Table 1.

Illustrating baseline levels of pTKa and on-treatment changes according to baseline characteristics of studied patient.

Baseline characteristicBaseline pTKa LOW (N = 33)Baseline pTKa HIGH (N = 11)POn-treatment pTKa NO INCREASE (N = 33)On-treatment pTKa INCREASE (N = 8)P
Age (range)66 (45–80)59 (39–82)0.1464 (44–82)66 (39–80)0.91
ECOG performance status
 026 (79%)9 (82%)0.3026 (79%)6 (75%)0.72
 17 (21%)1 (9%)6 (18%)2 (25%)
 20 (0%)1 (9%)1 (3%)0 (0%)
Sites of metastases
 Visceral24 (73%)8 (73%)1.0024 (73%)6 (75%)0.47
 Bone-only4 (12%)1 (9%)5 (15%)0 (0%)
 Other nonvisceral5 (15%)2 (18%)4 (12%)2 (25%)
Number of prior lines of endocrine therapy received for advanced disease
  One line22 (67%)7 (64%)1.0020 (61%)6 (75%)0.69
  Two lines11 (33%)4 (36%)13 (39%)2 (25%)
Duration of most recent endocrine therapy received
  ≤6 months4 (12%)3 (27%)0.346 (18%)1 (12%)1.00
  >6 months29 (88%)8 (73%)27 (82%)7 (88%)
Endocrine therapy most recently received prior to enrolment
  Aromatase inhibitor21 (64%)6 (55%)0.7219 (58%)5 (62%)1.00
  Fulvestrant12 (36%)5 (45%)14 (42%)3 (38%)
Receipt of prior chemotherapy for advanced disease?
  Yes6 (18%)2 (18%)1.005 (15%)1 (12%)1.00
  No27 (82%)9 (82%)28 (85%)7 (88%)
Total number of prior lines of systemic therapy received for advanced disease
  One line19 (58%)6 (55%)1.0019 (58%)5 (62%)0.86
  Two lines11 (33%)4 (36%)10 (30%)3 (38%)
  Three lines3 (9%)1 (9%)4 (12%)0 (0%)
Clinical benefit observed on trial?
  Yes21 (64%)7 (64%)1.0024 (73%)2 (12%)0.035
  No12 (36%)4 (36%)9 (27%)6 (88%)
Trial arm assignment
 Palbociclib alone17 (52%)3 (27%)0.2912 (36%)6 (75%)0.11
 Palbociclib plus ET16 (48%)8 (73%)21 (64%)2 (25%)