Background

A three-step chromatography process has been developed and manufactured at 1000L scale. During all pilot and GMP runs, the HCP levels average 100 ppm. For late stage process development, the client wanted to focus on reducing HCP levels while minimizing changes from the Phase 1 process.

Challenge

HCP has strong interaction with the protein of interest and was carried through the three step column process. HCP was only reduced when harsh wash conditions were used in the chromatography steps. Using harsh wash conditions is not ideal when scaling up due to the large quantities needed.

Outcome

• Added intermediate depth filtration after low pH step to have an orthogonal mode of separation.

• Screen depth filters to determine the load capacity

Results

In the optimized process, HCP level is less than 50 ppm after adding the intermediate depth filtration step and below 20 ppm after the full process.