Designing a Simple Purification Scheme
Cation capture chromatography removes process-related contaminants to such a low level that a single polishing step is enough
to clean the residuals. An additional advantage of cation capture is that it can reduce or remove the high molecular weight
product-related species and easily find optimized conditions. Protein A capture does not have this ability.
Table 3. Viral clearance comparison for non-affinity purification schemes
Membrane chromatography also has been shown to reduce adventitious agents by significant levels. We set up cation capture
and anion membrane units along with specific steps for viral inactivation and removal; these downstream process designs achieved
log reduction values (LRV) >20 and provide a >10 LRV safety factor for therapeutic grade antibodies (Table 3). Clearance capability
for process-related contaminants by ion exchange purification schemes for various HuMAbs are presented in Tables 4 and 5.
The progressive stages of non-affinity downstream process development are illustrated in Figure 1.
Table 4. CHO host cell protein removal by non-affinity purification schemes
A shortened purification scheme was designed for therapeutic grade HuMAbs by combining the desirable characteristics of cation
exchange capture and efficiency and the simplicity of membrane chromatography. An additional advantage of this process was
that it minimized validation requirements. Including a clarification and a recovery step, overall process recovery was more
Table 5. CHO DNA removal by non-affinity purification schemes
Scaling up the ion exchange schemes
Our ion exchange purification platform has been proven to be easy to scale up for commercial-scale manufacturing and has allowed
multiple campaigns per year for different HuMAbs. These processes, originally designed for early clinical phase trials, needed
minor changes to fit the process in large manufacturing and commercialization, but they paid off in large gains in time and
resources during product development.
These new simplified process designs resulted in up to a 10-fold improvement in the processing time over the original ion
exchange processes in addition to reducing the equipment, resin, buffer, and validation costs (Figure 2). Thus, the higher
batch capacity of this improved downstream platform technology significantly reduces the cost of developing and manufacturing
Figure 2. Comparison of process technology designs and their impact on the facility output
ALAHARI ARUNAKUMARI, PhD, is director of process development at Medarex Inc, 908.479.2451, email@example.com
JUE (MICHELLE) WANG, PhD, is senior manager of purification process development at Medarex, and GISELA FERREIRA, PhD, is
a scientist in purification process development at Medarex.