Lead Identification

Selexis' SUREvariant Screening reduces lead candidate development timelines and provides better-quality data for improved decision making.

The expressibility of a candidate product is critically important for all aspects along the drug discovery, development, and manufacturing continuum. Our SUREtechnology Platform™ (already well-established as a fast and cost-effective approach for generating manufacturing cell lines) has been adapted into our novel SUREvariant Screening, which allows selected DNA libraries in a CHO manufacturing cell line to be screened, thus linking the selection and expression of a gene of interest.

Selexis SUREvariant Screening Platform

  • Eliminates candidates that can not be easily expressed in mammalian cells
  • Determines key physico-chemical parameters of any recombinant protein early(from a gene of interest)
  • Ensures a steady supply of preclinical material
  • Significantly reduces development time and costs by eliminating the need for repeated transient transfections
  • Reduces manufacturing issues through early selection of candidates that are readily expressed
  • Promotes faster, more informed decision-making
  • Typically saves ≥6 months between initiation of the screen and completion of master cell banking
  • Typically reduces costs by over $1,000,000 per clinical candidate

Using the SUREvariant Screening Platform, Selexis can generate panels of up to 250 CHO-M cell pools (SUREpools), each expressing different protein variants. Typical expression levels in the supernatants (SUREnatants) for MAbs vary between 200-500 mg/L. As the SUREpools are generated from a mammalian cell line, all variant supernatants bear the appropriate post-translational modifications and can thus be readily assessed for activity. The Selexis SUREpools that express lead candidates are then banked (stored) and can be reused for future assays.

The Selexis SUREpools that express the top clinical candidates can be transferred to the Selexis’ SURE Cell Line Development Platform to generate high-producing clonal cell lines that are ready for cGMP manufacturing, ensuring a match between preclinical and clinical material, most notably with post-translational modifications. From SUREvariant Screening to the clonal cell line, this complex process may be completed in as short as 11 weeks. Further, Selexis SUREvariant Screening can reduce development costs by over $1,000,000 per clinical candidate.

Selexis partners have two options for obtaining preclinical material from the SUREvariant screening services:

Selexis SUREnatants

  • Transfections carried out in 6-well plates
  • Milligram quantities of protein available for testing (up to a 500 ml culture)
  • Supernatant transfer in 3 weeks
  • Transferred under simple MTA


Selexis SUREpools

  • Cell pools in 3 weeks (from transfection)
  • Typical protein expression levels at milligram quantities
  • Transferred under R&D license