A randomized, multicenter, double-blind phase III study of palbociclib (PD-0332991), an oral CDK 4/6 inhibitor, plus letrozole versus placebo plus letrozole for the treatment of postmenopausal women with ER(+), HER2(–) breast cancer who have not received any prior systemic anticancer treatment for advanced disease.
Bibliographic record
Abstract
TPS652 Background: Palbociclib (PD-0332991) is an orally bioavailable selective inhibitor of CDK4/6 that prevents DNA synthesis by prohibiting progression of the cell cycle from G1 to S phase. In a randomized phase II trial comparing palbociclib (PD-0332991) plus letrozole (P + L) to letrozole (L) in postmenopausal women with ER(+), HER2(–) advanced breast cancer (ABC) who had not received any prior systemic anticancer therapy for their advanced disease, P + L demonstrated significantly longer progression-free survival (PFS) vs L (26.1 vs 7.5 mo; HR = 0.37, P < .001) and was generally well tolerated, with uncomplicated neutropenia as the most frequent adverse event (Finn et al SABCS 2012). Methods: Based on phase II data, a global, randomized, double-blind, phase III clinical trial was designed to demonstrate that P + L provides superior clinical benefit compared with L + placebo in postmenopausal women with ER(+), HER2(–) ABC who have not received any prior systemic therapy for their advanced disease. The study aims to assess whether P + L improves median PFS over L at HR of at least 0.7. Approximately 450 eligible patients with locoregionally recurrent or metastatic, pathologically confirmed ABC who are candidates to receive L as first-line treatment for their advanced disease will be randomized 2:1 to receive either P (125 mg QD 3 wk on, 1 wk off) + L (2.5 mg QD) or L (2.5 mg QD) + placebo. Patients who received anastrozole or letrozole as part of their (neo)adjuvant regimen are eligible if their disease progressed more than 12 months from completion of adjuvant therapy. Tumor tissue is required for participation. Secondary endpoints include overall survival, objective response, duration of response, clinical benefit, safety and tolerability, and patient-reported outcomes of health-related quality of life and disease- or treatment-related symptoms. Clinical trial information: NCT01740427.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.003 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.004 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.005 |
| Insufficient payload (model declined to judge) | 0.008 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".