Tubulis has raised a €10.7 million ($12.3 million) series A round to advance antibody-drug conjugates (ADCs). The German biotech will use the money to build on research that identified linker chemistry that may be more stable than the technology used in ADCs such as Seattle Genetics’ Adcetris.
Researchers have access to drugs that are highly effective at killing cancer cells. However, the drugs are also very harmful to healthy tissues, resulting in dose-limiting toxicities that stop the molecules from fulfilling their therapeutic potential. ADCs lessen those concerns by using antibodies to deliver drugs to tumors but still cause adverse events by shedding their payloads en route to the cancer.
Tubulis is built on linker chemistry designed to reduce shedding and thereby enable the safe delivery of larger doses of cytotoxic drugs. If the technology works as hoped, Tubulis could develop ADCs that are safer and more effective than current treatments.
Christian Hackenberger, Heinrich Leonhardt and Jonas Helma-Smets, Tubulis’ co-founders, described the approach in papers published in Angewandte Chemie last year.
One of the papers describes the use of the novel linker chemistry to join brentuximab and vedotin, respectively the antibody and payload used in Seattle Genetics’ approved ADC Adcetris. After seven days in rat serum at 37 °C, 90% of the payload linked with the experimental technology was still connected. Adcetris lost more than 70% of its payload in three days.
Adcetris uses maleimides as linker reagents, as do other members of the current generation of ADCs including Roche’s Kadcyla. The similarities between existing products suggests the approach pursued by Tubulis’ co-founders, which uses Cys‐selective ethynylphosphonamidates as reagents, could better the stability of many existing ADCs.
Tubulis now has the money to start testing that idea. BioMedPartners and High-Tech Gründerfonds led the series A with assists from investors including Seventure Partners. The syndicate members list biotechs including Argenx, Okairòs and Rigontec among their successful investments.
Armed with conjugation technologies designed to quickly identify stable protein-drug combinations, Tubulis plans to build a pipeline of programs targeting cancers and other diseases. Tubulis already has two assets in its preclinical pipeline but is yet to disclose information beyond their code names.