Development of New Formulations of Biologics: Expectations, Immunogenicity, and Safety for Subcutaneous Trastuzumab

Subcutaneous injection of trastuzumab into the thigh versus abdominal wall in patients with HER2-positive early breast cancer: Pharmacokinetic, safety and patients' preference - Substudy of the randomised phase III GAIN-2 study

BACKGROUND

Trastuzumab given intravenously in combination with chemotherapy is standard of care for patients with early HER2-positive breast cancer (BC). Different randomised studies have shown equivalent efficacy of a subcutaneous injection into the thigh compared to the intravenous formulation. Other body regions for injection have not been investigated but might be more convenient for patients.

METHODS

After surgery, patients were randomised to receive either subcutaneous trastuzumab into the thigh or into the abdominal wall (AW). Patient preferences were evaluated using validated questionnaires (PINT). Primary objectives of this multicentre, non-blinded, randomised substudy of the GAIN-2 study were to investigate pharmacokinetics of the injection into the thigh versus AW and to determine patients' preferences of either administration site versus the previously received intravenous application.

RESULTS

226 patients were randomised and 219 patients (thigh: N = 110; AW: N = 109) formed the modified intent-to-treat (mITT). Overall, 83.5% (out of N = 182 with information about patients' preference) preferred subcutaneous over previous intravenous application or had no preference. Preference was similar between both administration sites (thigh: 80.6%; AW: 86.5; p = 0.322). Pharmacokinetic analysis included 30 patients. Geometric means of C_max and AUC_0-21d were higher in thigh than in AW group (geometric mean ratio with body weight adjustment: C_max: 1.291, 90%-CI 1.052-1.584; AUC_0-21d: 1.291, 90%-CI 1.026-1.626). Safety profile was in line with previous reports of subcutaneous trastuzumab.

CONCLUSION

Subcutaneous trastuzumab into the thigh showed an approximately 30% higher bioavailability. Injections were well tolerated and preferred over intravenous administration. The subcutaneous injection into the thigh should remain the standard of care.

Trastuzumab immunogenicity development in patients' sera and in laboratory animals

Background

Immunogenicity is a major challenge in drug development and patient care. Clinicians and regulators are familiar with immunogenicity concerns of monoclonal antibody (mAb) therapeutics, growth factors and enzyme replacements. Although most small therapeutic molecules are unlikely to trigger undesirable immunogenic responses against themselves upon their administration, the biological therapeutic agents are likely to induce such kind of immunogenicity. This imparts a problem that has to be considered upon judging their risk–benefit ratio. In this article, we tested the immunogenicity developed in patients’ sera due to the use of trastuzumab and that developed in laboratory animals injected with this recombinant humanized IgG1 monoclonal antibody.

Methods

We studied trastuzumab immunogenicity by: I in vitro detection of anti-trastuzumab antibody (Ab) levels in patient’s serum samples withdrawn at different points during trastuzumab treatment course; I.1 using an Affinity Capture Elution (ACE) assay, the assay is both sensitive and highly tolerant to free drug; I.2 using MTT cytotoxicity method against MCF-7 cell line as confirmatory method used in sample showed high level of anti-trastuzumab Ab and to determine neutralizing activity of the anti-trastuzumab Ab. II in vivo immunogenicity testing of trastuzumab in lab animals.

Results

In vitro analysis of patients’ sera for antibodies developed against trastuzumab revealed that this monoclonal antibody has low immunogenicity since most samples showed low levels of anti-trastuzumab antibodies that decreased progressively along the treatment course. Only 1% of samples showed high levels of anti-trastuzumab antibodies which might affect treatment course. In vivo immunogenicity testing in mice showed also low immunogenicity of trastuzumab that could support the in vitro clinical assessment applied in our study.

Conclusions

The study gives an evidence for the low trastuzumab immunogenicity when assessed in Egyptian patients under treatment with this biological therapeutic agent. This supports its prescription and continuous use across the approved indications as biological therapeutic agent.

Budget Impact Analysis of the Introduction of Rituximab and Trastuzumab Intravenous Biosimilars to EU-5 Markets

Background

Biologic treatments impose a large financial burden on healthcare payers. Subcutaneous formulations of trastuzumab and rituximab offer administration cost savings relative to the intravenous products through reduced preparation and infusion times. However, intravenous biosimilars have the potential to offset administration costs through lower drug costs.

Objective

The objective was to develop a budget impact model (BIM) from a payer’s perspective for the EU-5 countries (UK, France, Germany, Spain, Italy) to demonstrate the economic impact of using intravenous trastuzumab and rituximab biosimilars.

Methods

An incidence-based BIM was developed to estimate the net budget impact utilising epidemiology data from the literature, market research data on the use of relevant treatments in all approved indications, and corresponding costs. The budget impact was estimated for 5 years following introduction of the biosimilars.

Results

Analysis using the base-case results indicated that adoption of the biosimilars trastuzumab and rituximab would result in net cost savings. At year 5, the net budget saving ranged from €4.05 million to 303.86 million for rituximab and from €19 million to 172 million for trastuzumab. The cost saving could potentially extend treatment to 291–15,671 more patients with rituximab and 622–3688 more patients with trastuzumab.

Conclusion

This budget impact analysis emphasised that increased use of intravenous rituximab and trastuzumab biosimilars may result in cost savings from the payer’s perspective across the EU-5 countries.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40259-020-00461-8.

Biosimilars: A Value Proposition

Biosimilars are biological agents that effectively replicate original reference products. The main driver of their development is the promise of bringing competition into the marketplace, and consequently contributing to the sustainability of healthcare systems. By reducing financial barriers to biological therapies, biosimilars play a part in budgetary redistribution and, hence, in increasing patients' access to treatment. They also foster innovation and deliver other non-price-driven advantages. However, the market is such that harmonization of pricing of reference biologics and biosimilars may dissuade physicians from prescribing biosimilars and often creates an unfavorable market environment for the launch of biosimilars. Such dynamics result in a high cost by denying patients the full benefits and added value inherent in biosimilar agents. A more equitable offering of established original biologics and biosimilars is needed to ensure the viability of current healthcare services.

Current and future roles of biosimilars in oncology practice

Biologics have been used increasingly in the treatment and supportive care of cancer; however, their high cost places a significant burden on healthcare systems. The expiration of patents for biologics has led to the development of biosimilars, with the aim of reducing cost and increasing accessibility to novel treatments, which are affordable for a greater number of patients. Biosimilars are highly similar but not identical to the reference products; therefore, strict regulatory requirements have been formed for their approval. This ensures that there are no clinically meaningful differences compared with respective biologics, with regard to purity, safety and efficacy. In 2003, a regulatory framework for the approval of biosimilars was established in Europe, whereas the USA did not implement a framework until 2009, when the Biologics Price Competition and Innovation Act was formed. A number of biosimilars have currently been approved in oncology and the number is expected to rise in the near future. More than 10 years of evidence has revealed that biosimilars are safe and effective; however healthcare professionals need to be further educated to eliminate potential misconceptions and integrate biosimilars into routine clinical practice. The present review aims to provide an overview of the biosimilars used in Europe and the USA, present their main benefits and challenges, and discuss their current and future roles in medical oncology.

Humanistic and economic impact of subcutaneous versus intravenous administration of oncology biologics

More oncology biologics are becoming available for subcutaneous (sc.) administration and are expected to provide useful therapeutic options. We evaluated evidence published in the past 5 years to assess the humanistic and economic impact of sc. versus intravenous administration of approved cancer therapies and identify outcomes favoring either administration route. These publications focused predominantly on healthcare resource utilization and economic outcomes, demonstrating resource and cost savings with sc. administration. Patients reported a better health-related quality of life and preference for sc. formulations. Time-and-motion study analyses confirmed the convenience of sc. administration. These findings suggest that future availability of sc. oncology biologics, especially anti-PD-1/PD-ligand 1 antibodies due to their increased utility in various malignancies, may be beneficial for patients, healthcare providers and payers.

Current Advancements in Addressing Key Challenges of Therapeutic Antibody Design, Manufacture, and Formulation

Therapeutic antibody technology heavily dominates the biologics market and continues to present as a significant industrial interest in developing novel and improved antibody treatment strategies. Many noteworthy advancements in the last decades have propelled the success of antibody development; however, there are still opportunities for improvement. In considering such interest to develop antibody therapies, this review summarizes the array of challenges and considerations faced in the design, manufacture, and formulation of therapeutic antibodies, such as stability, bioavailability and immunological engagement. We discuss the advancement of technologies that address these challenges, highlighting key antibody engineered formats that have been adapted. Furthermore, we examine the implication of novel formulation technologies such as nanocarrier delivery systems for the potential to formulate for pulmonary delivery. Finally, we comprehensively discuss developments in computational approaches for the strategic design of antibodies with modulated functions.