Crystals of pembrolizumab and structurally similar anti-PD-1 monoclonal antibodies are provided, as well as methods of producing such crystals, and uses of compositions comprising such antibody crystals, e.g. in treatment of cancers.本文提供派姆單抗(pembrolizumab)及結構上類似之抗PD-1單株抗體之結晶體,以及產生該等結晶體之方法,及包含該等抗體結晶體之組合物在(例如)癌症治療上之用途。