The present invention provides an immunoconjugate formulation that is substantially free of particles, the immunoconjugate formulation comprising: an immunoconjugate and one or more excipients selected from the group consisting of: sucrose, polysorbate 20, polysorbate 80, cyclodextrin, dextrose, glycerol, polyethylene glycol, mannitol, sodium chloride, and an amino acid, wherein the formulation is a buffered aqueous solution having a pH of 4.5 to 7.6. The present invention also provides an immunoconjugate formulation that is substantially free of aggregates, the immunoconjugate formulation comprising: an immunoconjugate and one or more excipients selected from the group consisting of histidine, sucrose, glycine and sodium chloride, wherein the formulation is a buffered aqueous solution having a pH of 4.5 to 7.6. The present invention further provides an immunoconjugate formulation that is substantially free of both particles and aggregates.
