Method for the production of a glycosylated immunoglobulin

What is this patent about?

’728 is related to the field of biopharmaceutical manufacturing, specifically the large-scale production of therapeutic immunoglobulins in eukaryotic cell cultures. It addresses the technical challenge of controlling post-translational modifications, particularly the glycosylation pattern of antibodies, which significantly influences their therapeutic efficacy, stability, and circulatory half-life.

The underlying idea behind ’728 is that the specific carbohydrate structure of an antibody can be precisely engineered by manipulating the metabolic state of the host cell through controlled nutrient availability. The inventors discovered that the amount of the mannose-5 glycostructure (M5) is directly sensitive to the rate of glucose consumption, allowing for a predictable tuning of the antibody’s sugar profile by maintaining a specific level of glucose restriction.

The claims of ’728 focus on a composition containing the antibody Tocilizumab characterized by a specific, low-range fraction of the M5 glycostructure at the Asn 297 position. Specifically, the independent claims protect compositions where the M5 fraction is strictly maintained between 2.8% and 6% (or less than 5%) relative to the total sum of the major glycoforms (G0, G1, G2, and M5) as measured by liquid chromatography.

In practice, this is achieved by implementing a Degree of Glucose Limitation (DGL) control strategy during the cultivation process. Rather than providing excess glucose, the system limits the available sugar to a constant fraction—typically between 20% and 80%—of the maximum amount the cells could theoretically consume. This metabolic braking prevents the accumulation of undesirable high-mannose structures that often occur during uncontrolled or starving conditions.

This approach differs from prior methods by moving away from simple batch feeding or total glucose starvation, which often lead to inconsistent product quality. By keeping the DGL value constant throughout the production phase, the invention ensures a highly reproducible glycosylation profile. This level of control is critical for producing biosimilars or maintaining the batch-to-batch consistency of complex biologics like anti-IL-6R antibodies.