676 Pepinemab, a semaphorin 4D inhibitor, in combination with pembrolizumab induced formation of organized lymphoid aggregates in phase 1b/2 study for first-line treatment of R/M HNSCC (KEYNOTE-B84) - Elizabeth Evans; Nagashree Seetharamu; Crystal Mallow; Maurice Zauderer; Barbara Burtness; Marya Chaney; Alexander Spira; Conor Steuer; Tarek Mekhail; J Thaddeus Beck; Douglas Adkins; Terrence Fisher; et al. (Journal for ImmunoTherapy of Cancer, 2023)