Immuno-oncology drug Keytruda continued its high-altitude march in the domestic pharmaceutical market. Last year, Health Insurance 2 sales more than doubled as the number of recipients of the leading water-based benefits expanded for 13 consecutive quarters since the first quarter of 2020. Keytruda further strengthened its solo system by more than doubling the gap with second place. According to IQVIA, a drug research agency on the 22nd, Keytruda took the lead with sales of 87.8 billion won in the first quarter. Sales increased by 117.1% in one year from 40.4 billion won in the first quarter of last year. Released in Korea in 2015, Keytruda is an immune checkpoint inhibitor that inhibits the PD-1 protein on the surface o