Figure 10. Overlay of previous 1.09 compression and current 1.18 compression elution profiles
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Large-scale results matched the experimental data from laboratory and pilot runs for this project with improved resolution
at the beginning of the elution profile (Figure 10).
The bench-scale approach to evaluate end-of-collection was applied to pilot and large scales to evaluate the impact of the
shift in retention. A new elution collection set up was developed to handle the retention shift and generate data necessary
for a filing change. For each run with the proposed elution collection set up, the elute pool was well within historical results
and met all acceptance criteria. In fact, product purity improved.
Reproducibility between purity and recovery results between bench and large scales demonstrated that the process was scalable
and reproducible at both scales. This paved the way to qualify a bench-scale method to assist manufacturing events.
The overall chromatography process showed that it is receptive to the amount of resin or compression factor. A higher compression
sharpened the prepeak elution profiles. Specifying the compression factor as a process characterization variable is critical
in maintaining a scaled-down model.
LARGE-SCALE BLANK ELUTION RUN
The large-scale run was followed with a blank elution run to evaluate cleaning capability at a higher compression. The pool
was analyzed with molecule concentration of below maximum limits. The results indicated that the regeneration is sufficient
to mitigate concerns of product carry-over. Additional characterization efforts based on packing stability promoted the increase
in pack re-uses from 10 to 30 cycles. Significant improvement was seen on yield recovery and the performance was more stabilized.
The 30-cycle lifetime extension has been achieved at scale.
CONCLUSION
A scalable and consistent performance was demonstrated at large scale by an increase in both chromatographic step recovery
and product purity. Asymmetry and HETP results were improved in both average results and consistency. The stability of the
new pack procedure allowed for a lifetime extension for the chromatography step. The work culminated in the successful completion
of three validation lots in the facility. The filings were submitted and approved and the facility now runs with this new
large process.
Overall, the project had an impact of drug substance yield improvement by 7%, reduced recovery variability by 50%, reduced
impurity levels by 12%, and zero nonconformance events post implementation. The resin determination by centrifuge and changes
to packing procedure dramatically reduced cycle time.
AKNOWLEDGEMENTS
The authors are grateful to the cross-functional team of engineers and scientists for their dedication and support throughout
all stages of the project.
Javier O. Tapia is a process engineer, Carlos Escobar is a principal engineer, and James Weidner is a director, all at bulk process development, Amgen Manufacturing, Ltd., Juncos, PR, 787.916.6871, javiert@amgen.com
REFERENCES
1. Escobar C, Keener N. Chromatography unit operation optimization plan, process development study. PD-008-06, Amgen; 2006.
2. Rivera O. Determination resin percent for resin slurry by centrifuge method. Technical report 070072TR. Amgen; 2007.
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and production scale. Biotechnol Prog. 2001;17:744-751.
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5. Keener N. Column packing study. Technical report 060409TR. Amgen; 2007.
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