HSCT and allo-HSCT continue to improve, and HSCT represents a treatment modality that should be considered in all FL patients, especially while their disease remains chemoresponsive.

Autologous stem cell transplantation for aggressive lymphomas

The role of high-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) in the treatment armamentarium of aggressive B- and T-cell non-Hodgkin lymphoma (NHL) is still a matter of debate. In the pre-Rituximab era, the PARMA study demonstrated the superiority of HDT/ASCT over conventional salvage chemotherapy in chemosensitive, relapsed patients. Subsequently, HDT/ASCT has become a standard approach for relapsed NHL. With the advent of Rituximab in the landscape of NHL, transplantation as part of first-line therapy has been challenged. However, no benefit in terms of disease-free or overall survival of HDT/ASCT over standard therapy was shown when Rituximab was added to both arms. Moreover, the superiority of HDT/ASCT over conventional salvage therapy in patients relapsing from first-line therapy including Rituximab was not confirmed. From these disappointing results, novel strategies, which can enhance the anti-lymphoma effect, at the same time reducing toxicity have been developed, with the aim of improving the outcome of HDT/ASCT in aggressive NHL. In T-cell lymphoma, few publications demonstrated that consolidation of complete remission with HDT/ASCT is safe and feasible. However, up to one-third of patients may never receive transplant, mostly due to progressive disease, and relapse still remains a major concern even after transplant.

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.

Phase II trial of 131-Iodine tositumomab with high-dose chemotherapy and autologous stem cell transplantation for relapsed diffuse large B cell lymphoma

The purpose of this study was to evaluate the standard outpatient dose of 131-Iodine tositumomab (75 cGy) combined with high-dose carmustine, etoposide, cytarabine, and melphalan (BEAM) followed by autologous stem cell rescue for the treatment of chemotherapy-sensitive relapsed or refractory, or high-risk first complete remission (CR) patients with diffuse large B cell non-Hodgkin's lymphoma (DLBCL). Forty patients with chemotherapy-sensitive persistent or relapsed or high/intermediate or high international prognostic index DLCBL were treated in a phase II trial combining 75 cGy 131-Iodine tositumomab with high-dose BEAM followed by autologous stem cell transplantation. The CR rate after transplantation was 78%, and the overall response rate was 80%. Short-term and long-term toxicities were similar to historical control patients treated with BEAM alone. With a median follow-up of 6 years (range, 3-10 years), the 5-year overall survival (OS) was 72% (95% confidence interval [CI], 55%-83%), and the 5-year progression-free survival (PFS) rate was 70% (95% CI, 53%-82%). The PFS and OS were encouraging in this group of chemotherapy-sensitive persistent, relapsed, or high-risk patients with DLBCL. A follow-up phase III trial with 131-Iodine tositumomab/BEAM vs rituximab/BEAM was planned based on this information.

Hematopoietic cell transplantation for B-cell lymphoma: an update

BACKGROUND

B-cell lymphoma comprises the majority of non-Hodgkin lymphomas worldwide. Hematopoietic cell transplantation (HCT) is used for patients with high-risk, relapsed, or refractory B-cell lymphoma.

METHODS

The current medical literature and the results of recently published trials were reviewed to provide an update on the most common indications for HCT in B-cell lymphoma.

RESULTS

Autologous HCT has evolving and new roles in the treatment of patients with high-risk diffuse large B-cell cell lymphoma, mantle cell lymphoma, and HIV-related lymphoma. Reduced-intensity conditioning has largely replaced older myeloablative conditioning regimens, making allogeneic transplantation safer for more patients with lymphoma.

CONCLUSIONS

The indication and timing of HCT depend on the patient's histology, age, and response to previous therapies. HCT is an essential component in the armamentarium to treat B-cell lymphoma.

Cancer radioimmunotherapy

Targeting of radionuclides with antibodies, or radioimmunotherapy, has been an active field of research spanning nearly 50 years, evolving with advancing technologies in molecular biology and chemistry, and with many important preclinical and clinical studies illustrating the benefits, but also the challenges, which all forms of targeted therapies face. There are currently two radiolabeled antibodies approved for the treatment of non-Hodgkin lymphoma, but radioimmunotherapy of solid tumors remains a challenge. Novel antibody constructs, focusing on treatment of localized and minimal disease, and pretargeting are all promising new approaches that are currently under investigation.

A randomized study comparing yttrium-90 ibritumomab tiuxetan (Zevalin) and high-dose BEAM chemotherapy versus BEAM alone as the conditioning regimen before autologous stem cell transplantation in patients with aggressive lymphoma

BACKGROUND

High-dose chemotherapy combined with autologous stem-cell transplantation (ASCT) is the standard therapy for refractory/relapsed aggressive lymphoma. In the era of rituximab-containing frontline regimens, it is becoming more challenging to salvage patients in this setting, and novel approaches are required. This is a randomized study evaluating the safety and efficacy of standard-dose ibritumomab tiuxetan (Zevalin) combined with high-dose BEAM chemotherapy (Z-BEAM) and ASCT in refractory/relapsed aggressive lymphoma.

METHODS

Forty-three patients with CD20(+) -aggressive lymphoma were randomized to a treatment arm (Z-BEAM, n = 22) or control arm (BEAM alone, n = 21). Ibritumomab tiuxetan was given at 0.4 mCi/kg on day -14 before ASCT.

RESULTS

Patient characteristics, engraftment kinetics, and toxicity profile were similar between the 2 groups. Two-year progression-free survival (PFS) for all patients was 48% (95% confidence interval, 32%-64%): 59% and 37% after Z-BEAM and BEAM alone, respectively (P = .2). Multivariate analysis identified advanced age (hazard ratio [HR], 8.3; P = .001), high-risk disease (relapse within 12 months of diagnosis and/or secondary International Prognostic Index >2; HR, 2.8; P = .04), positive positron emission tomography-computed tomography pretransplant (HR, 2.4; P = .07), and BEAM alone (HR, 2.8; P = .03) as poor prognostic factors. Intermediate-risk patients with 1 or 2 risk factors had better PFS with Z-BEAM compared with BEAM: 69% and 29%, respectively (P = .07). Two-year overall survival was 91% and 62% after Z-BEAM and BEAM, respectively (P = .05). Similar prognostic factors determined survival. The HR for BEAM alone in the multivariate analysis was 8.1 (P = .01).

CONCLUSIONS

Standard-dose ibritumomab tiuxetan combined with BEAM high-dose chemotherapy is safe and possibly more effective than BEAM alone as a conditioning regimen for ASCT in the era of rituximab-containing chemotherapy regimens.

Hematopoietic Cell Transplantation for Lymphomas

Background

The heterogeneity of lymphomas results in numerous treatment options, including both autologous and allogeneic hematopoietic cell transplantation. However, the type of transplantation, the timing the procedure, and the selection of suitable patients for transplant continue to evolve.

Methods

We reviewed the current medical literature to provide a succinct synthesis for the most common types of lymphoma and the indications for transplantation.

Results

This review discusses the outcomes of autologous and allogeneic transplantation for patients with diffuse large B-cell lymphoma, follicular lymphoma, HIV-associated lymphomas, mantle cell lymphoma, T-cell lymphoma, and Hodgkin lymphoma.

Conclusions

Each of these histologies differs in the indications and timing for transplantation. However, ongoing clinical trials support the continuing role of both autologous and allogeneic transplantation for lymphoma management.

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.

Transplantation for non-Hodgkin lymphoma

High-dose therapy followed by autologous hematopoietic stem cell transplantation (auto-HCT) has become the treatment of choice for patients with relapsed aggressive non-Hodgkin lymphoma (NHL). However, relapse remains the most common cause of treatment failure after auto-HCT. More intensive regimens incorporating radioimmunotherapy into high-dose regimens have been developed to prevent relapse. The role of auto-HCT for follicular lymphoma and mantle cell lymphoma remain inconclusive. Since prognosis of patients with peripheral T-cell lymphoma, not otherwise specified are very poor with conventional chemotherapy, auto-HCT during first remission is being explored in peripheral T-cell lymphoma. Given the lower risk of relapse after allogeneic HCT (allo-HCT) in NHL, allo-HCT has been performed in patients with refractory or relapsed NHL, especially after auto-HCT failure. However, the transplant-related mortality remains high after myeloablative allo-HCT. Reduced-intensity conditioning followed by allo-HCT has been shown to reduce transplant-related mortality but graft-versus-host disease continues to be the major problem, thus the role of allo-HCT in NHL remains an investigational approach for NHL. The outcomes of auto-HCT and allo-HCT for various lymphomas are reviewed.

Radioimmunotherapy in follicular lymphoma: some like it hot…

Therapeutic monoclonal antibodies (MoAbs) have been the major breakthrough in the treatment of both indolent and aggressive B-cell non-Hodgkin's lymphoma (NHL), and have become standard of care for these diseases. However, patients may not respond to antibody therapy, or resistance can develop. Radioimmunotherapy (RIT) makes use of continuous low dose radiation emitted by radioisotopes targeted directly to the lymphoma cells. Both the (131)I-labeled murine CD20 MoAb tositumomab (Bexxar®) and (90)Y-labeled ibritumomab-tiuxetan (Zevalin®) have been shown to be more effective than unlabeled MoAbs in terms of overall and complete response rates in follicular lymphoma (FL) patients, and both agents have a high response rate even in rituximab-resistant patients. Long-term responses, especially in complete responders, have been described in up to one third of the patients. In FL patients consolidation with (90)Y-labeled ibritumomab-tiuxetan after first line treatment with chemotherapy has been shown to result in a high rate of conversion of partial to complete remissions, leading to a significant improvement in progression-free survival. Current (mostly phase II) clinical trials are investigating the role of RIT in induction or consolidation therapy after immunochemotherapy, and are incorporating RIT in high dose chemotherapy regimens followed by autologous stem cell rescue. However, phase III data are important to define the place of RIT in the treatment algorithm of patients with FL.

(90)Y-ibritumomab tiuxetan followed by reduced-intensity conditioning and allo-SCT in patients with advanced follicular lymphoma

RIC HSCT is a potentially curative therapeutic option for patients with advanced FL but disease relapse remains the most common cause of failure. Radioimmunoconjugates administered prior to RIC allogeneic HSCT may enhance cytoreduction and allow more time for graft versus lymphoma effect to develop without the associated toxicity of a myeloablative HSCT. We performed a retrospective study to describe the outcomes of patients with relapsed, refractory or transformed FL who received ⁹⁰Y ibritumomab tiuxetan followed by fludarabine and low-dose busulfan RIC allogeneic HSCT at the Dana-Farber Cancer Institute between 2006 and 2009, inclusively. Twelve patients were identified with a median age of 55 (40–66) years and a median number of lines of therapy of 5 (2–10). Two patients (17%) had transformed to a more aggressive histology and 5 (42%) had chemorefractory FL. Cumulative incidences of grade II–IV acute GVHD at 100 days were 17% (± 11%) and chronic GVHD at 12 months were 63% (±19%). Two-year non-relapse mortality was 18% (± 12%). Two-year OS and progression-free survival (PFS) were 83% (± 11%) and 74% (± 13%), respectively. This treatment is associated with favorable outcomes including acceptable rates of GVHD and relapse in advanced FL patients and warrants prospective studies.

Relapsed/refractory diffuse large B-cell lymphoma

Despite overall improvements in outcomes of diffuse large B-cell lymphoma (DLBCL), approximately one-third of patients will develop relapsed/refractory disease that remains a major cause of morbidity and mortality. Novel insights from gene-expression analyses have increased our understanding of chemotherapy resistance and yielded rational targets for therapeutic intervention to both prevent and treat relapsed/refractory DLBCL. The clinical approach to relapsed/refractory DLBCL should include high-dose therapy and autologous stem cell transplantation (HD-ASCT) with curative intent in patients without comorbidities. Results from the recently reported CORAL study suggest that patients refractory to rituximab-containing regimens have inferior outcomes with HD-ASCT. Ongoing efforts to improve ASCT include novel conditioning regimens and evaluation of maintenance approaches after ASCT. Unfortunately, because the majority of patients are not eligible for ASCT due to refractory disease or age/comorbidities, these approaches have limited impact. The large group of patients not eligible for ASCT have incurable disease and should be referred for clinical trials of rationally targeted agents.

Patterns of social support among lymphoma patients considering stem cell transplantation

There is lack of literature addressing factors that influence the process of care for patients with hematological malignancies. We evaluated the forms of social support available for patients with relapsed lymphoma considering stem cell transplantation and examined the influence of support on treatment delay. Data were collected from 119 patients with relapsed lymphoma using a questionnaire to capture sociodemographic information and emotional, informational, and instrumental forms of social support. Sixty-four percent of the patients were married, 56% had children over 18 years of age, 43% were employed, and 72% had private health insurance. Family members formed a major source of emotional support (83%), while 47% of patients considered personal prayers to be important. While 79% of patients received clinical support from nurses, few received formal group support or formal peer support (6.7% and 1.7% respectively). Support from extended family and peer groups reduced the likelihood of treatment delays. The potential benefits of peer group support should be reinforced for patients considering transplantation given how infrequent this form of social support is utilized and its positive impact on the process of care. Future studies should test the impact of social support on health outcomes especially among the underserved population.

I-131 tositumomab

IMPORTANCE OF THE FIELD

Follicular lymphoma (FL) is a subgroup of B-cell Non-Hodgkin's lymphomas (NHL) that account for 15 - 30% of all lymphomas. I-131 tositumomab is a radiommunoconjugate of (131)I and the anti-CD20 monoclonal antibody tositumomab. It is one of two available radioimmunoconjugates for the treatment of recurrent, refractory, or transformed FL.

AREAS COVERED IN THIS REVIEW

This review describes the clinical pharmacology of I-131 tositumomab, dosing and administration guidelines, and the key clinical trials providing evidence of its efficacy and safety in patients with FL, transformed, or other aggressive B-NHL, in combination with chemotherapy, or its incorporation in transplant conditioning regimens. This review also covers safety and regulatory concerns regarding the use of I-131 tositumomab.

WHAT THE READER WILL GAIN

This review critically appraises the clinical trials behind approval of I-131 tositumomab as a second-line agent for FL and also outlines the data supporting its use in the upfront setting.

TAKE HOME MESSAGE

I-131 tositumomab is a safe and effective option for patients with recurrent, refractory, or transformed FL and carries promise in the upfront treatment of FL, aggressive B-NHL, and as a transplant conditioning regimen.

Radioimmunotherapy for the treatment of non-Hodgkin lymphoma: current status and future applications

Radioimmunotherapy (RIT) has proved to be a safe and effective treatment for patients with relapsed or refractory indolent non-Hodgkin lymphoma (NHL) including rituximab-refractory follicular lymphoma. Further, FDA approval was recently granted for use in newly diagnosed follicular lymphoma as consolidative therapy immediately following induction chemotherapy. We detail herein the scope of clinical studies performed in relapsed/refractory and newly diagnosed indolent lymphoma and summarize the associated safety data. In addition, we discuss new applications of RIT that have been investigated in a variety of clinical scenarios (e.g. single-agent and sequential therapy in aggressive NHLs and as a component of stem cell transplant conditioning). The wide array of RIT-based studies have yielded encouraging data, although randomized controlled trials will be needed to prove superiority over conventional therapy. Novel therapeutic RIT-based strategies that continue to be explored include radiation-enhancing agents combined with RIT, pre-targeting, RIT fractionation, as well as the integration of new humanized antibodies. The field of RIT continues to evolve scientifically and grow clinically. A reappraisal of prior data and examination of recently published and ongoing studies will be important in recognizing the potential benefit of RIT in the treatment of NHL.

Radioimmunotherapy with yttrium-90-ibritumomab tiuxetan as part of a reduced- intensity conditioning regimen for allogeneic hematopoietic cell transplantation in patients with advanced non-Hodgkin lymphoma: results of a phase 2 study

Forty patients were enrolled in this phase 2 study combining radioimmunotherapy (RIT) using yttrium-90-ibritumomab-tiuxetan (15 MBq [0.4 mCi]/kg) with reduced-intensity conditioning (RIC) using fludarabine (90 mg/m2) and 2 Gy total body irradiation followed by allogeneic hematopoietic cell transplantation (HCT) from related (n = 13) or unrelated (n = 27) donors for the treatment of advanced non-Hodgkin lymphoma. Diagnoses were follicular lymphoma (n = 17), chronic lymphocytic leukemia (n = 13), mantle cell lymphoma (n = 8), marginal zone lymphoma (n = 1), and lymphoplasmacytic lymphoma (n = 1). Median age was 55 years (range, 34-68 years). All patients were high risk with refractory disease or relapse after preceding autologous HCT. No additional toxicities attributable to RIT were observed. Engraftment was rapid and sustained. Incidences of acute graft-versus-host disease 2-4 and chronic graft-versus-host disease were 43% and 53%, respectively. Kaplan-Meier–estimated nonrelapse mortality was 45% at 2 years. Twenty-two of 40 patients (55%) are alive, resulting in a Kaplan-Meier–estimated 2-year survival of 51% for all, 67% for follicular lymphoma, 49% for chronic lymphocytic leukemia, and 37% for mantle cell lymphoma patients. The combined use of RIT with RIC is feasible with acceptable toxicity, even in elderly and heavily pretreated patients. This study is registered at www.clinicaltrials.gov as #NCT00302757.

Response to second-line therapy defines the potential for cure in patients with recurrent diffuse large B-cell lymphoma: implications for the development of novel therapeutic strategies

BACKGROUND

Patients with diffuse large B-cell lymphoma (DLBCL) who are not cured by initial therapy sometimes experience disease-free survival after autologous stem cell transplantation. Chemotherapy responsiveness before transplantation is a major predictor of outcome. Patients not responding to second-line regimens may receive third-line therapy in the hopes of achieving response, but outcome data are limited.

PATIENTS AND METHODS

We identified patients with relapsed or refractory DLBCL at Weill Cornell Medical Center for whom data on responses to second-line chemotherapy were available.

RESULTS

A total of 74 patients with relapsed or refractory DLBCL who underwent second-line chemotherapy between 1996 and 2007 were identified. Of these patients, 27 (36%) did not respond. The median overall survival of nonresponding patients was 4 months, and only 1 patient (4%) survived for 1 year. The choice of third-line aggressive chemotherapy instead of less intensive approaches did not confer a survival benefit.

CONCLUSION

Our data demonstrate that patients with recurrent DLBCL not responding to second-line chemotherapy demonstrate dismal outcomes. Trials of novel regimens should be prioritized as management strategies for these patients. Our data provide an important benchmark in the evaluation of the potential clinical value of such approaches.