| abstract |
The invention provides methods for producing crystalline an anti- PD-1 monoclonal antibody (mAb), wherein the mAb is pembrolizumab or a pembrolizumab variant, comprising (1) mixing a solution comprising (a) the mAb, (b) polyethylene glycol (PEG), and (c) an additive selected from the group consisting of: caffeine, theophylline, 2' deoxyguanosine-5'-monophosphate, a bioactive gibberellin, and a pharmaceutically acceptable salt of said bioactive gibberellin, to form a crystallization solution, (2) incubating the crystallization solution for a period of time sufficient for crystal formation; and (3) optionally harvesting the crystalline anti-PD-1 mAb from the solution. In specific embodiments, the PEG is PEG 3350 and the additive is caffeine. The invention also relates to the novel anti-human PD-1 mAb crystals produced by the methods described herein. Characterization of re-dissolved crystalline suspensions using several biochemical methods showed the bio-physical properties of the re-dissolved mAb crystals were consistent with the intact antibody starting sample. The crystals and methods of the invention are amenable to multiple pharmaceutical applications such as purification, storage, formulation, and drug delivery. |