Use of monensin to regulate glycosylation of recombinant proteins

A method of regulating the high mannose denosumab glycoform content of a denosumab composition during a mammalian cell culture process, comprising:

• establishing, in a serum-free culture medium in a bioreactor, a cell culture comprising genetically engineered CHO expressing denosumab,
• maintaining the CHO cells during a production phase, and
• adding monensin to said CHO cell culture during the production phase at a concentration of about 25 nM to about 500 nM,
• wherein the addition of monensin increases the high mannose denosumab glycoform content of the denosumab composition.