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

Biosimilar monoclonal antibodies for cancer treatment in adults

BACKGROUND

Biosimilars are products containing an approved biological medicine. They are similar, but not identical, to an originator medicine. In cancer, biosimilars have been developed from the monoclonal antibodies, bevacizumab, rituximab, and trastuzumab. They have become available for the treatment of lung, colorectal, non-Hodkin's lymphoma, and breast cancers. As these biological products are not identical, synthesis of evidence of the clinical effects of biosimilars compared to their originators is needed to understand their comparative effectiveness and harms.

OBJECTIVES

To evaluate the benefits and harms of biosimilar monoclonal antibodies versus their originator drugs for adults with cancer.

SEARCH METHODS

We searched bibliographic (CENTRAL, MEDLINE, Embase, Web of Science) and clinical trials databases to February 2024.

SELECTION CRITERIA

We included head-to-head randomised controlled trials conducted in adults with cancer treated with biosimilar or originator monoclonal antibodies.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. Primary outcomes were progression-free survival, duration of response, overall survival, breast cancer's pathological complete response, serious adverse events, and health-related quality of life. If survival estimates were adjusted or provided as rates, we did not combine them. We used Cochrane's RoB 1 tool to assess the risk of bias and GRADE to evaluate the certainty of evidence of critical and important outcomes according to the relevance determined by consumers.

MAIN RESULTS

We included 55 studies with 22,046 adults (23 of bevacizumab, 10,639 participants with colorectal or lung cancer; 17 of rituximab, 4412 participants with non-Hodgkin's lymphoma; and 15 of trastuzumab, 6995 participants with breast cancer). Studies were conducted in all continents, most were multicentre, and all were funded by the drug manufacturer. Participants' ages ranged from 47 (mean) to 62 (median) years and the proportion of women from 18% to 100%. Fifteen studies were conducted as non-inferiority and 40 as equivalence. The overall risk of bias was low; main biases were in the incomplete outcome data and selective reporting domains. Bevacizumab biosimilar versus bevacizumab originator in lung or colorectal cancer Progression-free survival is likely similar between bevacizumab biosimilar and the originator (per 1000: 380 in both groups at 12 months, hazard ratio (HR) 1.00, 95% confidence interval (CI) 0.91 to 1.09; 5 studies, 2660 participants; moderate-certainty evidence). There were no differences in lung or colorectal cancer subgroups. Bevacizumab biosimilar is likely similar to the originator in duration of response (per 1000: 219 participants who achieved response progressed with biosimilar versus 210 with originator at 12 months; HR 1.05, 95% CI 0.81 to 1.37; 1 study, 762 participants; moderate-certainty evidence) and overall survival (per 1000: 592 with biosimilar versus 610 with originator at 12 months; HR 1.06, 95% CI 0.94 to 1.19; 5 studies, 2783 participants; moderate-certainty evidence). There were no differences in cancer type subgroups. Bevacizumab biosimilar is likely similar to the originator in serious adverse events (per 1000: 303 with biosimilar versus 309 with originator; risk ratio (RR) 0.98, 95% CI 0.93 to 1.03; 23 studies, 10,619 participants; moderate-certainty evidence). Bevacizumab biosimilar may be similar to originator in health-related quality of life as scores were comparable in the one study that assessed this outcome in metastatic colorectal cancer (low-certainty evidence). This critical outcome was not assessed in other biosimilars comparisons. Bevacizumab biosimilar is likely similar to originator in objective response (per 1000: 481 with biosimilar versus 501 with originator; RR 0.96, 95% CI 0.93 to 1.00; 23 studies, 10,054 participants; moderate-certainty evidence) and mortality (per 1000: 287 with biosimilar versus 279 with originator; RR 1.03, 95% CI 0.97 to 1.09; 19 studies, 9231 participants; moderate-certainty evidence). There were no differences in lung or colorectal cancers. Rituximab biosimilar versus rituximab originator in non-Hodgkin's lymphoma Rituximab biosimilar is likely similar to originator in progression-free survival (7 studies, 2456 participants), duration of response (2 studies, 522 participants), and overall survival (7 studies, 2353 participants; data not pooled as survival estimates were adjusted for different factors or reported as rates) (all moderate-certainty evidence). Rituximab biosimilar is likely similar to originator in the risk of serious adverse events (per 1000: 210 with biosimilar versus 204 with originator; RR 1.03, 95% CI 0.94 to 1.14; 15 studies, 4197 participants; moderate-certainty evidence) and objective response (per 1000: 807 with biosimilar versus 799 with originator; RR 1.01, 95% CI 0.98 to 1.04; 16 studies, 3922 participants; moderate-certainty evidence). No study reported quality of life. Rituximab biosimilar is similar to originator in mortality (per 1000: 52 with biosimilar versus 53 with originator; RR 0.97, 95% CI 0.70 to 1.35; 8 studies, 2557 participants; high-certainty evidence). Trastuzumab biosimilar versus trastuzumab originator in breast cancer Trastuzumab biosimilar is likely similar to originator in progression-free survival (4 studies, 2221 participants), duration of response (3 studies, 1488 participants), and overall survival (6 studies, 2221 participants), which were not pooled due to adjustment for different factors or provided as rates. No study reported quality of life. Trastuzumab biosimilar may be similar to originator in pathological complete response (per 1000: 459 with biosimilar versus 433 with originator; RR 1.06, 95% CI 0.95 to 1.17; 7 studies, 3403 participants; low-certainty evidence), is likely similar in serious adverse events (per 1000: 129 in both groups; RR 1.00, 95% CI 0.85 to 1.17; 13 studies, 6183 participants; moderate-certainty evidence), and slightly increases objective response (per 1000: 801 with biosimilar versus 777 with originator; RR 1.03, 95% CI 1.01 to 1.05; 13 studies, 5509 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Treatment with bevacizumab, rituximab, and trastuzumab biosimilars are likely similar to their originator drugs in terms of their impact on progression-free survival, duration of response, overall survival, serious adverse events, objective response, and mortality. Limited evidence showed similarity in pathological complete response for trastuzumab and quality of life for bevacizumab compared with originators, which was not assessed in the other comparisons. The overall certainty of evidence was moderate and imprecision was the main reason for downgrading our certainty in the findings.

Safety profile of trastuzumab originator vs biosimilars: a systematic review and meta-analysis of randomized clinical trials

PURPOSE

In the last decade trastuzumab biosimilars became more and more frequent. Among their uses, from several years, they have been available in Europe for the treatment of HER2-positive metastatic breast cancer, as an alternative to Herceptin®.

METHODS/PATIENTS

This meta-analysis aimed to analyze the available literature with particular focus on phase 3 randomized clinical trials (RCTs) comparing adverse events between trastuzumab biosimilar and originator. A systematic review was conducted in Pubmed and Scopus to include all phase 3 RCTs related to trastuzumab in patients with HER2-positive breast cancer and published up to July 31, 2023. Of the 508 records identified, 14 articles were meta-analyzed for safety information, including serious treatment emergent adverse events, death-related adverse events, neutropenia, leukopenia, infections, increased ALT, increased AST, anti-drug antibody, and neutralizing antibody.

RESULTS

Included patients had an early breast cancer (N=2,877) or a metastatic breast cancer (N=2,603). No significant difference in death-related adverse events was found for trastuzumab biosimilar and originator when evaluated for an early breast cancer in the neoadjuvant phase (Risk Ratio [RR], 1.30; 95% confidence interval [CI], 0.47-3.59; I2 = 0%; p = 0.57) and overall (RR, 0.43; 95%CI, 0.11-1.66; I2 = 20%; p = 0.26), and for metastatic breast cancer (RR, 0.61; 95%CI, 0.30-1.26; I2 = 0%; p = 0.85).

CONCLUSIONS

No difference was also observed for all other safety outcomes as in accordance with clinical studies necessary for the registration and approval of a biosimilar at a European level.

Subcutaneous versus intravenous administration of Trastuzumab: a minimization cost analysis with real world data from a reference cancer centre in Peru

Breast cancer (BC) is a global concern, with Peru experiencing a high incidence and mortality. Trastuzumab, a crucial treatment for human epidermal growth factor receptor 2-positive BC, is administered intravenously or subcutaneously (SC). This study evaluates the costs associated with both methods at Peru's Instituto Nacional de Enfermedades Neoplásicas. Real data indicate that SC administration reduces treatment costs by approximately S/15,049.09. Cross-continental comparisons highlight a global trend favouring SC administration for efficiency and cost-effectiveness. The analysis provides insights for informed decision-making in resource-constrained healthcare settings like Peru, emphasising the need to consider local contexts in optimising oncology care.

Comparison of the Real-World Reporting of Symptoms and Well-Being for the HER2-Directed Trastuzumab Biosimilar Ogivri With Registry Data for Herceptin in the Treatment of Breast Cancer: Prospective Observational Study (OGIPRO) of Electronic Patient-Reported Outcomes

BACKGROUND

Trastuzumab has had a major impact on the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). Anti-HER2 biosimilars such as Ogivri have demonstrated safety and clinical equivalence to trastuzumab (using Herceptin as the reference product) in clinical trials. To our knowledge, there has been no real-world report of the side effects and quality of life (QoL) in patients treated with biosimilars using electronic patient-reported outcomes (ePROs).

OBJECTIVE

The primary objective of this prospective observational study (OGIPRO study) was to compare the ePRO data related to treatment side effects collected with the medidux app in patients with HER2-positive BC treated with the trastuzumab biosimilar Ogivri (prospective cohort) to those obtained from historical cohorts treated with Herceptin alone or combined with pertuzumab and/or chemotherapy (ClinicalTrials.gov NCT02004496 and NCT03578731).

METHODS

Patients were treated with Ogivri alone or combined with pertuzumab and/or chemotherapy and hormone therapy in (neo)adjuvant and palliative settings. Patients used the medidux app to dynamically record symptoms (according to the Common Terminology Criteria for Adverse Events [CTCAE]), well-being (according to the Eastern Cooperative Oncology Group Performance Status scale), QoL (using the EQ-5D-5L questionnaire), cognitive capabilities, and vital parameters over 6 weeks. The primary endpoint was the mean CTCAE score. Key secondary endpoints included the mean well-being score. Data of this prospective cohort were compared with those of the historical cohorts (n=38 patients; median age 51, range 31-78 years).

RESULTS

Overall, 53 female patients with a median age of 54 years (range 31-87 years) were enrolled in the OGIPRO study. The mean CTCAE score was analyzed in 50 patients with available data on symptoms, while the mean well-being score was evaluated in 52 patients with available data. The most common symptoms reported in both cohorts included fatigue, taste disorder, nausea, diarrhea, dry mucosa, joint discomfort, tingling, sleep disorder, headache, and appetite loss. Most patients experienced minimal (grade 0) or mild (grade 1) toxicities in both cohorts. The mean CTCAE score was comparable between the prospective and historical cohorts (29.0 and 30.3, respectively; mean difference -1.27, 95% CI -7.24 to 4.70; P=.68). Similarly, no significant difference was found for the mean well-being score between the groups treated with the trastuzumab biosimilar Ogivri and Herceptin (74.3 and 69.8, respectively; mean difference 4.45, 95% CI -3.53 to 12.44; P=.28).

CONCLUSIONS

Treatment of patients with HER2-positive BC with the trastuzumab biosimilar Ogivri resulted in equivalent symptoms, adverse events, and well-being as found for patients treated with Herceptin as determined by ePRO data. Hence, integration of an ePRO system into research and clinical practice can provide reliable information when investigating the real-world tolerability and outcomes of similar therapeutic compounds.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05234021; https://clinicaltrials.gov/study/NCT05234021.

Acute thrombocytopenia induced by trastuzumab due to complement reaction: A case report

Background

The usual treatment option for HER2 breast cancer is targeted therapy with trastuzumab. The common adverse effects of trastuzumab treatment are thrombocytopenia, however, acute thrombocytopenia is rare and its mechanism is still largely unknown.

Case presentation

We reported a patient who presented with acute thrombocytopenia on two consecutive occasions, and the predisposing factor was identified on the second occasion because of trastuzumab-only treatment. Routine blood results showed a dramatic increase in white blood cell count and neutrophil count after both trastuzumab treatments. Moreover, the complement reaction results suggested that the dramatic thrombocytopenia was probably due to platelet destruction after complement activation.

Conclusion

This case suggests that it would be useful to perform a platelet complement reaction test before trastuzumab treatment in patients with HER2 breast cancer.

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.

Efficacy and Safety of Bevacizumab Biosimilars Compared With Reference Biologics in Advanced Non-small Cell Lung Cancer or Metastatic Colorectal Cancer Patients: A Network Meta-Analysis

Background: Bevacizumab biosimilars are slowly making their way into cancer treatment, but the data on their efficacy and safety in cancer patients are still poor. We systematically summarized the current evidence for the efficacy and safety of bevacizumab biosimilars in patients with advanced non-small cell lung cancer (NSCLC) or metastatic colorectal cancer (CRC).

Methods: This review searched CNKI, VIP, PubMed, Medline (Ovid), Embase, and Cochrane Library (Ovid) for randomized controlled trials of bevacizumab biosimilars treated in adults with advanced NSCLC or metastatic CRC. A pairwise meta-analysis and a Bayesian network meta-analysis based on the random-effect model were performed to summarize the evidence. We rated the certainty of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation framework.

Results: Ten eligible trials with a total of 5526 patients were included. Seven trials (n = 4581) were for the NSCLC population, while three trials (n = 945) were for patients with CRC. According to the pairwise meta-analysis, the efficacy (objective response rate: risk ratio (RR) 0.98 [0.92–1.04], p = 0.45; progression-free survival: hazard ratio (HR) 1.01 [0.92–1.10], p = 0.85; and overall survival: HR 1.06 [0.94–1.19], p = 0.35) and safety (incidence of grade 3–5 adverse events: odds ratio (OR) 1.03 [0.91–1.16], p = 0.65) of bevacizumab biosimilars performed no significant difference with reference biologics in patients with NSCLC as well as metastatic CRC patients (objective response rate: RR 0.97 [0.87–1.09], p = 0.60; overall survival: HR 0.94 [0.70–1.25], p = 0.66; incidence of grade 3–5 adverse events: OR 0.78 [0.59–1.02], p = 0.73). Network estimates displayed 7 types of bevacizumab biosimilars in the medication regime of NSCLC patients who had no significant difference among each other in terms of efficacy and safety. The certainty of the evidence was assessed as low to moderate. Three types of biosimilars were found to be clinically equivalent to each other in the patients with CRC, which were evaluated with very low to moderate certainty.

Conclusion: In patients with advanced NSCLC or metastatic CRC, the efficacy and safety of bevacizumab biosimilars were found to be comparable with those of reference biologics and each other.

Perspectives toward biosimilars among oncologists: A Malaysian survey

INTRODUCTION

Biosimilars confer significant cost-saving advantages and expand patients' access to biologic therapies in cancer care. In line with the increasing availability of antineoplastic biosimilars, it is pertinent to understand the oncologists' view on the adoption of biosimilars in their clinical practice. The study aimed to assess (i) the prevalence of biosimilar use, (ii) perception towards biosimilars, (iii) factors influencing the use of biosimilars and (iv) knowledge about biosimilars among Malaysian oncologists.

METHODS

A cross-sectional survey was conducted among clinical oncologists and medical oncologists in Malaysia between January 2020 and February 2021 using a structured 31-item questionnaire.

RESULTS

Among the 121 oncologists registered in the country, 36 responded (response rate  =  30%). A total of 64% of the respondents prescribed biosimilars either often or always. Most oncologists (72%) agreed or strongly agreed that switching will not have a significant effect on the treatment benefit, with lower percentages saying that they agreed or strongly agreed that it will not lead to the emergence of additional adverse effects (56%) or harmful immunogenicity (64%). Patients' preferences (40%) and the non-availability of biosimilars in hospitals (34%) are the major barriers cited to the prescribing of biosimilars. Cost differences and robust pharmacovigilance activities are the two most important factors that would influence the prescribing of biosimilars. The mean score of knowledge in biosimilar among respondents was 3.81 (± 0.86) out of a maximum possible score of 6.

CONCLUSIONS

The identified gap in prescribing and the use of biosimilars among Malaysian oncologists warrant educational intervention and robust pharmacovigilance activities to facilitate the prescribing of biosimilars and ultimately increase the accessibility to biologics in cancer treatment.

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.