Process for manipulating the level of glycan content of a glycoprotein

What is this patent about?

’630 is related to the field of recombinant protein production, specifically the control of post-translational modifications in mammalian cell cultures. In the manufacturing of therapeutic glycoproteins like antibodies, the specific sugar structures attached to the protein—known as glycans—are critical because they dictate how the drug interacts with the human immune system. Controlling these glycan profiles is a significant challenge in bioprocessing, as even minor shifts in culture conditions can alter the drug's efficacy or safety.

The underlying idea behind ’630 is that the specific concentration of trace metals, specifically copper and manganese, can be used as a dial to tune the levels of afucosylated glycans on a protein. While manganese was previously known to influence galactosylation, the inventors discovered that a synergistic combination of copper, manganese, and pH levels directly regulates the removal of fucose. This is a vital engineering insight because reducing fucose levels significantly boosts a drug's ability to kill target cells through antibody-dependent cellular cytotoxicity (ADCC).

The claims of ’630 focus on a method for manipulating the fucosylated glycan content by precisely controlling the environment within a bioreactor. The process requires inoculating mammalian host cells into a serum-free, chemically defined medium that has been specifically supplemented with copper in a range of 10 to 100 ppb and manganese between 50 and 1000 nM. By maintaining these specific metallic concentrations during the culture period, the manufacturer can reliably influence the final glycan structure of the harvested recombinant protein.

In practice, this invention allows bioprocess engineers to achieve higher levels of afucosylation—and thus higher therapeutic potency—without negatively impacting cell growth, viability, or overall protein yield. The method is particularly effective when the bioreactor is maintained at a neutral pH of 7.0, which the patent identifies as a major driver in increasing afucosylated glycan levels compared to slightly more acidic environments. This provides a predictable chemical lever to meet strict product quality specifications during large-scale manufacturing.

This approach differs from prior solutions that often relied on complex genetic engineering of host cells or the addition of expensive chemical inhibitors to block fucosylation enzymes. Instead, ’630 utilizes trace metal modulation within standard chemically defined media to achieve the same result. By identifying that copper and manganese act as environmental regulators of the fucosylation pathway, the invention provides a simpler, more robust means of controlling effector function in therapeutic antibodies.