| abstract |
FIELD: biochemistry.SUBSTANCE: group of inventions relates to an improved method for biochemical extraction of an IL-15/IL-15Rα-based conjugate in monomer form and a pharmaceutical composition comprising an effective amount of a composition comprising monomeric conjugates of IL-15/IL-15Rα. Method involves purification of a clarified supernatant from a culture medium of a transformed host cell expressing a conjugate having the amino acid sequence SEQ ID NO: 16 or SEQ ID NO: 17. Purification is carried out by means of anion-exchange chromatography (AEX) at pH equal to or higher than 7.0, preferably equal to or higher than 7.5. Further, obtained eluate is purified by chromatography of hydrophobic interaction (HIC) carried out in buffer solution containing 0.75 M - 2.5 M of ammonium sulphate, preferably 1 M - 2 M of ammonium sulphate. Conjugates are eluted in gradient from 2 M to 0 M, preferably from 1.5 to 0 M of ammonium sulphate. Obtained composition contains at least 80 % conjugates in a monomer form, which satisfies their use in a pharmaceutical composition for treating cancer in a subject.EFFECT: invention enables to obtain a conjugate with high output and reproducibility, with purity of more than 98 %, without detectable level of endotoxin, heat shock proteins or residual DNA.8 cl, 7 dwg, 3 tbl |