Real-world use and acceptance of biosimilar monoclonal antibodies of rituximab in oncology practice in the USA

Aim: To describe treatment patterns and patient and provider characteristics associated with the recently introduced biosimilar rituximab-pvvr. Methods: This retrospective analysis included adult patients with one or more claims for rituximab-pvvr, with an index date of 23 January 2020 and a study period covering 1 January 2019-31 July 2020. Results: Of 249 patients included, the most common rituximab-pvvr indications were non-Hodgkin's lymphoma (77.5%) and chronic lymphocytic leukemia (11.2%). Some patients with non-Hodgkin's lymphoma (42.5%) and chronic lymphocytic leukemia (39.3%) switched to rituximab-pvvr from the reference product or another rituximab biosimilar. Most patients were aged ≥65 years (63.5%) and were male (54.6%). Most (59.0%) rituximab-pvvr prescribers practiced in the south of the USA. Conclusion: Utilization occurred in approved and extrapolated indications. These preliminary findings suggest switching between reference product and rituximab biosimilars; rituximab-pvvr combination regimens are being adopted in real-world oncology practice.

Ofatumumab for post-transplant lymphoproliferative disorder

Posttransplant lymphoproliferative disorder (PTLD) includes a range of abnormal lymphoid proliferation following solid organ or allogeneic hematopoietic stem cell transplantation (HSCT), often associated with Epstein-Barr virus (EBV) infection. Treatment generally incudes rituximab, a chimeric monoclonal antibody directed against CD20. Here we present a 56-year-old woman with EBV-associated PTLD following allogeneic HSCT who was intolerant of rituximab. The patient was instead treated with ofatumumab, a fully human monoclonal antibody directed against CD20, with significant response in EBV viral load and lymphadenopathy. Ofatumumab could represent an important treatment option for patients unable to tolerate rituximab.

Anti-CD20 monoclonal antibodies: reviewing a revolution

Since the inception of rituximab in the 1990s, anti-CD20 monoclonal antibodies have revolutionised the treatment of B cell hematological malignancies and have become a cornerstone of modern gold-standard practice. Additionally, the potent efficacy of these agents in depleting the B cell compartment has been used in the management of a broad array of autoimmune diseases. Multiple iterations of these agents have been investigated and are routinely used in clinical practice. In this review, we will discuss the physiology of CD20 and its attractiveness as a therapeutic target, as well as the pharmacology, pre-clinical and clinical data for the major anti-CD20 monoclonal antibodies: rituximab, obinutuzumab and ofatumumab.

Biosimilars in oncology and inflammatory diseases: current and future considerations for clinicians in Latin America

Biological therapies have revolutionized the treatment of several cancers and systemic immune-mediated inflammatory conditions. Expiry of patents protecting a number of biologics has provided the opportunity to commercialize highly similar versions, known as biosimilars. Biosimilars are approved by regulatory agencies via an independent pathway that requires extensive head-to-head comparison with the originator product. Biosimilars have the potential to provide savings to healthcare systems and expand patient access to biologics. In Latin American countries, regulatory frameworks for biosimilar approval have been introduced in recent years, and biosimilars of monoclonal antibody and fusion protein therapies are now emerging. However, the situation in this region is complicated by the presence of "non-comparable biotherapeutics" (also known as "intended copies"), which have not been rigorously compared with the originator product. We review the considerations for clinicians in Latin American countries, focusing on monoclonal antibody biosimilars relevant to oncology, rheumatology, gastroenterology, and dermatology.

Biosimilars for the Treatment of Cancer: A Systematic Review of Published Evidence

Background

Biologic treatments for cancer continue to place a significant economic burden on healthcare stakeholders. Biosimilar therapies may help reduce this burden through cost savings, thereby increasing patient access.

Objectives

The purpose of this study was to collate all published data to assess the weight of available evidence (quantity and quality) for proposed monoclonal antibody biosimilars and intended copies, for the treatment of cancer.

Methods

MEDLINE^®, Embase^®, and ISI Web of Science^® databases were searched to September 2015. Conference proceedings (17) were searched (2012 to July 2015). Searches of the United States National Library of Medicine ClinicalTrials.gov registry were also conducted. Risk of bias assessments were undertaken to assess data strength and validity.

Results

Proposed biosimilars were identified in 23 studies (36 publications) in oncology and ten studies in 14 publications in oncology and chronic inflammatory diseases for bevacizumab, rituximab, and trastuzumab originators. Based on our review of the included published studies, and as inferred from the conclusions of study authors, the identified proposed biosimilars exhibit close similarity to their originators. Published data were also retrieved on intended copies of rituximab. It remains unclear what role these agents may have, as publications on rigorous clinical studies are lacking for these molecules.

Conclusion

While biosimilar products have the potential to improve patient access to important biologic therapies, robust evidence of outcomes for monoclonal antibody biosimilars in treating cancer patients, including data from comparative efficacy and safety trials, is not yet available in the published literature. Significant data gaps exist, particularly for intended copies, which reinforces the need to maintain a clear differentiation between these molecules and true biosimilars. As more biosimilars become available for use, it will be important for stakeholders to understand fully the robustness of overall evidence used to demonstrate biosimilarity and gain regulatory approval.

Electronic supplementary material

The online version of this article (doi:10.1007/s40259-016-0207-0) contains supplementary material, which is available to authorized users.

Comparability of Antibody-Mediated Cell Killing Activity Between a Proposed Biosimilar RTXM83 and the Originator Rituximab

BACKGROUND

Biosimilars are described as biological products that resemble the structure of original biologic therapeutic products, with no clinically meaningful differences in terms of safety and effectiveness from the original. A wide range of biosimilars are under development or are already licensed in many countries. Biosimilars are earning acceptance and becoming a reality for immunotherapy treatments mainly based on the alternatives for the commercial anti-CD20 monoclonal antibody rituximab. The most important mechanism of action reported for this antibody is the induction of antibody-dependent cell cytotoxicity (ADCC), which is associated with the polymorphisms present at the 158 position in the IgG receptor FcγRIIIa.

OBJECTIVE

The aim of the study was to validate the functional comparability between the proposed rituximab biosimilar RTXM83 and the original product. To achieve this we assessed the binding capacity and ADCC induction of this biosimilar, taking into account the different FcγRIIIa-158 polymorphisms.

METHODS

Binding capacity was evaluated by flow cytometry using CD20 positive cells and a wide range of antibody concentrations. The FcγRIIIa-158 polymorphisms were analyzed by polymerase chain reaction (PCR) followed by allele-specific restriction enzyme digestion. ADCC was measured by a colorimetric lactate dehydrogenase-release assay, using effector cells from donors with different FcγRIIIa-158 polymorphisms.

RESULTS

Binding capacity assay showed no differences between both products. Regarding ADCC, a similar relative potency was obtained between both antibodies, showing a higher response for the FcγRIIIa-158 valine/valine (V/V) polymorphism compared to the phenylalanine/phenylalanine (F/F), for both rituximab and RTXM83.

CONCLUSION

Our data strongly suggest the biocomparability between the proposed biosimilar and the originator rituximab, in antibody recognition and ADCC activity. Additionally, our results suggest that donors with the FcγRIIIa-158V/V polymorphism induce a higher ADCC response, as has been reported.

Monoclonal Antibody and Fusion Protein Biosimilars Across Therapeutic Areas: A Systematic Review of Published Evidence

BACKGROUND

Despite regulatory efforts to formalize guidance policies on biosimilars, there remains a need to educate healthcare stakeholders on the acknowledged definition of biosimilarity and the data that underpin it.

OBJECTIVES

The objectives of the study were to systematically collate published data for monoclonal antibodies and fusion protein biosimilars indicated for cancer, chronic inflammatory diseases, and other indications, and to explore differences in the type and weight (quantity and quality) of available evidence.

METHODS

MEDLINE, Embase, and ISI Web of Science were searched to September 2015. Conference proceedings (n = 17) were searched 2012 to July 2015. Included studies were categorized by originator, study type, and indication. To assess data strength and validity, risk of bias assessments were undertaken.

RESULTS

Across therapeutic areas, 43 named (marketed or proposed) biosimilars were identified for adalimumab, abciximab, bevacizumab, etanercept, infliximab, omalizumab, ranibizumab, rituximab, and trastuzumab originators. Infliximab CT-P13, SB2, and etanercept SB4 biosimilars have the greatest amount of published evidence of similarity with their originators, based on results of clinical studies involving larger numbers of patients or healthy subjects (N = 1405, 743, and 734, respectively). Published data were also retrieved for marketed intended copies of etanercept and rituximab.

CONCLUSIONS

This unbiased synthesis of the literature exposed significant differences in the extent of published evidence between molecules at preclinical, clinical, and post-marketing stages of development, providing clinicians and payers with a consolidated view of the available data and remaining gaps.

Role of Rituximab and Rituximab Biosimilars in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL), an aggressive non-Hodgkin lymphoma (NHL), is the most-common subtype of NHL. DLBCL can be classified into at least 3 major immunologically distinct types, which contributes to considerable variation in disease prognosis and response to treatment. DLBCL potentially is curable, even when diagnosed at advanced stages. The current standard of care for most patients with untreated or relapsed/refractory DLBCL is chemoimmunotherapy containing rituximab, an anti-CD20 monoclonal antibody. With advanced understanding of the molecular mechanisms involved in the pathogenesis of DLBCL and specific signaling pathways that are activated in different subtypes, potential new therapeutic targets have been identified, some of which are at the late stages of clinical development. This review summarizes the critical role of rituximab in the current standard of care treatment for DLBCL and discusses why rituximab is likely to remain an important component of treatment options for DLBCL in the foreseeable future. In addition, current and emerging therapeutic agents, including potential benefits of rituximab biosimilars, for patients with DLBCL are discussed. The advent of rituximab biosimilars may facilitate accessibility of rituximab-based chemotherapies to patients with DLBCL and has potential cost-saving benefits for healthcare systems globally.