Anti-Human CD38 (Daratumumab) – Fc Muted™

Anti-Human CD38 (Daratumumab) – Fc Muted™

Product No.: LT2505

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Product No.LT2505
Clone
HuMax-CD38
Target
CD38
Product Type
Biosimilar Recombinant Human Monoclonal Antibody
Alternate Names
Anti CD38, HuMax-CD38
Isotype
Human IgG1κ
Applications
ELISA
,
FA
,
FC
,
IP
,
WB

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Select Product Size
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Antibody Details

Product Details

Reactive Species
Human
Host Species
Human
Expression Host
HEK-293 Cells
FC Effector Activity
Muted
Immunogen
Human CD38
Product Concentration
≥ 5.0 mg/ml
Endotoxin Level
< 1.0 EU/mg as determined by the LAL method
Purity
≥95% by SDS Page
≥95% monomer by analytical SEC
Formulation
This biosimilar antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.
State of Matter
Liquid
Product Preparation
Recombinant biosimilar antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.
Pathogen Testing
To protect mouse colonies from infection by pathogens and to assure that experimental preclinical data is not affected by such pathogens, all of Leinco’s recombinant biosimilar antibodies are tested and guaranteed to be negative for all pathogens in the IDEXX IMPACT I Mouse Profile.
Storage and Handling
Functional grade preclinical antibodies may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.
Regulatory Status
Research Use Only (RUO). Non-Therapeutic.
Country of Origin
USA
Shipping
2-8°C Wet Ice
Additional Applications Reported In Literature ?
ELISA,
WB,
IP,
FA,
FC
Each investigator should determine their own optimal working dilution for specific applications. See directions on lot specific datasheets, as information may periodically change.

Description

Description

Specificity
This non-therapeutic biosimilar antibody uses the same variable region sequence as the therapeutic antibody Daratumumab. This product is for research use only. Daratumumab activity is directed against human CD38.
Background
CD38 is a type II transmembrane glycoprotein that functions as an adhesion molecule with ectoenzymatic activities that contribute to intracellular calcium mobilization1, 2. Dysregulation is associated with a number of diseases, including HIV, autoimmune, type II diabetes mellitus, osteoporosis, and hematological malignancies such as multiple myeloma (MM)1, a neoplasm characterized by clonal expansion of malignant plasma cells2. CD38 is a target of MM immunotherapy, and, in 2015, the US Food and Drug Administration approved the use of daratumumab for MM treatment3.

Daratumumab kills CD38-expressing tumor cells by inducing apoptosis directly through Fc mediated cross linking3, 4 as well as by immune-mediated tumor cell lysis via complement dependent cytotoxicity (CDC)5, antibody dependent cell mediated cytotoxicity (ADCC)5, and antibody dependent cellular phagocytosis (ADCP)3, 4, 6. Daratumumab also modulates CD38 enzymatic activities, blunting cyclase activity and enhancing hydrolase activity, resulting in decreased Ca2+ mobilization and reduced downstream signaling1. Furthermore, subsets of myeloid derived suppressor cells (CD38+MDSCs), regulatory T cells (CD38+Tregs), and B cells (CD38+Bregs) are decreased by daratumumab3, and CD38 is uniformly removed from the surface of red blood cells without inducing detectable hemolysis7.

Daratumumab was generated by immunizing HuMAb-mice with purified HA-CD38 recombinant protein alone or alternating with CD38-transfected NIH-3T3 cells5. Mouse splenocytes and lymph node cells were isolated, fused with SP2/0 myeloma cells, and tested for binding to CHO-CD38 cells. The daratumumab epitope maps to two β-strands containing amino acids 233–246 and 267–280 of CD38. Binding to CD38 is completely abolished when the serine at position 274 is replaced with phenylalanine. Daratumumab does not bind to cynomolgus CD38.

Daratumumab clone AL9, a non-therapeutic biosimilar antibody for research use only was developed recombinantly and has the same variable regions as the original therapeutic.
Antigen Distribution
CD38 is expressed on plasma cells, other lymphoid and myeloid cell populations, natural killer cells, B cells, activated T cells, some peripheral regulatory T cells, monocytes, lymph node germinal center lymphoblasts, intrafollicular cells, dendritic cells, erythrocytes, platelets, committed stem cells, Purkinje cells, neurofibrillary tangles in the brain, epithelial cells in the prostate, β‐cells in the pancreas, retinal cells in the eye, and sarcolemma of smooth and striated muscle. CD38 can also be detected on early osteoclast progenitors but not on osteoblasts and mature osteoclasts. CD38 expression is very high and uniform on all malignant cells in multiple myeloma. While generally found on the plasma membrane, CD38 has also been detected in the cytosol or nucleus in brain, pancreatic acinar cells, smooth muscle, and osteoclasts.
Ligand/Receptor
CD38 Receptor, Enzyme
NCBI Gene Bank ID
UniProt.org
Research Area
Biosimilars
.
Cancer
.
Immuno-Oncology
.
Immunology
.
Signal Transduction

Leinco Antibody Advisor

Powered by AI: AI is experimental and still learning how to provide the best assistance. It may occasionally generate incorrect or incomplete responses. Please do not rely solely on its recommendations when making purchasing decisions or designing experiments.

Research-grade Daratumumab biosimilars serve as critical analytical tools in pharmacokinetic bridging ELISA assays, functioning as both calibration standards and reference controls to enable accurate quantification of drug concentrations in serum samples. The implementation of these biosimilars follows established bioanalytical principles that ensure robust and reliable measurement of therapeutic antibody levels.

Calibration Standard Implementation

In pharmacokinetic bridging ELISA assays, research-grade Daratumumab biosimilars are used to create comprehensive calibration curves that span the expected concentration range found in clinical samples. The calibration standards are typically prepared at multiple concentration levels, such as 50, 100, 200, 400, 800, 1600, 3200, 6400, and 12800 ng/mL, which are serially diluted in human serum matrix to match the sample conditions. These standards serve as the analytical reference against which unknown sample concentrations are determined through interpolation from the standard curve.

The sandwich ELISA principle forms the foundation of these assays, where standards and samples are incubated in microtiter plates coated with anti-Daratumumab capture antibodies. Following incubation and washing steps, HRP-conjugated detection antibodies bind to the captured Daratumumab, and enzymatic activity is detected using TMB chromogen substrate. The color intensity developed is directly proportional to the Daratumumab concentration, enabling quantitative measurement through comparison with the calibration curve.

Single Assay Methodology

The optimal approach for biosimilar pharmacokinetic studies involves developing a single PK assay using a single analytical standard for quantitative measurement of both biosimilar and reference products. This methodology offers significant advantages by reducing inherent variability that would arise from multiple methods and eliminating the need for crossover analysis in blinded clinical studies. The biosimilar product itself is often selected as the analytical standard for the single method after demonstrating bioanalytical comparability between test products.

Quality Control and Reference Standards

Research-grade biosimilars function as quality control samples at defined concentrations, typically including low, medium, and high concentration levels such as 50, 150, 1250, 9600, and 12800 ng/mL. These quality controls are prepared independently from the calibration standards and are analyzed alongside unknown samples to monitor assay performance throughout the analytical run. The acceptance criteria for quality control samples ensure that the assay maintains its precision and accuracy specifications.

Method Validation Requirements

The use of Daratumumab biosimilars as calibration standards requires comprehensive method validation that demonstrates precision, accuracy, and robustness in measuring both biosimilar and reference products. Validation studies typically involve multiple independent sets of standards analyzed across multiple days by different analysts to establish inter- and intra-assay variability. Recovery rates are evaluated and should fall within acceptable ranges, such as 100 ± 30% for known concentrations in normal human serum samples.

Bioanalytical Comparability Assessment

A critical aspect of using biosimilars as calibration standards involves establishing bioanalytical equivalence between the biosimilar and reference products within the method. Statistical analysis of precision and accuracy data sets is performed to determine if test products are bioanalytically comparable, typically using 90% confidence intervals compared to predefined equivalence intervals of [0.8, 1.25]. This rigorous evaluation ensures that the single method approach provides reliable quantification across different product sources.

Assay Specifications and Performance

Modern Daratumumab PK bridging ELISA assays utilizing biosimilar standards demonstrate excellent analytical performance characteristics. Detection limits can reach as low as 30 ng/mL with spike recovery rates of 85-115%. The assays typically require minimal sample volumes (10 µL) and can be completed within 70 minutes, making them suitable for high-throughput pharmacokinetic studies. Cross-reactivity studies confirm specificity for Daratumumab with minimal interference from other therapeutic antibodies and native serum immunoglobulins.

The systematic use of research-grade Daratumumab biosimilars as calibration standards and reference controls in PK bridging ELISA assays provides the analytical foundation necessary for accurate pharmacokinetic characterization of biosimilar products, supporting regulatory submissions and ensuring therapeutic equivalence assessments are based on robust bioanalytical data.

The primary in vivo models where a research-grade anti-CD38 antibody is used to study tumor growth inhibition and characterize tumor-infiltrating lymphocytes (TILs) are mainly syngeneic tumor models in immunocompetent mice, particularly C57BL/6, 129/Sv, and BALB/c strains, engrafted with mouse tumor cell lines such as KP (KRas^G12D/+^; p53^-/-^), LLC (Lewis Lung Carcinoma), MC38, Hepa1-6, CT26, and EMT-6.

Key details:

  • Syngeneic Models (Mouse)

    • Most published studies utilize mouse tumor cell lines implanted into immunocompetent mice of the same genetic background (e.g., C57BL/6 with LLC or MC38 cells).
    • Anti-CD38 antibodies, such as NIMR-5 (a mouse anti-mouse CD38), are administered in vivo to these animals.
    • These models are specifically chosen to maintain functional murine immune systems, allowing for the characterization of TILs through flow cytometry and immune phenotyping after treatment.
    • Example: In the referenced study, anti-CD38 (NIMR-5) and anti-PD-L1 antibodies were used in combination to inhibit tumor growth, with comprehensive analysis of CD8^+^ TILs, including their activation, cytokine production (IFN-γ), and exhaustion markers (PD-1, TIM3).
    • The effect of anti-CD38 was shown to be CD8 T cell-dependent, as CD8 depletion abrogated antitumor efficacy.
  • Humanized Mouse Models

    • While humanized mouse models (e.g., NSG mice engrafted with human immune cells and human tumors) are ideal for testing clinical-grade anti-human CD38 antibodies (like daratumumab or isatuximab), they are not described in the directly cited studies.
    • Most published data on in vivo TIL characterization following anti-CD38 treatment comes from mouse syngeneic models due to easier immune system manipulation and well-established immunophenotyping platforms.
    • When humanized models are used in other literature (not in your search results), they typically measure similar readouts but face more technical challenges, such as incomplete human immune cell reconstitution and issues with cross-reactivity.

Summary Table: Prevalent Models for In Vivo Anti-CD38/TIL Studies

Model TypeHostTumor Cell LineAntibodyImmune System StatusTIL Characterization
SyngeneicC57BL/6 miceKP, LLC, MC38, Hepa1-6Anti-mouse CD38Intact murineCD8^+^, CD4^+^, Treg, NK
Syngeneic129/Sv mice531LN3Anti-mouse CD38Intact murineAs above
SyngeneicBALB/c miceCT26, EMT-6Anti-mouse CD38Intact murineAs above
Humanized (less common in cited studies)NSG mice (with hCD34^+^ HSC or PBMC)Human tumor linesAnti-human CD38Partial humanUsually flow cytometry, but not in provided search
  • Primary Readouts: Tumor growth inhibition, TIL subset enumeration and functionality (CD8^+^, CD4^+^, Tregs, NK, exhaustion & activation markers), cytokine profiling, sometimes RNA-seq or proteomic analysis of TILs.

  • Genetic Knockdown/Overexpression: Some studies manipulate CD38 genetically in tumor cells in addition to using antibodies, but still utilize the same syngeneic model format as above.

Conclusion: The field predominantly uses syngeneic mouse tumor models with anti-mouse CD38 antibodies to assess tumor growth and TIL function in vivo. Humanized models are less frequently used for this purpose in current literature, largely due to technical and logistical constraints.

Role of Daratumumab Biosimilar in Bridging ADA ELISA for Immunogenicity Testing

In immunogenicity testing, the bridging anti-drug antibody (ADA) ELISA is a widely used method to detect and quantify patient immune responses against biologic therapies, such as monoclonal antibodies (mAbs). When monitoring a patient’s immune response to a therapeutic mAb, the assay is designed to capture and detect ADAs that may develop during treatment. The capture and detection reagents are central to the assay’s specificity and sensitivity.

Bridging ELISA Principle

In a typical bridging ADA ELISA, the therapeutic drug (or its biosimilar) serves as both the capture and detection reagent. The format is as follows:

  • Capture: Biotinylated drug (e.g., Daratumumab biosimilar) is immobilized on streptavidin-coated microplates.
  • Incubation: Patient serum (potentially containing ADAs) is added. If present, bivalent ADAs can bind to the immobilized drug.
  • Detection: A labeled (e.g., horseradish peroxidase, HRP) version of the same drug is added. If ADAs are present, they will “bridge” the immobilized and labeled drug, forming a detectable immune complex.

Why Use a Daratumumab Biosimilar?

In the context of Daratumumab, a therapeutic mAb used in multiple myeloma, a biosimilar version of Daratumumab would be used in the bridging ELISA—instead of the reference product—in scenarios where:

  • Regulatory guidance or assay development protocols require head-to-head immunogenicity comparison between the biosimilar and the reference product.
  • Availability or cost favors the use of the biosimilar over the reference drug for assay optimization.
  • Assay specificity should reflect the actual drug being monitored, ensuring that detected antibodies are truly against the intended therapeutic.

Assay Design Details

  • Capture Step: The Daratumumab biosimilar (biotinylated) is immobilized on the plate, capturing any ADAs in the patient sample that recognize the biosimilar.
  • Detection Step: The same Daratumumab biosimilar (now labeled with an enzyme, e.g., HRP) is added. Only ADAs that can bind both the immobilized and labeled biosimilar will produce a signal, ensuring the assay detects bivalent (and thus clinically relevant) antibodies.
  • Specificity Considerations: Matrix effects, drug interference, and the presence of immune complexes may influence assay performance. Assay optimization—including the use of blocking reagents and drug-tolerant formats—is critical.

Advantages and Limitations

  • Advantages: High sensitivity for bivalent ADAs, suitability for high-throughput screening, and direct measurement of antibodies against the therapeutic agent (including biosimilars).
  • Limitations: Potential for false positives due to matrix effects or drug interference, and the need for rigorous validation to ensure the biosimilar behaves equivalently to the reference drug in the assay.

Summary Table: Role of Daratumumab Biosimilar in Bridging ADA ELISA

StepReagent UsedPurpose
CaptureBiotinylated Daratumumab biosimilarImmobilizes ADAs specific to the biosimilar
DetectionLabeled Daratumumab biosimilarDetects bivalent ADAs bridging capture and detection
SpecificitySame biosimilar for both stepsEnsures detection of antibodies against the intended drug

Conclusion

A Daratumumab biosimilar can be effectively used as both the capture and detection reagent in a bridging ADA ELISA to monitor a patient’s immune response against the therapeutic drug. This setup ensures the assay detects antibodies specifically directed against the biosimilar, providing clinically relevant immunogenicity data for both biosimilar and reference product development and post-marketing surveillance. Rigorous assay validation is essential to ensure that any differences in immunogenicity profiles between the biosimilar and the reference product are accurately reflected.

References & Citations

1. van de Donk NW, Janmaat ML, Mutis T, et al. Immunol Rev. 270(1):95-112. 2016.
2. Morandi F, Horenstein AL, Costa F, et al. Front Immunol. 9:2722. 2018.
3. https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/761036s004lbl.pdf
4. Phipps C, Chen Y, Gopalakrishnan S, et al. Ther Adv Hematol 6(3):120-127. 2015.
5. de Weers M, Tai YT, van der Veer MS, et al. J Immunol. 186(3):1840-1848. 2011.
6. Overdijk MB, Verploegen S, Bögels M, et al. MAbs. 7(2):311-321. 2015.
7. Sullivan HC, Gerner-Smidt C, Nooka AK, et al. Blood. 129(22):3033-3037. 2017.
8. Kong S-Y, Li X-F, Nahar S, et al. Blood. 116(21):3013. 2010.
9. Marco Jansen JH, Boross P, Overdijk MB, et al. Blood. 120(21):2974. 2012.
10. Plesner T, Lokhorst H, Gimsing P, et al. Blood. 120(21):73. 2012.
11. Krejcik J, Casneuf T, Nijhof IS, et al. Blood. 128(3):384-394. 2016.
12. Naeimi Kararoudi M, Nagai Y, Elmas E, et al. Blood. 136(21):2416-2427. 2020.
Indirect Elisa Protocol
FA
Flow Cytometry
Immunoprecipitation Protocol
General Western Blot Protocol

Certificate of Analysis

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Disclaimer AlertProducts are for research use only. Not for use in diagnostic or therapeutic procedures.