SIM0508

SIM0508 is a potent small molecule inhibitor that selectively targets and inhibits DNA polymerase theta (Pol θ), an enzyme involved in the microhomology-mediated end joining (MMEJ) pathway of DNA repair. By blocking MMEJ repair, SIM0508 effectively inhibits the proliferation of homologous recombination-deficient (HRD) tumor cells. The drug has shown potential synergy when used in combination with poly(ADP-ribose) polymerase (PARP) inhibitors or chemotherapeutic agents, with preclinical studies indicating favorable oral pharmacokinetics and safety profiles without significant hematologic toxicity. SIM0508 is being developed for the treatment of locally advanced or metastatic solid tumors and has received IND approval from both the US FDA and Chinese NMPA to begin clinical trials.