Pharmaceutical composition comprising erythrocytes encapsulating a plp-dependent enzyme and its cofactor

A kit or composition comprising:

• (a) an injectable pharmaceutical suspension, which provides long lasting PLP-dependent enzymatic activity to a patient or subject in need thereof, comprising erythrocytes and a pharmaceutically acceptable vehicle, the erythrocytes encapsulating a plurality of PLP-dependent enzyme molecules and comprising a sufficient amount of PN-kinase and PNPoxidase to produce a sufficient amount of pyridoxal phosphate (PLP) from PLP precursor present in the patient or subject's bloodstream to maintain a sufficient portion of the PLP-dependent enzyme molecules in their holoenzyme forms to preserve enzymatic activity beyond 24 hours after injection;
• wherein the suspension optionally comprises a preservation solution comprising inorganic phosphate to inhibit the enzymatic activity of intra-erythrocyte PLP-phosphatase;
• (b) a sufficient amount of a pharmaceutically acceptable PLP precursor, suitable for administration to the patient or subject;
• and
• (c) optionally instructions for dosing the patient or subject with the PLP precursor to allow for the production of the sufficient amount of PLP in said erythrocytes.

The kit or composition of claim 26, wherein the suspension is produced by opening pores in the erythrocyte membranes;

• contacting the erythrocytes with the PLP-dependent enzyme before, during and/or after opening the pores;
• allowing the enzyme to enter the erythrocytes;
• closing the pores of the erythrocytes containing the enzyme;
• collecting the enzyme-containing erythrocytes into a buffer to form a first suspension;
• optionally incubating the first suspension to allow the most fragile erythrocytes to lyse;
• removing the lysed erythrocytes;
• and suspending the erythrocytes in a preservation solution;
• thereby preparing the suspension of claim 41.