PF-05280014 (a trastuzumab biosimilar) plus paclitaxel compared with reference trastuzumab plus paclitaxel for HER2-positive metastatic breast cancer: a randomised, double-blind study

Survey of Data Package and Sample Size of Comparative Clinical Studies for Biosimilar Developments from PMDA Assessments

BACKGROUND

The Japanese biosimilar guideline requires that the sponsors conduct clinical studies such as comparative pharmacokinetic (PK), pharmacodynamic (PD), or efficacy studies. In each biosimilar development, the sponsors consider the clinical data package, and thus clinical data packages vary among biosimilar developments.

OBJECTIVES

The aim of this study was to elucidate the clinical data packages for the biosimilars approved in Japan. The details of clinical data packages and sample size for the regulatory approvals of biosimilars in Japan was reported.

METHODS

We surveyed the clinical data packages and sample size based on the Pharmaceuticals and Medical Devices Agency (PMDA) website review reports between 2009 and 2023.

RESULTS

Twenty-four biosimilars have been approved based on the comparative PK and efficacy studies, 10 biosimilars have been approved based on the comparative PK/PD study, and one biosimilar has been approved based on the comparative efficacy study. Regarding the sample size, comparative PK studies were conducted in healthy volunteers or patients for up to 300 cases, although the majority enrolled only 1-100 cases (68.1%, 32/47). Comparative PD studies enrolling 1-30, 31-60, and 61-90 cases totaled 4, 7, and 4 cases, respectively. Finally, comparative efficacy studies enrolling 1-300, 301-600, and 601-900 totaled 6, 10, and 11 cases, respectively. In particular, the oncology and rheumatology areas were the first and second disease areas recruiting 601-900 patients.

CONCLUSION

Large numbers of patients were enrolled to conduct a comparative efficacy study. Efficient biosimilar development should be considered on the basis of the accumulation of scientific understanding of comparable features of biosimilars and their development.

Clinical Benefit, Price, and Uptake for Cancer Biosimilars vs Reference Drugs in China: A Systematic Review and Meta-Analysis

Importance

The high cost of biologics used to treat cancer has been an increasing burden in the world. In China, the recent approval of cancer biosimilar drugs to resolve this problem is promising, but evidence of clinical benefits, price, and uptake for these drugs is still lacking.

Objectives

To compare characteristics of pivotal clinical trials in China and other countries for biosimilars of bevacizumab, rituximab, and trastuzumab and investigate the efficacy or effectiveness, safety, and immunogenicity outcomes of cancer biosimilars compared with reference drugs by meta-analysis.

Data Sources

For this systematic review and meta-analysis, PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov were searched for published studies from database inception to February 1, 2023, using the search topics (cancers) AND (biosimilars).

Study Selection

Randomized clinical trials and cohort studies that included patients with cancer were included.

Data Extraction and Synthesis

Two authors independently extracted the outcome estimates and characteristics for each study. A random-effects meta-analysis was performed to summarize the relative estimates with 95% CIs. This study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline.

Main Outcomes and Measures

Clinical trial characteristics were collected for biosimilars of bevacizumab, rituximab, and trastuzumab. The relative estimates of efficacy or effectiveness (objective response rate, progression-free survival, and overall survival), safety, and immunogenicity outcomes were analyzed for biosimilars vs reference drugs. The weighted average price and uptake rate were evaluated for biosimilars relative to their reference drugs between 2015 and 2022.

Results

A total of 39 RCTs (involving 18 791 patients) and 10 cohort studies (involving 1998 patients) were included. The biosimilars of bevacizumab (16 RCTs; risk ratio [RR], 0.97; 95% CI, 0.93-1.01; P = .17), rituximab (12 RCTs; RR, 1.03; 95% CI, 0.98-1.08; P = .70), and trastuzumab (9 RCTs: RR, 1.04; 95% CI, 0.97-1.12; P = .29) met equivalence with reference biologics in regard to the objective response rate. The results summarized from cohort studies were consistent with those from RCTs. In 2022, cancer biosimilars were priced at 69% to 90% of the costs for the reference drugs, and their uptake reached 54% to 83% in China.

Conclusions and Relevance

This systematic review and meta-analysis indicated that cancer biosimilars provided comparable clinical benefits at lower prices compared with reference drugs. These findings suggest the potential feasibility of expediting the transition from reference drugs to biosimilars to benefit more patients with cancer.

Comparison of Biosimilar Trastuzumab ABP 980 with Reference Trastuzumab in Neoadjuvant Therapy for HER2-positive Breast Cancer - an Analysis of a Large University Breast Cancer Centre

Background ABP 980 is a biosimilar antibody to reference trastuzumab (RTZ). Aim of the following study is to confirm the similarity of ABP 980 and RTZ in terms of clinical efficacy and safety in patients with HER2-positive early breast cancer (EBC) undergoing neoadjuvant trastuzumab-containing chemotherapy in a clinical real-world situation that also includes patients receiving pertuzumab. Methods Patients with HER2-positive EBC, who were treated from 12/2010 to 03/2020 at the Department of Women's Health at Tuebingen University Hospital, Germany, with at least four cycles of neoadjuvant chemotherapy (+/- pertuzumab) in combination with ABP 980 or RTZ were included in a retrospective analysis. For efficacy analysis patients achieving a pathologic complete remission (pCR = no invasive tumor in breast and lymph nodes) were compared. Safety was evaluated by comparing the number of patients with a decrease in left ventricular function (LVEF) of > 10%. Results 124 patients were included of whom 46 (37.1%) have received ABP 980 and 77 (62.9%) were treated with RTZ. A pCR was found in 77 patients (62.1%). For patients treated with ABP 980 as compared to RTZ, there was no significant difference regarding efficacy (pCR-rates of 60.9% versus 62.8%, p = 0.829) or cardiac safety (LVEF decline in 6.5% versus 2.6%, p = 0.274). Conclusion Similarity of ABP 980 as compared to RTZ was confirmed in a real-world situation, including a large proportion of patients that have also received pertuzumab treatment.

Safety survey on infusion reaction and cardiac dysfunction when switching from reference trastuzumab (HERCEPTIN®) to biosimilar trastuzumab (Trastuzumab‑NK) in the treatment of HER2‑positive breast cancer

The present study is a safety survey of patients with human epidermal growth factor receptor type 2-positive, chemotherapy-naive breast cancer treated with trastuzumab plus paclitaxel at the Saitama Cancer Center (Saitama, Japan) between April 2018 and March 2022. The expression of infusion reaction (IR) and the effect on cardiac function were investigated in patients who switched from reference trastuzumab (HERCEPTIN^®) to biosimilar trastuzumab (Trastuzumab-NK) and continued treatment (switching group). The two groups (reference vs. biosimilar trastuzumab) had no significant difference in the expression of IR (P>0.999). In the switching group, IR associated with switching did not occur in all nine eligible patients. Left ventricular ejection fraction (LVEF) was used to assess cardiac function, and no patient in either group experienced a significant decrease in LVEF with treatment, meaning that there was no effect of switching on the decrease in LVEF. These results suggested that switching from reference to biosimilar trastuzumab may not have a significant effect on the frequency of IR expression or the occurrence of cardiac dysfunction.

Comparative Safety Profiles of Oncology Biosimilars: A Systematic Review and Network Meta-analysis

BACKGROUND

It is crucial that the safety profiles of biosimilars are similar to those of the original biologics. A better understanding of biosimilars and their relative safety and immunogenicity profiles are required for healthcare providers to prescribe them to patients with life-threatening cancer diseases who receive chemotherapies with potentially serious adverse events (AEs).

OBJECTIVES

The purpose of this study was to collate and analyze currently available safety and immunogenicity outcomes of biosimilars used in oncology and compare their safety information with those of the original biologics.

METHODS

The MEDLINE and Cochrane Library databases were searched as at 28 February 2022. Four anti-cancer biosimilar molecules were considered: bevacizumab, trastuzumab, rituximab, and (peg)filgrastim. Through a systematic review, we selected the randomized controlled trials (RCTs) comparing safety outcomes between the biosimilars and original biologics of the four molecules. As safety outcomes, various treatment-emergent adverse events (TEAEs) were collated, such as any TEAE, serious AE, and TEAE higher than grade 3. A risk ratio (RR) per category of TEAE was estimated through a meta-analysis. A network meta-analysis (NMA) was also conducted to compare the safety among the biosimilar brands for TEAEs over 25% with higher variability in addition to the serious AE cases.

RESULTS

Forty-nine RCTs were identified. The results from the meta-analysis showed that the safety and immunogenicity profiles of all four biosimilar molecules are comparable with that of the original biologics at the TEAE level without statistically significant differences, except for diarrhea for (peg)filgrastim. The incidence of diarrhea with (peg)filgrastim was less than that with the original biologic (RR 0.66, 95% confidence interval 0.50-0.89). The NMA results showed similar safety profiles among the biosimilar brands for all four biosimilar molecules, except for the serious adverse event of a trastuzumab biosimilar (RR 0.296, 95% credible interval 0.109-0.840).

CONCLUSION

The meta-analysis and NMA for all four biosimilars showed that the safety and immunogenicity profiles of biosimilar products in oncology are generally comparable with that of the original biologics at the TEAE level. However, additional evidence needs to be collected since several TEAEs of specific biosimilars were out of the equivalent range. The results of this study provide comparative safety information and a better understanding of oncology biosimilars for healthcare providers to prescribe them to patients.

Trastuzumab biosimilars vs trastuzumab originator in the treatment of HER2-positive breast cancer: a systematic review and network meta-analysis

AIM

Breast cancer is the most frequently diagnosed cancer in women and ranks second among causes for cancer related death in women. Trastuzumab originator (Herceptin) is a monoclonal antibody used as a standard treatment for breast and metastatic gastric cancer when the cancer cells over-express human epidermal growth factor receptor type 2 (HER2). As the patent of Trastuzumab has now expired, biosimilars are moving into the market. It is still controversial to chose which trastuzumab biosimilar has the best treatment of HER2-positive breast cancer patients. We conducted this network meta-analysis to explore the best trastuzumab biosimilar in the treatment of HER2-positive breast cancer patients.

METHODS

PubMed, Cochrane library databases, China National Knowledge infrastructure (CNKI) and WanFang database up to November 2021 were systematically searched. The following search terms were used: 'trastuzumab originator', and 'trastuzumab biosimilar'. No language restriction was imposed. The reference lists of all retrieved articles were also reviewed to identify additional articles missed by using these search terms.

RESULTS

We got 10 studies to conduct network meta-analysis to evaluate efficacy and serious adverse reactions among various trastuzumab biosimilars and trastuzumab originator. The overall response rate (ORR) and pathological complete response (pCR) of SB3 were worse than trastuzumab originator significantly, while the ORR and pCR of other trastuzumab biosimilars had not yet reached statistical differences compared with each other. The cumulative ranking curve (SUCRA) probability indicated that the ORR from best to worst was CT-P6, Herceptin, HLX02, PF-05280014, R-TPR-016, BCD-022, MYL-1401O, SB3, and the pCR from best to worst was PF-05280014, CT-P6, Herceptin, ABP-980, SB3. The serious adverse events (SAEs) of CT-P6 were more than Herceptin and MYL-1401O significantly, while the SAEs of other trastuzumab biosimilars had not statistical differences. The SUCRA probability indicated that the SAEs from best to worst was MYL-1401O, Herceptin, PF-05280014, SB3, HLX02, BCD-22, CT-P6.

CONCLUSION

There was no statistical difference in both ORR and pCR of various trastuzumab biosimilars and Herceptin except SB3. The ORR and pCR of SB3 were worse than Herceptin. Both CT-P6 and PF-05280014 are better in the overall curative effect, but CT-P6 had the highest serious adverse reactions when compared with others. The PF-05280014 might be a better trastuzumab biosimilar in the treatment of HER2-positive breast cancer patients.

Switching Among Biosimilars: A Review of Clinical Evidence

Biological medicines have improved patients’ outcomes, but their high costs may limit access. Biosimilars, alternatives that have demonstrated high similarity in terms of quality, safety, and efficacy to an already licensed originator biological product, could increase competition and decrease prices. Given the expanding number of biosimilars, patients may switch from originator to biosimilar or among biosimilars. Randomized trials and observational studies conducted with multiple biosimilars over many disease areas confirmed the safety and efficacy of switching from originator to biosimilar. This study summarizes evidence on switching between biosimilars for which there are concerns to provide future guidance. A systematic search (MEDLINE, Embase, and Cochrane Library) for studies on anti-TNF agents, assessing clinical efficacy and safety of biosimilar-to-biosimilar switch in chronic inflammatory diseases, was performed. We retrieved 320 records and included 19 clinical studies. One study with historical control compared switching between biosimilars to maintenance of the same biosimilar. Ten were controlled cohort studies comparing switching between two biosimilars vs. switching from originator to a biosimilar or vs. multiple switches. Eight were single-arm cohort studies, where participants switched from one biosimilar to another, and the outcomes were compared before and after the switch. Overall, these studies did not highlight significant concerns in switching between biosimilars. Therefore, switching studies seem difficult to perform and unnecessary with the body of evidence suggesting no real problems in practice coupled with stringent regulatory requirements. Monitoring the use of biosimilars in clinical practice could support clinical decision-making, rational use of biological medicines, and help to further realize possible savings.

A Review of Trastuzumab Biosimilars in Early Breast Cancer and Real World Outcomes of Neoadjuvant MYL-1401O versus Reference Trastuzumab

The reduced cost of trastuzumab biosimilars has led to increased adoption for HER2-positive breast cancer. This review of trastuzumab biosimilars encompasses this development and real world clinical data in early breast cancer. In addition, we present a retrospective study evaluating the total pathological complete response (tpCR) rates (lack of residual invasive cancer in resected breast tissue and axillary nodes), of MYL-1401O to reference trastuzumab (TRZ) in the neoadjuvant setting for HER2+ early breast cancer (EBC) in Alberta, Canada. Neoadjuvant patients with HER2+ EBC treated with TRZ from November 2018–October 2019 and MYL-1401O from December 2019–September 2020 were identified. Logistic regression was used to control for variables potentially associated with tpCR: trastuzumab product, age, pre-operative T- and N-stage, grade, hormone receptor (HR)-status, HER2-status, chemotherapy regimen, and chemotherapy completion. tpCR was 35.6% in the MYL-1401O group (n = 59) and 40.3% in the TRZ (n = 77) group, p = 0.598. After controlling for clinically relevant variables, there was no significant difference in the odds of achieving tpCR in patients treated with TRZ versus MYL-1401O (OR 1.1, 95% CI 0.5–2.4, p = 0.850). tpCR rates were similar for patients treated with MYL-1401O compared to trastuzumab in our real world study of HER2+ neoadjuvant EBC and comparable to pivotal phase 3 trials.

Systemic Therapy for Advanced Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: ASCO Guideline Update

PURPOSE

To update evidence-based guideline recommendations to practicing oncologists and others on systemic therapy for patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer.

METHODS

An Expert Panel conducted a targeted systematic literature review (for both systemic treatment and CNS metastases) and identified 545 articles. Outcomes of interest included efficacy and safety.

RESULTS

Of the 545 publications identified and reviewed, 14 were identified to form the evidentiary basis for the guideline recommendations.

RECOMMENDATIONS

HER2-targeted therapy is recommended for patients with HER2-positive advanced breast cancer, except for those with clinical congestive heart failure or significantly compromised left ventricular ejection fraction, who should be evaluated on a case-by-case basis. Trastuzumab, pertuzumab, and taxane for first-line treatment and trastuzumab deruxtecan for second-line treatment are recommended. In the third-line setting, clinicians should offer other HER2-targeted therapy combinations. There is a lack of head-to-head trials; therefore, there is insufficient evidence to recommend one regimen over another. The patient and the clinician should discuss differences in treatment schedule, route, toxicities, etc during the decision-making process. Options include regimens with tucatinib, trastuzumab emtansine, trastuzumab deruxtecan (if either not previously administered), neratinib, lapatinib, chemotherapy, margetuximab, hormonal therapy, and abemaciclib plus trastuzumab plus fulvestrant, and may offer pertuzumab if the patient has not previously received it. Optimal duration of chemotherapy is at least 4-6 months or until maximum response, depending on toxicity and in the absence of progression. HER2-targeted therapy can continue until time of progression or unacceptable toxicities. For patients with HER2-positive and estrogen receptor-positive or progesterone receptor-positive breast cancer, clinicians may recommend either standard first-line therapy or, for selected patients, endocrine therapy plus HER2-targeted therapy or endocrine therapy alone.Additional information is available at www.asco.org/breast-cancer-guidelines.

Characteristics of Clinical Trials Evaluating Biosimilars in the Treatment of Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

Biologics account for almost half of US drug spending but may be subject to competitive pricing pressures by US Food and Drug Administration-approved biosimilars. The extent of the preapproval clinical testing that is needed and how these biosimilars compare with the originator biologic products remain critical issues in establishing a vibrant biosimilar market.

OBJECTIVES

To analyze the design of cancer biosimilar efficacy studies compared with the reference drug pivotal trials and provide summary risk ratio estimates for each cancer type drug subgroup.

DATA SOURCES

A systematic search was performed of articles and abstracts published using Embase, PubMed/MEDLINE, and ClinicalTrials.gov, last updated April 18, 2021.

STUDY SELECTION

All studies or abstracts in English comparing a disease-modifying cancer biologic and its biosimilar and reporting efficacy or surrogate efficacy results were included.

DATA EXTRACTION AND SYNTHESIS

Outcome estimates and study characteristics were extracted from each study. Among biosimilar efficacy studies, random-effects meta-analyses were performed for each cancer type molecule outcome subgroup, calculating pooled relative estimates and 95% CIs.

MAIN OUTCOMES AND MEASURES

Study characteristics, such as population size, blinding, and randomization, were compared between biosimilar trials and those of reference drugs. Risk ratio estimates for relative change to surrogate measures (eg, progression-free survival) were collected for biosimilars and their reference products.

RESULTS

A total of 31 cancer biosimilar studies of 3 reference products involving 12 310 patients were included. In all 7 subgroups, the biosimilars analyzed were indistinguishable from their reference drug on surrogate efficacy. Six reference drug trials were included, involving 1811 patients. On average, biosimilar studies involved more patients than reference drug trials (mean number of patients, 397 vs 302), were more likely to be randomized clinical trials rather than single-group or observational studies (100% [31 of 31] vs 50% [3 of 6]), and were more likely to be double blind rather than open label (84% [26 of 31] vs 17% [1 of 6]).

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis found that the biosimilars for the cancer drugs in this sample were subjected to rigorous clinical evaluations, and the results were statistically indistinguishable from those of original products across drugs, cancer types, and outcome measures.

An Introduction to Biosimilars for the Treatment of Retinal Diseases: A Narrative Review

Biological therapies have revolutionized the treatment of disease across a number of therapeutic areas including retinal diseases. However, on occasion, such treatments may be relatively more expensive compared to small molecule therapies. This can restrict patient access and treatment length leading to suboptimal clinical outcomes. Several biosimilar candidates of ranibizumab and aflibercept are currently in development and the first biosimilar of ranibizumab received EMA approval in August and FDA approval in September 2021. Biosimilars are biological medicines that are highly similar to an already-approved biological medicine (reference product). The physicochemical and clinical similarity of a biosimilar is determined by a rigorous analytical and clinical program, including extensive pharmacokinetic and pharmacodynamic analysis with phase III equivalence studies where appropriate. These phase III studies are carried out in a patient population that is representative of all of the potential approved therapeutic indications of the originator product and the most sensitive for detecting potential differences between the biosimilar and the reference product. Biosimilars have been used successfully across a wide range of therapeutic areas for the past 15 years where they have achieved substantial cost savings that can be reinvested into healthcare systems without affecting the quality of patient care. The current review provides an introduction to biosimilars with the aim of preparing retinal specialists for discussing these products with their patients.

Long-Term Safety and Effectiveness of PF-05280014 (a Trastuzumab Biosimilar) Treatment in Patients with HER2-Positive Metastatic Breast Cancer: Updated Results of a Randomized, Double-Blind Study

Background

PF-05280014 was compared with trastuzumab sourced from the European Union (trastuzumab-EU), each plus paclitaxel, as first-line treatment for human epidermal growth factor receptor 2-positive metastatic breast cancer in a phase III study. Equivalence between treatment groups was demonstrated.

Objective

The aim of this study was to report long-term safety and overall survival (OS) over 6 years after the first patient was screened.

Patients and methods

Randomized patients received intravenous PF-05280014 or trastuzumab-EU, each plus paclitaxel, until objective disease progression. OS, long-term safety, subgroup safety (patients ongoing after day 378), and time-to-treatment discontinuation (TTD) were assessed based on the final statistical analysis plan amended for the ad-hoc analyses.

Results

Of 707 randomized patients (n = 352, PF-05280014; n = 355, trastuzumab-EU), 252 (71.6%) in the PF-05280014 and 251 (70.7%) in the trastuzumab-EU group discontinued treatment due to objective progression. Overall, 451 (63.8%) patients completed the study. Between groups (PF-05280014; trastuzumab-EU), estimated median TTDs were 12.25 and 12.06 months (p = 0.692); 61 (17.3%) and 67 (18.9%) patients died; stratified hazard ratio for OS was 0.929 (95% confidence interval 0.656–1.316; p = 0.339); estimated survival rates were 82.3 and 77.4% at 2 years and 77.2 and 75.3% at 3 years. The incidences of treatment-emergent adverse events (TEAEs) overall (98.6%; 96.6%) and for grades ≥3 (41.0%; 43.1%) were comparable between groups. In patients (n = 265; n = 264) ongoing after day 378, the incidences of any TEAEs, grade ≥3 TEAEs, and serious TEAEs were comparable between the treatment groups.

Conclusion

Long-term safety and OS were consistent with previous results and demonstrated no clinically meaningful differences between treatment groups.

Trial registration

ClinicalTrials.gov: NCT01989676 (21 November 2013); and EudraCT: 2013-001352-34 (18 December 2013).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-021-00513-7.

Physicochemical stability of PF-05280014 (trastuzumab-qyyp; TrazimeraTM), a trastuzumab biosimilar, under extended in-use conditions

Introduction

The stability and functional activity of the trastuzumab biosimilar PF-05280014 (trastuzumab-qyyp; TrazimeraTM), was assessed under extended in-use conditions.

Methods

PF-05280014 was diluted in 0.9% sodium chloride to final concentrations of 0.2 mg/mL and 4 mg/mL in 3 different types of infusion bags (polyolefin, ethylene vinyl acetate, and polyvinyl chloride). Infusion bags containing diluted PF-05280014 were stored at 25 ± 5° C for 24 h, before storage at 5 ± 3° C for 0, 1, 2, 4, or 6 weeks. Following extended storage, samples of PF-05280014 were removed from the infusion bags and stored at 25 ± 5° C for 24 h before biophysical and functional characterization. In addition to the visual characteristics of each sample at the various time points, the stability of PF-05280014 was assessed using a variety of biophysical techniques, including size-exclusion high-performance liquid chromatography, non-reducing sodium dodecyl sulfate capillary electrophoresis, cation-exchange chromatography, peptide mapping, far-UV circular dichroism spectroscopy, and differential scanning calorimetry. The functional activity of PF-05280014 was evaluated using a cell-based growth inhibition assay.

Results

For all PF-05280014 concentrations, time points and infusion bags tested, there were no significant differences in visual characteristics or in protein concentration. The were no significant changes in the relative abundance of molecular weight or charge variants throughout the 6-week study period. Similarly, there were no significant changes in primary structure or in secondary structure content during the study. The relative potency of PF-05280014 was also maintained throughout the 6-week period.

Conclusions

The stability and functional activity of PF-05280014 was maintained following dilution in 0.9% sodium chloride and storage for up to 6 weeks at 2–8° C.

Use of Biosimilar Medications in Oncology

PURPOSE

The increased number and expanded utilization of biosimilars raise important considerations for their safe and appropriate use in oncology practice. This report provides an update on currently approved oncology biosimilars and identifies current knowledge gaps in the management of patients with cancer.

METHODS

An Expert Panel was convened to review the medical literature and to provide a practical summary of currently approved biosimilar therapeutics for cancer treatment or supportive care in the United States.

RESULTS

A total of 17 cancer or cancer-related biosimilar products have been approved by the US Food and Drug Administration since 2015. Despite years of clinical experience with oncology biosimilars, variance in their use persists. ASCO supports that biosimilars and reference products are considered equally efficacious for the purpose of inclusion in ASCO clinical practice guideline recommendations.

CONCLUSION

The use of biosimilars might provide competitive, lower-cost alternatives to biologics used in cancer care, and specific mention in ASCO guidelines and other evidence products is supported where appropriate.

Evidence-based public policy making for medicines across countries: findings and implications for the future

Aim: Global expenditure on medicines is rising up to 6% per year driven by increasing prevalence of non-communicable diseases (NCDs) and new premium priced medicines for cancer, orphan diseases and other complex areas. This is difficult to sustain without reforms. Methods: Extensive narrative review of published papers and contextualizing the findings to provide future guidance. Results: New models are being introduced to improve the managed entry of new medicines including managed entry agreements, fair pricing approaches and monitoring prescribing against agreed guidance. Multiple measures have also successfully been introduced to improve the prescribing of established medicines. This includes encouraging greater prescribing of generics and biosimilars versus originators and patented medicines in a class to conserve resources without compromising care. In addition, reducing inappropriate antibiotic utilization. Typically, multiple measures are the most effective. Conclusion: Multiple measures will be needed to attain and retain universal healthcare.

Targeting HER2 in Breast Cancer: Latest Developments on Treatment Sequencing and the Introduction of Biosimilars

Approximately 20% of all breast cancers overexpress the human epidermal growth factor receptor 2 (HER2). Targeting breast cancer through this vital oncogenic protein has been a major step towards improved patient outcomes. Today, several anti-HER2 agents are in clinical use including: the monoclonal antibodies trastuzumab and pertuzumab; the small molecule inhibitors lapatinib, neratinib, and tucatinib; and the antibody-drug conjugates ado-trastuzumab emtansine and trastuzumab deruxtecan, in some jurisdictions. In addition, several trastuzumab biosimilars have recently been granted regulatory approval in North America and the EU, and are enhancing patient access to HER2-directed therapy. The various agents differ greatly in their side-effect profiles and approved indications, from neoadjuvant and adjuvant use in early disease, to first- and later-line use in metastatic disease. This review discusses the current treatment recommendations for the use of anti-HER2 agents alone and in combination, examines the latest advances in HER2-targeted drugs and how they may be best applied in clinical practice, and provides guidance on optimal sequencing of the growing array of therapeutic options for HER2-positive breast cancer.

Progress in oncology biosimilars till 2020: Scrutinizing comparative studies of biosimilar monoclonal antibodies

Stupendous elevation in the healthcare costs has followed with the inception of the current unconventional options of treatment available for cancer patients. There is a dire need of innovative financing approaches to lessen the financial load on healthcare system. Biosimilars are biological drugs consisting of an active ingredient from a reference biological drug that has a great potential of relieving financial load. Strict requirements from regulatory point of view are required as biosimilars are exceedingly similar to but not identical to the reference product. This provides with a certainty that no consequential differences from clinical point of view as compared to the respective biologics exists with regards to efficacy, safety and purity. Safety and effectiveness of biosimilars have been disclosed since more than 10 years of affirmations. However, there is a need to educate the healthcare professionals to abolish potential misconceptions and coalesce biosimilars into regular clinical practice. The present review focuses on providing an overview of regulatory aspects and requirements for biosimilars, the main challenges in the selection and development of biosimilars and the economic impact and financial savings observed in recent studies carried out in different parts of the world. In addition, we have discussed the different successful comparative studies which have been done in different parts of the world to depict the biosimilarity for monoclonal antibodies such as bevacizumab, trastuzumab and rituximab.

Uptake of Trastuzumab Biosimilars for the Treatment of HER2-Positive Breast Cancer: A Real-World Experience from a Cancer Center

Background: The introduction of trastuzumab biosimilars in clinical practice plays an important role in promoting the sustainability of healthcare systems. By contrast, the switching process can be challenging to the clinics. This survey describes the switching process at a National Cancer Institute over a period of 2 years. Methods: Data regarding all trastuzumab-based regimens for breast cancer (BC) from 1 January 2019 and 31 December 2020 were extracted from both adverse drug reactions (ADRs) reporting systems and electronic systems involved in inventory management, prescribing, dispensing, and administration. Both patients under monotherapy and combination treatment regimens were included. There were no exclusion criteria. Results and Conclusions: Overall 354 patients received at least one trastuzumab-based regimen for a total of 493 lines of treatment and 5769 administrations. Biosimilar were used in 34.3% of trastuzumab-based treatments. No differences between biosimilars and reference drug have been observed in terms of ADRs. The effective cost-saving of the first 2 years is greater than EUR 800,000 and it is estimated to increase over time.

Current state and comparison of the clinical development of bevacizumab, rituximab and trastuzumab biosimilars

Monoclonal antibodies are highly complex, large and biologic products with a substantial impact on the clinical management of a variety of diseases including cancer. The expiry of patents for essential monoclonal antibodies in cancer care such as bevacizumab, rituximab and trastuzumab, has prompted the global development of biosimilars to balance the biologics market. However, an understanding of the different approach of biosimilar development compared with its reference medicinal product, especially in the context of clinical trial design and end point selection may help oncologists integrating biosimilars into clinical practice. Herein, we reviewed the clinical development of biosimilars in oncology comparing the available clinical data of proposed biosimilars of bevacizumab, rituximab and trastuzumab.

Efficacy, Safety, and Immunogenicity of HLX02 Compared with Reference Trastuzumab in Patients with Recurrent or Metastatic HER2-Positive Breast Cancer: A Randomized Phase III Equivalence Trial

BACKGROUND

HLX02 is an approved biosimilar of trastuzumab.

OBJECTIVE

This study aimed to evaluated the efficacy, safety, and immunogenicity of HLX02 compared with reference trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive recurrent or metastatic breast cancer.

PATIENTS AND METHODS

This randomized, double-blind, phase III study was conducted at 89 centers in China, the Philippines, Poland, and Ukraine. Eligible patients were randomized (1:1) to receive HLX02 or European Union (EU)-sourced trastuzumab (initial dose of 8 mg/kg, followed by 6 mg/kg every 3 weeks for up to 12 months) in combination with docetaxel intravenously. The primary endpoint was overall response rate up to week 24 (ORR₂₄). Equivalence was declared if the 95% confidence interval (CI) of difference was within ± 13.5%. Safety and immunogenicity were evaluated in patients who received at least one dose of study medication.

RESULTS

Between 11 November 2016 and 10 July 2019, a total of 649 patients were enrolled. The ORR₂₄ was 71.3 and 71.4% in the HLX02 (n = 324) and EU-trastuzumab (n = 325) groups, with a difference of - 0.1% (95% CI - 7 to 6.9), which fell entirely in the predefined equivalence margins. No statistically significant differences were observed in all secondary efficacy analyses. Safety profiles and immunogenicity were comparable in HLX02 and EU-trastuzumab groups. In total, 98.8% of patients in each group experienced at least one treatment-emergent adverse event (TEAE), 23.8 and 24.9% experienced serious TEAEs, and 0.6% in each group had antidrug antibodies.

CONCLUSIONS

Among patients with HER2-positive recurrent or metastatic breast cancer, HLX02 demonstrated equivalent efficacy and similar safety and immunogenicity to reference trastuzumab.

CLINICAL TRIAL REGISTRATION

Chinadrugtrials.org CTR20160526 (12 September 2016), ClinicalTrials.gov NCT03084237 (20 March 2017), EudraCT 2016-000206-10 (27 April 2017).

Feasibility of HER2-Targeted Therapy in Advanced Biliary Tract Cancer: A Prospective Pilot Study of Trastuzumab Biosimilar in Combination with Gemcitabine Plus Cisplatin

The prognosis of advanced biliary tract cancer (BTC) is poor with the standard gemcitabine and cisplatin (GemCis) regimen. Given that the rates of human epidermal growth factor receptor 2 (HER2) positivity in BTC reaches around 15%, HER2-targeted therapy needs further investigation. This study aims to evaluate the preliminary efficacy/safety of first-line trastuzumab-pkrb plus GemCis in patients with advanced BTC. Patients with unresectable/metastatic HER2-positive BTC received trastuzumab-pkrb (on day 1 of each cycle, 8 mg/kg for the first cycle and 6 mg/kg for subsequent cycles), gemcitabine (1000 mg/m² on day 1 and 8) and cisplatin (25 mg/m² on day 1 and 8) every 3 weeks. Of the 41 patients screened, 7 had HER2-positive tumours and 4 were enrolled. The median age was 72.5 years (one male). Primary tumour locations included extrahepatic (N = 2) and intrahepatic (N = 1) bile ducts, and gallbladder (N = 1). Best overall response was a partial response in two patients and stable disease in two patients. Median progression-free survival (PFS) was 6.1 months and median overall survival (OS) was not reached. The most common grade 3 adverse event was neutropenia (75%), but febrile neutropenia did not occur. No patient discontinued treatment due to adverse events. Trastuzumab-pkrb with GemCis showed promising preliminary feasibility in patients with HER2-positive advanced BTC.

Integrative Review of Managed Entry Agreements: Chances and Limitations

BACKGROUND AND OBJECTIVE

Managed entry agreements (MEAs) consist of a set of instruments to reduce the uncertainty and the budget impact of new high-priced medicines; however, there are concerns. There is a need to critically appraise MEAs with their planned introduction in Brazil. Accordingly, the objective of this article is to identify and appraise key attributes and concerns with MEAs among payers and their advisers, with the findings providing critical considerations for Brazil and other high- and middle-income countries.

METHODS

An integrative review approach was adopted. This involved a review of MEAs across countries. The review question was 'What are the health technology MEAs that have been applied around the world?' This review was supplemented with studies not retrieved in the search known to the senior-level co-authors including key South American markets. It also involved senior-level decision makers and advisers providing guidance on the potential advantages and disadvantages of MEAs and ways forward.

RESULTS

Twenty-five studies were included in the review. Most MEAs included medicines (96.8%), focused on financial arrangements (43%) and included mostly antineoplastic medicines. Most countries kept key information confidential including discounts or had not published such data. Few details were found in the literature regarding South America. Our findings and inputs resulted in both advantages including reimbursement and disadvantages including concerns with data collection for outcome-based schemes.

CONCLUSIONS

We are likely to see a growth in MEAs with the continual launch of new high-priced and often complex treatments, coupled with increasing demands on resources. Whilst outcome-based MEAs could be an important tool to improve access to new innovative medicines, there are critical issues to address. Comparing knowledge, experiences, and practices across countries is crucial to guide high- and middle-income countries when designing their future MEAs.

A randomized, double-blind, parallel pharmacokinetic study comparing the trastuzumab biosimilar candidate, AryoTrust®, and reference trastuzumab in healthy subjects

BACKGROUND

AryoTrust® (AryoGen Pharmed Co., Iran) is a biosimilar candidate for the EU-sourced reference trastuzumab, Herceptin®. This study was designed to evaluate the bioequivalence between AryoTrust® and Herceptin®.

RESEARCH DESIGN AND METHODS

In this double-blind, parallel study, 60 healthy male subjects were randomized 1:1 to receive a single dose of AryoTrust® or Herceptin® (6 mg/kg) as intravenous infusion. The primary endpoint of the study was the area under the concentration versus time to infinity (AUC_0-inf), and the main secondary endpoints were maximum measured concentration (C_max), area under the concentration versus time from zero to the last quantifiable concentration time (AUC_0-last), immunogenicity, and safety.

RESULTS

Sixty subjects were enrolled in the study and baseline demographics were similar between the two groups. The two groups demonstrated similar pharmacokinetic parameters and the 90% confidence interval (CI) for primary and secondary endpoints were within the bioequivalence acceptance range (80.00%-125.00%). No serious adverse event or immunogenicity was reported, and all of the adverse events reported were mild and similar between the two treatment groups.

CONCLUSION

AryoTrust® was well tolerated, had a similar safety profile to reference trastuzumab, and its pharmacokinetic bioequivalence was confirmed.

TRIAL REGISTRATION

The trial is registered at Indian Trials Registry (CTRI/2019/03/018218).

Comparative efficacy and safety of trastuzumab biosimilars to the reference drug: a systematic review and meta-analysis of randomized clinical trials

PURPOSE

To assess efficacy and safety of trastuzumab biosimilars in comparison to the reference drug through a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

A comprehensive search was conducted using PubMed, Web of Science, Cochrane library, Open Grey and ClinicalTrials.gov databases. Dichotomous data for efficacy and safety outcomes were pooled to obtain the relative risk (RR) and 95% confidence intervals (CIs). Meta-analysis was performed with the Mantel-Haenszel method using Revman 5.3 software.

RESULTS

Eight phase III RCTs including a total of 3913 patients with HER2 + breast cancer were identified that met the inclusion criteria. The pooled results for the comparison of trastuzumab biosimilars to the reference drug showed no differences of objective response rate (ORR) (RR 1.05, 95% CI 0.98-1.12, P = 0.20) or overall survival (RR 0.82, 95% CI 0.61-1.09, P = 0.17) in the intention-to-treat population, as well as no difference of ORR (RR 1.03, 95% CI 0.97-1.10, P = 0.30) in the per-protocol population. Similarly, no significant difference was detected in any type of adverse event reported in at least three RCTs, including any serious treatment-emergent adverse effects (RR 0.97, 95% CI 0.76-1.25, P = 0.83), heart failure (RR 1.47, 95% CI 0.69-3.14, P = 0.32), neutropenia (RR 1.05, 95% CI 0.96-1.15, P = 0.26), and infusion-related reaction (RR 1.10, 95% CI 0.89-1.36, P = 0.38).

CONCLUSION

This meta-analysis provides compelling evidence of clinical comparability between trastuzumab biosimilars and the originator product in terms of both efficacy and safety for the treatment of HER2 + breast cancer.

Trastuzumab Biosimilars in the Therapy of Breast Cancer - "Real World" Experiences from four Bavarian University Breast Centres

Introduction With the introduction of the first trastuzumab biosimilar in the summer of 2018, biosimilar antibodies for breast cancer have found their way into the area of gynaecological oncology. The switch of anti-human epidermal growth factor receptor 2 (HER2) therapy from the reference drug Herceptin ^® to a biosimilar has presented challenges to the clinics. In addition to structural and organisational measures, training of employees as well as patient briefing and acceptance were major challenges. The study presented here records - within the context of quality assurance - how the switch to a trastuzumab biosimilar was implemented at four Bavarian university clinics in the Purchasing Association of Bavarian University Pharmacies. Materials/Methods Questionnaires on treatment figures and the switching process were sent to breast centres and pharmacies of four Bavarian university clinics between July and December 2019. The neoadjuvant, adjuvant and metastasised anti-HER2 therapy with trastuzumab with or without pertuzumab was recorded, evaluated and summarised. Results In the anti-HER2-therapy, trastuzumab was used intravenously (i. v.) and subcutaneously. Between July and December 2018, all four clinics in the Purchasing Association switched the i. v. trastuzumab therapy from the reference drug (Herceptin) to a biosimilar (for 2018: Kanjinti ^® ). Over 200 patients were treated with trastuzumab i. v. in each of the two half-years of 2018 (before and after the switch). The spectrum of side effects and pCR rates under therapy with the biosimilar were comparable to the experiences made with the reference drug. Three out of four clinics provided training to employees and informed patients by means of a defined information leaflet. Patient acceptance was high. Summary The anti-HER2 therapy could be switched successfully and safely to trastuzumab biosimilars at the Bavarian university hospitals. This may serve as guideline for the further implementation of biosimilars. The structures necessary for this initial switching process have been prepared with trastuzumab as an example.

A Clinical Review of Biosimilars Approved in Oncology

Objective

To summarize and review the clinical data of Food and Drug Administration (FDA)-approved biosimilars for use in treatment of cancer and the current challenges health care institutions face when implementing a newly approved biosimilar.

Data Sources

A literature search of the following databases was performed between January 1, 2012, and December 31, 2019: PubMed, Google, and ClinicalTrials.gov. Search terms included the words biosimilar, bevacizumab, rituximab, and/or trastuzumab.

Study Selection and Data Extraction

Only primary literature on biosimilars with an ongoing or completed phase 3 trial and/or FDA approval were included in the final analysis. Primary literature consisted of peer-reviewed publications, published abstracts, and any results posted on the ClinicalTrials.gov database.

Data Synthesis

Clinical trials of FDA-approved biosimilars for bevacizumab, rituximab, and trastuzumab showed no significant differences with respect to efficacy, safety, and pharmacokinetics when compared with their reference products.

Relevance to Patient Care and Clinical Practice

The anticipated growth of biologics in oncology and the recent introduction of biosimilars over the past few years have placed a lot of emphasis on biosimilars as a significant source of cost savings for the health care system. Our article compiles and analyzes existing data on biosimilar efficacy, safety, and financial impact.

Conclusions

The major concerns of biosimilars revolve around their long-term efficacy and safety. Even with many questions to be answered, biosimilars have the potential for significant cost savings in the US health care system.

Totality of Scientific Evidence in the Development of ABP 980, a Biosimilar to Trastuzumab

ABP 980 was developed as a biosimilar to trastuzumab, a monoclonal antibody targeting human epidermal growth factor receptor 2 (HER2), that is indicated for the treatment of HER2-positive metastatic breast cancer, early breast cancer (EBC), and metastatic gastric cancer. ABP 980 is approved in the United States, European Union, and Japan for all the indications of trastuzumab, based on the totality of evidence (TOE) gathered by the systematic step-wise accumulation of comparative analytical, preclinical, and clinical (pharmacokinetics [PK], efficacy, safety and immunogenicity) data for ABP 980 and trastuzumab reference product (RP). As a key first step of the ABP 980 biosimilar program, comprehensive analytical characterization of critical quality attributes established that ABP 980 is structurally and functionally similar to trastuzumab RP. Complementing these data, results of non-clinical pharmacology, toxicology, and toxicokinetic studies supported similarity between ABP 980 and trastuzumab RP. A randomized study in healthy subjects demonstrated clinical PK equivalence of ABP 980 relative to trastuzumab RP in these subjects. In the final clinical evaluation step, a randomized comparative study (LILAC) confirmed the lack of clinically meaningful differences between ABP 980 and trastuzumab RP in efficacy, safety, and immunogenicity in women with HER2-positive EBC in the neoadjuvant–adjuvant setting. Neoadjuvant EBC represented a sensitive homogenous population for biosimilar demonstrations, and the primary endpoint of pathologic complete response served as a sensitive surrogate endpoint. An important aspect of the LILAC study design is that it is the only study that evaluated the effect of switching from the trastuzumab RP to a trastuzumab biosimilar during the adjuvant phase. No new or unexpected safety signals emerged in the clinical evaluations, with the safety profile of ABP 980 consistent with that previously described for trastuzumab. Overall, the TOE data generated for ABP 980 support the conclusion that it is highly similar to trastuzumab RP, thus providing the scientific justification for extrapolation to all the approved indications of trastuzumab.

Understanding the Role of Comparative Clinical Studies in the Development of Oncology Biosimilars

Biosimilars have the potential to broaden patient access to biologics and provide cost savings for health care systems. During the development of a biosimilar, data that directly compare the proposed biosimilar with the reference product are required. Such comparative data are generated in a stepwise hierarchical process that begins with extensive laboratory-based structural analyses and functional assays. This initial analytical phase serves as the foundation for the demonstration of biosimilarity and is followed by nonclinical in vivo testing (if required) and then clinical evaluation, including a comparative pharmacokinetics/pharmacodynamics study that is usually conducted in healthy volunteers. The development program typically culminates with a comparative clinical efficacy study. The aim of this study is to confirm clinical equivalence of the potential biosimilar and reference product on the basis of prespecified margins, using a study population and efficacy end point that are sufficiently sensitive for detecting potential product-related differences. Such studies also include detailed analyses of safety as well as evaluation of immunogenicity. As biosimilars become more widely available in oncology, especially with recent regulatory approvals of rituximab, trastuzumab, and bevacizumab biosimilars, it is critically important that clinicians understand how the comparative clinical study differs from a traditional phase III efficacy and safety study in the development of a novel biologic originator product. Here, we review the role of comparative clinical studies in biosimilar development, with a focus on trials conducted to support approved trastuzumab biosimilars. We discuss the study populations and end points used, extrapolation of indications, and the confirmatory nature of these studies within the totality of evidence supporting biosimilarity.

Overcoming trastuzumab resistance in HER2-positive breast cancer using combination therapy

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) comprises around 20-30% of all BC subtypes and is correlated with poor prognosis. For many years, trastuzumab, a monoclonal antibody, has been used to inhibit the HER2 activity. Though, the main resistance to trastuzumab has challenged the use of this drug in the management of HER2-positive BC. Therefore, the determination of resistance mechanisms and the incorporation of new agents may lead to the development of a better blockade of the HER family receptor signaling. During the last few years, some therapeutic drugs have been developed for treating patients with trastuzumab-resistant HER2-positive BC that have more effective influences in the management of this condition. In this regard, the present study aimed at reviewing the mechanisms of trastuzumab resistance and the innovative therapies that have been investigated in trastuzumab-resistant HER2-positive BC subjects.

Towards personalized treatment for early stage HER2-positive breast cancer

Advances in HER2-targeted therapies have improved the survival of patients with HER2-positive breast cancer. The standard-of-care treatment for localized disease has been chemotherapy and 1 year of adjuvant HER2-targeted therapy, typically with the anti-HER2 antibody trastuzumab. Despite the effectiveness of this treatment, disease relapse occurs in a subset of patients; thus, focus has been placed on escalating treatment by either combining different HER2-targeted agents or extending the duration of HER2-targeted therapy. Indeed, dual HER2-targeted therapies and extended-duration anti-HER2 therapy, as well as adjuvant therapy with the anti-HER2 antibody-drug conjugate T-DM1, have all been approved for clinical use. Emerging evidence suggests, however, that some patients do not derive sufficient benefit from these additional therapies to offset the associated toxicities and/or costs. Similarly, the universal use of chemotherapy might not benefit all patients, and treatment de-escalation through omission of chemotherapy has shown promise in clinical trials and is currently being explored further. The future of precision medicine should therefore involve tailoring of therapy based on the genetics and biology of each tumour and the clinical characteristics of each patient. Predictive biomarkers that enable the identification of patients who will benefit from either escalated or de-escalated treatment will be crucial to this approach. In this Review, we summarize the available HER2-targeted agents and associated mechanisms of resistance, and describe the current therapeutic landscape of early stage HER2-positive breast cancer, focusing on strategies for treatment escalation or de-escalation.

Time to Review Authorisation and Funding for New Cancer Medicines in Europe? Inferences from the Case of Olaratumab

The potential benefits of early patient access to new medicines in areas of high unmet medical need are recognised, but uncertainties concerning effectiveness, safety and added value when new medicines are authorised, and subsequently funded based on initial preliminary data only, have important implications. In 2016 olaratumab received accelerated conditional approval from both the European Medicines Agency and the US Food and Drug Administration for the treatment of soft-tissue sarcoma, based on the claims of a substantial reduction in the risk of death with an 11.8-month improvement in median overall survival in a phase II trial in combination with doxorubicin vs. doxorubicin alone. The failure to confirm these benefits in the post-authorisation pivotal trial has highlighted key concerns regarding early access and conditional approvals for new medicines. Concerns include potentially considerable clinical and economic costs, so that patients may have received suboptimal treatment and any money spent has foregone the opportunity to improve access to effective treatments. As a result, it seems reasonable to reconsider current marketing authorisation models and approaches. Potential pathways forward include closer collaboration between regulators, pharmaceutical companies and payers to enhance the generation of rapid and comparative confirmatory trials in a safe and fair manner, with minimal patient exposure as required to achieve robust evidence. Additionally, it may be time to review early access systems, and to explore new avenues regarding who should pay or part pay for new treatments whilst information is being collected as part of any obligations for conditional marketing authorisation. Greater co-operation between countries regarding the collection of data in routine clinical care, and further research on post-marketing data analysis and interpretation, may also contribute to improved appraisal and continued access to new innovative cancer treatments.

Biosimilars for breast cancer: a review of HER2-targeted antibodies in the United States

The utilization of trastuzumab biosimilar medications is of particular interest in HER2-positive breast cancer as these drugs have the potential for cost savings and increased utilization/access to HER2 targeted therapy in both early stage and metastatic HER2-positive breast cancers. Five trastuzumab biosimilars: MYL-1401O (Ogivri), CT-P6 (Herzuma), SB3 (Ontruzant), PF-05280014 (Trazimera), and ABP980 (Kanjinti), have now been approved by the US Food and Drug Administration (FDA) for use in HER2-positive breast cancers. This review provides an overview of these agents with special consideration of the development and approval process, including available clinical data results for these trastuzumab biosimilars. Adoption in the clinic will depend on the degree of comfort with the overall evidence.

Population pharmacokinetics of PF-05280014 (a trastuzumab biosimilar) and reference trastuzumab (Herceptin®) in patients with HER2-positive metastatic breast cancer

Purpose

PF-05280014 is a biosimilar to trastuzumab (Herceptin^®). Following demonstration of pharmacokinetic (PK) similarity in healthy volunteers, a comparative clinical study in patients with HER2-positive metastatic breast cancer (mBC) compared the efficacy, safety and immunogenicity of PF-05280014 and trastuzumab sourced from the EU (trastuzumab-EU), both with paclitaxel.

Methods

Population PK of PF-05280014 and trastuzumab-EU was evaluated.

Results

Overall, 702 patients were treated: PF-05280014 (n = 349) and trastuzumab-EU (n = 353). Peak-and-trough serum drug concentration samples were collected (selected doses) following repeated intravenous administration of PF-05280014 or trastuzumab-EU. Population PK analysis was performed with drug concentration–time data to cycle 17 for each compound, using nonlinear mixed effect modeling. Potential baseline covariates (circulating HER2 concentrations, body weight, Japanese race, Eastern Cooperative Oncology Group status, number of metastatic sites and antidrug antibody status) were evaluated. Concentration–time data of PF-05280014 and trastuzumab-EU were adequately described by a two-compartment model with first-order elimination, with inter-individual variability (IIV) on clearance (CL), volumes of distribution in central compartment (V₁) and peripheral compartments, and intercompartment clearance. Similar estimated PK parameters and IIV were obtained for both treatments. For PF-05280014 and trastuzumab-EU, baseline body weight was an influential covariate on CL and V₁; the magnitude was comparable between treatments. PK was consistent between the limited number of Japanese and non-Japanese patients for both compounds.

Conclusions

PF-05280014 and trastuzumab-EU had similar PK parameters and influential PK covariates in patients with HER2-positive mBC. These results provided further evidence in patients for PK similarity between PF-05280014 and trastuzumab-EU.

Clinical trial registration

ClinicalTrials.gov, NCT01989676.

Current situation and challenges regarding biosimilars in Japan: an example of trastuzumab biosimilars for breast cancer

Biologics have dramatically changed breast cancer treatment, and trastuzumab has been an essential treatment drug for HER2-positive breast cancer. The introduction of trastuzumab biosimilar offers the potential to deliver long-term cost savings plus efficiencies for healthcare systems in Japan. The goal of biosimilar development is to demonstrate comparability to the original biologic with a different development concept from that of the original biologic. Hence, a better understanding of the biosimilar itself is urgently needed for appropriate adoption and the integration of trastuzumab biosimilars into oncology clinical practice by all stakeholders. This article focuses on the current situation of biosimilars and future perspectives in Japan by using the trastuzumab biosimilar as an example.

What Does the Pipeline Promise about Upcoming Biosimilar Antibodies in Oncology?

The introduction of biosimilars of biological agents for which the patents and exclusivity periods have expired is an attractive way of reducing healthcare spending through price competition with the reference product. In oncology, biosimilars of growth factors for supportive therapy were the pioneers; now, monoclonal antibody biosimilars are conquering the market. In Europe, this is currently limited to biosimilars of the monoclonal antibodies trastuzumab and rituximab. However, the pipeline is full and several monoclonal antibody biosimilars in oncology are now in late-stage development. We are expecting not only more biosimilar versions of the top 3 blockbuster monoclonal antibodies, trastuzumab, rituximab and bevacizumab, to enter the market; as patent expiration of multiple other cancer biologicals will occur in the next few years, the biosimilar landscape will become much more diversified. Several biosimilars of monoclonal antibodies used in targeted therapy such as cetuximab, pertuzumab, or denosumab are in early development.

Biosimilar Trastuzumab in Clinical Trials: Differences or Not?

In the last decade, cancer therapies have increasingly taken the form of combination treatments in which biologic agents play a crucial role. In breast cancer, the treatment strategy is adjusted to intrinsic subtypes such as human epidermal growth factor receptor-2(HER2)-positive. With the introduction of trastuzumab, a monoclonal antibody against HER2, survival has significantly improved in early and metastatic breast cancer. Trastuzumab's patent has now expired and biosimilars are moving into the market. Several clinical trials have led to the approval of 5 different biosimilar trastuzumabs. Results proved similarity between the proposed biosimilar and the reference product without significant differences in efficacy and safety, although follow-up has been short. However, the shorter drug development process with its goal of showing similarity rather than patient benefit uses surrogate endpoints such as pathologic complete response and overall response rate, not survival endpoints in terms of the 'gold standarD' in evaluating cancer therapies. The aim of this article is to give insight into how to plan and perform a clinical trial to prove equivalence between a biosimilar trastuzumab and its reference product and to elucidate the setup and outcome of published clinical trials.