Biosimilars lining up to compete with Herceptin--opportunity knocks

Locally Advanced Breast Cancer—A Narrative Review of Management in the Indian Scenario

Locally advanced breast cancer (LABC) forms a significant proportion of the total breast cancer (BC) burden in the country. It is a heterogeneous entity, encompassing a variety of presentations indicative of advanced disease. The standard of care for the treatment of LABC is multimodal, involving chemotherapy, surgery, radiation, and/or hormonal therapy. With improved understanding of the biology of BC, addition of newer agents of systemic therapy to our armamentarium, advances in surgical techniques and radiation delivery, clinicians are now able to tailor treatment according to the individual and consider a more conservative approach to management (in contrast to a mandatory radical mastectomy, decades ago), disease biology, and stage permitting with better survival outcomes. Here, we review all the treatment modalities and options available to aid a clinician in formulating an optimal treatment plan for a patient presenting with LABC and also how best to tailor the treatment to enable cost effectiveness in the Indian setting.

Cell Populations Expressing Stemness-Associated Markers in Vascular Anomalies

Treatment of vascular anomalies (VAs) is mostly empirical and, in many instances unsatisfactory, as the pathogeneses of these heterogeneous conditions remain largely unknown. There is emerging evidence of the presence of cell populations expressing stemness-associated markers within many types of vascular tumors and vascular malformations. The presence of these populations in VAs is supported, in part, by the observed clinical effect of the mTOR inhibitor, sirolimus, that regulates differentiation of embryonic stem cells (ESCs). The discovery of the central role of the renin-angiotensin system (RAS) in regulating stem cells in infantile hemangioma (IH) provides a plausible explanation for its spontaneous and accelerated involution induced by β-blockers and ACE inhibitors. Recent work on targeting IH stem cells by inhibiting the transcription factor SOX18 using the stereoisomer R(+) propranolol, independent of β-adrenergic blockade, opens up exciting opportunities for novel treatment of IH without the β-adrenergic blockade-related side effects. Gene mutations have been identified in several VAs, involving mainly the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways. Existing cancer therapies that target these pathways engenders the exciting possibility of repurposing these agents for challenging VAs, with early results demonstrating clinical efficacy. However, there are several shortcomings with this approach, including the treatment cost, side effects, emergence of treatment resistance and unknown long-term effects in young patients. The presence of populations expressing stemness-associated markers, including transcription factors involved in the generation of induced pluripotent stem cells (iPSCs), in different types of VAs, suggests the possible role of stem cell pathways in their pathogenesis. Components of the RAS are expressed by cell populations expressing stemness-associated markers in different types of VAs. The gene mutations affecting the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways interact with different components of the RAS, which may influence cell populations expressing stemness-associated markers within VAs. The potential of targeting these populations by manipulating the RAS using repurposed, low-cost and commonly available oral medications, warrants further investigation. This review presents the accumulating evidence demonstrating the presence of stemness-associated markers in VAs, their expression of the RAS, and their interaction with gene mutations affecting the PI3K/AKT/mTOR and/or the Ras/RAF/MEK/ERK pathways, in the pathogenesis of VAs.

Screening and selection strategy for the establishment of biosimilar to trastuzumab-expressing CHO-K1 cell lines

The high prices of biopharmaceuticals or biologics used in the treatment of many diseases limit the access of patients to these novel therapies. One example is the monoclonal antibody trastuzumab, successfully used for breast cancer treatment. An economic alternative is the generation of biosimilars to these expensive biopharmaceuticals. Since antibody therapies may require large doses over a long period of time, robust platforms and strategies for cell line development are essential for the generation of recombinant cell lines with higher levels of expression. Here, we obtained trastuzumab-expressing CHO-K1 cells through a screening and selection strategy that combined the use of host cells pre-adapted to protein-free media and suspension culture and lentiviral vectors. The results demonstrated that the early screening strategy obtained recombinant CHO-K1 cell populations with higher enrichment of IgG-expressing cells. Moreover, the measurement of intracellular heavy chain polypeptide by flow cytometry was a useful metric to characterize the homogeneity of cell population, and our results suggest this could be used to predict the expression levels of monoclonal antibodies in early stages of cell line development. Additionally, we propose an approach using 25 cm² T-flasks in suspension and shaking culture conditions as a screening tool to identify high producing cell lines. Finally, trastuzumab-expressing CHO-K1 clones were generated and characterized by batch culture, and preliminary results related to HER2-recognition capacity were successful. Further optimization of elements such as gene optimization, vector selection, type of amplification/selection system, cell culture media composition, in combination with this strategy will allow obtaining high producing clones.

Biological Characterization of SB3, a Trastuzumab Biosimilar, and the Influence of Changes in Reference Product Characteristics on the Similarity Assessment

Background

SB3 has been developed as a trastuzumab biosimilar, a therapeutic monoclonal antibody targeted to human epidermal growth factor receptor 2 (HER2), and approved by the European Commission and United States (US) Food and Drug Administration (FDA). During the developmental period of a biosimilar, setting an appropriate quality target is critical for assessing the similarity of the biosimilar product to the reference product. A stepwise approach should be taken to assessing similarity, beginning with extensive characterization of the reference product to establish the quality target.

Objective

In this study, we evaluated the similarity of SB3 to the reference product and the impact of changes in the biological profile of the reference product on similarity assessment.

Methods

Analytical similarity was assessed with defined test procedures in terms of critical quality attributes (CQAs) that could affect efficacy, potency, and safety, as well as for the non-CQAs that are related to process consistency. The quality target was established using up to 154 lots of European Union (EU)- and US-sourced Herceptin^® (reference product), analyzed during the developmental period of SB3.

Results

Trends of the EU- and US-sourced reference product showed that the biological profile exhibited two marked changes for Fc-related attributes, and then recovered to pre-change quality level. Since the similarity range set by pre-change lots was considered most relevant, the changed lots were excluded from establishing the similarity range, which resulted in tightened acceptance criteria. As shown in the results of similarity assessment using the stringent quality target ranges, SB3 exhibits highly similar functional activities compared to the reference product in terms of both CQAs and non-CQAs.

Conclusion

SB3 has been developed as a trastuzumab biosimilar approved in the EU and USA, and its manufacturing process is deemed to be robust and well-controlled within stringent quality target ranges.

The arrival of biosimilar monoclonal antibodies in oncology: clinical studies for trastuzumab biosimilars

The monoclonal antibody trastuzumab (Herceptin®), which targets the human epidermal growth factor receptor 2 (HER2), is approved for the treatment of early breast and advanced breast and gastric cancer in which HER2 is overexpressed. Several biosimilar versions of trastuzumab are expected to enter the European market over the course of 2018 and 2019. The biosimilar development pathway consists of a comprehensive comparability exercise between the biosimilar candidate and the reference product, primarily focussing on data from analytical studies. Clinical studies for biosimilar candidates follow a different design to those for a new biological, as the aim is not to independently establish clinical benefit, but to confirm biosimilarity between the two agents. The different trastuzumab biosimilar candidates have followed diverse pathways in their clinical development, with differences in clinical trial design (equivalence or non-inferiority design), patient population (those with metastatic or early breast cancer) and endpoint (overall response rate or pathological complete response). These differences in approach in phase 3 testing must be viewed in the totality of evidence demonstrating biosimilarity. Adequate information on the biosimilar approval pathway, the nature of the biosimilarity exercise and how the clinical development of a biosimilar is tailored to meet the licensing requirements can help informed decision making in clinical practice.

Randomised clinical endpoint studies for trastuzumab biosimilars: a systematic review

PURPOSE

Uptake of biosimilars depends on clinicians and patients having confidence in the evidential basis of marketing approval. The aim of this systematic review was to assess the evidential role of randomised clinical endpoint studies in the marketing approval of trastuzumab biosimilars.

METHODS

We searched PubMed for any published reports of randomised studies associated with the five trastuzumab biosimilars approved by the EMA, as on 31 January 2019. We also searched ClinicalTrials.gov for any ongoing studies for other trastuzumab biosimilars.

RESULTS

We identified eight published papers or abstracts for seven randomised clinical endpoint studies for five trastuzumab biosimilars approved by the EMA: four studies in the neoadjuvant setting and three in the first-line metastatic setting. Another six unpublished or ongoing studies for other trastuzumab biosimilars were identified via ClinicalTrials.gov. According to GRADE, and considered in isolation, the randomised studies would be categorised as low-quality evidence because of the use of surrogate endpoints and the small sample size. However, according to GRADE, the totality-of-evidence for each of the five approved trastuzumab biosimilars would be categorised as high quality in that further data would be unlikely to change the conclusion that each biosimilar was not different from Herceptin in any clinically important way.

CONCLUSION

The pivotal data for each marketing approval was not the randomised clinical endpoint study, but the in vitro analytic characterisation. Regulatory confidence in in vitro analytic characterisation stems from years of experience with manufacturing changes for originator biological medicines. This emphasis on in vitro data, as the most sensitive way to detect clinically important differences, will be a new way of thinking for many oncologists.

Nursing Roles: Clinical Implications Regarding Trends, Administration, and Education for Biosimilars in Oncology Practice

BACKGROUND

With the advent of biosimilars into the U.S. healthcare market, knowledge deficits exist for nurses and patients regarding the regulatory approval process and key nursing considerations for each of these new medications.

OBJECTIVES

This article provides essential clinical information for oncology nurses who are directly involved in patient care who will be administering U.S. Food and Drug Administration (FDA)-approved biosimilars for oncologic use. Oncology nurses must be informed on their therapeutic uses, mechanisms of action, and administration considerations.

METHODS

An overview of biosimilars in the United States is given, and each FDA-approved oncology biosimilar medication is described in detail.

FINDINGS

Oncology biosimilars are safe and effective treatment options that may increase patient access, decrease healthcare costs through competition, and improve the lives of patients with certain malignancies. Nurses are in key roles in patient care to foster the transition from previously patented, branded, and expensive medications to biosimilars that can achieve the same desired effects for a lower cost.

Efficacy and safety of the trastuzumab biosimilar candidate CT-P6

Trastuzumab is an anti-HER2 monoclonal antibody indicated for the treatment of HER2-overexpressing breast and gastric cancers. Despite its clinical efficacy, access to the biological drug can be limited due to its relatively high price, especially in low-income countries. CT-P6 (Herzuma®) is a biosimilar candidate of originator or ‘reference’ trastuzumab, which may offer an alternative, more cost-effective treatment option. This article reviews the unmet needs of patients eligible to receive reference trastuzumab and the potential place of a trastuzumab biosimilar within the market. The review also summarizes the available clinical evidence supporting the biosimilarity of CT-P6 and reference trastuzumab with respect to pharmacokinetics, efficacy, safety and immunogenicity.

ABP 980: promising trastuzumab biosimilar for HER2-positive breast cancer

INTRODUCTION

Approval of the HER2-targeted antibody trastuzumab dramatically improved outcomes for patients with HER2-positive breast cancer. Multiple trastuzumab biosimilars, including ABP 980, are in clinical development. Biosimilars are not identical to the reference biologic, but exhibit equivalence and safety in analytical and clinical studies. Areas covered: A brief introduction to trastuzumab, overview of trastuzumab biosimilars, and detailed review of ABP 980 preclinical and clinical studies are included. We searched PubMed and 2016-2017 ASCO and ESMO conference proceedings for 'ABP 980' or 'trastuzumab biosimilar'. 'ABP 980 and breast cancer' or 'trastuzumab biosimilar and breast cancer' were used to search clinicaltrials.gov for phase III trials. Analytical studies of ABP 980 pharmacokinetics (PK) or pharmacodynamics (PD), phase I studies of ABP 980 safety and PK/PD, and phase III studies of clinical efficacy vs trastuzumab are included. Expert opinion: Questions remain regarding long-term impact of biosimilars on overall healthcare costs, insurance coverage of multiple approved biosimilars, and extensive clinical safety and efficacy follow-up. By producing a competitive market, trastuzumab biosimilars are anticipated to improve access to standard of care therapies, although real-world evidence remains to be obtained. Increased global access to HER2-targeted therapy may eventually alter the landscape of breast cancer and survival rates.

Budget Impact Analysis of Biosimilar Trastuzumab for the Treatment of Breast Cancer in Croatia

BACKGROUND AND OBJECTIVE

Breast cancer is the most common cancer in women and has considerable impact on healthcare budgets and patients' quality of life. Trastuzumab (Herceptin^®) is a monoclonal antibody directed against the human epidermal growth factor receptor (HER2) for the treatment of breast cancer. Several trastuzumab biosimilars are currently in development. In 2015, trastuzumab was the drug with the highest financial consumption among all drugs in Croatia. This model estimates the 1-year budget impact of the introduction of biosimilar trastuzumab in Croatia.

METHODS

A budget impact model, based on approvals for trastuzumab treatment in 2015, was developed for the introduction of biosimilars. Two biosimilar scenarios were developed: biosimilar scenario 1, based on all approvals in 2015, and biosimilar scenario 2, based on approvals after February 2015 and the reimbursement of the subcutaneous formulation of trastuzumab in Croatia. Only trastuzumab-naïve patients and drug-acquisition costs were used in the model. Uptake of biosimilar was assumed at 50 %. Scenarios were calculated with price discounts of 15, 25 and 35 %. The robustness of the model was tested by extensive sensitivity analyses.

RESULTS

The projected drug cost savings from the introduction of biosimilar trastuzumab range from €0.26 million (scenario 2, 15 % price discount) to €0.69 million (scenario 1, 35 % price discount). If budget savings were reinvested to treat additional patients with trastuzumab, 14 (scenario 2, 15 % price discount) to 47 (scenario 1, 35 % price discount) additional patients could be treated. Sensitivity analyses showed that the incidence of breast cancer had the highest impact on the model, with a 10 % decrease in incidence leading to an 11.3 % decrease in projected savings.

CONCLUSION

The introduction of biosimilar trastuzumab could lead to significant drug cost savings in Croatia.

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.

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.

Adjuvant Trastuzumab in HER2-Positive Early Breast Cancer by Age and Hormone Receptor Status: A Cost-Utility Analysis

BACKGROUND

The anti-human epidermal growth factor receptor 2 (HER2) monoclonal antibody trastuzumab improves outcomes in patients with node-positive HER2+ early breast cancer. Given trastuzumab's high cost, we aimed to estimate its cost-effectiveness by heterogeneity in age and estrogen receptor (ER) and progesterone receptor (PR) status, which has previously been unexplored, to assist prioritisation.

METHODS AND FINDINGS

A cost-utility analysis was performed using a Markov macro-simulation model, with a lifetime horizon, comparing a 12-mo regimen of trastuzumab with chemotherapy alone using the latest (2014) effectiveness measures from landmark randomised trials. A New Zealand (NZ) health system perspective was adopted, employing high-quality national administrative data. Incremental quality-adjusted life-years for trastuzumab versus chemotherapy alone are two times higher (2.33 times for the age group 50-54 y; 95% CI 2.29-2.37) for the worst prognosis (ER-/PR-) subtype compared to the best prognosis (ER+/PR+) subtype, causing incremental cost-effectiveness ratios (ICERs) for the former to be less than half those of the latter for the age groups from 25-29 to 90-94 y (0.44 times for the age group 50-54 y; 95% CI 0.43-0.45). If we were to strictly apply an arbitrary cost-effectiveness threshold equal to the NZ gross domestic product per capita (2011 purchasing power parity [PPP]-adjusted: US$30,300; €23,700; £21,200), our study suggests that trastuzumab (2011 PPP-adjusted US$45,400/€35,900/£21,900 for 1 y at formulary prices) may not be cost-effective for ER+ (which are 61% of all) node-positive HER2+ early breast cancer patients but cost-effective for ER-/PR- subtypes (37% of all cases) to age 69 y. Market entry of trastuzumab biosimilars will likely reduce the ICER to below this threshold for premenopausal ER+/PR- cancer but not for ER+/PR+ cancer. Sensitivity analysis using the best-case effectiveness measure for ER+ cancer had the same result. A key limitation was a lack of treatment-effect data by hormone receptor subtype. Heterogeneity was restricted to age and hormone receptor status; tumour size/grade heterogeneity could be explored in future work.

CONCLUSIONS

This study highlights how cost-effectiveness can vary greatly by heterogeneity in age and hormone receptor subtype. Resource allocation and licensing of subsidised therapies such as trastuzumab should consider demographic and clinical heterogeneity; there is currently a profound disconnect between how funding decisions are made (largely agnostic to heterogeneity) and the principles of personalised medicine.