Palbociclib Plus Letrozole in Hormone Receptor Positive Residual Disease After Neoadjuvant Chemotherapy

  • End date
    Mar 25, 2022
  • participants needed
  • sponsor
    SOLTI Breast Cancer Research Group
Updated on 25 January 2021
tumor cells
adjuvant therapy
cancer treatment


PROMETEO II is a single-arm window of opportunity trial to evaluate biologic and anti-proliferative effects of palbociclib and letrozole in HR+/HER2-negative operable breast cancer (BC) patients with residual disease after neoadjuvant chemotherapy (NAC) and help to identify biomarkers for better patient selection.


This is a single-arm window of opportunity trial to evaluate biologic and anti-proliferative effects of palbociclib and letrozole in HR+/HER2-negative operable BC patients with residual disease after NAC and help to identify biomarkers for better patient selection.

The primary endpoint will be the Complete Cell Cycle Arrest (CCCA) determined by Ki67<2.7%, centrally assessed at surgery after 4 weeks of palbociclib and letrozole.

Tumor measurement will be performed by ultrasound (US) for disease evaluation and confirmation of residual disease will be performed at screening at the end of NAC. The biopsy after chemotherapy will only be done after confirmation of residual disease by US. Ki67% 5% after NAC by local determination will be necessary to be included in the study.

Patients will be administered palbociclib at a dose of 125 mg once daily, day 1 to day 21 followed by 7 days off treatment in a 28-day cycle and letrozole: oral, 2.5 mg per day continuously, one cycle of treatment.

After the finalization of the neoadjuvant treatment, patients will undergo surgery. Surgery specimens will be collected for histological examination and biomarker analysis

The end of the study is defined as the date of post-surgery visit and will take place 4 weeks (+/- 7days) after the surgery in order to monitor the patient's safety and collect the surgery information.

Condition Breast Cancer, Breast Cancer Diagnosis, breast carcinoma, cancer, breast
Treatment Letrozole, Palbociclib
Clinical Study IdentifierNCT04130152
SponsorSOLTI Breast Cancer Research Group
Last Modified on25 January 2021


Yes No Not Sure

Inclusion Criteria

Is your age greater than or equal to 18 yrs?
Are you female?
Do you have Breast Cancer?
Do you have any of these conditions: cancer, breast or Breast Cancer Diagnosis or Breast Cancer or breast carcinoma?
Written and signed informed consent for all study procedures according to local regulatory requirements prior to beginning specific protocol procedures
Female patients age 18 years
ECOG (Eastern Cooperative Oncology Group) Performance Status of 0 to 1
Histologically confirmed non-metastatic primary HR-positive/HER2 negative breast cancer with all the following characteristics
Breast cancer eligible for surgery
ER-positive and/or PgR-positive and HER2-negative tumor by the most recent ASCO/CAP guidelines, before neoadjuvant treatment locally assessed
Ki67% 5% after neoadjuvant chemotherapy locally assessed (Dowsett M et al JNCI 2011)
A lesion that could be confirmed by ultrasound (US) after neoadjuvant chemotherapy
Completed 80% total dose of an anthracycline/taxane-based neoadjuvant regimen planned. The allowed chemotherapy regimens will be AC (cyclophosphamide, doxorubicin) or EC (epirubicin, cyclophosphamide) 4 cycles followed by weekly paclitaxel x 12 or AC or EC 4 cycles followed by docetaxel 4 cycles. It would be acceptable to change the administration sequence to paclitaxel followed by AC/EC. AC can be given either a standard dose or in a dose-dense schedule. Paclitaxel could be administered as a solvent-based or Nanoparticle albumin-bound (Nab) formulation
Availability of a recent formalin-fixed paraffin-embedded (FFPE) tumor sample before NAC and a research tumor biopsy after NAC. Minimal sample requirements are to have at least 2 tumor cylinders with a minimal tissue surface of 10 mm2 tissue, containing at least 10% tumor cells and having enough tissue to do at least 2 cuts of 10 m each
Adequate organ function determined within 28 days prior to enrollment, defined as
Absolute neutrophil count (ANC) 1.5 x 109/L
Platelet count 100 x 109/L
Hemoglobin 9 g/dL (red blood cell transfusion and/or erythropoietin allowed)
Serum creatinine 1.5 x upper limit of normal (ULN), or 24-hour creatinine
clearance 60 mL/min for a subject with creatinine levels >1.5 x ULN. (Note
Creatinine clearance does not need to be determined if the baseline serum
creatinine is within normal limits. Creatinine clearance should be calculated
per institutional standard)
Serum bilirubin 1.5 x ULN OR direct bilirubin ULN for a subject with total bilirubin level > 1.5 x ULN
Aspartate aminotransferase (AST) 2.5 x ULN
Alanine aminotransferase (ALT) 2.5 x ULN Coagulation International normalization ratio (INR) or prothrombin time (PT) 1.5 x ULN 8. Serum or urine pregnancy test must be negative within 7 days prior enrollment in women of childbearing potential. If the urine pregnancy test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. Pregnancy testing does not need to be pursued in patients who are judged as postmenopausal before randomization, as determined by local practice, or who have undergone bilateral oophorectomy, total hysterectomy, or bilateral tubal ligation. Women of childbearing potential enrolled to the treatment must use adequate contraception for the duration of protocol treatment. 9. Absence of any psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before registration in the trial. 10. Resolution of all acute toxic effects of prior anti-cancer therapy to NCI CTCAE version 5.0 Grade 1 (except alopecia or other toxicities not considered a safety risk for the patient at investigators discretion). 11. Pre/peri-menopausal and post-menopausal women are allowed; menopausal status is relevant for the requirement of goserelin or triptorelin to be used concomitantly with palbociclib plus letrozole. Post-menopausal status is defined either by
Prior bilateral oophorectomy or
Age 60 or
Age < 60 and amenorrhea for 12 months prior to the start of neoadjuvant chemotherapy and FSH and estradiol in the post-menopausal range per local standards prior to the start of neoadjuvant chemotherapy
For patients who do not meet the one of the previous parameters, therapy-
induced amenorrhea (goserelin or triptorelin), it must have been started more
days before the start of palbociclib plus letrozole treatment

Exclusion Criteria

Non-operable, locally advanced breast cancer (inoperable stage III) after NAC
Bilateral or metastatic invasive breast cancer at the time of the diagnosis
Known severe hypersensitivity reactions to compounds similar to palbociclib or to excipients or to endocrine treatments
History of any previous treatment using Aromatase inhibitors (AI) o selective estrogen receptor modulator (SERMs) in the past 5 years
Prior therapy with palbociclib or any cyclin-dependent kinase (CDK) inhibitor
Concurrent treatment with other experimental drugs. Participation in another clinical trial with any investigational not marketed drug within 30 days prior to enrollment
Patients receiving any medications or substances that are strong inhibitors or inducers of CYP3A isoenzymes within 7 days of randomization
Any surgery (not including minor procedures such as primary tumor core biopsy, fine needle aspiration) within 4 weeks of start of study treatment; or not fully recovered from any side effects of previous procedures
Sentinel lymph node biopsy is not allowed before NAC
Diagnosis of any previous malignancy within the last 3 years, except for adequately treated basal cell carcinoma, or squamous cell skin carcinoma, or in situ cervical carcinoma
Malabsorption syndrome or other condition that would interfere with enteric absorption
Clinically significant history of liver disease, including viral or other hepatitis, current alcohol abuse, or cirrhosis
Uncontrolled electrolyte disorders (eg, hypocalcemia, hypokalemia, hypomagnesemia)
Any of the following within 6 months of enrollment: myocardial infarction, severe/unstable angina, ongoing cardiac dysrhythmias of NCI CTCAE version 5.0 Grade 2, atrial fibrillation of any grade, coronary/peripheral artery bypass graft, symptomatic congestive heart failure, cerebrovascular accident including transient ischemic attack, or symptomatic pulmonary embolism
Corrected QT interval (QTc) greater than 480 msec or a family or personal history of long or short QT syndrome, Brugada syndrome or know history of QTc prolongation, or Torsade de Pointes (TdP)
Uncontrolled current illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, diabetes, or psychiatric illness/social situations that would limit compliance with study requirements. Ability to comply with study requirements is to be assessed by each investigator at the time of screening for study participation
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