From target to optimal development candidates against a challenging GPCR target, in 8 months
GPCRs and ion channels are tough targets. Technical and biochemical challenges, including producing proteins, driving immune responses, and finding hits, have limited antibody drug discovery.
With technologies intentionally built to break the barriers of conventional discovery, we’re helping partners unlock new opportunities to bring new treatments to patients sooner.
The Challenge
A GPCR with high homology to the species used for immunization, particularly in the extracellular loops where the desired antibodies needed to bind.
The Goal
Find antibodies that are:
- Functional GPCR inhibitors
- Cross-reactive to human and rat homologs
- As potent as a clinical benchmark
The Outcome
125 functional anti-GPCR antibodies, six of which were more potent than a clinical benchmark.
Our Approach
SOURCE
We immunized rats, wildtype mice, and humanized mice using proprietary genetic immunization protocols. Approximately 80% of rats and 30% of mice had cross-reactive titers and were selected for screening.
SEARCH
We screened 2.7 million single antibody-producing cells using a multiplexed live cell-binding assay and identified 618 target-specific hits.
DECODE
We used single-cell sequencing to identify 309 unique antibody sequences from 86 different clonal families. 142 of these antibodies were cross-reactive to the human and rat homologs.
Bioinformatic analyses demonstrated that the antibodies were derived from mature immune responses with somatic hypermutation observed. The antibody sequences had a high degree of sequence diversity with 35 different VH genes used and CDR3 lengths ranging from 5-24 amino acids.
ANALYZE
We used high-throughput expression and characterization to analyze all 309 unique antibodies. Of these, 125 were functional GPCR inhibitors, and had cross-reactivity to human and rat homologs.
From this panel, we found six antibodies that were cross-reactive and more potent than a clinical benchmark, allowing our partner to select antibodies for validation in an animal model eight months after initiating antibody discovery.
