Anti-Human IL-17A (Secukinumab) [Clone AIN457] — Fc Muted™

Research-grade Secukinumab biosimilars are used as calibration standards or reference controls in pharmacokinetic (PK) bridging ELISAs to establish accurate, quantitative measurement of drug concentration in serum samples, typically by serving as the analytical standard curve against which test samples—including reference and biosimilar products—are measured.

This process supports the bioanalytical comparability assessments that underpin PK bridging studies in biosimilar development.

Key details on use:

• Single Analytical Standard: Industry consensus and regulatory practice recommend the use of a single analytical standard (often the biosimilar) to generate the calibration (standard) curve for a PK ELISA assay. This standard is spiked into pooled human serum to prepare calibrators covering the expected drug concentration range (for example, 50–12,800 ng/mL).

• Reference Controls (Quality Controls): Both biosimilar and reference Secukinumab products are prepared in serum at low, medium, and high concentrations as QC samples. These controls are assayed alongside the calibrators to validate assay accuracy and precision across products.

• Bridging ELISA Format: In a bridging ELISA, both the biosimilar and reference versions of Secukinumab are detected and quantified with the same method, leveraging antibodies that recognize structural features common to both molecules. The assay's output (signal) is directly proportional to drug concentration in the sample.

• Bioanalytical Equivalence Testing: By measuring the concentration of both products using the single standard curve, analytical equivalence can be statistically assessed (typically, 90% confidence intervals of the concentration ratios must fall within the 0.8–1.25 interval). This demonstrates methodological suitability and quantifies method-related variability.

• Why Research-Grade Biosimilars?: They are commonly used because they are manufactured under known conditions, closely represent the structure/function of the reference, and are often more available/accessible for assay development and validation.

Workflow summary:

1. Prepare a standard curve using the research-grade Secukinumab biosimilar spiked into human serum for a series of concentrations.
2. Run unknown serum samples, QC controls (using both biosimilar and reference products), and the calibrators in the same assay.
3. Quantify measured concentrations using the standard curve.
4. Statistically assess equivalence and accuracy to validate the ELISA for bridging PK assessments.

This process ensures consistent, reproducible, and comparable quantitation of Secukinumab (biosimilar and reference) in PK studies, meeting regulatory expectations for demonstrating biosimilar pharmacokinetic similarity.

The primary mouse models used to study anti-IL-17A antibody effects on tumor growth inhibition and tumor-infiltrating lymphocytes (TILs) are predominantly syngeneic models, with some studies utilizing xenograft approaches.

Syngeneic Models

EO771 Breast Cancer Model represents one of the most extensively characterized syngeneic systems for anti-IL-17A research. In this model, mice are challenged with 1 × 10⁶ syngeneic EO771 tumor cells, followed by anti-IL-17A antibody treatment at doses ranging from 200-400 mg/mouse administered four times at weekly intervals. This model demonstrated that anti-IL-17A treatment significantly reduced tumor burden and, when combined with anti-PD-L1 antibodies, substantially improved survival rates by approximately 70%.

MT/ret-derived Primary Cutaneous Melanoma (CM) Model utilizes mice carrying the human ret transgene with wild-type BRAF status. This syngeneic model specifically examines the interaction between IL-17A signaling and dual immune checkpoint inhibition (CTLA-4 and PD-1). The model employs both IL-17A-neutralizing antibodies and recombinant mouse IL-17A to demonstrate that IL-17 signaling creates a favorable tumor microenvironment with increased immune infiltration, particularly neutrophils.

B16-F10 Melanoma Models have been employed in multiple configurations. One approach uses standard B16F10 cells in syngeneic settings, while another utilizes B16F10 cells in Foxp3 DTR (diphtheria toxin receptor) mice to study the relationship between IL-17A and CD8+ T cell exhaustion. Additionally, xenograft studies using B16-F10 cells in IL-17⁻/⁻ mice have been conducted to examine IL-17A's role in melanoma progression.

Characterization of Tumor-Infiltrating Lymphocytes

The syngeneic models are particularly valuable for TIL characterization because they maintain fully intact and functional immune systems. Anti-IL-17A treatment in these models has revealed several key immunological changes:

Enhanced CD8+ T Cell Response: Anti-IL-17A treatment promotes stronger CD8+ T cell responses within the tumor microenvironment, contributing to improved antitumor immunity. The treatment appears to reverse IL-17A-mediated promotion of CD8+ T cell terminal exhaustion.

Neutrophil Modulation: IL-17 signaling significantly influences neutrophil infiltration patterns, with IL-17A creating conditions that favor increased neutrophil presence in tumors. This neutrophil recruitment appears to support the clinical benefit observed with dual checkpoint inhibition.

Regulatory T Cell Reduction: Anti-IL-17A treatment decreases the percentage of regulatory T cells (Tregs) in tumor tissues, contributing to a more immunologically active tumor microenvironment.

Model-Specific Considerations

Syngeneic tumor models present unique advantages for anti-IL-17A research because they recapitulate the complex interactions between the immune system and tumors. However, these models require cross-reactive therapeutics that can recognize murine targets, which can be addressed through transgenic syngeneic mice expressing human targets, syngeneic tumor models overexpressing human antigens, or chimeric antibody-based agents.

The research demonstrates that anti-IL-17A treatment works synergistically with other immunotherapies, particularly PD-L1 blockade, by reducing PD-L1 expression in tumor tissues and enhancing tumor-specific immune responses. This combination approach has proven more effective than single-agent therapy in extending survival in these preclinical models.

Researchers investigating combinations of Secukinumab biosimilars (targeting IL-17A) with checkpoint inhibitors such as anti-CTLA-4 or anti-LAG-3 biosimilars in complex immune-oncology models primarily aim to evaluate synergistic antitumor effects and immune modulation, though clinical data remains limited and such combinations are generally considered experimental.

Key points based on available evidence:

• Secukinumab is an IL-17A inhibitor used mainly for autoimmune conditions; its primary oncology-related role studied to date has been the management of immune checkpoint inhibitor (ICI)-induced adverse events, not direct antitumor synergy.
• The combination of multiple immune checkpoint inhibitors (such as anti-CTLA-4 with anti-PD-1 or anti-LAG-3) has shown promising synergy in preclinical models and early clinical trials, as their mechanisms target distinct immune pathways: CTLA-4 blockade primarily enhances T cell priming and activation (lymph nodes), while PD-1/PD-L1 (and by extension, LAG-3) blockade acts within the tumor microenvironment to prevent effector T cell suppression.
• Combining checkpoint inhibitors with other biologics (including IL-17A inhibitors) is experimental; effectiveness and safety are unproven for most indications, especially in complex cancer immunotherapy regimens.
• Preclinical and translational research settings may utilize such combinations to address:
  • Mechanistic questions about immune cell interactions, cytokine balance, and regulatory cell populations (e.g., Tregs, myeloid-derived suppressor cells).
  • Overcoming resistance to immunotherapy in models where single-agent checkpoint blockade is ineffective, by modulating additional inflammatory or immunosuppressive pathways (IL-17/Th17 axis).
  • Assessment of immune-related adverse events (irAEs) mitigation strategies, since IL-17A inhibition may reduce the toxicity profile associated with dual or triple checkpoint blockade.

Experimental models typically involve:

• Animal (murine) tumor models genetically engineered or engrafted with tumors, treated with combinations of IL-17A blockade and checkpoint inhibitors.
• In vitro coculture systems investigating tumor-immune cell and cytokine dynamics under multi-drug conditions.
• Early-phase (phase I/II) clinical studies may explore pilot combinations, almost always under strict safety monitoring due to compounded immunosuppression risks and potential for infection or tolerance breakdown.

Cautions and limitations:

• Toxicity and safety concerns are substantial, as combining multiple immunomodulating agents increases the risk of severe and unpredictable immune-related adverse events.
• There is very limited published clinical evidence supporting synergistic antitumor efficacy for IL-17A inhibitor and checkpoint inhibitor combinations in humans; most experience is derived from their use in managing ICI-associated toxicities, not for direct tumor therapy.
• Clinical guidelines currently consider such combination regimens experimental or investigational outside of research protocols.

Summary Table — Combination Use in Research:

In summary, while checkpoint inhibitor combinations are established in some cancer types, use of Secukinumab biosimilar with other checkpoint inhibitors remains primarily an experimental research approach reserved for complex immune-oncology models or for addressing immune toxicity, with clinical application largely unproven and limited to case reports or ongoing trials.

A Secukinumab biosimilar can be used as both the capture and detection reagent in a bridging ADA ELISA to monitor a patient’s immune response (ADA formation) against Secukinumab therapy by taking advantage of its structural similarity to the reference drug. This format relies on the ability of bivalent anti-drug antibodies in patient samples to “bridge” between Secukinumab biosimilar molecules immobilized on the plate and those labeled with a detection tag, such as biotin or HRP.

Essential context:

• In a typical bridging ADA ELISA:

  • The plate is coated with the Secukinumab biosimilar (capture reagent).
  • Patient serum is added; if present, any anti-Secukinumab antibodies (ADA) will bind to the immobilized biosimilar.
  • A second, labeled Secukinumab biosimilar (e.g., biotinylated or HRP-conjugated) is added as the detection reagent. The ADA, if present, will bridge the capture and detection biosimilar molecules.
  • After washes, the detection signal indicates presence of ADA, and its strength correlates with ADA concentration.

• Rationale for using a biosimilar:

  • The biosimilar's close structural and epitope similarity to reference Secukinumab ensures that the assay detects all clinically relevant ADAs that would also react to the originator drug.
  • If the biosimilar is analytically and functionally similar, it is suitable for ADA assays in preclinical and post-marketing studies.

Supporting details:

• Bridging ELISAs are described as the gold standard for detecting anti-drug antibodies due to their sensitivity and ability to detect bivalent antibodies.
• This approach is widely used for biologics, including mAbs and biosimilars, with modifications only for specific assay requirements.
• High-quality biosimilar reagents ensure specificity and reproducibility, as matrix interferences are a known challenge in patient serum.

Summary of technique:

• Plate coating: Secukinumab biosimilar.
• Sample addition: Patient serum; possible ADA will bind biosimilar.
• Detection step: Biotinylated/HRP-labeled Secukinumab biosimilar binds to ADA, completing the bridge.
• Signal development: Indicates presence/amount of ADA.

This use of the Secukinumab biosimilar as both capture and detection reagent allows robust and clinically relevant monitoring of ADA formation during Secukinumab therapy.