Composition comprising a mixture of CD95-Fc isoforms and methods of producing same
The present invention relates to a composition comprising a mixture of fusion protein isoforms, each fusion protein comprising an extracellular CD95 domain or a functional fragment thereof or an Fc domain or functional fragment thereof, formulations providing such composition in a stable form as well as a method for producing such a composition.
1. A composition comprising a mixture of fusion protein isoforms, each fusion protein comprising at least an extracellular CD95 domain or a functional fragment thereof and at least a Fc domain or a functional fragment thereof distributing within a pI range of 4.0-8.5, wherein the mixture inhibits apoptosis.
2. The composition according to claim 1 , wherein the Fc domain is a human Fc domain.
3. The composition according to claim 1 , wherein the fusion protein is APG101, a polypeptide having at least 95% identity to APG101 and or a functional fragment of APG101.
4. The composition according to claim 1 , wherein the pI range is 4.5 -7.8.
5. The composition according to claim 1 , wherein 0.0-5.0 mol % of said fusion proteins are high molecular weight forms of dimers and/or aggregates.
6. The composition according to claim 1 , wherein said fusion proteins comprise sialic acids.
7. The composition according to claim 3 , wherein said fusion proteins are N-terminally shortened.
8. The composition according to claim 1 , wherein the Fc domain or functional fragment thereof is N-linked glycosylated.
9. The composition according to claim 1 , wherein said fusion proteins are N-terminally blocked.
10. The composition according to claim 1 , wherein 80-99 mol % of said fusion proteins are N-terminally blocked fusion proteins and/or 1-20 mol % of said fusion proteins have a free N-terminus.
11. A formulation comprising the composition of claim 1 , further comprising
(a) phosphate,
(b) a viscosity enhancing agent, and/or
(c) having a pH value in the range of 4-8.
12. The composition according to claim 4 , wherein the pI range is 5.0-7.5.
13. The composition according to claim 7 , wherein the N-terminally shortened fusion proteins are N-terminally truncated by 17, 21, or 26 amino acids.
14. The composition according to claim 8 , wherein the Fc domain or functional fragment thereof is characterized by having fucosylated forms.
15. The composition according to claim 9 , wherein the N-terminally blocked fusion proteins are fusion proteins blocked by pyro-Glu modification, and/or fusion proteins having a free N-terminus.
16. The formulation of claim 11 , wherein the viscosity enhancing agent is sorbitol.
17. The formulation of claim 11 , wherein the viscosity enhancing agent is about 0.1-10 weight %.
18. A method for producing the composition according to claim 1 , comprising the steps of:
(a) producing a composition comprising a mixture of fusion protein isoforms, each fusion protein comprising at least an extracellular CD95 domain or a functional fragment thereof and at least a Fc domain or a functional fragment thereof distributing within a pI range of 4.0-8.5 by a fed-batch production process providing a cell harvest, and
(b) isolating the composition from step (a) from the cell harvest.
19. The method according to claim 18 , wherein step (a) comprises a series of cultivation steps of a given master cell batch until relevant harvest parameters are reached, followed by cell sedimentation and filtration of fusion protein containing supernatant, and/or
step (b) comprises capture chromatography, virus inactivation, a series of anion and/or cation chromatography, virus filtration and/or adjustment to a desired final protein concentration.