Afraid that specific HCPs in your drug product may halt regulatory approval?
HCPs may influence the overall safety profile of product by:
- Immunogenicity. May induce an immune response against the product by adjuvant effects.
- Homology to endogenous human proteins. Immunogenecity to induce cross reactivity against the human protein.
- Enzymatic activity. May cleave and modify the drug substance or constituents in the drug product.
- Biological activity.
- Homology to the drug substance protein.
We determine the quantity of your HCPs of concern by LC MS/MS analysis. For this purpose we identify unique signature peptides for the HCP of concern. We then use synthetic isotope-labeled signature peptides for MRM quantitation. The labeled peptides are spiked into the drug sample in known amounts. Standard curves are generated for linearity and quantitative analysis. The quantitation assay can be developed for in-solution samples. It can also be used for HCPs detected by 1D and 2D Western blots.
The service includes:
- Absolute quantification of HCP of concern.
- Identification of 3 unique signature peptides for isotope labelling.
- Standard curves and linearity assessment for dilution series of drug substance and isotope labeled peptide standards.
- Quantification by peak areas in MRM LC-MS/MS.
If you do not know the identity of the host cell proteins in your samples, we can identify the HCPs prior to quantification. Take a look at our services for Identification of HCPs in pre-clinical and clinical batches.
How a customer used this service
One of Alphalyse’s biopharma customers produced a recombinant human protein in e. coli. In 2D Western Blot HCP antibodies recognized a HCP in exactly the same position as their drug substance protein. Using “Identification of host cell proteins >10 ppm” we identified an e.coli. HCP with very high sequence similarity to their drug substance protein. Hereafter, “Quantification of host cell proteins by AQUA peptide and MRM” showed that the sample contained 23 ppm of this specific HCP relative to their drug substance protein.