Evidence Level:Sensitive: B - Late Trials
Title:
Early Switch to Fulvestrant Plus Palbociclib Improves Outcomes in ESR1-Mutated, Estrogen Receptor-Positive Metastatic Breast Cancer
Excerpt:For patients with estrogen receptor-positive metastatic breast cancer who are treated with palbociclib plus an aromatase inhibitor, the strategy of switching to palbociclib plus fulvestrant upon detection of a resistance mutation more than doubled progression-free survival, according to results from the phase III PADA-1 trial.
DOI:10.1093/oncolo/oyac016
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Palbociclib combined with letrozole versus epirubicin combined with cyclophosphamide and sequential docetaxel as neoadjuvant chemotherapy for inoperable postmenopausal estrogen receptor-positive breast cancer with low Ki67 expression: a prospective randomized controlled double-blind phase IV trial
Excerpt:...pathological examination confirms estrogen receptor positive, and Ki67 =T3, or lymph node stage >=N2, or ipsilateral upper extremity edema or the extent of lesions exceeds the scope of radical surgery; 4. ...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Palbociclib and Letrozole or Fulvestrant in Treating Patients With Estrogen Receptor Positive, HER2 Negative Metastatic Breast Cancer
Excerpt:...estrogen receptor positive and/or progesterone receptor (PR) positive, HER2 negative metastatic breast cancer; histologic confirmation is required...
More C2 evidence

Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Palbociclib + Letrozole Versus Epirubicin + Cyclophosphamide and Sequential Docetaxel as Neoadjuvant Chemotherapy
Excerpt:...- pathological examination confirms estrogen receptor positive, and Ki67 < 30% in breast cancer patients;...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
A Study of GDC-0810 Single Agent or in Combination With Palbociclib and/or a Luteinizing Hormone-Releasing Hormone (LHRH) Agonist in Women With Locally Advanced or Metastatic Estrogen Receptor Positive Breast Cancer
Excerpt:...or metastatic disease, both progressing after at least 6 months of hormonal therapy for estrogen receptor (ER) positive breast cancer...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Phase II Trial of the Cyclin-Dependent Kinase Inhibitor PD 0332991 in Patients With Cancer
Excerpt:...ER positive metastatic breast tumors (data now shows all to be Rb positive.) B....
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Hydroxychloroquine, Palbociclib, and Letrozole Before Surgery in Treating Patients With Estrogen Receptor Positive, HER2 Negative Breast Cancer
Excerpt:...- Diagnosis of estrogen positive breast cancer, estrogen receptor-positive and HER2-negative by American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) criteria...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Two Different Schedules of Palbociclib + Second Line Endocrine Therapy in Estrogen Receptor Positive, HER2 Neg Advanced/Metastatic Breast Cancer
Excerpt:...- Histologically confirmed adenocarcinoma of the breast, with ER positive and HER2 negative status based on local testing on most recent pathological tumour specimen....
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Genetic Analysis in Blood and Tumor Samples From Patients With Advanced or Metastatic Estrogen Receptor Positive and HER2 Negative Breast Cancer Receiving Palbociclib and Endocrine Therapy
Excerpt:...- Histologic confirmation from the pre-registration biopsy of either locally advanced or metastatic breast cancer that is ER-positive and HER2 -negative -...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Palbociclib in Combination With Tamoxifen as First Line Therapy for Metastatic Hormone Receptor Positive Breast Cancer
Excerpt:...- Histologically and/or cytologically confirmed diagnosis of ER positive and/or PR positive (ER >1%, PR >1%), HER2 negative breast cancer....
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
Neoadjuvant Biomarker ResearcH Study of Palbociclib Combined With Endocrine Therapy in Estrogen Receptor Positive/HER2 Negative Breast CAncer (NeoRHEA)
Excerpt:...Histological diagnosis of breast adenocarcinoma that is estrogen receptor-positive, and HER2- negative as per the updated American Society of Clinical Oncology (ASCO)...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
PAlbociclib and Circulating Tumor DNA for ESR1 Mutation Detection
Excerpt:...Estrogen Receptor (ER)-positive and HER2-negative breast cancer. ...
Evidence Level:Sensitive: C2 – Inclusion Criteria
New
Title:
A Phase II Randomized Study Evaluating the Biological and Clinical Effects of the Combination of Palbociclib With Letrozole as Neoadjuvant Therapy in Post-Menopausal Women With Estrogen-Receptor Positive Primary Breast Cancer
Excerpt:...- Operable ER-positive/HER2- negative, invasive early breast cancer, suitable for neoadjuvant AI treatment....
Less C2 evidence

Evidence Level:Sensitive: D – Preclinical
Title:
Selective Androgen Receptor Modulators in combination with CDK4/6 inhibitors demonstrate anti-cancer activity in preclinical treatment resistant ER+AR+ breast cancer models
Excerpt:...enobosarm or DHT and palbociclib treatment were evaluated in vivo using endocrine and CDK4/6i resistant ER+ patient derived xenograft models (PDX) and cell line xenograft models….growth inhibition was more potent and durable in combination with a CDK4/6i.
Evidence Level:Sensitive: D – Preclinical
Title:
The Combination of the CDK4/6 Inhibitor, Palbociclib, With the Vitamin D 3 Analog, Inecalcitol, Has Potent In Vitro and In Vivo Anticancer Effects in Hormone-Sensitive Breast Cancer, But Has a More Limited Effect in Triple-Negative Breast Cancer
Excerpt:we evaluated if the combination of the potent vitamin D3 analog, inecalcitol, with a selective CDK4/6 inhibitor, palbociclib, enhanced the antiproliferative effects of both single compounds in hormone-sensitive (ER+) BC, for which palbociclib treatment is already approved, but also in triple-negative BC (TNBC). Inecalcitol and palbociclib combination treatment decreased cell proliferation in both ER+ (T47D-MCF7) and TNBC (BT20-HCC1143-Hs578T) cells, with a more pronounced antiproliferative effect in the former.
DOI:10.3389/fendo.2022.886238
Evidence Level:Sensitive: D – Preclinical
Title:
6280 / 15 - CDK4/6 inhibitor-mediatated radiosensitization of estrogen receptor positive breast cancer
Excerpt:Palbociclib significantly radiosensitized ER+ cell lines at concentrations at or below the IC50 value in clonogenic survival assays (MCF-7 rER: 1.22-1.52, T47D rER: 1.23-1.50) and led to a decrease in the surviving fraction of cells at 2 Gy (p < 0.001). Similar results were observed in ribociclib- (rER: 1.08 - 1.68) and abemaciclib-treated (rER: 1.19 - 2.05) cells....Our data suggests that CDK4/6 inhibitor-mediated radiosensitization may be effective in ER+ breast cancers prior to the development of CDK4/6 inhibitor resistance.
Evidence Level:Sensitive: D – Preclinical
New
Title:
eIF4A Inhibitors Suppress Cell-Cycle Feedback Response and Acquired Resistance to CDK4/6 Inhibition in Cancer
Excerpt:Furthermore, ER+ breast cancer and KRAS-mutant NSCLC cells that acquired resistance to palbociclib after chronic drug exposure are also highly sensitive to this combination treatment strategy.
DOI:10.1158/1535-7163.MCT-19-0162