Table 1.
Characteristics of study population and outcomes of PALLAS and MonarchE trials
| PALLAS | MonarchE | |||
| Palbociclib+ET | ET alone | Abemaciclib + ET | ET alone | |
| N | 2883 | 2877 | 2808 | 2829 |
| Median age (range) | 52 (25–90) | 52 (22–85) | 51 (23–89) | 51 (22–86) |
| Menopausal status | ||||
| Pre | – | – | 1221 (43.5%) | 1232 (43.5%) |
| Post | – | – | 1587 (56.5%) | 1597 (56.5%) |
| Stage | ||||
| IA | – | – | 2 (0.1%) | 1 (0%) |
| IIA | 504 (17.5%) | 509 (17.7%) | 323 (11.5%) | 353 (12.5%) |
| IIB | 968 (33.6%) | 951 (33.1%) | 389 (13.9%) | 387 (13.7%) |
| III | 1402 (48.6%) | 1408 (48.9%) | 2081 (74.1%) | 2077 (73.4%) |
| T size | ||||
| T0, T1, Tx, Tis | 557 (19.3%) | 500 (17.4%) | 780 (27.8%) | 765 (27.0%) |
| T2 | 1603 (55.6%) | 1636 (56.9%) | 1369 (48.8%) | 1419 (50.2%) |
| T3, T4 | 722 (25.0%) | 741 (25.8%) | 610 (21.7%) | 612 (21.6%) |
| Nodal status | ||||
| 0 LN | – | – | 7 (0.2%) | 7 (0.2) |
| 1–3+LN | – | – | 1119 (39.9%) | 1143 (40.4%) |
| ≥4 + LN | – | – | 1680 (59.8%) | 1679 (59.3%) |
| Grade | ||||
| G1 | 300 (10.4%) | 313 (10.9%) | 209 (7.4%) | 215 (7.6%) |
| G2 | 1622 (56.3%) | 1658 (57.6%) | 1373 (48.9%) | 1395 (49.3%) |
| G3 | 836 (29.0%) | 767 (26.7%) | 1090 (38.8%) | 1066 (37.7%) |
| Ki67 | ||||
| <20% | – | – | 953 (33.9%) | 973 (34.4%) |
| ≥20% | – | – | 1262 (44.9%) | 1233 (43.6%) |
| Prior CT | 2384 (82.7%) | 2370 (82.4%) | 2681 (95.5%) | 2695 (95.3%) |
| Adjuvant ET | ||||
| Tamoxifen | 923 (32.0%) | 949 (33.0%) | 857 (30.7%) | 898 (32.1%) |
| Tamoxifen + ovarian suppression | – | – | 192 (6.9%) | 232 (8.3%) |
| AI | 1954 (67.8%) | 1918 (66.7%) | 1928 (69.1%) | 1891 (67.5%) |
| AI + ovarian suppression | – | – | 410 (14.7%) | 386 (13.8%) |
| Ovarian suppression (any time) | 532 (18.5%) | 604 (21.1%) | 606 (21.7%) | 627 (22.4%) |
| Median follow-up | 23.7 months | 15.5 months | ||
| IDFS events | 351 events (67% of expected events) | 323 events (75% of expected events) | ||
| IDFS | 3 years IDFS 88.2 vs 88.5% HR 0.93; 95% CI 0.76 to 1.15; p=0.51 |
2 years IDFS 92.2 vs 88.7% HR 0.75; 95% CI 0.60–0.93; p=0.01 |
||
| DRFS | 3 years DRFS 89.3 vs 90.7% HR 1.00; 95% CI 0.79 to 1.27; p=0.99 |
2 years DRFS 93.6 vs 90.3% HR 0.72; 95% CI 0.56 to 0.92; p=0.01 |
||
| Early CDK4-6i discontinuation due to AEs | 770 (26.7%) | 463 (16.5%) | ||
| Most frequent AEs in CDK4-6i arm (any grade and grade 3–4) | Neutropenia (83% and 61%) Leucopenia (55% and 30%) Fatigue (40% and 2%) Upper respiratory tract infection (28% and 1%) |
Diarrhoea (82% and 8%) Neutropenia (45% and 18%) Leucopenia (37% and 11%) Fatigue (38% and 3%) VTEs 2.3% ILD 2.7% |
||
AEs, adverse events; AI, aromatase inhibitor; CDK4-6i, cyclin-dependent kinase 4–6 inhibitor; CT, chemotherapy; DRFS, distant relapse-free survival; ET, endocrine therapy; IDFS, invasive disease-free survival; ILD, interstitial lung disease; VTEs, venous thromboembolisms.