Versant's Repare raises $82M to trial synthetic lethality drugs

Repare Therapeutics CEO Lloyd Segal (Repare Therapeutics)

Repare Therapeutics has raised an $82.5 million series B round to take synthetic lethality drugs into humans. The Versant Ventures-founded biotech plans to start testing ATR inhibitor RP-3500 in the clinic next year while putting a second asset through the final steps of preclinical development. 

U.S.-Canadian biotech Repare exited stealth in 2017 with $68 million in series A funding from backers including Versant, MPM Capital and Celgene. Repare planned to use the money to take a candidate targeted at DNA-directed DNA polymerase theta (Polθ) into the clinic in 2019. That plan has changed somewhat, but Repare will still close out 2019 on the cusp of the clinic.

Cowen Healthcare Investments has stepped up to enable Repare to execute the next stage of its plan. The financier led the series B with the support of fellow new investors OrbiMed, Redmile, BVF Partners and Logos Capital. Existing investors including Versant and MPM also participated.

Repare will use the money to take ATR inhibitor RP-3500 into the clinic next year. The role of ATR in protecting cells from replication-related stresses has made it a target of interest for years, leading to clinical trials of assets in development at AstraZeneca, Bayer and Merck KGaA. 

The leadership at Repare thinks RP-3500 can compete. Talking to The Globe and Mail, CEO Lloyd Segal sketched out a timeline that would see Repare start testing RP-3500 in 40 to 60 patients next summer, deliver data one year later and secure FDA approval in 2023 or 2024. Versant foresees the biotech going public in the next year or two.

Repare is also working to get another drug into the clinic. The second asset is an undisclosed CCNE1 synthetic lethal targeted therapy code-named Manchester. Repare expects to get that drug into the clinic within the next 18 months. 

Polθ, which ONO Pharmaceutical licensed in Asian countries including Japan in January, has slipped down the pecking order as Repare has turned its attention to RP-3500 and the undisclosed drug. Repare’s pipeline shows the Polθ program as being back in the late stages of lead generation, while the other two programs are nearing or at the end of lead optimization.