Table 2.

Phase III trials with cyclin-dependent kinase4/6 inhibitors in hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer: median progression-free survival (PFS) and objective response rate

Trial	Line in the metastatic setting	Patients (n)	Treatment	HR for PFS	Median PFS, months	Objective response rate (ITT population) (%)
PALOMA-2	1L	666	Palbociclib + letrozole vs placebo + letrozole	0.58	24.8 vs 14.5	42.1 vs 34.7
PALOMA-3	>1L	521	Palbociclib + fulvestrant vs placebo + fulvestrant	0.46	9.5 vs 4.6	19 vs 8
MONALEESA-2	1L	668	Ribociclib + letrozole vs placebo + letrozole	0.56	NR vs 14.7	40.7 vs 27.5
MONARCH 3	1L	493	Abemaciclib + NSAI vs placebo + NSAI	0.54	NR vs 14.7	59 vs 44
MONARCH 2	1L or 2L	669	Abemaciclib + fulvestrant vs placebo + fulvestrant	0.55	16.4 vs 9.3	48.1 vs 21.3

ITT, intentiontion to treat; NR, not reached; NSAI, non-steroidal aromatase inhibitor.