Development Of Radioimmunotherapy Research Articles

Abstract PO-098: Development of radioimmunotherapy using IL7 and FLT3 in a murine HPV related head and neck squamous cell carcinoma model

Abstract PO-098: Development of radioimmunotherapy using IL7 and FLT3 in a murine HPV related head and neck squamous cell carcinoma model

Radioimmunotherapy of Non-Hodgkin B-cell Lymphoma: An update.

Systemic radioimmunotherapy (RIT) is arguably the most effective and least toxic anticancer treatment for non-Hodgkin lymphoma (NHL). In treatment-naïve patients with indolent NHL, the efficacy of a single injection of RIT compares with that of multiple cycles of combination chemotherapy. However, 20 years following the approval of the first CD20-targeting radioimmunoconjugates 90Y-Ibritumomab-tiuxetan (Zevalin) and 131I-tositumomab (Bexxar), the number of patients referred for RIT in western countries has dramatically decreased. Notwithstanding this, the development of RIT has continued. Therapeutic targets other than CD20 have been identified, new vector molecules have been produced allowing for faster delivery of RIT to the target, and innovative radionuclides with favorable physical characteristics such as alpha emitters have been more widely available. In this article, we reviewed the current status of RIT in NHL, with particular focus on recent clinical and preclinical developments.

"Surgery only" is not enough: potential of multimodal therapy in urothelial bladder carcinoma

Radical cystectomy is the standard treatment for muscle invasive bladder cancer. Using perioperative cisplatin-based chemotherapy, 5‑year overall survival rates are 5% higher with neoadjuvant chemotherapy compared to local therapy alone. New multimodal concepts have been developed to improve oncologic efficacy and to reduce treatment-related morbidity. Perioperative use of checkpoint inhibitors aims at improving efficacy, while bladder-preserving concepts try to avoid cystectomy in good responders. This article reviews new developments in radioimmunotherapy and perioperative combination therapies as well as bladder-preserving concepts like trimodal bladder therapy.

Preclinical study of 212Pb alpha-radioimmunotherapy targeting CD20 in non-Hodgkin lymphoma.

Despite therapeutic advances, Non-Hodgkin lymphoma (NHL) relapses can occur. The development of radioimmunotherapy (RIT) with α-emitters is an attractive alternative. In this study, we investigated the potential of α-RIT in conjunction with 212Pb-rituximab for the treatment of NHL. EL4-hCD20-Luc cells (mouse lymphoma cell line) were used for in vitro and in vivo studies. Biodistribution and efficacy studies were performed on C57BL/6 mice injected intravenously with 25 × 103 cells. 212Pb-rituximab (0.925-7.4 kBq/mL) inhibit proliferation of EL4-hCD20-Luc cells in vitro. Biodistribution of 203/212Pb-rituximab in mice showed a significant tumour uptake and suggested that the liver, spleen, and kidneys were the organs at risk. For efficacy studies, mice were treated at either 11 days (early stage) or 20-30 days after injection of tumour cells (late stage). Treatment with 277.5 kBq 212Pb-rituximab significantly prolonged survival. Even at an advanced tumour stage, significant tumour regression occurred, with an increase in the median survival time to 28 days, compared with 9 days in the controls. These results show the efficacy of 212Pb-rituximab in a murine syngeneic lymphoma model, in terms of significant tumour regression and increased survival, thereby highlighting the potency of α-RIT for the treatment of NHL.

Radioimmunotherapy of solid tumors: Approaches on the verge of clinical application.

While radioimmunotherapy (RIT) for the treatment of hematological malignancies such as indolent B-cell lymphoma has proven quite successful, clinical results of RIT in solid tumors have only been moderate in the past. The reasons were manifold and can be mostly attributed to the different biological properties of solid tumors vs hematological cancers. Furthermore, the slow clearance of the radiolabelled antibody prevents the use of radiation doses necessary to achieve clinical responses. The long biological half-life of radioimmunoconjugates results in high background levels and is the main reason for radiation related toxicities. In recent years, researchers and clinicians have developed solutions for the successful application of RIT for the treatment of solid tumors. These include compartmental route of administration, neoadjuvant therapies, and pretargeting approaches. In this review, recent developments in RIT for the treatment of solid tumors that address these restrictions as well as future perspectives will be highlighted from a clinical perspective.

Nontargeted Effect after Radiotherapy in a Patient with Non-Small Cell Lung Cancer and Bullous Pemphigoid.

Purpose. To describe tumor shrinkage of nonirradiated lung metastases in a patient with non-small cell lung cancer. Case Report. The patient had a concurrent autoimmune condition, bullous pemphigoid, which was clinically exacerbated during radiotherapy of mediastinal and axillary lymph node metastases. He also developed a series of infections during and after irradiation, and we hypothesize that the immunological events during this phase might have influenced the size of the nonirradiated metastases. Conclusion. Ionizing radiation generates inflammatory signals and, in principle, could provide both tumor-specific antigens from dying cells and maturation stimuli that are necessary for dendritic cells' activation of tumor-specific T cells. Even if the detailed mechanisms causing nontargeted immune modulatory effects in individual patients are poorly understood, clinical development of radioimmunotherapy is underway.

188Re-HYNIC-trastuzumab enhances the effect of apoptosis induced by trastuzumab in HER2-overexpressing breast cancer cells.

The development of radioimmunotherapy has provided an impressive alternative approach in improving trastuzumab therapy. However, the mechanisms of trastuzumab and radiation treatment combined to increase therapeutic efficacy are poorly understood. Here, we try to examine the efficacy of cytotoxicity and apoptosis induction for (188)Re-HYNIC-trastuzumab in cancer cell lines with various levels of Her2. Fluorescence flow cytometry was used to detect the alterations of apoptosis induction after (188)Re-HYNIC-trastuzumab treatment in two breast cancer cell lines with different levels of HER2 (BT-474 and MCF-7) and a colorectal carcinoma cell line (HT-29) for control. Our results indicated that (188)Re-HYNIC-trastuzumab led to cell death of breast cancer cells specifically in HER2 level-dependent and radioactivity dose-dependent fashions. In BT-474 cells, 370kBq/ml of (188)Re-HYNIC-trastuzumab enhanced the cytotoxicity to a level nearly 100-fold that of trastuzumab-alone treatment. The results also revealed that the mitochondria-dependent pathway attenuated irradiation-induced apoptosis in HER2-expressing breast cancer cells after (188)Re-HYNIC-trastuzumab treatment. In contrast, only after 48h of (188)Re-HYNIC-trastuzumab treatment, BT-474 cells exhibited typical apoptotic changes, including exposure of phospholipid phosphatidylserine on the cell surface, or fragmented DNA formation, in a radioactivity dose-dependent manner. Briefly, our study demonstrates that (188)Re-labeled HYNIC-trastuzumab not only enhances cell death in a radioactivity dose-dependent fashion, but may also prolong the effects of apoptosis involved with the mitochondria-dependent pathway in HER2-overexpressing breast cancer cells. It is possible that the (188)Re-HYNIC-trastuzumab treatment induced a second round of apoptosis to prolong the effects of cell kill in these cancer cells. These data revealed that (188)Re-HYNIC-trastuzumab has the potential for use as a therapeutic radiopharmaceutical agent in HER2-overexpressing breast cancer cell treatment.

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 radioimmunotherapy for non-Hodgkins lymphoma

放射免疫治疗(RIT)是非霍奇金淋巴瘤治疗的一种新方法,将单克隆抗体与放射性同位素结合,注入人体内与肿瘤细胞特异性结合,以实现对瘤体的内照射治疗.RIT是在分子靶向治疗的基础上发展起来的,因其具有放射性同位素的作用,故能补充分子靶向治疗的不足.近年来RIT的研究取得了显著进展,主要被应用于治疗复发、难治性、低度恶性、滤泡性、转化型B细胞淋巴瘤。

Radioimmunoconjugates in acute leukemia treatment: the future is radiant

Targeted radiotherapy of the bone marrow using radiolabeled monoclonal antibodies is a therapeutic approach of considerable potential for the treatment of acute leukemia in addition to or as a substitute for total body irradiation. The data currently available, of about 300 patients, suggest that radioimmunotherapy (RIT) with beta-emitters in acute leukemia is feasible and safe using a variety of antibodies (anti-CD33, anti-CD45, anti-CD66) and radionuclides (131I, 90Y, 188Re). It appears to reduce the risk of relapse in high-risk acute myelogenous leukemia (AML) patients transplanted early in the course of their disease (<15% blasts) to 20-30%. Furthermore, it has shown the potential to safely intensify reduced-intensity conditioning regimens (nonrelapse mortality of 25% compared to relapse rate of 55% within 2 years). Significant improvements in the results of refractory patients will probably depend on the successful further development of RIT with alpha-emitters or the use of a cocktail of antibodies labeled with alpha- and beta-emitters, in a first dose escalation study of 213Bi-labeled anti-CD33 in refractory AML (partial) remission could be achieved in 5/18 patients. Randomized trials to evaluate the therapeutic efficacy of RIT in the context of stem cell transplantation have been initiated and the results are keenly anticipated.

Targeting osseous metastases: rationale and development of radioimmunotherapy for prostate cancer

For patients with metastatic prostate cancer, bone is the primary site of tumor localization and the major cause of disease-related morbidity and mortality. Hormonal therapy and chemotherapy alone cannot eradicate disease harbored in bone. The delivery of radiotherapy to the reservoir of disease is an approach previously only achievable using bone-seeking radiopharmaceuticals. Now, however, with the identification of tumor-specific targets, antibodies are being used to deliver radiotherapy to these sites. In this article, we review the rationale behind this approach, the targets being explored, the radiation sources available, and the antibodies currently under clinical development.

Importance of receptor density in alpha radioimmunotherapy in B cell malignancies: an in-vitro study

External beam radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. To assess the binding of rituximab to samples of B cell chronic lymphocytic leukaemia (B-CLL) and splenic lymphoma with villous lymphocytes (SLVL), and to evaluate the induction of apoptosis by conventional therapies as well as with Bi conjugated to rituximab. 213Bi was eluted from a 225Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as chelator. Binding assays with 213Bi-rituximab were correlated to antibody binding capacity obtained by flow cytometry. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-amino-actinomycin D. Binding of 213Bi-rituximab was significantly lower for B-CLL compared to SLVL samples (12+/-3 and 42+/-10 213Bi atoms per cell, respectively, at 370 kBq.ml(-1)). The induction of apoptosis did not differ significantly between the two groups (B-CLL and SLVL) after external gamma irradiation or treatment with methylprednisolone and fludarabine (17+/-12% and 18+/-11%; 23+/-14% and 21+/-12%; 9+/-9% and 11+/-8%, respectively; all results expressed as percentages of all cells). Rituximab conjugated or not to 213Bi induced significantly more apoptosis in SLVL (42+/-19% and 42+/-17%) compared to B-CLL samples (27+/-12% and 6+/-8%). Binding assays confirm that SLVL samples present more CD20 antigens compared to B-CLL samples. Conventional therapies such as fludarabine, methylprednisolone or external gamma irradiation induce similar responses in the two populations but SLVL samples present higher sensitivity towards 213Bi-rituximab. These data are in favour of alpha-RIT in SLVL patients.

Factors Associated with Toxicity and Response to Yttrium 90–Labeled Ibritumomab Tiuxetan in Patients with Indolent Non-Hodgkin's Lymphoma

Treatment of patients with indolent non-Hodgkin's lymphoma (NHL) is evolving. These patients usually present with advanced-stage disease. Treatment options for patients who experience relapse are limited, and no treatment has been shown to be superior to others in improving overall survival of this group of patients, with the possible exception of allogeneic stem cell transplantation. Therefore, new approaches are needed to improve outcomes in patients with relapsed or refractory disease. The anti-CD20 monoclonal antibody, rituximab, was the first monoclonal antibody approved for the treatment of indolent B-cell NHL. As a single agent in the treatment of relapsed or refractory indolent lymphoma, response rates as high as 56% have been observed. This promising new therapy was followed by development of radioimmunotherapy, a novel treatment approach that combines the targeting capability of monoclonal antibodies with the additional cytotoxic effects of radiation. Yttrium 90–labeled ibritumomab tiuxetan (Zevalin®) is a radiolabeled monoclonal antibody that has been shown to produce clinically significant responses in up to 80% of patients with indolent NHL and is the first radiolabeled monoclonal antibody approved for therapeutic use in the treatment of lymphoma. This article reviews some of the safety and efficacy data for this agent in addition to examining factors that could aid in predicting response and toxicity in patients with low-grade relapsed or refractory NHL treated with 90Y ibritumomab tiuxetan.

Bexxar: novel radioimmunotherapy for the treatment of low-grade and transformed low-grade non-Hodgkin's lymphoma.

Immunotherapy using monoclonal antibodies to specifically target B cells has provided new hope to many patients with indolent lymphomas, particularly those with chemotherapy-refractory disease. Lymphomas are extremely sensitive to radiation, and significant progress has been made over the last decade in the development of radioimmunotherapy with anti-CD20 antibodies. Herein we review clinical experience with tositumomab and iodine I 131 tositumomab (Bexxar; Corixa Corporation; South San Francisco, CA; and GlaxoSmithKline; Philadelphia, PA) in patients with non-Hodgkin's lymphoma. Therapy with Bexxar has demonstrated high response rates and long durations of response compared with unconjugated anti-CD20 antibodies in patients with relapsed low-grade and transformed low-grade non-Hodgkin's lymphomas. Iodine-131 (I-131) has a long history of clinical experience, an excellent safety record, and favorable nuclear and pharmacologic properties. Importantly, the gamma emissions of iodine-131 facilitate accurate dosimetry to calculate the appropriate patient-specific therapeutic activity to deliver a predetermined total-body dose of radiation, thereby minimizing hematologic toxicity. In clinical trials of Bexxar, objective response rates ranged from 54%-71% in heavily pretreated patients. In the pivotal trial, the number of patients with a longer duration of response after treatment with Bexxar was significantly greater than the number of patients with a longer duration of response after their last qualifying chemotherapy regimen. In 76 newly diagnosed patients, the objective response rate was 97%, and 63% of patients achieved complete responses. These data suggest that Bexxar will become an important new option in the treatment of indolent lymphoma.

The rationale for and background of radioimmunotherapy: an emerging therapy for B-cell non-hodgkin’s lymphoma

Objectives To present the rationale for and development of radioimmunotherapy (RIT) for non-Hodgkin’s lymphoma (NHL), which culminated in the FDA’s approval of yttrium 90 ( 90Y) ibritumomab tiuxetan in February 2002. Data sources Published clinical trials of 90Y ibritumomab tiuxetan and secondary literature on immunotherapy, RIT, and NHL. Conclusion Monoclonal antibodies to the CD20 antigen have become an accepted therapy for NHL. Factors such as the poor vascularization of some tumors and the variable expression of the antigen can mitigate the efficacy of monoclonal antibodies, which prompted the development of a new strategy, RIT. Implications for nursing practice Knowledge of the background and development of RIT is essential for nurses to educate and manage patients with NHL.

Future directions in radioimmunotherapy for B-cell lymphoma

Rituximab has become a staple in the management of B-cell non-Hodgkin’s lymphoma, but it has limited activity as a single agent, with responses in about half of patients with recurrent follicular and low-grade lymphoma. Radioimmunotherapy (RIT) may surmount inherent or acquired antibody resistance by targeting a radionuclide to tumor cells. This strategy is particularly appealing for B-cell lymphoma because CD20 affords an outstanding target and lymphomas are inherently radiosensitive. The efficacy and safety of RIT have been established in the treatment of relapsed or refractory indolent non-Hodgkin’s lymphoma, and yttrium 90 ibritumomab tiuxetan (Zevalin; Biogen Idec Inc, Cambridge, MA) was the first RIT agent to be approved by the US Food and Drug Administration. This supplement to Seminars in Oncology seeks to present hematologists and medical oncologists with the most recent developments in RIT with 90Y ibritumomab tiuxetan for non-Hodgkin’s lymphoma, to clarify the role of the medical oncologist in the administration of the ibritumomab tiuxetan regimen, to indicate how and when RIT with 90Y ibritumomab tiuxetan may most successfully be integrated into the continuum of treatment for patients with B-cell lymphoma, and to describe ongoing clinical trials with 90Y ibritumomab tiuxetan in B-cell lymphomas.

A clinical and scientific overview of tositumomab and iodine I 131 tositumomab

The majority of patients with non-Hodgkin's lymphoma (NHL) who respond to conventional chemotherapy will relapse and eventually become refractory to chemotherapy. Each subsequent remission is typically of similar or shorter duration than the last. Recent developments in radioimmunotherapy using monoclonal antibodies to specifically target malignant B cells have yielded promising results in relapsed and refractory NHL patients. The radiolabeled anti-CD20 antibody tositumomab and iodine 131 tositumomab (Bexxar; Corixa Corp, South San Francisco, CA and GlaxoSmithKline, Philadelphia, PA) has been shown to be safe and effective in the treatment of patients with relapsed low-grade (indolent) NHL. Objective responses were achieved in 57% to 71% of patients in phase I to phase III trials, and remission durations were significantly longer in the phase III trial compared with the last remission induced by chemotherapy. In addition, tositumomab and iodine I 131 tositumomab was shown to be effective in the subset analysis of patients with transformed low-grade NHL, which is particularly resistant to conventional therapies. The incidence of transient, nonhematologic adverse events was low and mainly mild to moderate in severity. Hematologic toxicity is the major dose-limiting toxicity associated with radioimmunotherapy; however, patient-specific dosimetry maintained hematologic toxicity within predictable, transient, and manageable limits in the phase II and phase III trials of tositumomab and iodine I 131 tositumomab. Although approximately 10% of patients treated with tositumomab and iodine I 131 tositumomab developed human-antimouse antibodies, treatment with tositumomab does not preclude the administration of subsequent chimeric antibody therapies. In conclusion, these studies show that tositumomab and iodine I 131 tositumomab treatment is safe and induces high response rates and durable remissions in heavily pretreated patients with low-grade or transformed low-grade NHL. Semin Oncol 30 (suppl 4):22-30. © 2003 Elsevier Inc. All rights reserved.

A clinical and scientific overview of tositumomab and iodine I 131 tositumomab.

The majority of patients with non-Hodgkin's lymphoma (NHL) who respond to conventional chemotherapy will relapse and eventually become refractory to chemotherapy. Each subsequent remission is typically of similar or shorter duration than the last. Recent developments in radioimmunotherapy using monoclonal antibodies to specifically target malignant B cells have yielded promising results in relapsed and refractory NHL patients. The radiolabeled anti-CD20 antibody tositumomab and iodine 131 tositumomab (Bexxar; Corixa Corp, South San Francisco, CA and GlaxoSmithKline, Philadelphia, PA) has been shown to be safe and effective in the treatment of patients with relapsed low-grade (indolent) NHL. Objective responses were achieved in 57% to 71% of patients in phase I to phase III trials, and remission durations were significantly longer in the phase III trial compared with the last remission induced by chemotherapy. In addition, tositumomab and iodine I 131 tositumomab was shown to be effective in the subset analysis of patients with transformed low-grade NHL, which is particularly resistant to conventional therapies. The incidence of transient, nonhematologic adverse events was low and mainly mild to moderate in severity. Hematologic toxicity is the major dose-limiting toxicity associated with radioimmunotherapy; however, patient-specific dosimetry maintained hematologic toxicity within predictable, transient, and manageable limits in the phase II and phase III trials of tositumomab and iodine I 131 tositumomab. Although approximately 10% of patients treated with tositumomab and iodine I 131 tositumomab developed human-antimouse antibodies, treatment with tositumomab does not preclude the administration of subsequent chimeric antibody therapies. In conclusion, these studies show that tositumomab and iodine I 131 tositumomab treatment is safe and induces high response rates and durable remissions in heavily pretreated patients with low-grade or transformed low-grade NHL.

Recent developments in radioimmunotherapy

With the advent of monoclonal antibody techniques, there has been renewed interest in RIT as a treatment modality in patients with a variety of tumour types. There has been a considerable research effort to increase understanding of the scientific basis of such therapy at all levels. Antibody, chelator and radioisotope factors are all the subject of research aimed at producing a potent effector system capable of maximal target cell kill with acceptable normal tissue toxicity. Improved knowledge of the host and tumour factors which limit access to the target cell offers the possibility of optimizing targeting and increasing the therapeutic index. Target cell factors that influence response to low dose rate RIT have been elucidated and provide an opportunity to integrate the treatment modality into radical therapy regimens. A number of Phase I and II trials have now been performed in various tumour types. The results have been promising but, as yet, the prospect of radical RIT remains a research goal. Before it can be achieved it will be necessary to improve specific tumour cell targeting and to increase both the initial dose rates and the total dose delivered to tumour deposits. Until such time, it is likely that RIT will be incorporated into multimodality protocols to deliver a moderate (10-20 Gy) tumour boost, or in an adjuvant setting in patients with minimal residual disease.