Table 2.

Subsequent second-line anticancer treatments in cohorts after sIPTW analysis

Treatments, n (%)	Palbociclib + letrozole (n = 839)	Letrozole alone (n = 698)
First-line treatment only*	448 (53.4)	233 (33.4)
Any second-line treatment received†	391 (46.6)	465 (66.6)
CDK4/6 inhibitor	165 (42.2)	292 (62.9)
Chemotherapy	100 (25.6)	44 (9.4)
Endocrine therapy alone	64 (16.4)	96 (20.7)
Other anticancer treatments	88 (22.5)	56 (12.0)

CDK4/6 cyclin-dependent kinase 4/6, sIPTW stabilized inverse probability of treatment weighting

*Includes patients who continued treatment, died, or were censored in the first-line setting

^†Patients could have received > 1 category of second-line treatment