What is Host Cell Protein?
Host Cell Proteins, or HCPs, are endogenous to the cell line which has been used to express your protein or biopharmaceutical. They are removed during the manufacturing process using a variety of purification techniques. However, it is likely that a low-level of HCP material will remain, and this is where host cell protein analysis comes into play. It is important to continuously monitor the level of host cell protein throughout your process and show a reduction following each purification step. This is because HCPs can cause immunogenicity in the patient and therefore pose a significant safety risk.
Acceptable limits of host cell protein in the final drug product have been set by the FDA and EMA as 1-100ppm, but unknown HCPs at a level lower than this could still cause an immunogenic effect. This is why it is crucial to fully characterize the HCP profile in your drug using various orthogonal tests.
Host Cell Protein Analysis- Orthogonal Testing
HCP analysis has historically been performed using ELISA (enzyme-linked immunosorbent assay) tests. The level of coverage achieved using off-the-shelf kits can be improved with the use of product-specific methods, but a significant number of HCPs are still likely to be missed, especially very weakly immunogenic or non-immunogenic species.
In contrast to HCP-ELISA, which relies on the presence of polyclonal antibodies for positive Host Cell Protein detection, Mass Spectrometric (MS) approaches have the advantage of detecting a wider population of HCPs in a de novo manner, without specialized polyclonal antibody reagents or product and process-specific method development.
Due to these technical benefits, HCP-MS has emerged as an orthogonal technique that serves to expand the identification of Host Cell Proteins, with regulatory advice stating that HCP assessments should include MS as part of the normal process and product development.
The BioPharmaSpec Approach to Host Cell Protein Analysis
BioPharmaSpec has developed a service for MS based HCP detection and quantitation as an orthogonal support to HCP-ELISA. The service is set up as a phased approach:
HCP-MS is an orthogonal approach to Host Cell Protein analysis and can be used to enhance ELISA data. HCPs should be assessed from early in the product development. It can then be shown that improvements in the downstream purification through process-development are having a positive impact on the levels of HCPs present.
BioPharmaSpec can provide a full service for MS analysis of HCPs including accurate detection of HCPs of interest i.e. those present in amounts >100ng per mg of product or those that are immunogenic.
Determine the HCP profile of your molecule using LC-MS
Talk to a BioPharmaSpec scientist about the best analytical strategies to employ in order to start using HCP-MS in your process development/ final product testing.