Halda Therapeutics

Targeting Cancer with a Novel RIPTAC “Hold and Kill” Mechanism

Halda Therapeutics, LLC (Branford, CT) Halda is developing RIPTAC therapeutics, which are bifunctional small molecules that selectively target tumors by holding a tumor-specific protein and a protein with essential function together in a trimeric complex which involves the formation of neo protein-protein-interactions. This mode of action results in abrogation of the essential protein function and subsequent cancer cell death. Unlike other therapeutic modalities, the hold and kill mechanism of RIPTAC therapeutics does not rely on disease drivers to achieve selective cancer killing. This unique mode of action addresses the various ways cancer has evolved bypass mechanisms of resistance, a common limitation of precision oncology medicines. Halda’s initial focus is to develop RIPTAC therapeutics that extend treatment options for cancer patients resistant to standard of care as well as applications in earlier lines of therapy. Halda was founded by Craig Crews, Yale professor and founder of Arvinas (NASDAQ: ARVN) and co-founder of Proteolix (developer of Kyprolis®, sold to Onyx, which was acquired by Amgen). Elm Street Ventures participated in the Series A financing in early 2019 led by Canaan Partners and the Series B financing in 2022 led by Access Industries. ESV’s Rebecca Frey is a member of the board of directors.