A review of tositumomab and I131tositumomab radioimmunotherapy for the treatment of follicular lymphoma

Overview of Current Targeted Anti-Cancer Drugs for Therapy in Onco-Hematology

The upgraded knowledge of tumor biology and microenviroment provides information on differences in neoplastic and normal cells. Thus, the need to target these differences led to the development of novel molecules (targeted therapy) active against the neoplastic cells' inner workings. There are several types of targeted agents, including Small Molecules Inhibitors (SMIs), monoclonal antibodies (mAbs), interfering RNA (iRNA) molecules and microRNA. In the clinical practice, these new medicines generate a multilayered step in pharmacokinetics (PK), which encompasses a broad individual PK variability, and unpredictable outcomes according to the pharmacogenetics (PG) profile of the patient (e.g., cytochrome P450 enzyme), and to patient characteristics such as adherence to treatment and environmental factors. This review focuses on the use of targeted agents in-human phase I/II/III clinical trials in cancer-hematology. Thus, it outlines the up-to-date anticancer drugs suitable for targeted therapies and the most recent finding in pharmacogenomics related to drug response. Besides, a summary assessment of the genotyping costs has been discussed. Targeted therapy seems to be an effective and less toxic therapeutic approach in onco-hematology. The identification of individual PG profile should be a new resource for oncologists to make treatment decisions for the patients to minimize the toxicity and or inefficacy of therapy. This could allow the clinicians to evaluate benefits and restrictions, regarding costs and applicability, of the most suitable pharmacological approach for performing a tailor-made therapy.

Emerging immunotherapy and strategies directly targeting B cells for the treatment of diffuse large B-cell lymphoma

During the last decade, significant prolonged survival in diffusive large B-cell lymphoma (DLBCL) has been observed. The efficacy of initial treatment improved mostly due to addition of a chimeric anti-CD20 monoclonal antibody (rituximab) to standard chemotherapeutic regimens. Moreover, accurate understanding of DLBCL pathogenesis and remarkable progress in gene expression profiling have led to the development of a variety of tumor-specific regimens. Novel agents target directly the pathways involved in signal transduction, lead to apoptosis and cancer cells differentiation. In this article, we mainly focus on new treatment options, such as monoclonal antibodies, tyrosine kinase inhibitors and immunomodulatory drugs, currently investigated in aggressive B-cell lymphoma with particular attention to DLBCL type.

Tositumomab and iodine I 131 tositumomab (Bexaar)

Tositumomab and iodine I 131 tositumomab (Bexaar) therapeutic regimen targets monoclonal antibodies against the CD20 antigen expressed in non-Hodgkin lymphoma. This article reviews the mechanism of action and clinical indications for this regimen.

Economic burden of follicular non-Hodgkin's lymphoma

Follicular non-Hodgkin's lymphoma (FNHL), a slow-growing cancer of the immune system, constitutes about 15-30% of all incident non-Hodgkin's lymphoma in developed countries. Its incidence is rising worldwide. Patients can live many years, but FNHL is considered incurable. We systematically reviewed the English-language MEDLINE-indexed and non-indexed economic literature published in the past 10 years on FNHL, identifying 23 primary economic studies. The economic burden of FNHL is significant, but available data are generally limited to retrospective considerations of hospital-based direct treatment costs, with little information available regarding societal cost of illness. Most direct cost information originates from the US, with one estimate of $US36 000 for the per-patient incremental cost of FNHL care during the first year following diagnosis. The most studied treatment is rituximab, which may offer similar overall costs to fludarabine considering higher resource use with fludarabine complications. Nearly all cost-effectiveness models identified by this review evaluated rituximab for relapsed/refractory FNHL responding to chemotherapy induction. Rituximab is supported as a cost-effective addition to standard chemotherapy by two models in the UK and one in the US, as maintenance therapy instead of stem-cell transplant by one UK model, and as maintenance therapy instead of observation alone by one model each in France, Spain and Canada. The UK National Institute for Health and Clinical Excellence updated guidance on rituximab in February 2008, concluding that it is cost effective when added to induction chemotherapy, and when used as maintenance therapy. No studies of per-patient or national indirect costs of illness were identified, with the only study of indirect costs a Canadian survey documenting lost work productivity. Across all study types identified by our review, the most common focus was on the direct costs of rituximab. As new treatments for FNHL come to market, more real-life cost data are imperative to calculate their relative cost effectiveness.

Follicular lymphoma: today's treatments and tomorrow's targets

Over the past two decades, the incidence of follicular lymphoma has increased. Contemporary treatments include combinations of chemotherapy and monoclonal antibodies, radioimmunotherapy, new targeted agents and stem-cell transplantation. Prognostic tools are becoming more important in helping clinicians and patients decide on the most appropriate therapeutic regimens. Gene expression profiling and biomarkers are promising additions to this armamentarium. When patients do require therapy, the addition of rituximab to chemotherapy seems to improve remission duration and may improve overall survival. Radioimmunotherapy capitalises on the capacity to target radiation directly to malignant cells, and is currently approved for the treatment of relapsed/refractory follicular lymphoma. Further investigation is needed to clarify the role of stem-cell transplantation in follicular lymphoma. Only well-designed clinical trials can provide answers to the many questions that remain regarding the optimal treatment and sequence of treatments for patients with follicular lymphoma.

Radioimmunotherapy for non-Hodgkin's lymphoma

OBJECTIVES

To describe the rationale for radioimmunotherapy as a treatment of non-Hodgkin's lymphoma. To present the similarities and differences in the two radioimmunotherapies and the nursing implications in caring for patients receiving these agents.

DATA SOURCES

Published literature and review of published clinical trials.

CONCLUSION

Radiolabeled monoclonal antibodies bind to specific antigens and provide a means of targeting tumor cells with cytotoxic radioactivity. The infusion of radiolabeled monoclonal antibodies requires an understanding of antibody therapy, radiation therapy, and principles of time, distance, and shielding.

IMPLICATIONS FOR NURSING PRACTICE

As the use of radioimmunotherapy grows, nurses must be aware of the background for, logistics of, and follow-up required for patients receiving this form of radiation treatment.

Novel approaches to the immunotherapy of B-cell malignancies: An update

Immunotherapy of cancer includes both active and adoptive, or passive, forms of immunization to target and eradicate malignant B cells in the host. Advances in the understanding of immunology and tumor-cell evasion of the host immune system, coupled with improved technologies to manipulate immune effectors and tumors, have led to a wide array of novel therapies for B-cell malignancies. As a result, investigators have proposed and tested numerous vaccine strategies able to elicit immune responses to tumor antigens. Furthermore, novel approaches to B-cell-targeted antibody therapies hold promise in advancing this line of treatment, and efficient gene transfer technologies have enabled investigators to manipulate immune effector cells to enhance antitumor activity. Significantly, an increasing number of these novel immune-based therapies are being applied to the clinical setting. Whether findings from these clinical trials, in combination with further preclinical studies, will ultimately translate into improved survival of patients with B-cell malignancies remains to be seen.

Current controversies in follicular lymphoma

Follicular lymphoma (FL) is characterized by its responsiveness to initial therapy, a pattern of repeated relapses, and a tendency for histologic progression to a process resembling diffuse, large B-cell lymphoma. Treatment decisions are complicated by the many effective options now available including combinations of conventional chemotherapy and monoclonal antibody, radioimmunotherapy, new targeted agents, and autologous and allogeneic stem cell transplantation. For selected patients, "watch and wait" or involved field irradiation may still be the most appropriate strategy. When therapy is required, a combination of rituximab and conventional chemotherapy results in improved outcomes compared to chemotherapy alone. Radioimmunotherapy alone or in combination with chemotherapy is an attractive strategy for patients with relapsed disease and may prove to be appropriate first line therapy. The role of stem cell transplant in FL requires further investigation. Novel agents with varied mechanisms of action continue to be developed. Enrollment of patients into clinical trials designed to address the many unanswered questions in FL is essential to improving clinical outcomes.