Competition for breast cancer-treating cyclin-dependent kinases (CDK) 4/6 inhibitors in the market are heating up. Kisqali, which was the last to enter the market, has grown rapidly in the first half of this year and exceeded sales of the runner-up product in the market, Verzenio. Ibrance, the sole leader in the market, has also seen a downfall in semiannual sales for the first time this year.

According to the market research institution IQVIA, the domestic market size for CDK 4/6 inhibitors in 1H this year was ₩44.5 billion, an 8.4% increase from the ₩41.1 billion of the previous year. CDK 4/6 inhibitors control cell division and growth and selectively inhibit the proliferation of