Merck & Co. agreed to buy respiratory drugmaker Verona Pharma Plc for around $10 billion as part of its ongoing search for ways to fill the Keytruda-sized hole that will emerge over the next few years.

The move bolsters Merck’s lineup as it braces for the 2028 loss of patent exclusivity for blockbuster cancer drug Keytruda.

Merck said it will buy Verona Pharma for $10 billion to bolster its lung-disease business and help replace the expected loss of revenue once Keytruda patent protection lapses.