Safety and clinical activity of PD-L1 blockade in patients with aggressive recurrent respiratory papillomatosis =============================================================================================================== * Clint T. Allen * Sunmin Lee * Scott M. Norberg * Damian Kovalovsky * Hong Ye * Paul E. Clavijo * Siwen Hu-Lieskovan * Richard Schlegel * Jeffrey Schlom * Julius Strauss * James L. Gulley * Jane Trepel * Christian S. Hinrichs