Anti-Human IL-17RA (CD217) (Brodalumab) [Clone AMG-827] — Fc Muted™

Research-grade Brodalumab biosimilars are used as calibration standards or reference controls in pharmacokinetic (PK) bridging ELISAs to ensure consistent, robust quantification of drug concentration in serum samples by establishing a standard curve against which unknowns are measured.

Essential context and methodology:

• Calibration Standard Use: In a PK bridging ELISA, a single analytical standard—often a research-grade biosimilar—is used to generate the assay’s calibration curve. This involves preparing serial dilutions of the biosimilar in a matrix (typically human serum) to establish known concentration points, which allow generation of a standard curve fitted to the assay’s readout (e.g., absorbance values).

• Assay Workflow: Unknown serum samples from subjects dosed with Brodalumab (reference or biosimilar) are introduced into the ELISA. The assay quantifies Brodalumab concentration in these samples by interpolating their signals onto the generated standard curve.

• Reference Controls: Both reference (innovator) and biosimilar Brodalumab (including research-grade preparations) are used in method qualification and validation to confirm that the assay equally and accurately measures both molecules.

  • During validation, both the biosimilar standard and reference product are spiked into human serum at various concentrations, and recovery/quantification is compared.

• Single Assay Approach: Regulatory and industry guidance recommend employing a single PK assay and a single standard (often the biosimilar), provided bioanalytical equivalence is rigorously demonstrated. This minimizes assay variability and is particularly advantageous for blinded clinical studies.

  • Scientific rigor demands demonstrating (typically via statistical analysis, e.g., equivalence intervals and precision/accuracy metrics) that the assay measures both biosimilar and reference comparably. If so, the biosimilar can become the default calibration standard for all samples in the study.

Key practical points:

• The research-grade biosimilar is chosen for its high purity, defined concentration, and traceable quality attributes—mirroring the structural and functional properties of the reference Brodalumab, but lacking clinical grade status.
• Concentration range and preparation: Standard curves in validation typically span concentrations bracketing expected serum drug levels; for example, from 50 to 12,800 ng/mL.
• Batch records and controls: Sets of QC samples containing both biosimilar and reference are included to ensure ongoing assay equivalency throughout the clinical study.

Summary Table

In summary, research-grade Brodalumab biosimilars serve as both calibration standards and reference controls in PK bridging ELISAs, enabling precise, comparable quantification of drug across clinical samples and facilitating robust biosimilarity assessments.

The primary in vivo models used to study tumor growth inhibition and tumor-infiltrating lymphocytes (TILs) following administration of research-grade anti-IL-17RA antibodies are murine syngeneic tumor models and humanized mouse models.

Key models and details:

• Syngeneic mouse models are the dominant platforms, as they employ immune-competent mice implanted with murine tumors (such as B16-F10 melanoma, MC38 colon cancer, and others) and allow assessment of immunotherapies, including anti-IL-17RA antibodies that are cross-reactive to mouse IL-17RA. These models enable detailed TIL profiling and monitoring of changes in immune cell populations within the tumor microenvironment.

• Specific syngeneic models highlighted in published research:

  • B16-F10 melanoma (C57BL/6 mice): Anti-IL-17RA and anti-IL-17A antibodies have been evaluated for their impact on tumor growth, immune infiltrates, and synergy with checkpoint inhibitors.
  • AOM-DSS-induced colorectal cancer (C57BL/6 mice): Anti-IL-17A/IL-17RA treatments have shown efficacy in reducing tumor burden and altering TIL composition, primarily by decreasing pro-tumor immune subsets like regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs).
  • CPC-APC model (colon adenoma/carcinoma): Genetic ablation or antibody targeting of IL-17RA inhibits tumor progression and modifies the TIL landscape.
  • Osteosarcoma models: IL-17RA-deficient mice or antibody blockade demonstrates reduced tumor progression, supporting the model’s suitability for TIL and growth studies.

• Humanized mouse models — mice engrafted with a human immune system or expressing humanized immune receptors — are sometimes used when testing human-specific antibodies. However, most published work with research-grade anti-IL-17RA focuses on murine-reactive antibodies in syngeneic mouse models, due to cross-species compatibility issues and the widespread availability of murine-sensitive reagents.

• Key considerations:

  • Antibody cross-reactivity: Because most research antibodies are species-specific, anti-IL-17RA studies typically use murine versions or cross-reactive agents for syngeneic models.
  • Combination with other immunotherapies: Anti-IL-17RA antibodies are often studied alongside checkpoint inhibitors (e.g., anti-CTLA-4, anti-PD-1) to better define TIL dynamics and therapeutic synergy.

Summary Table:

Conclusion:
Research-grade anti-IL-17RA antibodies are most commonly studied in murine syngeneic tumor models (e.g., B16-F10, MC38), where they are used to inhibit tumor growth and assess changes in immune cell composition within tumors, including TIL populations such as Tregs, Th17 cells, and cytotoxic T lymphocytes. Humanized models are less common and typically used when the antibody is specific to human IL-17RA.

Researchers utilize Brodalumab biosimilars (anti-IL-17RA) in combination with other checkpoint inhibitors (such as anti-CTLA-4 or anti-LAG-3 biosimilars) to investigate synergistic immunomodulatory effects in complex immune-oncology models, focusing on how simultaneous blockade of multiple immune regulatory pathways can enhance antitumor responses and overcome resistance mechanisms.

Brodalumab biosimilar is a monoclonal antibody that specifically binds to IL-17RA, blocking downstream inflammatory signaling driven by the IL-17 cytokine family. Its mechanism targets the innate and adaptive immune components involved in chronic inflammation, autoimmunity, and cancer, making it suitable for research into tumor immune microenvironment modulation.

Synergistic studies typically involve:

• Combining Brodalumab biosimilar with checkpoint inhibitors targeting CTLA-4, PD-1/PD-L1, or emerging targets like LAG-3, to test whether modulating both IL-17 signaling and exhaustion/inhibition pathways (like CTLA-4 or LAG-3) leads to enhanced antitumor activity.
• Using complex immune-oncology models such as humanized mouse xenografts, organoids, and sophisticated co-culture systems, which allow researchers to study the dynamic interactions between various immune cells and tumor cells under combinatorial therapeutic blockade.

Experimental goals and endpoints include:

• Assessing tumor growth inhibition, T-cell activation, cytokine profiles, and immune-cell infiltration after dual or triple checkpoint blockade.
• Investigating resistance mechanisms by observing whether blockade of IL-17RA synergizes with CTLA-4/LAG-3 inhibition to overcome pathways tumors use to evade immune destruction.
• Monitoring toxicities and immune-related side effects in preclinical and early clinical studies, as combination regimens often increase immune-related adverse events.

While Brodalumab biosimilars are mainly researched for autoimmune and inflammatory conditions, their use in immune-oncology is emergent, with pilot studies examining how they might ameliorate immune-related adverse events caused by other immunotherapies and exploring their potential direct antitumor effects when used in combination regimens.

In summary, researchers leverage Brodalumab biosimilars’ unique IL-17RA blockade mechanism in tandem with established and novel checkpoint inhibitors to dissect and enhance interactions in immune-oncology models, aiming to identify potent synergistic effects, broaden therapeutic windows, and generate insights for future combinatorial cancer immunotherapies.

A Brodalumab biosimilar can be used as both the capture and detection reagent in a bridging anti-drug antibody (ADA) ELISA to monitor a patient’s immune response (immunogenicity) against Brodalumab by detecting anti-Brodalumab antibodies in serum.

Context and Application in Bridging ADA ELISA:

• In bridging ADA ELISAs for therapeutic antibodies such as Brodalumab, you need two forms of the drug: one for capture and one for detection, relying on the bivalent nature of patient-derived ADAs.
• Capture: The microtiter plate is coated with Brodalumab (which may be a biosimilar), allowing any ADAs (anti-Brodalumab antibodies) present in the patient sample to bind to it.
• Detection: After incubation, a separately labeled version of Brodalumab biosimilar (commonly HRP- or biotin-labeled) is added. This binds to another epitope on the ADA, forming a “bridge.” Detection is achieved by adding a substrate (e.g., TMB), leading to a colorimetric or fluorescence signal proportional to ADA concentration.

How the Brodalumab Biosimilar Functions in the Assay:

• Both coating (capture) and labeling (detection) reagents can be the Brodalumab biosimilar, given its structural and antigenic similarity to the reference product, ensuring it will bind patient-derived ADAs targeting Brodalumab identically.
• Advantages: Using a biosimilar allows reliable, consistent supply of the drug reagent for the ELISA, and demonstrates that the detected ADA response is genuinely against Brodalumab, not a structurally unrelated molecule.

Interpretation:

• Patient serum containing anti-Brodalumab antibodies will “bridge” between plate-bound and labeled Brodalumab biosimilar, generating a measurable signal.
• This format specifically detects bivalent or multivalent ADAs capable of simultaneous binding, a standard for immunogenicity monitoring of monoclonal antibody therapeutics.

Summary:A Brodalumab biosimilar is functionally interchangeable with the reference drug in this context, serving as both the “bait” on the plate and as a detection probe, together enabling sensitive detection of immune responses (anti-drug antibodies) developed by patients in response to Brodalumab therapy.