STX-100 (SyntheX)

STX-100 is a small-molecule inhibitor of the DNA repair protein RAD51, being developed by SyntheX as an anticancer agent targeting tumors that rely on homologous recombination–mediated DNA repair for survival.[11] By inhibiting RAD51, STX-100 is intended to impair repair of DNA double-strand breaks, promote accumulation of lethal DNA damage, and thereby enhance tumor cell death, potentially as monotherapy or in combination with DNA-damaging agents.[11] The program is in preclinical development, with active exploration across solid tumor indications where RAD51 dependence or homologous recombination proficiency contributes to therapeutic resistance.[11]