a weak acid and a conjugate salt or a weak base and a conjugate salt ( e.g sodium acetate). Buffers suitable for use in connection with this invention may have a pH in the range from about 4.0 to about 9.0; from about pH 4.0 to about 7.0; or from about pH 4.5 to about 6.5. A pH of any point in between the above ranges is also contemplated. 

[0114] As used herein, the terms "buffer-free" or "free of buffer" are synonymous and intend to exclude components traditionally used to introduce buffer capacity in the formu› lation in addition to any buffering capacity present in the formulation absent the buffer component. For example, proteins are known to provide buffering capacity to a for› mulation. Hence, these terms do not mean a formulation cannot have any buffering capacity. In one embodiment, a buffer-free protein formulation is self-buffering. 

[0115] As used herein, "purified" means that a molecule is present in a sample at a concentration of at least 95% by weight, or at least 98% by weight of the sample in which it is contained. 

[0116] The term "organic co-solvent" is used herein in the same sense as it is used in U.S. Pat. No. 9,580,489. See, for example, colunm 2, lines 25-38. U.S. Pat. No. 9,580,489 states "organic co-solvent may be polysorbate, for example, polysorbate 20 or polysorbate 80, polyethylene glycol (PEG), for example, PEG 3350, or propylene glycol, or a combination thereof." An organic co-solvent is an organic (i.e., carbon-based) substance that is added to composition primarily to keep the ingredients of the composition in solution (i.e. dissolved). This includes preventing precipita› tion, aggregation, and adsorption of composition ingredi› ents. 

[0117] Substances defined or recited separately from "organic co-solvent" in U.S. Pat. No. 9,580,489 are excluded from term "organic co-solvent" in the present application. For example, U.S. Pat. No. 9,580,489 lists types of substances, and gives examples thereof, as distinct from an "organic co-solvent." See, colunm 2, lines 25-38. In particular, U.S. Pat. No. 9,580,489 provides the following examples of substances that are not organic co-solvents: a tonicity agent for example sodium chloride or potassium chloride; a stabilizing agent for example sucrose, sorbitol, glycerol, trehalose, or mannitol; and a buffering agent for example phosphate buffer. Examples of compounds that are not an "organic co-solvent," as used herein, include salt ( e.g. sodium chloride, magnesium chloride), sugar (e.g. dextran or other polysaccharides), polyol (e.g. sorbitol, glycerol, mannitol), and amino acid (e.g. arginine, glycine, praline). Additional examples of compounds that are not an organic co-solvent include block copolymers, alkyl saccharides (e.g., a ProTek alkyl saccharides, octyl glucoside, N-decyl› pyranoside, N-octyl-glucopyranoside, Intravailfi, and those described in U.S. Pat. Nos. 9,446,134; 8,846,044, 8,226,949; 7,998,927; 8,084,022; 7,425,542; and 10,046,025), and FM! 000, or any combination thereof. 

[0118] When pharmaceutical compositions containing aflibercept are stored, the activity of aflibercept can be lost or decreased due to aggregation and/or degradation. Thus, the present invention provides aqueous formulations of aflibercept that allow stable storage of aflibercept, so that aflibercept is stable over the course of storage either in liquid or frozen states. The provided formulations do not require any extra steps such as rehydrating. 

[0119] Numerous embodiments of the present invention are explained in a greater detail below. 

[0120] A. Aflibercept 

[0121] Aflibercept suitable for storage in one of the pres› ent pharmaceutical compositions or formulations can be produced by standard methods known in the art. For example, U.S. Pat. No. 9,580,480 and WO 2006/104852 describe various methods that a skilled artisan could use to prepare aflibercept protein for use in the formulations of the present invention. These methods are incorporated by ref› erence herein. 

[0122] Aflibercept can also be produced by purifying and/or diluting from commercially-available Eyleafi and/or Zaltrapfi preparations using standard methods 

[0123] Purification of the expressed aflibercept can be performed by standard methods known in the art. When aflibercept is produced intracellularly by host cells, the host cells are lysed and particulate debris is removed, for example, by centrifugation or ultrafiltration. When afliber› cept is secreted into the medium by host cells, supematants from such expression systems can be first concentrated using standard polypeptide concentration filters. Protease inhibi› tors can also be added to inhibit proteolysis and antibiotics can be included to prevent the growth of microorganisms. 

[0124] For example, aflibercept can be purified using, for example, hydroxyapatite chromatography, gel electrophore› sis, dialysis, ion exchange chromatography and affinity chromatography, and any combination of known or yet to be discovered purification techniques, including but not limited to Protein A chromatography, fractionation on an ion-ex› change column, hydrophobic interaction chromatography (HIC), ethanol precipitation, reverse phase HPLC, chroma› tography on silica, chromatography on heparin SEPHARO› SETfi, an anion or cation exchange resin chromatography (such as a polyaspartic acid colunm), chromatofocusing, SDS-PAGE, and ammonium sulfate precipitation. 

[0125] B. pH/Buffer Selection for Aflibercept Formula› tions 

[0126] The formulations of the invention may include buffers, tonicity modifiers, excipients, pharmaceutically acceptable carriers and other commonly used inactive ingre› dients of the pharmaceutical compositions. However, for› mulations that indicate that an ingredient is excluded ( e.g. buffer-free formulations) do not include such ingredient. 

[0127] Buffers maintain pH in a desired range, e.g., between pH 4 and pH 9. Buffers may also serve to stabilize aflibercept by a variety of other mechanisms, meaning they may be used outside of the nominal buffer capacity range indicated by their respective pKa values. Examples of suit› able buffers include acetate (e.g., at pH 4 to 5.5), citrate (e.g., at pH 5 to 6.5), histidine ( e.g., at pH 5 to 7), phosphate ( e.g., at about pH 6 and 8), Tris (e.g., at pH 7 to 8), and glycine (e.g., at pH 8 to 9). Specific embodiments include, without limitation, sodium or potassium phosphate, sodium or potas› sium citrate, ammonium acetate, tris-(hydroxymethyl)› aminomethane (tris), various forms of acetate and dietha› nolamine. Other suitable buffers include succinate, histidine, tartrate, bicarbonate, borate, imidazole, and maleate. In one embodiment, the concentration of the buffer in the formu› lation is between about 1 mM to about IM ( e.g., about 1 mM to about 950 mM, about 1 mM to about 900 mM, about 1 mM to about 850 mM, about 1 mM to about 800 mM, about 1 mM to about 750 mM, about 1 mM to about 700 mM, about 1 mM to about 650 mM, about 1 mM to about 600 mM, about 1 mM to about 550 mM, about 1 mM to about 500 mM, about 1 mM to about 450 mM, about 1 mM to 

