55%
DISPLAY POTENTIALLY TOXIC OR UNEXPECTED OFF-TARGET BINDING
Building a picture of a biotherapeutic’s off-target binding liability reduces risk by contributing to a more comprehensive safety assessment, saving considerable time and resources by identifying potential clinical risks earlier in your program.
Rapidly Identify Biologically Relevant Off-Target Binding
Toxicity due to cross-reactivity or 'off-target' binding is a serious cause for concern in drug development. Off-target screening via the Retrogenix® Cell Microarray Technology is the only method which assesses off-targets against both human plasma membrane and secreted proteins that are overexpressed in human cells.
This highly specific screen demonstrates a low false positive rate, typically reporting one or two confirmed interactions rather than hundreds of erroneous results, saving months of additional work and unnecessary investigation. In-house hit validation is available following delivery of initial results, typically performed with materials available from the main study. Retrogenix® off-target binding data have been used extensively in regulatory BLA and IND submissions, where high confidence in the specificity of a novel biotherapeutic is required, with a greater than 95% success rate.
eGuide for Off-Target Screening via the Retrogenix Platform
Download the eguide for all the information you need on how the Retrogenix platform can be leveraged to screen for specificity in vitro against a physiologically relevant human protein library from early-phase discovery onwards, to aid candidate selection, downstream study design, and IND approval.
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The Impact of Off-Target Binding
←
Unidentified
Off-Target Binding
- Potential toxicity to patients
- Potential clinical and regulatory failure
- Reduced downstream program progression flexibility
- Downstream study complications
- Costly unplanned late-stage optimization or attrition
Identified
Off-Target Binding
→
- Early attrition from lead-candidate pool
- Progression of safer / more effective candidates
- Focusing of resources on viable candidates
- Identify new applications for your molecule
- Early understanding of optimization requirements
Key Features of Retrogenix® Off-Target Screening
- Assess off-targets against human plasma membrane and secreted proteins that are expressed in human cells
- Highly validated and specific with very low false positive / negative rates
- Can predict and explain unexpected toxicity due to off-target binding
- Can inform pre-clinical tox model selection, reducing in vivo testing
- Prioritizes drug leads or avoidance of off-target activities in next-generation molecules
- Screening library includes >98% of the human surfaceome and secretome represented at 10 to 18 weeks of pregnancy, enabling generation of prenatal safety confidence data as standard
- Can be used as a standalone screen or combined with IHC-Tissue Cross-Reactivity (TCR)
- Uses biosynthesized proteins in vitro, mitigating the lead times associated with ex vivo testing
Graphic images showing the binding of a test article to an overexpressed human protein in HEK293 cells using the Retrogenix® Cell Microarray for off-target screening. Binding will typically be assessed via fluorescence (right image).
Screen for cross-reactivity across a broad range of modalities including:
- Antibodies (monospecific, bispecific and multispecific)
- ADCs
- ScFvs, Fabs or antibody derivatives
- Whole CAR cells
- Peptides
- Protein ligands
- Labelled small molecules
- Vaccine delivery vehicles
WEBINAR: Maximize Safer, Targeted Biologic Development with Smarter NAMs-Based Off-Target Screening
This webinar showcases how the Retrogenix® platform empowers smarter, earlier decisions across biologic formats. You’ll also learn how this platform, recently accepted into the FDA’s ISTAND Pilot Program, aligns with evolving regulatory support for NAMs and the shift toward reduced animal use.
Watch the Replay
Frequently Asked Questions (FAQs) About Screening for Off-Target Binding
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Do I need to include specificity analysis in an IND submission?
Yes. To minimize the chance of off-target toxicities in clinic, the regulatory agencies recommend performing specificity assessment of each biotherapeutic. Find out more about our off-target screening data in IND submissions.
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What's the probability of my biotherapeutic displaying off-target binding?
Our data indicates that approximately 55% of biotherapeutics screened using the Retrogenix® platform display at least one specific off-target, highlighting the importance of screening biotherapeutics for specificity.
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Can multi-specific biotherapeutics be profiled?
Yes. We can use off-target screening for a range of multi-specific molecules, and we can deconvolute which binding arm is responsible for each interaction, provided the appropriate controls are available.
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When should I screen my biotherapeutic for off-targets?
We would recommend profiling for specificity at least once during the preclinical process. While many clients screen for off-target binding during IND-enabling stages in order to generate supporting data for IND / BLA applications, screening earlier during lead selection can promote early attrition of unviable candidates and influence downstream study design.
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Can Charles River screen antibody-drug conjugates (ADCs)?
Yes. We can screen ADCs and the respective naked antibody to assess specificity profile of each component. As our protocols allow us to fix the cells prior to assessing binding to each over-expressed target, the toxicity of the ADC payload does not affect the results.