PDCD1 and glioblastoma: Although the IMA950/poly-ICLC peptide vaccine has shown no clinical benefit for recurrent GBM [89], a phase II clinical trial (NCT03665545) was designed to evaluate the antitumor efficacy of the IMA950/poly-ICLC vaccine combined with the anti-PD-1 antibody pembrolizumab in recurrent GBM patients [90].