Why is there no biosimilar of Erbitux®?

Monoclonal antibody (mAb)-based therapies have been a major advance in oncology patient care, even though they represent a significant healthcare cost. Biosimilars, launched in Europe in 2004 are an economically attractive alternative to expensive originator biological drugs. They also increase the competitiveness of pharmaceutical development. This article focuses on the case of Erbitux® (cetuximab). This anti-EGFR (Epidermal Growth Factor Receptor) monoclonal antibody is indicated for metastatic colorectal cancer (2004) and squamous cell carcinoma of the head and neck (2006). However, despite the expiration of the patent in Europe in 2014 and estimated annual sales of 1.681 million US dollars in 2022, Erbitux® has not yet faced any approved biosimilar challenges in the United States or in Europe. Here, we outline the unique structural complexity of this antibody highlighted by advanced orthogonal analytical characterization strategies resulting in risks to demonstrate biosimilarity, which may explain the lack of Erbitux® biosimilars in the European and US markets to date. The development of Erbitux® biobetters are also discussed as alternative strategies to biosimilars. These biologics offer expected additional safety and potency benefits over the reference product but require a full pharmaceutical and clinical development as for New Molecular Entities.

Safety and Effectiveness of Multiple Switching Between Originators and Biosimilars: Literature Review and Status Report on Interchangeability

To date, numerous biosimilars are available in Europe and the practice of switching between originator and biosimilar or between two different biosimilars has become very widespread. However, multiple switching has not been adequately studied. The aim of this study is to conduct a literature review to assess the effectiveness and safety of multiple switches. All PubMed articles involving multiple switches from originator to biosimilars or between different biosimilars were considered. The relevant data on effectiveness and safety were extracted from these studies and the results were reported through descriptive analysis. Fifteen studies were considered, of which 11 were observational and 4 clinical trials. Inflammatory bowel disease and psoriasis were the most studied diseases. All studies reported that the effectiveness and safety in patients whose treatment involved multiple switches, was comparable to patients whose treatment involved a single or no switch at all. Some therapeutic fields such as oncology and renal insufficiency were not represented at all in the multiple switch studies. New evidence is desperately needed and should be made available to the scientific community and decision-makers.

Pharmacokinetic bioequivalence, safety, and immunogenicity of GB222, a bevacizumab biosimilar candidate, and bevacizumab in Chinese healthy males: a randomized clinical trial

BACKGROUND

This study was conducted to compare the similarity of the pharmacokinetics (PKs), safety, and immunogenicity of GB222, a potential bevacizumab biosimilar, to that of reference bevacizumab in Chinese healthy males.

RESEARCH DESIGN AND METHODS

This was a randomized, double-blind, single-dose, parallel-group clinical trial performed in 84 Chinese healthy males, who were randomly assigned to receive a single infusion dose of 1 mg/kg GB222 or bevacizumab with an 84-days follow-up. The primary endpoint was the area under the plasma concentration-time curve (AUC) from zero to the last quantifiable concentration at time t (AUC_0-t). The second endpoints were the safety and immunogenicity evaluation. The PK bioequivalence was verified by the 90% confidence intervals (CIs) of the geometrical mean (GM) ratio for AUC_0-t falling within the bioequivalence margin, 80-125%.

RESULTS

The PK profiles of GB222 and bevacizumab were comparable. The 90% CIs of GM ratio of GB222 to bevacizumab for AUC_0-t was within the pre-specified bioequivalence margin. The most common treatment-related adverse event was sinus bradycardia. Seventeen subjects (20.2%) tested positive for anti-drug antibodies (ADAs).

CONCLUSION

GB222 was found to be comparable to bevacizumab in terms of PKs, safety, and immunogenicity for Chinese healthy males.

TRIAL REGISTRATION

ChiCTR-IIR-17,011,143.

Comparative effectiveness of two adalimumab biosimilars in 1318 real-world patients with inflammatory rheumatic disease mandated to switch from originator adalimumab: nationwide observational study emulating a randomised clinical trial

OBJECTIVES

In 2018, a nationwide mandatory switch from originator to biosimilar adalimumab was conducted in Denmark. The available biosimilar was GP2017 (Hyrimoz) in Eastern regions and SB5 (Imraldi) in Western regions. We aimed to assess the comparative effectiveness of GP2017 versus SB5 in patients with rheumatoid arthritis (RA)/psoriatic arthritis (PsA)/axial spondyloarthritis (AxSpA).

METHODS

Observational cohort study based on the DANBIO registry with geographical cluster pseudo-randomisation, analysed by emulating a randomised clinical trial. Main outcome was adjusted 1-year treatment retention (Cox regression). Furthermore, 6 months' remission rates (logistic regression), reasons for withdrawal and back-switching to originator were investigated (overall and stratified by indication).

RESULTS

Overall, of 1570 eligible patients, 1318 switched and were included (467 RA/321 PsA/530 AxSpA); 623 (47%) switched to GP2017, 695 (53%) to SB5. Baseline characteristics of the two clusters were largely similar, but some differences in registration practice were observed. The combined 1-year retention rate for the two biosimilars was 89.5%. Compared with SB5, estimated risk of withdrawal for GP2017 was lower (HR 0.60; 95% CI 0.42 to 0.86) and 6 months' remission rate was higher (OR 1.72; 95% CI 1.25 to 2.37). Stratified analyses gave similar results (statistically significant for RA). During 1 year, 8.5% and 12.9% withdrew GP2017 and SB5, respectively (primarily lack of effect and adverse events), of whom 48 patients (3.6%) back-switched.

CONCLUSION

This head-to-head comparison of GP2017 versus SB5 following a mandatory switch from the originator indicated differences in effectiveness in routine care. This may reflect a true difference, but other explanations, for example, differences in excipients, differences between clusters and residual confounding cannot be ruled out.

Clinical Trial Design and Drug Approval in Oncology: A Primer for the Advanced Practitioner in Oncology

Evidenced-based practice requires timely and accurate integration of scientific advances. This presents a challenge for the oncology clinician given the robust pace of scientific discovery and the increasing number of new drug approvals and expanded indications for previously approved drugs. All currently available antineoplastic therapies have been developed through the clinical trials process. Advanced practitioners (APs) in oncology are often involved in the conduct of clinical trials as primary investigators, sub-investigators, study coordinators, or in the delivery and monitoring of care to patients enrolled in these trials. A prerequisite to evidenced-based practice is understanding how clinical trials are conducted and how to critically analyze published results of studies leading to U.S. Food & Drug Administration approval. Any AP involved in the clinical management and supportive care of patients receiving antineoplastic therapies should be able to critically review published data to glean findings that warrant a change in practice. The goals of this manuscript are to summarize key elements of the clinical trial process for oncology drug development and approval in the United States and to provide a primer for the interpretation of clinical data.

Biosimilars as a Future, Promising Solution for Financial Toxicity: A Review with Emphasis on Bevacizumab

A biosimilar is a biochemical product like another already approved biologic agent, known as the reference agent. To be endorsed by the Food and Drug Administration (FDA), biosimilars must demonstrate that they are as safe and effective as their reference item, with no clinical distinction. Humanized monoclonal antibodies (mAb) are revolutionizing the treatment of gastrointestinal and gynecologic malignancies. Bevacizumab, trastuzumab, cetuximab, rituximab, and pegfilgrastim are the most widely used mAb products with oncologic indications. Due to the complexities of the regulatory system, it may take time for anti-cancer biosimilars to play a significant game-changing role. Over the last decade, the use of generics has saved billions of dollars every year, and it is expected that biosimilars will soon prove to be a cost-effective alternative and can play an important role in driving down healthcare costs globally. In this review, we provide a critical appraisal of biosimilars with an emphasis on bevacizumab-awwb (Avastin) and its clinico-pharmacologic characteristics, safety, efficacy, interchangeability, regulatory and oncologic perspectives, and overall clinical perception.

Safety of Intravitreal Injection of Biosimilar of Aflibercept in Rabbit Eyes

Purpose

To assess the safety of biosimilar intravitreal aflibercept (CinnaGen Co., Iran) compared to the reference product (Eylea®; Bayer Schweiz AG, Zurich, Switzerland) in rabbit eyes through functional and histologic studies.

Methods

Forty New Zealand albino rabbits were recruited to the study and were divided into four groups to be sacrificed at 48 hours, one, two, and four weeks after injections. In each group, five rabbits received 0.05 mL (2 mg) biosimilar aflibercept in the right eye and 0.05 mL saline in the left eye as the control, and in a similar manner, the remaining five rabbits received the reference drug in the right eye and saline in the left eye. All the rabbits underwent comprehensive ophthalmic examination and electroretinography (ERG) tests at baseline and also just before enucleation at the specific predefined time points. The enucleated eyes were prepared for retinal toxicity histological examination.

Results

No retinal toxicity was observed based on histologic and ERG findings in all groups. Choroidal congestion was revealed after 1 week in an eye that was injected with biosimilar aflibercept, although the similar finding was detected in the contralateral eye which received saline. Also, one subject which received the reference drug showed chronic vitritis and lymphoplasmocytic reaction of the optic disc at week 4. The remaining subjects showed no histologic changes.

Conclusion

The 2 mg intravitreal injection of biosimilar aflibercept (CinnaGen Co., Iran) was found to be nontoxic in rabbit eyes in the short-term period. Further studies are required to warrant the efficacy and safety profile of the drug in human subjects.

Conversion Chemotherapy With a Modified FLOX Regimen for Borderline or Unresectable Liver Metastases From Colorectal Cancer: An Alternative for Limited-Resources Settings

PURPOSE

Conversion chemotherapy is often used for borderline or unresectable (B/U) liver metastases from colorectal cancer (CRC) with the aim of achieving resectability. Although intensive and costly regimens are often used, the best regimen in this scenario remains unclear. We aimed to evaluate the outcomes of patients with B/U liver metastases from CRC treated with conversion chemotherapy with the modified fluorouracil, leucovorin, and oxaliplatin (mFLOX) regimen followed by metastasectomy.

METHODS

We performed a single-center retrospective analysis of patients with B/U liver metastases from CRC treated with chemotherapy with the mFLOX regimen followed by surgery. B/U disease was defined as at least one of the following: more than four lesions, involvement of hepatic artery or portal vein, or involvement of biliary structure.

RESULTS

Fifty-four consecutive patients who met our criteria for B/U liver metastases were evaluated. Thirty-five patients (64%) had more than four liver lesions, 16 (29%) had key vascular structure involvement, and 16 (29%) had biliary involvement. After chemotherapy, all patients had surgery and 42 (77%) had R0 resection. After a median follow-up of 37.2 months, median progression-free survival (PFS) was 16.9 months and median overall survival (OS) was 68.3 months. R1-R2 resections were associated with worse PFS and OS compared with R0 resection (PFS: hazard ratio, 2.65; P = .007; OS: hazard ratio, 2.90; P = .014).

CONCLUSION

Treatment of B/U liver metastases from CRC with conversion chemotherapy using mFLOX regimen followed by surgical resection was associated with a high R0 resection rate and favorable survival outcomes. On the basis of our results, we consider mFLOX a low-cost option for conversion chemotherapy among other options that have been proposed.

Efficacy and Safety of Supportive Care Biosimilars Among Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Biologics are widely used to manage the side effects of cancer treatment (e.g., epoetin alfa is used to treat chemotherapy-induced anemia [CIA] and granulocyte colony-stimulating factors [G-CSFs] are used to treat chemotherapy-induced neutropenia [CIN]). As several patents for biologics used in cancer treatment have expired, a number of companies have developed supportive care biosimilars (e.g., epoetin alfa biosimilar, filgrastim biosimilar, pegfilgrastim biosimilar).

OBJECTIVE

The objective of this study was to synthesize current evidence on the efficacy and safety of supportive care biosimilars compared with their reference biologics in oncology.

METHODS

We searched PubMed, Embase, the Cochrane library, ClinicalTrials.gov, ISI Web of Science and several Chinese databases from their inception dates to December 31, 2018 for randomized controlled trials (RCTs) or comparative observational studies that compared the efficacy and safety of supportive care biosimilars and their reference biologics in oncology. We pooled results separately for RCTs and observational studies, as such studies involve different patient populations and are designed differently. We pooled binary outcomes using risk ratios (RR) with confidence intervals (CIs) and continuous outcomes using weighted mean differences (WMD) with 95% CIs, then conducted subgroup and sensitivity analyses. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate the quality of evidence.

RESULTS

We identified 28 studies that compared biosimilars of G-CSF or epoetin alfa: one RCT and five cohort studies (total N = 2816) of epoetin alfa biosimilars, and 13 RCTs and 9 cohort studies (total N = 23,043) of G-CSF biosimilars [corrected]. Despite involving different populations, RCTs and observational studies comparing biosimilars and reference biologics indicated similar efficacy and safety results. Overall, there was no statistically significant difference in any efficacy or safety outcomes between any biosimilars and their corresponding original biologics (all p > 0.05). The quality of GRADE evidence of efficacy and safety outcomes was moderate or low. Findings were robust for all prespecified subgroup and sensitivity analyses.

CONCLUSION

Existing evidence suggests highly comparable efficacy and safety profiles for supportive care biosimilars and their reference biologics in oncology.

Humanistic and economic impact of subcutaneous versus intravenous administration of oncology biologics

More oncology biologics are becoming available for subcutaneous (sc.) administration and are expected to provide useful therapeutic options. We evaluated evidence published in the past 5 years to assess the humanistic and economic impact of sc. versus intravenous administration of approved cancer therapies and identify outcomes favoring either administration route. These publications focused predominantly on healthcare resource utilization and economic outcomes, demonstrating resource and cost savings with sc. administration. Patients reported a better health-related quality of life and preference for sc. formulations. Time-and-motion study analyses confirmed the convenience of sc. administration. These findings suggest that future availability of sc. oncology biologics, especially anti-PD-1/PD-ligand 1 antibodies due to their increased utility in various malignancies, may be beneficial for patients, healthcare providers and payers.

The Breakthrough of Biosimilars: A Twist in the Narrative of Biological Therapy

The coming wave of patent expiries of first generation commercialized biotherapeutical drugs has seen the global market open its doors to close copies of these products. These near perfect substitutes, which are termed as “biosimilars”, do not need to undergo intense clinical trials for their approval. However, they are mandated to produce identical similarity from their reference biologics in terms of clinical safety and efficacy. As such, these biosimilar products promise to foster unprecedented access to a wide range of life-saving biologics. However, seeing this promise be fulfilled requires the development of biosimilars to be augmented with product trust, predictable regulatory frameworks, and sustainable policies. It is vital for healthcare and marketing professionals to understand the critical challenges surrounding biosimilar use and implement informed clinical and commercial decisions. A proper framework of pharmacovigilance, education, and scientific exchange for biologics and biosimilars would ensure a dramatic rise in healthcare access and market sustainability. This paper seeks to collate and review all relevant published intelligence of the health and business potential of biosimilars. In doing so, it provides a visualization of the essential steps that are required to be taken for global biosimilar acceptance.

Determination of Cetuximab in Plasma by Liquid Chromatography-High-Resolution Mass Spectrometry Orbitrap With a Stable Labeled 13C,15N-Cetuximab Internal Standard

BACKGROUND

Cetuximab (CTX) is a chimeric IgG1 Kappa monoclonal antibody used to treat head and neck cancer and colorectal cancer. Previous clinical studies indicated that the pharmacokinetics of CTX influences patient survival. Thus, individualizing CTX treatment by measuring trough levels of the drug in plasma could have a major impact on clinical efficacy.

METHODS

To measure these levels, a full-length stable isotope-labeled CTX standard was used in a generic, rapid, and high-throughput sample preparation protocol based on IgG capture followed by trypsin digestion, on-line solid-phase extraction cleanup, and liquid chromatography-high resolution mass spectrometry (LC-HRMS).

RESULTS

The optimized method displayed good analytical performance and was linear over a range from 5 to 150 mcg/mL. The within-run and between-run imprecision of the assay were equal to or less than 10%, for 6 replicates at 3 different concentrations and for runs performed on 5 separate days. The plasma CTX concentrations in 19 patients were also determined.

CONCLUSIONS

The results showed that quantification of mAb in clinical samples does not strictly require a tandem mass spectrometry system, and LC-HRMS is also relevant in this context. This first study implementing a quantitative LC-HRMS assay with a specific stable isotope-labeled mAb internal standard paves the way for more robust clinical monitoring of anticancer mAbs.

Myelodysplastic syndrome and acute myeloid leukemia after receipt of granulocyte colony-stimulating factors in older patients with non-Hodgkin lymphoma

BACKGROUND

Granulocyte colony-stimulating factors (G-CSFs), which are used for the prevention of complications from chemotherapy-related neutropenia, are linked to the risk of developing second primary myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The objective of this study was to examine the correlation between using a specific G-CSF agent and the risk of MDS/AML among older patients with non-Hodgkin lymphoma (NHL).

METHODS

This was a retrospective cohort study of adults aged >65 years who were diagnosed with first primary NHL between 2001 and 2011. With data from the Surveillance, Epidemiology, and End Results-Medicare-linked database, adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for the risk of MDS/AML associated with the receipt of G-CSF(filgrastim and pegfilgrastim) in Cox proportional-hazards models, which were stratified according to treatment accounting for confounding by indication.

RESULTS

Among 18,245 patients with NHL patients who had a median follow-up of 3.5 years, 56% received chemotherapy and/or immunotherapy, and G-CSF was most commonly used in those who received rituximab plus multiple chemotherapy regimens (77%). Subsequent MDS/AML diagnoses were identified in 666 patients (3.7%). A modest increased risk of MDS/AML was observed with the receipt of G-CSF (HR, 1.28; 95% CI, 1.01-1.62) and a trend was observed with increasing doses (Ptrend < .01). When specific agents were analyzed, an increased risk of MDS/AML was consistently observed with filgrastim (≥10 doses: HR, 1.67; 95% CI, 1.25-2.23), but not with pegfilgrastim (≥10 + doses: HR, 1.11; 95% CI, 0.84-1.45).

CONCLUSIONS

A higher of MDS/AML was observed in patients with NHL risk among those who received G-CSF that was specific to the use of filgrastim (≥10 doses), but not pegfilgrastim. Neutropenia prophylaxis is an essential component of highly effective NHL treatment regimens. The differential risk related to the types of G-CSF agents used warrants further study given their increasing use and newly available, US Food and Drug Administration-approved, biosimilar products.

Access to high-cost drugs for advanced breast cancer in Latin America, particularly trastuzumab

Provision of high-level healthcare is a challenge for all low- to middle-income countries (LMICs) since healthcare systems are heterogeneous, face many challenges such as inadequate funding, inequitable distribution of resources and services and usually are not adequately equipped to deal with a huge problem such as breast cancer. The development of anti-HER2 therapies can be considered one of the most important examples of the translation of molecular biology knowledge into clinical benefits for cancer patients. While a variety of novel therapeutic strategies are emerging, current treatment regimens remain focussed on targeted therapy with monoclonal antibodies, mainly trastuzumab, the first agent developed in this field. While these results have revolutionised the outcome of HER2+ patients in clinical trials and in high-income countries where they are widely available, results have not impacted the natural history of this aggressive disease in most of the world. Unfortunately, the availability of these drugs is far from universal in many LMICs, and in Latin America, in particular, patients with HER2+ breast cancer are treated exclusively with standard chemotherapy, a more toxic and less efficient therapy. While the complexity of the situation and the multiple factors that have an impact in this scenario are recognised, we need to map the future and develop feasible strategies to address possible solutions to the problem of drug access. A clear and unbiased diagnosis of the situation is a good starting point. Defining healthcare priorities and a clear strategy for the allocation of resources is difficult but mandatory. In this article, we will discuss current and future challenges regarding access (and lack of access) to high-cost cancer drugs in Latin America, with a focus on anti-HER2 therapies.

Barriers to Oncology Biosimilars Uptake in the United States

Biosimilars are biological compounds that contain an active substance that is similar to the active substance in an already approved biologic. This commentary focuses on the barriers to the use of biosimilars in the United States.