The present disclosure provides indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors of Formula I: or pharmaceutically acceptable salts thereof, in which X, L, n, m, R1, R2a, R2b, Rn, Rm, and Rt are as defined herein, as well as pharmaceutical compositions that include a compound of Formula I, or pharmaceutically acceptable salts thereof, and methods of using the same to treat conditions mediated by IDO1.