Pharmaceutical kit comprising erythrocytes encapsulating a PLP-dependent enzyme and, a non-phosphate PLP precursor

A kit comprising:

• (a) an injectable pharmaceutical suspension, which provides long lasting pyridoxal phosphate (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 PNP oxidase to produce a sufficient amount of 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 non-phosphate PLP precursor, suitable for administration to the patient or subject;
• and
• (c) optionally instructions for dosing the patient or subject with the non-phosphate PLP precursor to allow for the production of the sufficient amount of PLP in said erythrocytes.