Virally-safe factor VIII with a low content of higher multimers
La present invention pertains to a composition of plasma-derived virally-safe factor VIII, obtained after nanometric filtration, said composition comprising von Willebrand factor (vWF) at a rate of 15% or less of decamers and higher multimers. Such compositions have a reduction factor of the virus titre higher than 4 log and are thus suitable for treatment of hemophilia.
1. A method for preparing a virally safe Factor VIII solution, the method comprising:
filtering a solution comprising Factor VIII through nanometric filters having a pore size of 13 nm to 25 nm;
assaying the filtrate to determine the residual content of high multimerization von Willebrand Factor (vWF); and
wherein the content of vWF hexadecamers and higher multimers is at least 2% in the filtrate.
2. The method of claim 1 , wherein the step of assaying the filtrate includes verifying that the content of vWF decamers and higher multimers is 15% or less.
3. The method of claim 1 , wherein a vWF decamer and higher multimer content of 15% or less indicates that the titre reduction factor of a virus having a size diameter of 24 nm to 30 nm is 4 log or more, to about 6 log as compared with the solution before filtration.
4. The method of claim 1 , wherein a vWF decamer and higher multimer content of 15% or less indicates that the titre reduction factor of a virus having a size of 24 nm to 30 nm is 5 log or more, to about 6 log as compared with the solution before filtration.
5. The method of claim 1 , wherein a vWF decamer and higher multimer content of 15% or less indicates that the titre reduction factor of a virus having a size of 24 nm to 30 nm is about 6 log as compared with the solution before filtration.