FibroGen has developed FG-5009, a low molecular weight (8.5 kDa) synthetic gelatin molecule optimized for use as a stabilizing component in vaccine and biologic formulations.

Development Status
Working with leaders in the vaccine market, FibroGen has tested the ability of FG-5009 to stabilize several live attenuated viral vaccines. In vitro stabilization studies have demonstrated that FG-5009 is equivalent to the animal-derived gelatin stabilizer in commercially available vaccines. FibroGen is currently working with customers on formulation development and testing FG-5009 as a stabilizer for other biopharmaceuticals and as an alternative to human serum albumin.

Read more about Data Master Files for FG-5009.

Human Safety Data
The safety of FG-5009 was examined in human volunteers at doses similar to, and significantly greater than, the dosage of animal-derived gelatin found in marketed vaccines. Healthy volunteers received a total of three doses of either 1 mg, 15 mg, or 60 mg of recombinant gelatin administered intramuscularly at two-week intervals. The subjects were followed for 56 days after administration of the last dose. No adverse events related to the study material were observed in any of the three dose groups. Serum was analyzed by ELISA for antibody production against recombinant gelatin or potential yeast host cell contaminants. No significant changes in antibody titers against recombinant gelatin or yeast-derived protein were seen over the course of the study. Finally, no significant changes related to study material were observed for the standard serum chemistry parameters measured over the course of the study.

Product Details
Purity: FG-5009 has been subjected to a battery of analytical tests to demonstrate its suitability as a key component of pharmaceutical preparations. These tests were used to characterize product purity, heterogeneity, endotoxin levels, bioburden, and the levels of various contaminants, including those associated with the yeast expression system. The results of the studies are shown below and demonstrate that FG-5009 is suitable for use in pharmaceutical preparations.

Immunogenicity: FG-5009 has been the subject of studies designed to establish its immunogenicity profile. In one study carried out with an academic collaborator in Japan, FibroGen tested the immunogeneicity of FG-5009 using serum from children with confirmed gelatin allergies. Specifically, the reactivity of FibroGen's product with anti-gelatin IgE antibodies from serum samples was tested in an in vitro binding assay. These antibodies recognized bovine and human collagens but not FG-5009, establishing the low allergenic potential of FibroGen's product. Furthermore, as described above, in our human safety study no significant antibody response to gelatin was noted in any of the subjects.

Additional Information
For more information or a data package on this product, please contact our Business Development group at FibroGen: bd@fibrogen.com or 1-650-866-7291.