Optimization of Downstream Purification of Lucentis

Abstract

A base case for the production and purification of the fragmented antibody, Lucentis, was explored and compared to several alternative cases that were hypothesized to optimize the purification process. The base case consisted of using a series of chromatography columns including anion exchange, cation exchange, and hydrophobic interaction chromatography (TOSOH Bioscience) resins followed by a 30 kDa tangential flow filtration (TFF) cassette (Pall Corp). Alternative case 1 consisted of a multimodal resin (hydrophobic and cation exchange) followed by a TFF unit, hydrophobic interaction exchange resin column, and another TFF unit. This specific alternative case provided the ability for buffer exchange between chromatography units that was initially not available in the base case. Alternative case 2 is structured similarly to the base case but allows for buffer exchange between the chromatography units. Alternative case 3, exhibits the addition of Affinity chromatography to Alternative case 1. Samples obtained from each case were analyzed using ELISA Assay, electrophoresis, and EZQ to indicate the presence of a Lucentis like fAb-2 molecule. The base case and alternative cases were analyzed for product purity and yield and an economic analysis of all four processes were performed. Other separation techniques were also explored to better the purification process. Preliminary results show high yield but poor purity for Alternative Case 1 while the base case was not able to be analyzed. A purity of 99% and yield of 70% are desired.