NCI protocol #10250 is a single-arm, multicenter, phase 2 trial evaluating O+T in advanced uLMS pts with progression on ≥1 prior line....31% (5/16) pts had a mutation (Mut) or homozygous deletion (Hd) in the HR panel: ATRX Mut (2), ATR Mut, PALB2 Hd, RAD51B Hd. Pts with PALB2 and RAD51B Hd had longest PFS on study.