The company is set to campaign against plans currently being mooted through the European Commission to create a tiered pricing system in a bid to make access to drugs fairer.
Newly appointed public affairs agency APCO will assist on the drugs giant's campaign.
MSD's political and economic policy manager Katy Munns said the best way to create fairer access to drugs is 'not to impose prices ... it is to work with governments to provide a proper infrastructure'.
It is understood that APCO will be working specifically to lobby UK politicians on the issue.
Other areas that APCO will assist with are to continue working on building the firm's profile at the Department of Health, Department of Trade and Industry and the Treasury.
The agency has also been tasked with helping the firm gain a strong presence at the annual party conferences this autumn.
Public affairs was previously handled by GPC. The APCO team is led by the agency's healthcare practice head Tamsin Richmond-Watson.