However, the ch14.18 antibody for this Phase III trial was recloned and produced in Chinese hamster ovary (CHO) cells in contrast to ch14.18 antibody used for previous clinical trials, which was produced in murine, non-secreting myeloma cells (SP2/0). Although the antibody-gene transfer into CHO and SP2/0 was done with exactly the same plasmid assuring an identical protein sequence, changes in the glycosylation of the final protein product may occur since the glycosylation pattern varies between different production cell lines. Glycosylation is important for the immunological effector function of the antibody and the pharmacokinetics in patients. Therefore, this change is considered to be a major change in production requiring the reassessment of the new product in a Phase I clinical trial.