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

Achieving white blood cell equity: are the safety profiles of biosimilar and reference pegfilgrastims comparable?

Biosimilars can provide choices for patients and may provide cost savings; however, their uptake has been slow in the USA, in part due to limited knowledge. To provide additional confidence in US pegfilgrastim biosimilars, this narrative review compared the safety profiles of biosimilar pegfilgrastims, currently approved or filed for approval in the USA, with the EU- and US-approved reference pegfilgrastims. Headache and bone pain were common to biosimilars and reference products and occurred at a similar incidence. Clinical trial data on the safety profiles of biosimilar pegfilgrastims and reference products have demonstrated similarity and comparability, with no unexpected safety outcomes. Overall, the safety profiles of biosimilar pegfilgrastims and reference pegfilgrastims demonstrated a high degree of similarity and comparability.

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.

Regulatory Evaluation of Biosimilars: Refinement of Principles Based on the Scientific Evidence and Clinical Experience

The World Health Organization (WHO) guidelines on evaluation of similar biotherapeutic products (SBPs; also called biosimilars) were adopted by the WHO Expert Committee on Biological Standardization (ECBS) in 2009. In 2019, the ECBS considered that a more tailored and potentially reduced clinical data package may be acceptable in cases where this was clearly supported by the available scientific evidence. The goal of this publication is to review the current clinical experience and scientific evidence and to provide an expert perspective for updating the WHO guidelines to provide more flexibility and clarity. As the first step, the relevant guidelines by other regulatory bodies were reviewed in order to identify issues that might help with updating the WHO guidelines. Next, a literature search was conducted for information on the long-term efficacy, safety, and immunogenicity of biosimilars to identify possible long-term problems. Finally, a search for articles concerning the role of clinical studies in the benefit-risk evaluation of biosimilars was conducted. The analysis of other guidelines suggested that the WHO guidelines may need more emphasis on the importance of the state-of-the-art physicochemical and structural comparability exercise and in vitro functional testing. The use of "foreign" reference product will also need clarifications. The value of in vivo toxicological tests in the development of biosimilars is questionable, and the non-clinical part needs revisions accordingly. The concepts of "totality of evidence," "stepwise development," and "residual uncertainty" were applied in the evaluation of the clinical sections of the guideline. The review of long-term safety and efficacy demonstrated the robustness of the current biosimilar development concept. The analysis of the roles of different development phases suggested that the large efficacy, safety, and immunogenicity studies are, in most cases, redundant. The residual uncertainty of safety, immunogenicity, and efficacy of biosimilars that has shaped the current regulatory guidelines is now substantially reduced. This will allow the re-evaluation of the non-clinical and clinical requirements of the current WHO main guideline. The shift of the relative impact of the development phases towards physico-chemical and in vitro functional testing will provide a relief to the manufacturers and new challenges to the regulators.

Long-acting versus short-acting granulocyte colony-stimulating factors among cancer patients after chemotherapy in China: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Granulocyte colony-stimulating factors (G-CSFs) include long-acting ones and short-acting ones. They have been mainly applied in Chinese clinical practice for years to prevent neutropenia. However, which type of G-CSF is more superior has not been conclusively determined.

METHODS

A systematic literature search was conducted using the PubMed, Embase, Cochrane Library, clinical trials.gov, China National Knowledge Infrastructure, and WAN FANG databases for related studies published till August 2021. Revman 5.3 software was used to assess the effectiveness and safety of these 2 types of G-CSFs in patients undergoing chemotherapy.

RESULTS

Ten studies involving 1916 patients were included in our meta-analysis to compare the effectiveness and safety of long-acting G-CSFs and short-acting G-CSFs. We found that the incidence of febrile neutropenia (relative risk [RR] 0.82; 95% confidence interval [CI] 0.57-1.17), the recovery time of the absolute neutrophil count (mean difference -0.23; 95% CI -0.49 to 0.03), and the fatigue rate (RR 0.82; 95% CI 0.62-1.07) were similar between the long- and the short-acting G-CSFs. However, the long-acting G-CSFs significantly decreased the incidence (RR 0.86; 95% CI 0.76-0.96) and shortened the duration (mean difference -0.19; 95% CI -0.38 to 0.00) of severe (grade ≥3) neutropenia, and decreased the rate of bone and/or muscle pain (RR 0.75; 95% CI 0.58-0.98).

CONCLUSION

Primary prophylaxis with long-acting G-CSFs was more effective and safer than primary prophylaxis with short-acting G-CSFs in Chinese adults undergoing chemotherapy.

Comparative effectiveness and safety of pharmaceuticals assessed in observational studies compared with randomized controlled trials

BACKGROUND

There have been ongoing efforts to understand when and how data from observational studies can be applied to clinical and regulatory decision making. The objective of this review was to assess the comparability of relative treatment effects of pharmaceuticals from observational studies and randomized controlled trials (RCTs).

METHODS

We searched PubMed and Embase for systematic literature reviews published between January 1, 1990, and January 31, 2020, that reported relative treatment effects of pharmaceuticals from both observational studies and RCTs. We extracted pooled relative effect estimates from observational studies and RCTs for each outcome, intervention-comparator, or indication assessed in the reviews. We calculated the ratio of the relative effect estimate from observational studies over that from RCTs, along with the corresponding 95% confidence interval (CI) for each pair of pooled RCT and observational study estimates, and we evaluated the consistency in relative treatment effects.

RESULTS

Thirty systematic reviews across 7 therapeutic areas were identified from the literature. We analyzed 74 pairs of pooled relative effect estimates from RCTs and observational studies from 29 reviews. There was no statistically significant difference (based on the 95% CI) in relative effect estimates between RCTs and observational studies in 79.7% of pairs. There was an extreme difference (ratio < 0.7 or > 1.43) in 43.2% of pairs, and, in 17.6% of pairs, there was a significant difference and the estimates pointed in opposite directions.

CONCLUSIONS

Overall, our review shows that while there is no significant difference in the relative risk ratios between the majority of RCTs and observational studies compared, there is significant variation in about 20% of comparisons. The source of this variation should be the subject of further inquiry to elucidate how much of the variation is due to differences in patient populations versus biased estimates arising from issues with study design or analytical/statistical methods.

Efficacy and Safety of Filgrastim and Its Biosimilars to Prevent Febrile Neutropenia in Cancer Patients: A Prospective Study and Meta-Analysis

Simple Summary

Febrile neutropenia is the serious side-effect associated with myelosuppressive chemotherapy. Filgrastim, the first granulocyte colony-stimulating factor (G-CSF) was approved by the Food and Drug Administration for the treatment of neutropenia. Subsequently, pegfilgrastim (long-acting G-CSF) and filgrastim biosimilars were developed to have comparable efficacy to filgrastim. Therefore, it is necessary to produce a systematic review and meta-analysis that provides evidence that filgrastim is more efficacious than placebo/no-treatment, as it provides evidence on the comparable efficacy of filgrastim versus pegfilgrastim and biosimilar filgrastim.

Abstract

Background: The aim of this review and meta-analysis was to identify, assess, meta-analyze and summarize the comparative effectiveness and safety of filgrastim in head-to-head trials with placebo/no treatment, pegfilgrastim (and biosimilar filgrastim to update advances in the field. Methods: The preferred reporting items for systematic reviews and meta-analyses PRISMA statement were applied, and a random-effect model was used. Primary endpoints were the rate and duration of grade 3 or 4 neutropenia, and an incidence rate of febrile neutropenia. Secondary endpoints were time to absolute neutrophil count ANC recovery, depth of ANC nadir (lowest ANC), neutropenia-related hospitalization and other neutropenia-related complications. For filgrastim versus biosimilar filgrastim comparison, the primary efficacy endpoint was the mean difference in duration of severe neutropenia DSN. Results: A total of 56 studies were considered that included data from 13,058 cancer patients. The risk of febrile neutropenia in filgrastim versus placebo/no treatment was not statistically different. The risk ratio for febrile neutropenia was 0.58, a 42% reduction in favor of filgrastim. The most reported adverse event with FIL was bone pain. For pegfilgrastim versus filgrastim, no statistically significant difference was noted. The risk ratio was 0.90 (95% CI 0.67 to 1.12). The overall difference in duration of severe neutropenia between filgrastim and biosimilar filgrastim was not statistically significant. The risk ratio was 1.03 (95% CI 0.93 to 1.13). Conclusions: Filgrastim was effective and safe in reducing febrile neutropenia and related complications, compared to placebo/no treatment. No notable differences were found between pegfilgrastim and filgrastim in terms of efficacy and safety. However, a similar efficacy profile was observed with FIL and its biosimilars.

Prognostic value of pretreatment anemia in patients with soft tissue sarcoma: A meta-analysis

BACKGROUND

Anemia is one of the most common manifestations in patients with cancer. Recently, multiple studies have shown a positive correlation between pretreatment anemia and tumor prognosis. Yet, the relationship between pretreatment anemia and the prognosis of soft tissue sarcomas (STS) is unclear.

METHODS

We searched the PubMed and EMBASE databases to identify relevant studies. Eligible studies were included according to the inclusion criteria to assess the relationship between pretreatment anemia and the prognosis of patients with STS. Prognostic significance was determined by studying hazard ratios (HR) and 95% confidence intervals (CIs).

RESULTS

A total of 12 studies are included. If there is significant heterogeneity, a random-effects model is used. Pooled data indicated that pretreatment anemia is related to poor overall survival (HR = 2.13; 95%CI = 1.52-2.98), disease-specific survival (HR = 1.53; 95%CI = 1.20-1.96), and disease-free survival (HR = 1.55; 95%CI = 1.10-2.17). The results of the subgroup analysis also support this conclusion.

CONCLUSION

Our results suggest that pretreatment anemia may be a prognostic biomarker for STS.

Uptake and cost of biosimilar filgrastim among Medicare and Medicaid populations in 2015-2018

BACKGROUND: The first biosimilar product filgrastim-sndz was approved by the FDA in 2015, but real-world evaluations of its uptake and cost in nationally representative populations are limited. OBJECTIVE: To evaluate the uptake and cost of filgrastim-sndz, relative to its originator filgrastim and alternative biologic tbofilgrastim, among Medicare and Medicaid populations. METHODS: Using the annually aggregated, product-level utilization and cost data of biologic and biosimilar filgrastim products in 2015-2018 from CMS drug spending data, total number of claims and costs for all 3 filgrastim products were identified and extracted for Medicare Part B, Part D, and Medicaid reimbursement. Annual average cost per claim and per beneficiary of individual filgrastim products were also extracted, and their annual growth rates were calculated. RESULTS: Three years after entering the US market, use of filgrastim-sndz increased to 49.1% and 46.0% of all filgrastim claims paid by Medicare Parts B and D, respectively, and to 38.7% of filgrastim Medicaid claims in 2018. Total cost for filgrastim-sndz also reached 42.8%, 41.8%, and 26.9% of all filgrastim products paid by Medicare Parts B and D and Medicaid, respectively. Significant reductions in average cost per claim for filgrastim-sndz in 2017 and 2018 were observed in Medicare Part B and Medicaid. CONCLUSIONS: Significant uptake of biosimilar filgrastim in Medicare and Medicaid programs occurred during the first 3 years of marketing. Policymakers may use the evidence to evaluate existing barriers and policies regarding biosimilar adoption. DISCLOSURES: No outside funding supported this work. The author has no conflicts of interest to disclose.

Safety of Marketed Cancer Supportive Care Biosimilars in the US: A Disproportionality Analysis Using the Food and Drug Administration Adverse Event Reporting System (FAERS) Database

BACKGROUND

Since the approval and availability of the first biosimilar in 2015 in the United States (US), evidence regarding the post-marketing safety of cancer supportive care biosimilars remains limited.

OBJECTIVE

The aim was to explore the adverse event (AE) reporting patterns and detect disproportionate reporting signals for cancer supportive care biosimilars in the US compared to their originator biologics.

METHODS

The US Food and Drug Administration Adverse Event Reporting System database (January 1, 2004-March 31, 2020) was used to identify AE reports for filgrastim, pegfilgrastim, and epoetin alpha by type of product (originator biologics vs. biosimilars) and report characteristics. Plots of AE reports against years were used to reveal the reporting patterns. Disproportionality analyses using reporting odds ratios (RORs) were conducted to detect differences in serious and specific AEs between studied drugs and all other drugs. Breslow-Day tests were used to determine homogeneity between the originator biologic-biosimilar pair RORs for the same AE.

RESULTS

Total numbers of AEs for all studied biosimilars increased after marketing. More AE reports were from female patients for all of the studied drugs. More AEs for originator biologics and filgrastim biosimilar were reported by health professionals, while the highest proportion of reports came from consumers for pegfilgrastim and epoetin alpha biosimilars (29% and 44.1%, respectively). Signals of disproportionate reporting in serious AEs were detected for a pegfilgrastim biosimilar (Fulphila^®) compared to its originator biologic.

CONCLUSION

Our findings support the similarity in the signals of disproportionate reporting between cancer supportive care originator biologics and biosimilars, except for Fulphila^®.

Pharmacoeconomic Evaluation of Cancer Biosimilars Worldwide: A Systematic Review

Background and Purpose: The availability of oncology biosimilars is deemed as a fundamental strategy to achieve sustainable health care. However, there is scarce systematic evidence on economic effectiveness of cancer biosimilars. We aimed to synthesize evidence from pharmacoeconomic evaluation of oncology biosimilars globally, provide essential data and methodological reference for involved stakeholders. Materials and Methods: This systematic review was conducted in PubMed, embase, the Cochrane library, CRD, ISPOR and NICE utill December 31, 2019. Information on basic characteristics, evaluation methodology and results were extracted. Quality of included studies was assessed using the Consolidated Health Economic Evaluation Reporting Standards Checklist. Results: For 17 studies identified (13 from Europe and four from United States), the overall quality was generally acceptable. A total of seven biological molecules involved with filgrastim, EPOETIN α, and trastuzumab leading the three. The mostly common evaluation perspective was payer, but the time horizon varied greatly. There were ten studies which adopted cost minimization analysis to evaluate efficiency while seven studies adopted budget impact analysis to address affordability, with cost ratio and cost saving being its corresponding primary endpoint. Although the comparability of included studies was limited and specific results were largely affected by uptake and price discount rates of the oncology biosimilar, the comprehensive results consistently favored its promotion. Conclusion: Globally, the economic evaluation of cancer biosimilars is in its initial phase. However, limited evidence from developed countries consistently supported both cost-effectiveness of efficiency and affordability of oncology biosimilars, while they were largely affected by uptake and price discount rate.

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.

Biosimilars in supportive care

PURPOSE OF REVIEW

This review covers recent publications relating to the use of biosimilar medicines in the supportive care of cancer patients, and broader publications focussed on the benefits and challenges of implementing biosimilars into clinical practice.

RECENT FINDINGS

A metaanalysis and a number of systematic literature reviews have confirmed that the safety and efficacy of biosimilar versions of epoetin-α, filgrastim and infliximab are equivalent to those of their corresponding reference biologics. New guidelines have been issued concerning the interchangeability of biosimilars and the practice of substituting a biosimilar in place of a prescribed reference product. The introduction of biosimilars into a health system has been shown to improve patient access to treatment while also delivering cost savings, however, there are a number of barriers that can prevent or delay the adoption of biosimilars into clinical practice which must be overcome for the potential benefits of biosimilars to be realized.

SUMMARY

There is a large amount of data to demonstrate that supportive care biosimilars are well tolerated and effective, with over 10 years of experience in Europe. We can learn from the challenges faced when introducing biosimilars into supportive care to facilitate the introduction of newer biosimilars into the treatment setting.