Exploring the Combined Action of Adding Pertuzumab to Branded Trastuzumab versus Trastuzumab Biosimilars for Treating HER2+ Breast Cancer.

The binding activity of various trastuzumab biosimilars versus the branded trastuzumab towards the glycosylated extracellular domain of the human epidermal growth factor receptor 2 (HER2) target in the presence of pertuzumab was investigated. We employed size exclusion chromatography with tetra-detection methodology to simultaneously determine absolute molecular weight, concentration, molecular size, and intrinsic viscosity. All trastuzumab molecules in solution exhibit analogous behavior in their binary action towards HER2 regardless of the order of addition of trastuzumab/pertuzumab. This analogous behavior of all trastuzumab molecules, including biosimilars, highlights the robustness and consistency of their binding activity towards HER2. Furthermore, the addition of HER2 to a mixture of trastuzumab and pertuzumab leads to increased formation of high-order HER2 complexes, up to concentrations of one order of magnitude higher than in the case of sequential addition. The observed increase suggests a potential synergistic effect between these antibodies, which could enhance their therapeutic efficacy in HER2-positive cancers. These findings underscore the importance of understanding the complex interplay between therapeutic antibodies and their target antigens, providing valuable insights for the development of more effective treatment strategies.

Evaluation of bevacizumab biosimilar on wound healing complications in patients with colorectal cancer undergoing endoscopic mucosal resection: A systematic review and meta-analysis in anorectal medicine.

Complications related to wound healing pose substantial obstacle in the management of colorectal cancer (CRC), specifically in the field of anorectal medicine. Biosimilars of bevacizumab have emerged as crucial therapeutic agents in the management of these complications. With the particular emphasis on effects of Bevacizumab Biosimilar Plus on wound healing among patients diagnosed with CRC, this review underscores the potential of this anorectal medication to improve patient outcomes and was aimed to assess the safety and efficacy of Bevacizumab Biosimilar Plus in relation to complications associated with wound healing in patients with CRC. The assessment centers on its therapeutic potential and safety profile within the domain of anorectal medicine. In accordance with the PRISMA guidelines, a comprehensive literature search was performed, resulting in the identification of 19 pertinent studies out of an initial 918. Priority was given to assessing the safety and adverse effects of Bevacizumab Biosimilar Plus in conjunction with its effectiveness in wound healing. The extracted data comprised the following: study design, patient demographics, comprehensive treatment regimens, wound healing-specific outcomes and adverse effects. The evaluation of study quality was conducted utilizing the instruments provided by the Cochrane Collaboration and the Newcastle-Ottawa Scale (NOS). Bevacizumab Biosimilar Plus demonstrates efficacy in the management of wound healing complications among patients with CRC, with a safety and efficacy profile similar to that of the original Bevacizumab, according to the analysis. Notably, several studies reported improved rates of wound healing in relation to the biosimilar. The safety profiles exhibited similarities to the anticipated anti-VEGF agent effects. In wound management, the biosimilar also demonstrated advantages in terms of prolonged efficacy. In addition, analyses of cost-effectiveness suggested that the use of biosimilars could result in cost reductions. Bevacizumab Biosimilar Plus exhibited potential as an anorectal medication for the effective management of wound healing complications in patients with CRC. This has substantial ramifications for improving the quality of patient care, encompassing the affordability and effectiveness of treatments.

Highly purified charge variants of a proposed biosimilar to Omalizumab: impact on in vitro potency and stability under thermal stress.

Biosimilars are highly complex and similar biological drugs are developed with different manufacturing processes which are not similar to originator manufacturing process. Due to this, biosimilar products inherently have quality differences in comparison to innovator molecule which may be related to size, charge and glycosylation. Despite these differences they are supposed to demonstrate similar behaviour in safety and efficacy profile to the reference product and these differences should not be clinically meaningful. Charge variants are one of the critical quality attributes and sources of heterogeneity. In this study, highly purified charge variants cluster (acidic, main peak and basic) of biosimilar product of Xolair were assessed for their impact on in vitro potency and stability at different thermal stress conditions (2-8 °C and - 20 °C). The study data indicating purified charge variants (> 90%) have no impact on in vitro potency and are stable at different thermal stress conditions up to a week.

Imbalanced machine learning classification models for removal biosimilar drugs and increased activity in patients with rheumatic diseases.

OBJECTIVE: Predict long-term disease worsening and the removal of biosimilar medication in patients with rheumatic diseases. METHODOLOGY: Observational, retrospective descriptive study. Review of a database of patients with immune-mediated inflammatory rheumatic diseases who switched from a biological drug (biosimilar or non-biosimilar) to a biosimilar drug for at least 6 months. We selected the most important variables, from 18 variables, using mutual information tests. As patients with disease worsening are a minority, it is very difficult to make models with conventional machine learning techniques, where the best models would always be trivial. For this reason, we computed different types of imbalanced machine learning models, choosing those with better f1-score and mean ROC AUC. RESULTS: We computed the best-imbalanced machine learning models to predict disease worsening and the removal of the biosimilar, with f1-scores of 0.52 and 0.63, respectively. Both models are decision trees. In the first one, two important factors are switching of biosimilar and age, and in the second, the relevant variables are optimization and the value of the initial PCR. CONCLUSIONS: Biosimilar drugs do not always work well for rheumatic diseases. We obtain two imbalanced machine learning models to detect those cases, where the drug should be removed or where the activity of the disease increases from low to high. In our decision trees appear not previously studied variables, such as age, switching, or optimization.

Analytical and Functional Similarity of the Biosimilar Candidate ABP 654 to Ustekinumab Reference Product.

BACKGROUND AND OBJECTIVE: ABP 654 is a proposed biosimilar to ustekinumab reference product (RP), a human immunoglobulin isotype class G subclass 1 kappa monoclonal antibody that acts as an antagonist of interleukin (IL)-23 and IL-12. Ustekinumab RP is indicated for the treatment of some forms of plaque psoriasis, active psoriatic arthritis, Crohn's disease, and ulcerative colitis. ABP 654 and ustekinumab RP utilize different expression systems, and the purpose of this study was to assess analytical similarity between ABP 654 and ustekinumab RP sourced from the United States (US) and the European Union (EU). METHODS: The analytical testing plan included general properties, primary structure, higher-order structure, product-related substances and impurities, particles and aggregates, biological activity, and thermal stability and degradation studies. RESULTS: ABP 654 was found to be analytically similar to ustekinumab RP with respect to physicochemical and biological properties, including structure, function, purity, and potency. CONCLUSIONS: Based on a comprehensive similarity assessment, ABP 654 was found to be similar to ustekinumab RP, notwithstanding minor physicochemical differences that are not expected to have a clinically meaningful effect on safety or efficacy.

Sustainable Integration of US Food and Drug Administration-Approved Biosimilars: Pharmacy- Versus Physician-Driven Change.

PURPOSE: Biosimilars are clinically equivalent to branded products yet cost significantly less. Interchangeability is a US Food and Drug Administration (FDA) designation that allows generic drugs to be substituted for reference drugs at the pharmacy, without a physician's consent. Currently, no oncologic biosimilar has FDA approval for interchangeability. METHODS: Building on pharmacy auto-substitution processes with therapeutic interchange, Plan-Do-Study-Act methodology was used to automate conversions from reference biological products to Pharmacy and Therapeutics-/Physician-approved biosimilars. After establishing the baseline metrics, cycle 1 focused on full staff education (completed July 2020) with systematic pharmacy-driven biosimilar conversion initiated in September 2020 for rituximab, trastuzumab, and bevacizumab. Physician-initiated conversion of Neulasta biosimilar products was encouraged but not mandated. During cycle 2 (May 1, 2021-November 30, 2021), pharmacy-driven Neulasta biosimilar conversion was mandated. In cycle 3 (December 1, 2021-April 30, 2023), stakeholder education was reinforced and the sustainability of conversions was confirmed. RESULTS: Systematic pharmacy-driven conversion to biosimilar products improved over cycles 1 and 2 from baseline: 1.8% to 90.3% for rituximab, 9.2% to 89.7% for trastuzumab, and 20.5% to 96.1% for bevacizumab. Physician-driven biosimilar conversion for Neulasta was lower at 12.7% through April 2021. Pharmacy-driven Neulasta biosimilar conversion was initiated during cycle 2, resulting in a conversion rate of 39.7%. The conversion rates remained sustainable through April 2023. CONCLUSION: Pharmacy-driven auto-substitution of biosimilar products results in rapid and statistically significant biosimilar adoption. The pharmacy-based substitution approach was found to be far more effective than physician-driven substitution. Rapid conversion from branded products to FDA-approved biosimilar is feasible, measurable, and sustainable and can be scaled. Barriers to Neulasta conversion warrant further investigation.

Future Evolution of Biosimilar Development by Application of Current Science and Available Evidence: The Developer's Perspective.

Biosimilars have been available in the USA for over a decade, and in Europe for almost two decades. In that time, biosimilars have become established in the treatment landscape for a wide range of diseases, facilitating patient access and affordability of healthcare. However, patients can still struggle to access biological therapies in some markets. There is a need to streamline the process of developing biosimilars without compromising their quality, safety, or efficacy. This opinion piece considers the efficiencies that could be achieved within the biosimilar approval process. In clinical trials for biosimilars, clinical efficacy endpoints have been shown to be less sensitive measures of biosimilarity than biochemical, biophysical, and biological functional assays. Additional clinical efficacy studies comparing potential biosimilars and reference products do not add information that is useful for regulatory purposes. Large clinical studies of biosimilars with immunogenicity endpoints are of limited value, given the quality control processes in place for all biologics, including biosimilars. The expectation for multiple-switch studies for US interchangeability designation should be reconsidered immediately, and the category should be eliminated in the future. As biosimilars are typically approved globally based on a single set of clinical trials, and all subsequent manufacturing changes are already carefully monitored by regulatory authorities, comparative pharmacokinetic testing of EU and US reference products is unnecessary. Manufacturers and regulators could take greater advantage of existing real-world evidence. Streamlining biosimilar development would enable biosimilar development of more and a wider variety of biological drugs, accelerating biosimilar development without impacting patient safety or effectiveness.

Physicochemical and Functional Similarity Assessment Between Proposed Bevacizumab Biosimilar BAT1706 and Reference Bevacizumab.

BACKGROUND: BAT1706 is a proposed biosimilar of bevacizumab, a vascular endothelial growth factor A (VEGF-A)-targeting biologic used to treat several different cancers, including metastatic colorectal cancer. A comprehensive physicochemical and functional similarity assessment is a key component of demonstrating biosimilarity between a reference biologic and a proposed biosimilar. Here we report the physicochemical and functional similarity of BAT1706 and reference bevacizumab sourced from both the United States (US-bevacizumab) and the European Union (EU-bevacizumab). METHOD: A large range of product attributes, including primary and higher order structure, post-translational modifications, purity, stability, and potency, were characterized for BAT1706 and EU/US-bevacizumab using sensitive state-of-the-art analytical techniques. Up to 18 lots of US- and 29 lots of EU-bevacizumab, and 10 unique drug substance lots of BAT1706, were assessed. RESULT: BAT1706 was shown to have an identical amino acid sequence and an indistinguishable higher-order structure compared with EU/US-bevacizumab. BAT1706 and EU/US-bevacizumab also exhibited similar post-translational modifications, glycan profiles, and charge variants. Potency, assessed using a wide range of bioassays, was also shown to be comparable between BAT1706 and EU/US-bevacizumab, with statistical equivalence demonstrated for VEGF-A binding and neutralizing activity. CONCLUSION: Overall, this extensive comparability exercise demonstrated BAT1706 to match EU/US-bevacizumab in terms of all physicochemical and functional attributes assessed.

Production of a biosimilar version of aflibercept to improve VEGF blocker cytotoxicity on endothelial cells.

This project aimed to produce a biosimilar version of aflibercept (AFL) and evaluate the effect of the co-treatment of AFL with other vascular endothelial growth factor (VEGF) blocker drugs. For this purpose, the optimized gene was inserted into the pCHO1.0 plasmid and transfected into the CHO-S cell line. The final concentration of biosimilar-AFL for the selected clone was 782 mg/L. Results revealed that the inhibition potential of the biosimilar-AFL on HUVEC cells was significant at 10 and 100 nM concentrations and in a dose-dependent manner. Furthermore, co-treatment of biosimilar-AFL with Everolimus (EVR), Lenvatinib (LEN), and Sorafenib (SOR) could reduce HUVEC cell viability/proliferation, more than when used alone. When LEN and SOR were co-treated with biosimilar-AFL, their cytotoxicity increased 10-fold. The most and least efficient combination was seen when biosimilar-AFL combined with LEN and EVR, respectively. Finally, biosimilar-AFL may improve the efficiency of LEN, EVR, and SOR in reducing the VEGF effect on endothelial cells.

Biosimilar Use Among 38 ASCO PracticeNET Practices, 2019-2021.

PURPOSE: Biosimilars offer increased patient choice and potential cost-savings, compared with originator biologics. We studied 3 years of prescribed biologics among US physician practices to determine the relationship of practice type and payment source to oncology biosimilar use. METHODS: We acquired biologic utilization data from 38 practices participating in PracticeNET. We focused on six biologics (bevacizumab, epoetin alfa, filgrastim, pegfilgrastim, rituximab, and trastuzumab) for the period from 2019 to 2021. We complemented our quantitative analysis with a survey of PracticeNET participants (prescribers and practice leaders) to reveal potential motivators and barriers to biosimilar use. We implemented logistic regression to evaluate the biosimilar use for each biologic, with covariates including time, practice type, and payment source, and accounted for clusters of practices. RESULTS: Use of biosimilars increased over the 3-year period, reaching between 51% and 80% of administered doses by the fourth quarter of 2021, depending on the biologic. Biosimilar use varied by practice, with independent physician practices having higher use of biosimilars for epoetin alfa, filgrastim, rituximab, and trastuzumab. Compared with commercial health plans, Medicaid plans had lower biosimilar use for four biologics; traditional Medicare had lower use for five biologics. The average cost per dose decreased between 24% and 41%, dependent on the biologic. CONCLUSION: Biosimilars have, through increased use, lowered the average cost per dose of the studied biologics. Biosimilar use differed by originator biologic, practice type, and payment source. There remains further opportunity for increases in biosimilar use among certain practices and payers.

Characterization for the Similarity Assessment between Proposed Biosimilar SB12 and Eculizumab Reference Product Using a State-of-the-Art Analytical Method.

BACKGROUND: SB12 is being developed as a proposed biosimilar to eculizumab reference product (RP), a humanized monoclonal antibody (IgG2/4 kappa immunoglobulin) that binds to the human C5 complement protein. Binding to this protein inhibits complement-mediated intravascular hemolysis by blocking its cleavage into C5a and C5b. Eculizumab RP is indicated for the treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH) to reduce hemolysis, atypical hemolytic uremic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy, generalized myasthenia gravis who are anti-acetylcholine receptor antibody-positive, and neuromyelitis optica spectrum disorder in adult patients who are anti-aquaporin-4 antibody-positive. OBJECTIVE: The objective of this study was to demonstrate structural, physicochemical, and biological similarity between eculizumab RP and SB12 using various state-of-the-art analytical methods. METHODS: Comprehensive analytical characterization was conducted with side-by-side comparison of SB12 with European Union (EU) and United States (US) eculizumab RPs using various analytical methods (more than 40 state-of-the-art assays). Comparisons included purity, product-related impurity, charge heterogeneity, primary structure, post-translational modification, higher-order structure, quantity, Fab-related biological activities (potency and binding activity), and Fc-related biological activities. RESULTS: Based on the analytical similarity assessment, the structural, physicochemical, and biological characterization results demonstrated that SB12 is highly similar to the EU and US eculizumab RP. In the structural aspects, it was confirmed that there is no difference between post-translational modification profiles and higher-order structures of SB12 compared with the eculizumab RP. Product-related impurities in the form of aggregates and charge variants were also confirmed to be similar. Mechanism of action (MoA)-related biological activities showed that SB12 is highly similar to the EU and US eculizumab RP with respect to overall critical and non-critical quality attributes analyzed. Moreover, similarity of comparative binding tendency of SB12 and eculizumab RP to Fc gamma receptors and C1q was confirmed through additional characterization methods. Based on these results, SB12 is expected to have highly similar safety and efficacy compared with eculizumab RP. CONCLUSION: In summary, the overall analytical characterization and similarity assessment results show that SB12 is highly similar to the EU and US eculizumab RP in terms of structural, physicochemical, biophysical, and biological attributes.

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.

Biosimilar Competition and Payments in Medicare: The Case of Trastuzumab.

PURPOSE: Numerous biologic drugs will soon be facing biosimilar competition. We study the case of trastuzumab, a revolutionary drug approved in 1998 to treat human epidermal growth factor receptor 2-positive breast cancer, to understand how trends in the price and treatment cost of the originator brand and biosimilar forms of trastuzumab evolved following biosimilar entry. METHODS: We use average sales price data from the Centers for Medicare and Medicaid Services, adjusted for inflation to real 2020 dollars using the consumer price index, to describe price changes for the originator biologic and biosimilar versions of trastuzumab between 2019, when the first biosimilar was covered by Medicare, and 2022, when a total of five biosimilar competitors were on the market. We also estimate total treatment costs of biologic and biosimilar forms of trastuzumab from 2005 to 2022 and describe changes in their market share. RESULTS: We find that the first biosimilar entrant's price was 15% lower than the originator brand in 2019, and the fifth biosimilar entrant's price in 2022 was 58% lower than the originator brand in 2019. Contrary to expectations from prior research, the originator biologic price in 2022 decreased 29% from its 2019 average sales price. Average treatment cost for the biologic and biosimilar versions of trastuzumab combined was $45,659 US dollars lower in 2022 compared with the year before biosimilar entry, 2018. Finally, biosimilar market share grew from only 7% in the first year of entry to 32% in the second year, when three biosimilars were on the market. CONCLUSION: Biosimilar entry may be an effective means of decreasing the cost of biologic cancer treatments. Our findings suggest that policies that support biosimilar entry and encourage use may expand access to necessary treatment and reduce health care costs.

Effects of a milk oligosaccharide biosimilar on fecal characteristics, microbiota, and bile acid, calprotectin, and immunoglobulin concentrations of healthy adult dogs treated with metronidazole.

In recent dog and cat experiments, a novel milk oligosaccharide biosimilar (GNU100) positively modulated fecal microbiota and metabolite profiles, suggesting benefits to gastrointestinal health. The objective of this study was to investigate the effects of GNU100 on the fecal characteristics, microbiota, and bile acid (BA) concentrations of healthy adult dogs treated with antibiotics. Twelve healthy adult female dogs (mean age: 3.74 ± 2.4 yr) were used in an 8-wk crossover design study (dogs underwent both treatments). All dogs were fed a control diet during a 2-wk baseline, then randomly allotted to 1 of 2 treatments (diet only or diet + 1% GNU100) for another 6 wk. From weeks 2 to 4, dogs were orally administered metronidazole (20 mg/kg BW) twice daily. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, and 8 for measurement of pH, dry matter, microbiota populations, and BA, immunoglobulin A, and calprotectin concentrations. On weeks 0, 4, and 8, blood samples were collected for serum chemistry and hematology analysis. All data were analyzed as repeated measures using the Mixed Models procedure of SAS version 9.4, with significance considered P < 0.05. Metronidazole increased (P < 0.0001) fecal scores (looser stools) and modified (P < 0.05) fecal microbiota and BA profiles. Using qPCR, metronidazole reduced fecal Blautia, Fusobacterium, Turicibacter, Clostridium hiranonis, and Faecalibacterium abundances, and increased fecal Streptococcus and Escherichia coli abundances. DNA sequencing analysis demonstrated that metronidazole reduced microbial alpha diversity and influenced the relative abundance of 20 bacterial genera and families. Metronidazole also increased primary BA and reduced secondary BA concentrations. Most antibiotic-induced changes returned to baseline by week 8. Fecal scores were more stable (P = 0.01) in GNU100-fed dogs than controls after antibiotic administration. GNU100 also influenced fecal microbiota and BA profiles, reducing (P < 0.05) the influence of metronidazole on microbial alpha diversity and returning some fecal microbiota and secondary BA to baseline levels at a quicker (P < 0.05) rate than controls. In conclusion, our results suggest that GNU100 supplementation provides benefits to dogs treated with antibiotics, providing more stable fecal scores, maintaining microbial diversity, and allowing for quicker recovery of microbiota and secondary BA profiles which play an essential role in gut health.

Our objective was to test the effects of a novel milk oligosaccharide biosimilar (GNU100) on the fecal characteristics, microbiota, and bile acid (BA) concentrations of healthy adult dogs treated with antibiotics. Dogs were fed a control diet during a 2-wk baseline, then randomly allotted to 1 of 2 treatments (diet only or diet + 1% GNU100) for another 6 wk. From weeks 2 to 4, dogs were given an oral antibiotic. Fecal scores were recorded and fresh fecal samples were collected over time to assess fecal characteristics, microbiota populations, and BA concentrations. The antibiotic was shown to increase fecal scores (looser stools) and modify fecal microbiota populations (altered diversity and ~20 bacterial genera and families) and BA profiles (increased primary and reduced secondary BA). Most antibiotic-induced changes returned to baseline by week 8. In dogs fed GNU100, fecal scores were more stable and changes to microbial diversity were lower than controls after antibiotic administration. Fecal microbiota and secondary BA of GNU100-fed dogs also returned to baseline levels at a quicker rate than controls. These results suggest that GNU100 provides benefits to dogs given antibiotics, providing more stable fecal scores, maintaining microbial diversity, and allowing for quicker recovery of microbiota and BA profiles.

Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (II) A Randomized Trial with IL-5 Antagonists.

The US Food and Drug Administration (FDA) guidance describes how pharmacodynamic (PD) biomarkers can be used to address residual uncertainty and demonstrate no clinically meaningful differences between a proposed biosimilar and its reference product without relying on clinical efficacy end point(s). Pilot studies and modeling can inform dosing for such PD studies. To that end, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants to evaluate approaches to address information gaps, inform best practices for analysis of biomarker samples and study results, and apply emerging technologies in biomarker characterization. Seventy-two healthy participants (n = 8 per arm) received either placebo or 1 of 4 doses of the interleukin-5 inhibitors mepolizumab (3-24 mg) or reslizumab (0.1-0.8 mg/kg). A clinical study using doses lower than approved therapeutic doses was combined with modeling and simulation to evaluate the dose-response relationship of the biomarker eosinophils. There was no dose-response relationship for eosinophil counts due to variability, although the mepolizumab 24 mg and reslizumab 0.8 mg/kg doses showed clear effects. Published indirect-response models were used to explore eosinophil data across doses from this study and the unstudied therapeutic doses. Simulations were used to calculate typical PD metrics, such as baseline-adjusted area under the effect curve and maximum change from baseline. The simulation results demonstrate sensitivity of eosinophils as a PD biomarker and indicate doses lower than the approved doses would have PD responses overlapping with variability in the placebo arm. The simulation results further highlight the utility of model-based approaches in supporting use of PD biomarkers in biosimilar development.

Evaluating the efficacy and microenvironment changes of HER2 + gastric cancer during HLX02 and Endostar treatment using quantitative MRI.

BACKGROUND AND OBJECTIVES: Trastuzumab is an important targeted drug for HER2-positive gastric cancer. The treatment efficacy of a more cost-effective and accessible trastuzumab biosimilar, HLX02, was not well investigated, especially when combined with antiangiogenic treatment. In addition, the tumour microenvironment detected by functional MRI was still unclear during treatment. This study attempts to evaluate the therapeutic effect of antiangiogenic agents combined with HLX02 in a HER2-positive gastric cancer xenograft model and to detect microenvironmental changes using intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI). MATERIALS AND METHODS: We subcutaneously injected MKN-45 human gastric cancer cells into BALB/C nude mice to establish a tumour model. Twenty-eight mice were divided into four groups and treated with saline (Group 1), Endostar (Group 2), trastuzumab biosimilar HLX02 (Group 3), or the combination of Endostar and HLX02 (Group 4). We then performed IVIM-DWI before and at different time points after treatment. HE, HER2, TUNEL, E-cadherin staining, and α-SMA and CD31 double-staining were used to confirm the pathological changes. RESULTS: Group 4 demonstrated the smallest tumour volume at the end of treatment. The D value in Group 4 increased more dramatically, with the highest value on Day 20, compared with the other groups. Perfusion-related parameters (D* and f values) in Groups 2 and 4 increased initially and reversed after Day 10. Group 4 showed the lowest CD31 and HER2 and the highest TUNEL- and E-cadherin-positive staining rates. The D value was positively correlated with TUNEL but negatively correlated with HER2 staining. The D* and f values had positive correlations with CD31 and E-cadherin expression and the vessel maturity index. CONCLUSIONS: The trastuzumab biosimilar drug HLX02 exhibited good treatment efficacy in HER2-positive gastric cancer, especially when combined with Endostar. IVIM-DWI can noninvasively monitor the process of vascular normalization and reflect the treatment effect early at the molecular level.

Molecular Biosimilarity-An AI-Driven Paradigm Shift.

Scientific, technical, and bioinformatics advances have made it possible to establish analytics-based molecular biosimilarity for the approval of biosimilars. If the molecular structure is identical and other product- and process-related attributes are comparable within the testing limits, then a biosimilar candidate will have the same safety and efficacy as its reference product. Classical testing in animals and patients is much less sensitive in terms of identifying clinically meaningful differences, as is reported in the literature. The recent artificial intelligence (AI)-based protein structure prediction model, AlphaFold-2, has confirmed that the primary structure of proteins always determines their 3D structure; thus, we can deduce that a biosimilar with an identical primary structure will have the same efficacy and safety. Further confirmation of the thesis has been established using technologies that are now much more sensitive. For example, mass spectrometry (MS) is thousands of times more sensitive and accurate when compared to any form of biological testing. While regulatory agencies have begun waiving animal testing and, in some cases, clinical efficacy testing, the removal of clinical pharmacology profiling brings with it a dramatic paradigm shift, reducing development costs without compromising safety or efficacy. A list of 160+ products that are ready to enter as biosimilars has been shared. Major actions from regulatory agencies and developers are required to facilitate this paradigm shift.

Scientific Rationale for Waiving Clinical Efficacy Testing of Biosimilars.

After 18 years and the administration of billions of doses, there is little doubt about biosimilars' safety and efficacy. Yet, only 14 molecules in the EU and 9 in the US are available as biosimilars, among the 200+ targets, due mainly to the high development cost attributed to clinical efficacy testing after extensive analytical assessment, nonclinical testing, and clinical pharmacology comparisons. So far, none of the hundreds of clinical efficacy testing has failed because it cannot fail due to its lack of sensitivity for multiple reasons, as argued in this paper. This analysis is unique since biosimilars are the first category of products that are put to comparative testing as if these were new biological drugs. Clinical efficacy testing used to overcome differences in the analytical, nonclinical, and clinical pharmacology comparisons can lead to the approval of unsafe products. Only recently the regulatory agencies have begun to talk about this risk and shown their willingness to waive these studies. However, a clear change in the regulatory guidelines is required to change the mindset of all biosimilar stakeholders to bring a pivotal change in the availability of affordable biosimilars.