Process for manipulating the level of glycan content of a glycoprotein

What is this patent about?

’492 is related to the field of recombinant protein production and specifically to the control of post-translational modifications during cell culture. In the biopharmaceutical industry, the sugar structures attached to proteins, known as glycans, are critical because they dictate the therapeutic efficacy, safety, and immune response of the drug. Controlling these glycoforms is a significant engineering challenge, as traditional methods often struggle to balance specific glycan targets with the need for high cell viability and productivity.

The underlying idea behind ’492 is that the specific ratio of trace metals and the environmental acidity of the culture medium can be used as a precision lever to adjust the sugar profile of a protein. While manganese is a known cofactor for adding galactose, the inventors discovered that combining copper and manganese at a specific neutral pH unexpectedly increases the level of afucosylated glycans. This insight allows for the fine-tuning of antibody effector functions without the need for complex enzymatic inhibitors or genetic engineering of the host cell line.

The claims of ’492 focus on a method for increasing the level of afucosylated glycans on a recombinant protein by regulating the chemical composition and pH of a serum-free, chemically defined medium. The process requires inoculating a bioreactor with mammalian cells and maintaining a specific concentration range of 10 to 100 ppb copper and 50 to 1000 nM manganese. Crucially, the independent claim specifies that these concentrations must be paired with a pH of 7.0 to achieve a higher level of afucosylation compared to results at lower pH levels.

In practice, the invention is implemented by monitoring the bioreactor environment and ensuring that the trace metal levels and pH set-points are strictly maintained during the production phase. By shifting the pH to 7.0 and maximizing the concentrations of copper and manganese within the specified ranges, manufacturers can enhance the antibody-dependent cellular cytotoxicity (ADCC) of the resulting protein. This is particularly useful for therapeutic antibodies where a stronger immune response is required to kill target cells, such as in oncology applications.

This approach differs from prior solutions by providing a dual-benefit control mechanism that simultaneously influences both galactosylation and fucosylation through simple media additives. Unlike previous methods that might negatively impact cell growth or require expensive supplements, this method maintains high viable cell density and titer while achieving precise glycan targets. It effectively replaces the need for specialized fucosyltransferase inhibitors by utilizing the synergistic effects of metal ion cofactors and pH regulation to direct the metabolic pathways of the host cell.