{"entity":{"id":"paper-penelope-b-j-clin-oncol-2021","kind":"paper","name":"Palbociclib for Residual High-Risk Invasive HR-Positive and HER2-Negative Early Breast Cancer-The Penelope-B Trial","aka":[],"tldr":"Published report from the PENELOPE-B trial registered as NCT01864746, in Journal of Clinical Oncology (2021), chosen as the most cited paper whose own text cites the registry id.","summary":"Purpose: About one third of patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer who have residual invasive disease after neoadjuvant chemotherapy (NACT) will relapse. Thus, additional therapy is needed. Palbociclib is a cyclin-dependent kinase 4 and 6 inhibitor demonstrating efficacy in the metastatic setting.\n\nPatients and methods: PENELOPE-B (NCT01864746) is a double-blind, placebo-controlled, phase III study in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative primary breast cancer without a pathological complete response after taxane-containing NACT and at high risk of relapse (clinical pathological staging-estrogen receptor grading score ≥ 3 or 2 and ypN+). Patients were randomly assigned (1:1) to receive 13 cycles of palbociclib 125 mg once daily or placebo on days 1-21 in a 28-day cycle in addition to endocrine therapy (ET). Primary end point is invasive disease-free survival (iDFS). Final analysis was planned after 290 iDFS events with a two-sided efficacy boundary P <.0463 because of two interim analyses.\n\nResults: One thousand two hundred fifty patients were randomly assigned. The median age was 49.0 years (range, 19-79), and the majority were ypN+ with Ki-67 ≤ 15%; 59.4% of patients had a clinical pathological staging-estrogen receptor grading score ≥ 3. 50.1% received aromatase inhibitor, and 33% of premenopausal women received a luteinizing hormone releasing hormone analog in addition to either tamoxifen or an aromatase inhibitor. After a median follow-up of 42.8 months (92% complete), 308 events were confirmed. Palbociclib did not improve iDFS versus placebo added to ET-stratified hazard ratio, 0.93 (95% repeated CI, 0.74 to 1.17) and two-sided weighted log-rank test (Cui, Hung, and Wang) P =.525. There was no difference among the subgroups. Most common related serious adverse events were infections and vascular disorders in 113 (9.1%) patients with no difference between the treatment arms. Eight fatal serious adverse events (two palbociclib and six placebo) were reported.\n\nConclusion: Palbociclib for 1 year in addition to ET did not improve iDFS in women with residual invasive disease after NACT.\n\nIndexed on Europe PMC as PubMed record 33793299 (DOI 10.1200/jco.20.03639). Its abstract cites the registry id NCT01864746, which is how it was matched to this trial; no figure has been checked by an editor.","asOf":"2026-09-22","links":[{"label":"J Clin Oncol 2021","url":"https://doi.org/10.1200/jco.20.03639"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/33793299/"},{"label":"Europe PMC","url":"https://europepmc.org/article/MED/33793299"},{"label":"ClinicalTrials.gov NCT01864746","url":"https://clinicaltrials.gov/study/NCT01864746"}],"tags":["europepmc-ingest"],"related":[],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["penelope-b"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":["jco"],"dependsOn":[],"notes":[],"journal":"Journal of Clinical Oncology","year":2021,"doi":"10.1200/jco.20.03639","pmid":"33793299","authors":"Loibl S, Marmé F, Martin M, et al.","paperType":"rct","findings":[],"whatItMeans":"This is the paper Europe PMC returns for registry id NCT01864746 with the most citations, so it is the natural first reading for anyone following the PENELOPE-B trial. Read the abstract above alongside the trial page and the registry entry; the record was linked automatically and its figures have not been checked by hand.","caveats":["Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper."]},"route":"/key-papers/paper-penelope-b-j-clin-oncol-2021/","neighbours":{"trial":[{"id":"penelope-b","kind":"trial","name":"PENELOPE-B","route":"/trials/penelope-b/"}],"journal":[{"id":"jco","kind":"journal","name":"Journal of Clinical Oncology","route":"/journals/jco/"}]}}