Today, UK-based biotech firm Polytherics has announced it is expanding a licensing deal of its site-specific cytotoxic conjugation technology, ThioBridge, with MacroGenics’ Dual Affinity Re-Targeting (DART) proteins in order to produce a number of ADC candidates.
According to Polytherics CEO Dr. John Burt, the platform is able to provide more stable and less heterogeneous products than alternative ADC technologies being used, due to the targeting of disulphide bonds in the antibody.
He told Biopharma-Reporter.com: “The ThioBridge technology has the advantage of rebridging these disulphide bonds with our linker reagent rather than leaving the bridge broken when alternative maleimide – [often used as flexible linking molecules to attach proteins to surfaces] - chemistries are used.”
This enables “multiple copies of cytotoxic drugs to be conjugated to an antibody at a single site,” he added, with the further advantage of the platform being the ability to work with a variety of different cytotoxic payloads.
MacroGenics’ research plan has been broadened with this extension and whilst Burt did not disclose financial or timescale details of the agreement, he did tell us PolyTherics would be “conducting bioconjugation research activities on behalf of MacroGenics in advance of nomination of development candidates.”
Furthermore, the use of the platform is not exclusive and the firm currently has collaborations with Spirogen and Biotecnol, with other biopharma companies evaluating the technology.
More approved ADCs
Industry has been increasingly focused on ADCs in the last couple of years – within the last month alone Takeda, ArGEN-X and Catalent have all expanded license agreements for various technology platforms – but only two products are currently approved and available: Seattle Genetics’ Adcetris and Genentech’s Kadcyla.
Commenting on the market, Burt told us while “the increased investment in ADCs over the last few years is evidenced by the increased number of products in clinical development,” but the development process takes many years.
“It will take time for the increased investment to translate through to more approved products,” he said.
Following the launch of Kadcyla in Europe earlier this year, the European Medicines Agency (EMA) told this publication it had not seen many ADCs reach the marketing authorisation application stage and did “not expect to see a high number of applications for this type of medicines in the future.”