Biosimilar Use in Breast Cancer Treatment: A National Survey of Brazilian Oncologists' Opinions, Practices, and Concerns

Barriers and Enablers Affecting the Uptake of Biosimilar Medicines Viewed Through the Lens of Actor Network Theory: A Systematic Review

BACKGROUND AND OBJECTIVE

Biosimilars represent an opportunity to realise savings against the costs of innovative medicines. Despite efforts made by stakeholders, there are numerous barriers to the uptake of biosimilars. To realise the promise of biosimilars reducing costs, barriers must be identified, understood, and overcome, and enablers magnified. The aim of this systematic review is to summarise the enablers and barriers affecting uptake of biosimilars through the application of a classification system to organise them into healthcare professional (HCP), patient, or systemic categories.

METHODS

A systematic literature search was performed in PubMed, Scopus, CINAHL, eConlit, and Embase. Included were primary research studies published in English between Jan 2017 through June 2023 focused on enablers and barriers affecting uptake of biosimilars. Excluded studies comprised comparisons of biosimilar efficacy and safety versus the reference biologic. One reviewer extracted data that included classification of barriers or enablers, the sub-classification, and the identification of the degree of agency associated with the actor through their role and associations as a mediator within their network, through the application of Actor Network Theory. The data were validated by a second reviewer (PV).

RESULTS

Of the 94 studies included, 59 were cross-sectional, 20 were qualitative research, 12 were cohort studies, and three were economic evaluations. Within the review, 51 of the studies included HCP populations and 35 included patients. Policies and guidelines were the most cited group of enablers, overall. Systemic enablers were addressed in 29 studies. For patients, the most frequently cited enabler was positive framing of a biosimilar, while for HCPs, cost benefit was the most frequently noted enabler. The most frequently discussed systemic barrier to biosimilar acceptance was lack of effective policies or guidelines, followed by lack of financial incentives, while the most significant barriers for HCPs and patients, respectively, were their lack of general knowledge about biosimilars and concerns about safety and efficacy. Systemic actors and HCPs most frequently acted with broad degree of agency as mediators, while patient most frequently acted with a narrow degree of agency as mediators within their networks.

CONCLUSIONS

Barriers and enablers affecting uptake of biosimilars are interconnected within networks, and can be divided into systemic, HCP, and patient categories. Understanding the agency of actors within networks may allow for more comprehensive and effective approaches. Systemic enablers in the form of policies appear to be the most effective overall levers in affecting uptake of biosimilars, with policy makers advised to give careful consideration to appropriately educating HCPs and positively framing biosimilars for patients.

Monoclonal antibody biosimilars for cancer treatment

Monoclonal antibodies are important cancer medicines. The European Medicines Agency (EMA) approved 48 and the Food and Drug Administration (FDA) 56 anticancer monoclonal antibody-based therapies. Their high prices burden healthcare systems and hamper global drug access. Biosimilars could retain costs and expand the availability of monoclonal antibodies. In Europe, five rituximab biosimilars, six trastuzumab biosimilars, and eight bevacizumab biosimilars are available as anti-cancer drugs. To gain insight into the biosimilar landscape for cancer treatment, we performed a literature search and analysis. In this review, we summarize cancer monoclonal antibodies' properties crucial for the desired pharmacology and point out sources of variability. The analytical assessment of all EMA-approved bevacizumab biosimilars is highlighted to illustrate this variability. The global landscape of investigational and approved biosimilars is mapped, and the challenges for access to cancer biosimilars are identified.

Unveiling the Biosimilar Paradox of Oncologists' Perceptions and Hesitations in South Korea: A Web-Based Survey Study

INTRODUCTION

Biosimilars offer a cost-effective alternative to original biopharmaceuticals with comparable efficacy and safety. The perception and familiarity of prescribers toward biosimilars play a critical role in their market penetration. Yet, few studies have explored the perception of oncologists toward biosimilars, much less in Asia.

OBJECTIVES

The objective of this study is to understand barriers of adopting biosimilars among oncologists and explore strategies to promote their use in clinical practice settings.

METHODS

A web-based survey was conducted among Korean oncologists from September to October 2022, assessing their perception of biosimilars and prescribing practices.

RESULTS

Among the 118 surveyed oncologists, 75.4% (89 out of 118) had previously prescribed biosimilars. When asked about their preference, 48.3% (57 out of 118) of the respondents preferred originators to biosimilars, whereas 16.1% (19 out of 118) favored biosimilars over the originators. The primary reason for preferring the originators was trust in safety and efficacy (94.7%, 54 out of 57). Still, a paradox was noted as 87.0% (47 out of 54) and 85.2% (46 out of 54) of these also acknowledged the comparable efficacy and safety of biosimilars. A relatively small number of the respondents (16.1%, 19 out of 118) did not consider prescribing biosimilars to biologic-naïve patients at all, and up to 56.8% (67 out of 118) expressed reluctance to switch prescriptions from originators to biosimilars. However, 90.7% (107 out of 118) of respondents considered changing their prescription to biosimilars if patients faced financial stress. Concerns regarding the efficacy when switching to biosimilars were expressed by 42.7% (38 out of 89) of oncologists with biosimilar prescribing experience, increasing to 69.0% (20 out of 29) among those without such experience.

CONCLUSION

Korean oncologists perceived biosimilars to be as safe and effective as originators. However, there is a notable mismatch between this perception and their prescribing practices, particularly among those who have not prescribed biosimilars before. The financial burden of patients served as a significant driver for prescribing biosimilars, yet marginal price differences between originators and biosimilars may be associated with the low adoption rate of biosimilars in Korea. Active price competition may enhance market penetration of biosimilars.

Biosimilar in Breast Cancer: A Narrative Review

Breast cancer (BC) has been identified as a major public health cancer as it topped the list of most prevalent cancers among women in the last three years. Rigorous research has been conducted to improve the prognosis of cancer therapies since the time of inception. Recent advancements in cancer therapy have introduced monoclonal biosimilars as a promising treatment alternative. Monoclonal antibodies (mAbs), produced through cloning, have demonstrated effectiveness in targeting diverse antigens. Biosimilar, considered complex entities compared to small-molecule drugs, pose challenges in replication due to their biological nature. The manufacturing process involves rigorous comparability testing to ensure similarity in quality, safety, and efficacy with the reference product. Trastuzumab biosimilars, such as CT-P6, Ontruzant®, ABP 980, and PF-05280014, have shown efficacy in treating HER2-positive metastatic BCs, presenting a viable alternative to the reference product. The implications of monoclonal biosimilars extend beyond trastuzumab, with bevacizumab emerging as another significant biosimilar for BC treatment. The shift toward biosimilar aims to enhance accessibility to biologics by reducing costs. Health economic analyses indicate potential cost savings, contributing to the overall cost-effectiveness of biosimilar adoption. While concerns about switching between reference products and biosimilars exist, evidence suggests a lower risk of immunogenicity-related side effects with mAbs like trastuzumab. Monoclonal biosimilars present a promising avenue in BC therapy, demonstrating efficacy, safety, and potential cost savings. The integration of biosimilars into cancer treatment strategies offers a means to improve accessibility to effective care while addressing economic considerations in healthcare.

Overall survival and associated factors in women with metastatic breast cancer treated with trastuzumab at a public referral institution

OBJECTIVE

To characterize associated factors and overall survival of women with metastatic breast cancer treated with trastuzumab after its incorporation into the SUS, and additionally to present the direct costs of this technology.

METHODS

This is a retrospective cohort, based on data from computerized medical records from one of the units of the National Cancer Institute (INCA), in Rio de Janeiro-RJ, Brazil. Women with HER-2 positive metastatic breast cancer undergoing trastuzumab treatment from September 2017 to August 2018 were included. Overall survival was estimated using the Kaplan-Meier method and compared between groups using the log-rank test.

RESULTS

136 women were selected, whose median age at diagnosis was 51 years (range: 21-81 years). The median OS was 43.63 months (95%CI 33.92-53.34). It is observed that the median OS for the population already diagnosed with metastatic disease (stage IV) was significantly lower than for patients diagnosed in stages I-III (37.43 months vs. 48.6 months, p<0, 01). Women without previous use of trastuzumab had a higher median OS than patients pretreated with trastuzumab (45.16 months vs. 40.73 months, p<0.01).

CONCLUSION

Trastuzumab improves survival in HER-2 positive metastatic breast cancer. Brain and multiple metastases are associated with a worse prognosis. It is essential to avoid advanced staging and perform surgical treatment, with emphasis on radical mastectomy. The SUS must adopt policies and strategies for early diagnosis and guarantee access to trastuzumab, considering its high cost.

ASCO Policy Statement on Biosimilar and Interchangeable Products in Oncology

As the voice of cancer care clinicians and the patients they serve, ASCO has taken steps to elevate awareness about biosimilar products and their use in oncology. In 2018, ASCO released its Statement on Biosimilars in Oncology which was subsequently published in the Journal of Clinical Oncology to serve as an educational tool which highlighted and provided guidance on several topical areas surrounding biosimilars. At the time of its publication, the US Food and Drug Administration (FDA) had approved eight biosimilar products for use in the United States, including one product for use as a supportive care agent in the cancer setting and two products for use in the treatment for cancer. This number has risen dramatically (40 approvals), with a total of 22 cancer or cancer-related biosimilar products approved since 2015. Recently, the FDA also approved the four interchangeable biosimilar products for diabetes, certain inflammatory diseases, and certain ophthalmic diseases. Given the current market dynamics and the regulatory landscape, this ASCO manuscript now seeks to propose several policy recommendations across the scope of value, interchangeability, clinician barriers, and patient education and access. This policy statement is intended to guide ASCO's future activities and strategies and serves to affirm our commitment to providing education to the oncology community on the use of biosimilars in the cancer setting.

Characterizing experiences of non-medical switching to trastuzumab biosimilars using data from internet-based surveys with US-based oncologists and breast cancer patients

PURPOSE

To characterize current experiences with communication and decision-making practices when non-medical switching to a biosimilar trastuzumab is proposed or required by cancer center or insurer.

METHODS

We developed and launched 60- and 51-item internet surveys to elicit US breast cancer patient and medical oncologist lived experiences with trastuzumab biosimilars and patient information needs and seeking practices. We recruited participants using social media and administered via REDCap in 2020-2021.

RESULTS

143 breast cancer patients and 33 medical oncologists completed the surveys. 63.9% patients reported having switched to a trastuzumab biosimilar and 40.8% reported receiving no prior notification about switching. 44% of patients reported learning about biosimilars primarily through self-directed learning and 41% wanting more time to discuss with oncologist. None of the oncologists reported that the decision to switch a patient to a biosimilar was initiated by them, but rather more frequently by the insurer (45.2%). About 54.8% reported not receiving any pharmaceutical manufacturer material related to the selected biosimilar. Patients and oncologists diverged in their responses to items regarding patient opportunities to ask questions, adequacy of resources, effectiveness of treatment, patient worry, and magnitude of change.

CONCLUSION

There is a need for tailored and effective patient and oncologist information and education on trastuzumab biosimilars, along with improved healthcare communication regarding switching. The discrepancy between patient-reported experiences and oncologist perceptions of the patient experience, suggests a lack of adequate information that may be a challenge not only to the uptake of trastuzumab biosimilars, but to the patient-oncologist relationship.

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.