During the development of therapeutic protein and peptide biopharmaceutical products, potency assays are considered critical to quantify the biological effects of the product. All analytical results obtained for therapeutic proteins & peptides must be correlated with potency assay results. According to ICH guideline Q6B, biological activity should be measured using an appropriate quantitative bioassay, also called a titer assay or bioassay. CD Formulation's senior protein scientists have extensive experience in biopharmaceutical potency assay development, optimization, validation, and transfer, and we can perform analytical work in a GMP-compliant environment according to sponsor requirements to ensure the smooth release and release of customer products.

What is a Potency Assay?

Potency assay refers to a quantitative measurement of the biological activity of a given biopharmaceutical product. Potency assay involves comparing the biological activity of the product to that of a reference formulation during the development of biologics. Although previously preferred for clinical relevance, in vivo bioassays have been greatly reduced with the emergence of dependent cell lines and ethical concerns. Cell-based potency assays are a core tool for measuring drug efficacy during potency testing. Additionally, various procedures including ligand and receptor binding assays, enzyme assays, etc., can also be used for potency testing based on a product's mechanism of action. Potency assays allow scientists to understand how a specific dose of a drug will react in a given biological system and fully explain:

• Whether the compound acts on a biological target.
• Whether biopharmaceuticals have any side effects and potentially harmful toxic effects.

Fig.1 The ex vivo potency assay comprises four basic steps. (Schäfer M, et al., 2015)

Explore Our Proteins & Peptides In Vitro Potency Assay

The biological activity of each batch of biopharmaceuticals must be confirmed before therapeutic proteins and peptides are released for use. At CD Formulation, our experienced protein and peptide experts will work with you to explore the best solutions for in vitro potency assays to ensure the smooth release and listing of your products. We provide the following in vitro potency assay services, including but not limited to:

Ligand and Receptor Binding Assays for Proteins and Peptides

When your protein and peptide biologic's mechanism of action requires binding to a receptor or protein, and exerts its function by binding to a cellular or soluble target. For these products, we will select the ligands and receptor binding assays, which offer direct measurement of the product's affinity for its intended target and may be suitable for potency testing. Our commonly used assay types include:

• Enzyme-Linked Immuno-Sorbent Assay (ELISA)
• "Homogeneous" Immunosorbent Assay
  Time-resolved Homogeneous Fluorescence Resonance Energy Transfer Assay
  Amplified Luminescence Proximity Homogeneous Assays
  Proximity Based Electrochemiluminescence Immunoassay
• Surface Plasmon Resonance (SPR) Assay

Enzyme Activity Assay for Proteins and Peptides

Enzyme activity assays are primarily used to determine the potency of enzyme products and involve testing individual functions and activities of therapeutic products. We will use it in conjunction with binding assays to fully characterize biological potency if necessary depending on the mode of action. Our commonly used enzyme activity assays include:

• Spectrophotometry Assay
• Fluorescence Assay
• Calorimetry Assay
• Chemiluminescence Assay
• Light Scattering Assay

Cell-Based Potency Assays for Proteins and Peptides

Our cell-based assays are your first choice when your protein and peptide biopharmaceutical contains multiple functional domains that all need to be complete for the product to be effective. Our cell-based potency assays include:

• Cell Proliferation Assay
• Cell Cytotoxicity Assay
• Cell Apoptosis Assay
• Cell Signal Assay
• Reporter Gene Assay

Our Expertise and Technologies

At CD Formulation, we can develop any ligand-receptor binding assay, cell-based assay, and enzyme activity assay based on your needs, thereby accelerating the rapid development, licensing, and commercial launch of your protein and peptide biopharmaceutical products. Our experienced team of experts provides support services in the following areas of biopharmaceutical potency determination, including but not limited to:

• Proteins and peptides in vitro potency assay method development.
• Proteins and peptides in vitro potency assay method verification: Verify the accuracy, precision, linear range, specificity, robustness, and LOD/LOQ of in vitro potency according to ICH drug requirements.
• Proteins and peptides in vitro potency assay method optimization: Improve existing assays and find the best strategies to optimize your method.
• Proteins and peptides in vitro potency assay method transfer: Transfer methods back to your lab or another testing lab with a transfer protocol and smoothly perform routine lot release testing.
• Proteins and peptides biopharmaceutical batch release testing: Specialized in various batch releases of different products, such as therapeutic antibodies (such as monoclonal antibodies, antibody-drug conjugates, bispecific antibodies), recombinant proteins, and therapeutic peptides.
• Proteins and peptides forced degradation study.
• Proteins and peptides in vivo potency assay evaluation.

Why Choose Us for Protein & Peptide In Vitro Potency Assay?

• Our protein and peptide biopharmaceutical in vitro potency assay method development and validation strategies are based on customer requirements and international regulatory guidelines such as ICH, FDA, ISO, EMA, and USP/Ph, and are conducted in accordance with GMP regulations.
• Our team of protein and peptide experts has extensive experience in performing a variety of cell-based assays as well as binding assays to support the development, licensing, and commercial launch of a variety of protein and peptide biopharmaceutical products.
• We perform dozens of protein and peptide biopharmaceutical in vitro potency assay projects every year.
• We have established and validated various sponsor-specific assays, compendial methods, and generic biosimilar methods.
• Flexible test design and customized solutions to meet any product type and customer needs.

Publication

CD Formulation's extensive expertise in complex in vitro potency assay development and bioactivity assessment of therapeutic proteins and peptides can provide you with insights into your products and accelerate your development process. Please feel free to contact us to speak with our team of scientists and learn how our expertise and technology can support your product development.