Cell culture and purification process--purity and safety testing

Viral safety of B-domain deleted recombinant factor VIII

The possible transmission of blood-borne pathogens has been the impetus behind the development of recombinant products formulated in the absence of human-derived components. The viral safety of Chinese hamster ovary (CHO)-cell-based pharmaceuticals is well established. Over 100 million infusions have been administered without a single known incident of CHO-related viral transmission. The manufacturing process for B-domain deleted recombinant factor VIII (BDDrFVIII) builds on this safety record by using a state-of-the-art multitiered approach to viral safety. This approach includes: (1) extensive testing of the CHO cells used to produce BDDrFVIII; (2) routine viral monitoring of the cell culture production process; (3) a purification process in which a specific viral inactivation procedure has been included; (4) a final formulation that does not incorporate human albumin as the stabilizer; and (5) a thorough validation of the viral inactivation and removal capacity of the purification process. This multifaceted viral safety program offers the hemophilia community a factor VIII product with an exceptional degree of viral safety.

Biotechnology: alternatives to human plasma-derived therapeutic proteins

Proteins derived from human plasma have become critically important therapeutic products since their introduction in the 1940s. In the last 20 years, the tools of molecular biology have provided alternatives to the administration of the natural products. Recombinant analogues of Factor VIII and Factor IX are commercially available, and recombinant forms of other plasma proteins are under development. Genetic engineering also provides the opportunity to modify a natural protein to improve the efficiency with which it can be produced in vitro, or to change its therapeutic profile. More efficient production systems, such as transgenic plants or animals, may yield less costly therapies and a wider availability of products that are now in limited supply. Finally, gene therapy offers the prospect of permanently correcting conditions arising from deficiencies in any one of several plasma proteins, freeing individuals from the need to undergo periodic treatments with exogenous proteins.

Evaluation of genetic stability of recombinant human factor VIII by peptide mapping and on-line mass spectrometric analysis

PURPOSE

The genetic stability of a recombinant human factor VIII (rhFVIII) product expressed in Chinese hamster ovary cells (Recombinate) has been evaluated through comparisons of the protein produced at the beginning, middle and end of a typical production campaign.

METHODS

Recombinant human factor VIII was incubated with thrombin, the resulting four polypeptides were isolated by RP-HPLC, subjected to proteolysis with trypsin, and the peptide mixtures were resolved by RP-HPLC. Tryptic peptide mixtures were subjected to online mass spectrometric analysis using an electrospray ionization source interfaced to a quadrupole mass analyzer scanning from 1950-200 amu, and the peptide ion data were compared for three lots produced from the beginning, middle and end of a production campaign.

RESULTS

The UV elution profiles for each of the rhFVIIIa polypeptides were highly similar for factor VIII isolated from the beginning, middle and end of production. Total ion data from the peptide maps derived from three lots of rhFVIII were compared by MH1+ values as a function of scan range. A total of 918 ions were analyzed for the four polypeptides of rhFVIII produced at the beginning, middle and end of a production campaign. The ions were detected at the same relative retention times, as indicated by the similar scan numbers for the three lots.

CONCLUSIONS

These observations support that rhFVIII preparations produced from the beginning, middle and end of a production campaign were highly similar, and demonstrate genetic stability in the manufacturing process of Recombinate.