The drug – a monoclonal antibody – was approved by the European Medicines Agency (EMA) for eosinophilic asthma earlier this week in a decision that came just a month after US regulators cleared it for the same indication.
Producing the drug is a transatlantic endeavour according to Claire Brough, GSK’s head of global pharmaceutical communications, who told us “the actual drug substance for mepolizumab is made by GSK in the US, which is finished and filled into vials at the GSK facility in Parma.”
CHO, no CMO
Nucala, like the vast majority of monoclonal antibody (mAb) drugs, is made in Chinese hamster ovary (CHO) cells Brough said, adding that: “Each batch undergoes extensive biochemical and biophysical testing before the batch is released and the manufacturing process is complete.”
She declined to say how much it costs to produce the drug, but did confirm that the UK-based drug major has no immediate plans to outsource manufacturing to a contractor.
Nucala is used to treat severe asthma in people 12 years old and over. The drug functions by blocking the protein cytokine interleukin-5 to prevent the build-up of white blood cells in the lungs that can exacerbate asthma.
GSK welcomed the European approval and hinted at a quick roll out. Eric Dube, Senior Vice President & Head, GSK Global Respiratory Franchise, said: “We aim to offer this medicine to patients as soon as possible.”
GSK’s asthma franchise has been an important source of revenue for the firm. However, in recent years this has started to decline, primarily because of the loss of patent production for Advair, known as Seretide elsewhere.
Advair revenue fell 15% in 2014 to £4.2bn ($6.4bn) globally and 25% in the US to $1.9bn, largely as a result of competition and a punishing contract negotiation with Express Scripts forced the UK firm to discount the drug.
This decline, coupled with the underperformance of more recently launched drugs - Breo and Anoro Ellipta – saw revenue generated by GSK’s asthma franchise fall 10% to £6.1bn in 2014.
GSK has not given a forecast for Nucala, but clearly it hopes the drug will help replace some lost Advair revenue.
In May it included the drug on a list of new products that it predicted would generate £6bn ($9bn) a year by 2020.
However, the drugmaker may not be the only company with an asthma mAb for long.
UK rival AstraZeneca began a Phase III trial of its IL-5-blocker drug benralizumab in October and Teva Pharmaceutical Industries had reslizumab, which also targets IL-5-blocker, accepted for review by the US FDA in June.