ARTICLE Fed-Batch Bioreactor Process Scale-Up From 3-L to 2,500-L Scale For Monoclonal Antibody Production From Cell Culture Jeng-Dar Yang, Canghai Lu, Brad Stasny, Joseph Henley, Woodrow Guinto, Carlos Gonzalez, Joseph Gleason, Monica Fung, Brett Collopy, Michael Benjamino, Jennifer Gangi, Melissa Hanson, Elisabeth Ille Immunomedics, Inc. 300 American Road, Morris Plains, New Jersey 07950; telephone: 973-605-8200 ext. 205; fax: 973-605-3112; e-mail: Jyang@Immunomedics.com Received 17 October 2006; accepted 23 February 2007 Published online 9 March 2007 in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/bit.21413 ABSTRACT: This case study focuses on the scale-up of a Sp2/0 mouse myeloma cell line based fed-batch bioreactor process, from the initial 3-L bench scale to the 2,500-L scale. A stepwise scale-up strategy that involved several intermedi- ate steps in increasing the bioreactor volume was adopted to minimize the risks associated with scale-up processes. Care- ful selection of several available mixing models from litera- ture, and appropriately applying the calculated results to our settings, resulted in successful scale-up of agitation speed for the large bioreactors. Consideration was also given to scale- up of the nutrient feeding, inoculation, and the set-points of operational parameters such as temperature, pH, dissolved oxygen, dissolved carbon dioxide, and aeration in an inte- grated manner. It has been demonstrated through the qualitative and the quantitative side-by-side comparison of bioreactor performance as well as through a panel of biochemical characterization tests that the comparability of the process and the product was well controlled and main- tained during the process scale-up. The 2,500-L process is currently in use for the routine clinical production of Epratuzumab in support of two global Phase III clinical trials in patients with lupus. Today, the 2,500 L, fed-batch production process for Epratuzumab has met all scheduled batch releases, and the quality of the antibody is consistent and reproducible, meeting all specifications, thus confirm- ing the robustness of the process. Biotechnol. Bioeng. 2007;98: 141–154. ß 2007 Wiley Periodicals, Inc. KEYWORDS: Epratuzumab; fed-batch bioreactor process; scale-up; comparability; mammalian cell culture; Sp2/0 Introduction Sp2/0-derived cell line is a mammalian cell line suitable for commercial production of monoclonal antibodies for therapeutic use. To date, there are at least four FDA- approved monoclonal antibody drugs, namely Remicade, ReoPro, Simulect, and Erbitux, produced by Sp2/0-derived cell lines. Before commercial manufacturing can be realized in a large-scale setting, bioreactor process scale-up is often required that involves many steps of volume increase in bioreactors. Any scale-up work that is originated from the bench-scale bioreactor of only few liters of volume and targets the final scale at hundred or thousand liters of volume is not a trivial task. It is indeed challenging when one considers all the added difficulty in operational complexity, logistic supports, utility supplies, regulatory and safety compliance besides already broad technical issues ought to be addressed. Although a lot of information and knowledge are available to assist the task, one still needs to integrate many different approaches and tailor them to the specific situation. Much information on the mammalian cell culture scale-up was available in literature and conference pre- sentations (Caccluttolo et al., 2001; Humphrey, 1998; Marks, 2003; Nienow, 2006). These literatures and the presentations are very informative in either describing the scale-up concepts and considerations, or reporting their scale-up end results. Barely seen in publication was the accurate study that integrated various engineering scale-up approaches and applied them correctly to the industrial setting with a case study as demonstration. This article discusses the rationale and the systematic approach taken for the scale-up of a mammalian cell culture-based fed-batch bioreactor process from the 3-L to the 2,500-L scale. In particular, it describes how we scaled up several operational parameters, especially the agitation speed. In the end, the data generated from growth profiles Correspondence to: J.-D. Yang ß 2007 Wiley Periodicals, Inc. Biotechnology and Bioengineering, Vol. 98, No. 1, September 1, 2007 141