Ofatumumab for newly diagnosed and relapsed/refractory chronic lymphocytic leukemia

Emerging trends and therapeutic applications of monoclonal antibodies

Monoclonal antibodies (mAbs) are being used to prevent, detect, and treat a broad spectrum of malignancies and infectious and autoimmune diseases. Over the past few years, the market for mAbs has grown exponentially. They have become a significant part of many pharmaceutical product lines, and more than 250 therapeutic mAbs are undergoing clinical trials. Ever since the advent of hybridoma technology, antibody-based therapeutics were realized using murine antibodies which further progressed into humanized and fully human antibodies, reducing the risk of immunogenicity. Some of the benefits of using mAbs over conventional drugs include a drastic reduction in the chances of adverse reactions, interactions between drugs, and targeting specific proteins. While antibodies are very efficient, their higher production costs impede the process of commercialization. However, their cost factor has been improved by developing biosimilar antibodies, which are affordable versions of therapeutic antibodies. Along with biosimilars, innovations in antibody engineering have helped to design bio-better antibodies with improved efficacy than the conventional ones. These novel mAb-based therapeutics are set to revolutionize existing drug therapies targeting a wide spectrum of diseases, thereby meeting several unmet medical needs. In the future, mAbs generated by applying next-generation sequencing (NGS) are expected to become a powerful tool in clinical therapeutics. This article describes the methods of mAb production, pre-clinical and clinical development of mAbs, approved indications targeted by mAbs, and novel developments in the field of mAb research.

Pharmacological management of chronic lymphocytic leukemia: current and emerging therapies

INTRODUCTION

Chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL), characterized by its monoclonal lymphoproliferative nature, is an indolent but incurable malignancy. The treatment landscape of CLL/SLL has drastically transformed in the last decade since the introduction of targeted therapy and immune-effector T-cell therapy. The paradigm shift from chemoimmunotherapy to targeted and cellular therapies was largely driven by improved efficacy and safety. With the success of targeted therapies, novel agents and combinations are rapidly emerging on the horizon.

AREAS COVERED

In this review, we will summarize clinical evidence supporting current and emerging therapies with emphasis on investigational therapies and novel combinations of commercial agents. Clinical trials were identified via clinicaltrials.gov, and a PubMed literature search was last performed in June 2024.

EXPERT OPINION

With the availability of more effective and better-tolerated treatments for CLL/SLL, the role of early intervention should be further investigated due to its potential to alter disease course, delay progression, and improve overall survival rates. With many highly effective agents and combinations expected to become commercially available, attention to safety profiles and careful selection of patients for each treatment will be critical, with consideration of comorbidities, logistical issues, and financial burden of treatment.

Shedding light on the side effects of immunotherapies used for leukemia: an updated review of the literature

INTRODUCTION

Leukemia is an abnormal clonal development of leukemic cells originating from the bone marrow, which is widely known for its significant prevalence and mortality rate. Chemotherapy, surgery, radiation, and combination therapies have been its routine therapeutic methods; however, the advent of cancer immunotherapy is known as revolutionary for its higher efficacy and lesser toxicity.

AREAS COVERED

Immunotherapy boosts the body's immune system by using components from other living organisms. Although immunotherapy seems to be safer than chemotherapy, many studies have noticed different immune-related side effects in various body systems (e.g. cardiovascular, neurologic) which we have reviewed in this investigation as the main goal. We tried to describe immunotherapy-related side effects in human body systems in detail.

EXPERT OPINION

Being aware of these side effects leads to better clinical decision-making for each individual, and a one-step-ahead management in case of occurrence. We also briefly discussed the role of immunotherapy in treating leukemia as one of the most prevalent cancers in children and tried to emphasize that it is crucial to monitor adverse events as they may remain obscure until adolescence.

Intravenous ofatumumab treatment of multiple sclerosis and related disorders: An observational study

BACKGROUND

Ofatumumab is an anti-CD20 monoclonal antibody approved for subcutaneous administration for the treatment of relapsing multiple sclerosis (MS), but intravenously administered ofatumumab has been investigated in a phase 2 trial and used off-label. The objective of the present study was to assess disease activity and side effects in relation to longer-term intravenous ofatumumab treatment of MS and related disorders.

METHODS

We conducted a retrospective study of patients treated off-label with intravenous ofatumumab for MS, neuromyelitis optica spectrum disease (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) at the Danish Multiple Sclerosis Center. Data was retrieved from the Danish Multiple Sclerosis Registry and through medical chart review.

RESULTS

Fifty patients were identified with a median treatment duration of 2.2 years. Annualized relapse rate decreased from 1.03 at baseline to 0.38 during ofatumumab treatment. At 24 months, the probability of having experienced a relapse was 55% and confirmed disability worsening 7%. Frequency of infusion-related reactions was 86% during the first infusion and 42% during the last infusion. Six experienced infections requiring hospitalization.

CONCLUSION

Our data indicate a reduction of relapse frequency, stabilization of disability worsening and an acceptable safety profile, although we observed a higher frequency of infusion reactions compared to data from other intravenously administered anti-CD20 monoclonal antibodies. The study supports a class effect of anti-CD20 monoclonal antibodies and the hypothesis that complement activation may be associated to a higher frequency of infusion related reactions.

Second-generation immunotherapeutics in multiple sclerosis: can we discard their precursors?

Options for disease-modifying therapies in multiple sclerosis have increased over the past two decades. Among these innovations are interferon-β, glatiramer acetate, fumaric acid and dihydroorotate dehydrogenase inhibitors, an antibody targeting the migration of immune cells, a compound that traps immune cells in lymphoid organs by sphingosine 1-phosphate receptor (S1PR) modulation and immune-reconstitution therapies. Second-generation drugs such as pegylated interferon-β, advanced CD20 depleting antibodies, more-specific S1PR modulators and new formulations have been developed to achieve higher efficacy while exhibiting fewer side effects. In this review, we address the shortcomings of the parent drugs, present the pros and cons of the second-generation therapies and summarize upcoming developments in the field of immunotherapy for multiple sclerosis.

Anti-CD20 Agents for Multiple Sclerosis: Spotlight on Ocrelizumab and Ofatumumab

Until recently, in the pathogenesis of Multiple Sclerosis (MS), the contribution of B cells has been largely underestimated, and the disease was considered a T-cell-mediated disorder. However, newer evidence shows that B cells play a crucial role in the pathogenesis of MS via antigen-driven autoantibody responses and through the cross regulation of T-helper cells. As B cells express the surface molecule CD20 at all points of differentiation, it provides a specific target for monoclonal antibodies, and the development and clinical testing of anti-CD20 antibody treatments for MS have been successful. After some observations, some small clinical trials found positive effects for the first anti-CD20 therapeutic rituximab in MS; newer agents have been specifically evaluated, resulting in the development of ocrelizumab and ofatumumab. Ocrelizumab, a humanized anti-CD20 monoclonal antibody, was approved in March 2017 by the Food and Drug Administration (FDA) and is also the first proven therapy to reduce disability progression in primary progressive MS. This is particularly significant considering that disease-modifying treatment options are few for both primary and secondary progressive MS. Ofatumumab, a fully human anti-CD20 monoclonal antibody, that binds a distinct epitope, has been further investigated in phase 3 trials for relapsing forms of MS. In this review, we discuss in detail these two anti-CD20 agents and their advent for treatment of MS.

Monoclonal antibodies in the treatment of multiple sclerosis: emergence of B-cell-targeted therapies

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS, and one of the most common causes of disability in young adults. Over the last decade, new disease-modifying therapies have emerged, including monoclonal antibodies (mAbs) that provide highly targeted therapies with greater efficacy than platform therapies. In particular, monoclonal antibodies directed against CD20-positive B cells have shown remarkable results in recent clinical trials and renewed interest in the mechanism of B cell-depleting therapies to ameliorate relapse activity and progression in MS. Here, we review the mechanisms of action and clinical evidence of approved and emerging mAbs, with a focus on B cell-targeted therapies.

Haematological malignancies: at the forefront of immunotherapeutic innovation

The recent successes of cancer immunotherapies have stimulated interest in the potential widespread application of these approaches; haematological malignancies have provided both initial proofs of concept and an informative testing ground for various immune-based therapeutics. The immune-cell origin of many of the blood malignancies provides a unique opportunity both to understand the mechanisms of cancer immune responsiveness and immune evasion, and to exploit these mechanisms for therapeutic purposes.

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.

Ofatumumab, the first human anti-CD20 monoclonal antibody for the treatment of B cell hematologic malignancies

Ofatumumab is the first human anti-CD20 monoclonal antibody to be approved for patients in the United States and the European Union. Ofatumumab received accelerated approval from the U.S. Food and Drug Administration in October 2009 and was granted a conditional marketing authorization by the European Medicines Agency in April 2010 for the treatment of patients with chronic lymphocytic leukemia (CLL) refractory to fludarabine and alemtuzumab, based on interim results of a pivotal phase 2 trial. Preliminary positive results for ofatumumab in combination with chemotherapy in patients with CLL are currently being confirmed in larger randomized trials in both the frontline setting and the relapsed/refractory setting. Ofatumumab has also shown potential in treating B cell non-Hodgkin's lymphoma, such as follicular lymphoma (FL), diffuse large B cell lymphoma (DLBCL), and Waldenström's macroglobulinemia. Additional trials are ongoing to confirm activity of ofatumumab as monotherapy and in combination with chemotherapy in patients with FL or DLBCL.