Our team, relying on its prior knowledge and platform approach, acted quickly to deliver a process that would result in a high titer of the desired product quality. The upstream strategy consisted of the following milestones.

1. Screening and selection of clones

After developing the cell lines, we generated stable pools and evaluated them for titer and potency. This was followed by a selection of monoclones  through monoclonal sorting. We then performed monoclonal sorting to select individual clones for further analysis. Subsequently, we performed monoclonal screening to choose the top 10 clones based on product quality and titer.

2. Upstream platform strategy

Our experimental strategy comprised a Design of Experiments (DoE) approach that included two selected clones as one of the six key parameters, alongside medium composition, feed types and percentages, seeding densities, and pH dead bands. A total of 24 bioreactors were utilized for screening, with 22 experimental runs through the DoE as part of a definitive screening design. Additionally, we introduced two conditions based on Syngene’s extensive mAb development experience. After evaluating process attributes such as titer and specific productivity (Qp), we chose ten conditions for a one-step purification process and subsequent product quality analysis. This streamlined approach reduced the number of experiments required to identify high-quality clones capable of industry-leading yields for mAb production.

3. Process scale-up and adaptation

In the final stage of the production process, we scaled up the top condition to 10L bioreactors. We conducted two adaptation batches at this scale, implementing minor process adjustments. During the initial adaptation batch, we achieved a titer of 5800 mg/L. We improved this further to 7000 mg/L by increasing the initial seeding density. Following this, we executed two additional 10L batches, resulting in titers of 7000 mg/L and 7200 mg/L, respectively.