FLX475: A CCR4 antagonist that mounts an immune response against a broad range of "charged" and virally associated tumors

FLX475 is a small molecule CCR4 antagonist designed to block the migration of regulatory T cells (T_reg) specifically into tumors, but not healthy tissues, without depleting T_reg throughout the body, which we believe may decrease the likelihood of side effects. We are developing FLX475 for the treatment of a broad range of charged tumors, which represent cancer types we believe are most likely to respond to FLX475. In cancer, the secretion of certain chemokines from tumor cells and tumor-resident immune cells is responsible for recruitment of immunosuppressive T_reg to tumor sites. T_reg represent a dominant pathway for downregulating the immune response, and thus may limit the effectiveness of currently available therapies such as checkpoint inhibitors. Therefore, blocking the migration of T_reg has the potential to restore naturally occurring antitumor immunity as well as to synergize with a variety of both conventional and immune-based therapies, such as radiation, chemotherapy, checkpoint inhibitors, immune stimulators and adoptive T cell therapy.

We believe that the inhibition of CCR4 has the potential to bring therapeutic benefit to patients across a wide spectrum of tumors in a manner similar to other immuno-oncology therapies that have been shown to be effective against multiple tumor types, while also potentially deepening or broadening clinical responses to these therapies.