President Donald Trump intensified efforts to lower drug prices in the US by issuing letters to 17 major pharmaceutical companies, demanding compliance with a 'most favored nation' pricing plan within 60 days. The plan calls for offering Medicaid drugs at prices comparable to the lowest in OECD countries with at least 60% of US GDP. Additional demands include expanding direct-to-consumer sales for drugs with high rebates and repatriating increased revenues earned abroad. Industry groups and CEOs expressed cautious responses, citing challenges related to pharmacy benefit managers and international pricing structures. The announcement affected market indices, reflecting investor concerns over pricing pressures.