PDCD1 and mature T-cell and NK-cell non-Hodgkin lymphoma: A phase 2 study reported modest activity of the single agent tislelizumab, a programmed cell death protein 1 inhibitor, in 44 patients with refractory PTCL including 11 AITL patients with an ORR of 20.5% and a CR rate of 9.1% (16).