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Breast CancerPhase 2NCT02764541

Palbociclib and Endocrine Therapy for LObular Breast Cancer Preoperative Study (PELOPS)

A Phase 2 study testing Letrozole, Tamoxifen and Palbociclib in people with Breast Cancer, run by Dana-Farber Cancer Institute at 11 sites in United States.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
Search all trials

Trial summary

This research study is evaluating how well Breast Cancer responds to preoperative treatment with Endocrine treatment in combination with a drug called Palbociclib or Endocrine treatment alone as possible treatments for Hormone Receptor Positive Breast Cancer. Read more about this study

Who is it for?
Ages 18 years and older, women only
Conditions the study is for
Breast Cancer
What is being tested?
Letrozole, Tamoxifen and Palbociclib
Could I receive a placebo?
No, everyone receives an active treatment
How many people
195 participants
Where
11 sitesUnited States
Study dates
24 May 2016to Apr 2031
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Patients must have Stage I to III histologically confirmed invasive carcinoma of the breast. A minimum tumor size of at least 1.5 cm determined by physical exam or imaging (whichever is larger) is required.
  • Patients must have histologically confirmed hormone receptor positive (ER and/or PR), HER2 negative, invasive breast cancer. ER, PR and HER2 measurements should be performed according to institutional guidelines, in a CLIA-approved setting in the US or certified laboratories for Non-US regions. Cut-off values for positive/negative staining should be in accordance with current ASCO/CAP (American Society of Clinical Oncology/College of American Pathologists) guidelines. Central confirmation is not required for ER, PR, or HER statuses.
  • Patients with equivocal HER2 in situ hybridization results according to current ASCO/CAP guidelines are allowed, as long as the clinician has determined that they should be treated as HER2 negative.
  • For the window phase: Patients must have histologically confirmed invasive lobular carcinoma or invasive ductal carcinoma. No central confirmation of histological subtype is necessary for enrollment.
  • For the treatment phase: Patients with any histological subtype are eligible.
  • Women 18 years of age. Men are not eligible.
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  • ECOG performance status 0 or 1
  • Required laboratory values:
  • Absolute neutrophil count ≥ 1,500/mm3
  • Platelets ≥ 100,000/mm3
  • Hemoglobin ≥ 10g/dL
  • Total serum bilirubin ≤ ULN; or total bilirubin ≤ 3.0 × ULN with direct bilirubin within normal range in patients with documented Gilbert's Syndrome
  • Aspartate amino transferase (AST or SGOT) and alanine amino transferase (ALT or SGPT) ≤ 2.0 × institutional ULN
  • Serum creatinine within normal institutional limits or creatinine clearance ≥ 60 mL/min/1.73 m2 for patients with serum creatinine levels above institutional ULN
  • Postmenopausal patients defined as no spontaneous menses ≥1 year (12 months) or post bilateral surgical oophorectomy. Premenopausal patients are eligible to participate provided they are considered in chemical menopause. Premenopausal patients should receive ongoing treatment with LHRH agonists (goserolin or leuprolide). Premenopausal patients must be enrolled directly into the treatment phase of the study.
  • Patient must agree to the required research biopsies at baseline and after the two-week treatment with endocrine therapy in the initial part of the study ("window phase"); or at baseline and after two-week treated with endocrine therapy plus or minus palbociclib for those patients enrolled directly into the treatment phase of the study.
  • Patients must be able and willing to swallow and retain oral medication without a condition that would interfere with enteric absorption.
  • Breast imaging should include imaging of the ipsilateral axilla. For subjects with a clinically negative axilla, a sentinel lymph node biopsy will be performed either before or after preoperative therapy at the discretion of the subject's physicians. For subjects with a clinically positive axilla, a needle aspiration, core biopsy or SLN procedure will be performed to determine the presence of metastatic disease in the lymph nodes.
  • Patients with multifocal or multicentric disease are eligible if the treating clinician has determined the patient should be treated as ER+ and HER2- negative.
  • Bilateral breast cancers are allowed if the treating clinician has determined the patient should be treated as ER+ and HER2- negative.
  • Serum or urine pregnancy test must be negative in women judged premenopausal within 7 days of randomization, or in women with amenorrhea of less than 12 months at time of randomization. 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.
  • Premenopausal patients must agree to use adequate contraception for the duration of protocol treatment and for 6 months after the last treatment with palbociclib. Adequate contraception is defined as one highly effective form (i.e. abstinence, male or female sterilization) OR two effective forms (e.g. non-hormonal IUD and condom/occlusive cap with spermicidal foam / gel / film / cream/ suppository). Hormonal contraceptive methods are not allowed.
  • Patients with a history of ipsilateral or contralateral DCIS are eligible.
  • Patients may concurrently receive bisphosphonates or rank ligand inhibitors while on this study if necessary for treatment or prevention of osteopenia or osteoporosis. Prior treatment with LHRH agonists is allowed for premenopausal women. Topical vaginal estrogen therapy is allowable.
  • Ability to understand and the willingness to sign a written informed consent document.

Who cannot join

  • Concurrent therapy with other Investigational Products.
  • Prior therapy with any CDK inhibitor.
  • Patients with Stage IV breast cancer are not eligible. Baseline staging to document absence of metastatic disease is not required, however is recommended as determined by institutional practice (in patients where there may be a reasonable suspicion of advanced disease e.g., large tumors, clinically positive axillary lymph nodes, signs and symptoms). If performed, reports of these examinations must be available. Examination type for staging, i.e. X-ray, sonography, bone scans, CT, MRI, and/or PET-CT, is at the discretion of the investigator.
  • History of allergic reactions attributed to compounds of chemical or biologic composition similar to palbociclib.
  • Patients receiving any medications or substances that are potent inhibitors or inducers of CYP3A isoenzymes within 7 days of randomization
  • Uncontrolled 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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  • Pregnant women, or women of childbearing potential without a negative pregnancy test (serum or urine) within 7 days prior to randomization, irrespective of the method of contraception used, are excluded from this study because the effect of palbociclib on a developing fetus is unknown. Breastfeeding must be discontinued prior to study entry.
  • Patients with a history of any malignancy are ineligible except for the following circumstances:
  • Patients with a malignancy history other than invasive breast cancer are eligible if they have no active malignancy and are deemed by the investigator to be at low risk for recurrence of that malignancy.
  • Patients with the following cancers are eligible: ductal carcinoma in situ of the breast, cervical cancer in situ, and non-metastatic non-melanomatous skin cancers.
  • Patients on combination antiretroviral therapy, i.e. those who are HIV-positive, are ineligible because of the potential for pharmacokinetic interactions or increased immunosuppression with palbociclib. HIV testing is not required, but patients must not be known to be HIV-positive.
  • Patients receiving concurrent exogenous hormone therapy (hormone replacement therapy, oral or any other hormonal contraceptives such as hormonal contraceptive coil are not eligible.
  • Patients are not eligible if they have previously received endocrine therapy within 5 years prior to diagnosis of the current malignancy. This includes use for prophylactic reasons, including treatment of osteoporosis or cancer prevention with tamoxifen, raloxifene, or AI.

Trial locations and contacts

11 sites in 1 country.

11 sites in 1 country

United States11 sites

  • Dana-Farber at St. Elizabeth's Medical Center

    Boston, Massachusetts, 02135

  • Beth Israel Deaconess Medical Center

    Boston, Massachusetts, 02215

  • Dana-Farber Cancer Institute

    Boston, Massachusetts, 02215

  • Eastern Maine Medical Center

    Brewer, Maine, 04412

  • MD Anderson Cancer Center

    Houston, Texas, 77030

  • DF/BWCC at Milford Regional Medical Center

    Milford, Massachusetts, 01757

  • Sarah Cannon Research Institute

    Nashville, Tennessee, 37203

  • Vanderbilt University Medical Center

    Nashville, Tennessee, 37232

  • Lifespan

    Providence, Rhode Island, 02903

  • DF/BWCC in clinical affiliation with South Shore Hospital

    South Weymouth, Massachusetts, 02190

  • Stamford Hospital

    Stamford, Connecticut, 06904

Other trials in United States

About this study

Official title: Palbociclib and Endocrine Therapy for LObular Breast Cancer Preoperative Study (PELOPS): A Randomized Phase II Study of Palbociclib With Letrozole Versus Letrozole Alone for Invasive Lobular Carcinoma and Invasive Ductal Carcinoma

This research study is evaluating how well Breast Cancer responds to preoperative treatment with Endocrine treatment in combination with a drug called Palbociclib or Endocrine treatment alone as possible treatments for Hormone Receptor Positive Breast Cancer.

Read the detailed description

This is an open label phase II neoadjuvant clinical trial of Palbociclib in combination with endocrine therapy for hormone receptor positive early-stage breast cancer. The planned sample size is 180 participants. The study includes a "window treatment" phase followed by a treatment phase. In the window phase, participants will be treated with a two-week course of tamoxifen (Arm A) or letrozole (Arm B). In the treatment phase participants will be randomized to receive endocrine therapy in combination with palbociclib (Arm C) or endocrine therapy alone (Arm D) for a total duration of 24 weeks. Premenopausal patients with either invasive lobular or ductal carcinoma will be eligible to enroll directly into the treatment phase of the study. The study has two co-primary objectives: 1) To evaluate the difference in anti-proliferative activity of letrozole versus tamoxifen measured by changes in Ki67 from baseline to research biopsy (day 15) within cohorts of hormone receptor positive breast cancer for patients with invasive lobular and ductal carcinoma. 2) To evaluate the pathologic complete response (pCR) of endocrine therapy plus palbociclib and of endocrine therapy alone in breast cancer patients diagnosed with hormone receptor positive invasive breast cancer.

Conditions
Breast Cancer
Being tested
Letrozole, Tamoxifen, Palbociclib, Endocrine Therapy
Keywords
Breast Cancer, Invasive Lobular Carcinoma
Medical subject headings
Breast Neoplasms, Carcinoma, Lobular

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT02764541
Study groupRoleWhat they receive
Arm A Tamoxifen followed by Endocrine TherapyExperimentalTamoxifen is given in the Window of Treatment phase for 2 weeks followed by Endocrine Therapy for 24 weeks.
Receives: Drug: Tamoxifen; Drug: Endocrine Therapy
Arm B Letrozole Followed By Endocrine TherapyExperimentalLetrozole is given in the Window of Treatment phase for 2 weeks followed by Endocrine Therapy for 24 weeks.
Receives: Drug: Letrozole; Drug: Endocrine Therapy
Tamoxifen Followed By Endocrine Therapy and PalbociclibExperimentalTamoxifen is given in the Window of Treatment phase for 2 weeks followed by Endocrine Therapy in combination with Palbociclib for 24 weeks.
Receives: Drug: Tamoxifen; Drug: Palbociclib; Drug: Endocrine Therapy
Letrozole Followed By Endocrine Therapy and PalbociclibExperimentalLetrozole is given in the Window of Treatment phase for 2 weeks followed by Endocrine Therapy in combination with Palbociclib for 24 weeks.
Receives: Drug: Letrozole; Drug: Palbociclib; Drug: Endocrine Therapy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Difference in Anti-proliferative Activity of Patients Given Letrozole Versus Tamoxifen During the Window Phase

    Log fold change in anti-proliferative activity of Letrozole versus Tamoxifen within cohorts of hormone receptor positive breast cancer for patients with invasive lobular and ductal carcinoma during the window phase. Higher absolute value indicates larger change in the anti-proliferative activity

    Measured: baseline to day 15

  2. Pathologic Complete Response (pCR) of Patients Given Endocrine Therapy Plus Palbociclib and of Endocrine Therapy Alone During the Treatment Phase

    Residual Cancer Burden index (RCB) between hormone receptor positive invasive breast cancer patients given endocrine therapy plus palbociclib (Arm C) and endocrine therapy alone (Arm D). RCB score is used to assess the response to neoadjuvant chemotherapy in breast cancer patients and is in a scale of 0 to infinity. Higher RCB score indicates more tumor burden remaining, thus worse outcome.

    Measured: day 15 to 24 weeks

Secondary outcomes (4)

  1. Odds Ratio of Achieving Cell Cycle Arrest at the End of Window Phase

    Odds Ratio of Achieving Cell Cycle Arrest at the end of Window Phase in hormone receptor positive invasive breast cancer patients given Tamoxifen vs Letrozole. Cell cycle arrest is defined to be percentage of Ki67<2.7

    Measured: baseline to day 15

  2. Change in RCB Index Between Arm C and Arm D During the Treatment Phase

    The estimate of RCB index change for patients who receive both endocrine and Palbociclib instead of endocrine alone, but have the same lymph node status, tumor size and menopausal status. RCB score is used to assess the response to neoadjuvant chemotherapy in breast cancer patients and is in a scale of 0 to infinity. Higher RCB score indicates more tumor burden remaining, thus worse outcome.

    Measured: day 15 to 24 weeks

  3. Number of Participants With RCB Response in Arm C and Arm D During the Treatment Phase

    RCB response is defined as RCB-0 or RCB-I; RCB not response is defined as RCB-II or RCB-III Residual Cancer Burden (RCB) considers residual disease in the tumor bed and lymph nodes after NAC, generating a continuous score which is then grouped into four categories: RCB-0, RCB-I, RCB-II and RCB-III. Higher RCB group reflects more tumor burden remaining, thus worse outcome

    Measured: day 15 to 24 weeks

  4. Percentage of Participants With Clinical Response in Arm C and Arm D in the Treatment Phase

    Percentage of Participants with Clinical Response in Arm C and Arm D in Breast cancer patients diagnosed with hormone receptor positive invasive breast cancer; Clinical response rate is defined as the number of partial and complete responses after preoperative endocrine therapy plus palbociclib (Arm C) and of endocrine therapy alone (Arm D)

    Measured: day 15 to 24 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 May 2016 (estimated)
  2. Study start24 May 2016
  3. Primary completionFeb 2022
  4. Study completionApr 2031 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
195 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02764541
Sponsor's protocol ID
16-052
Status last verified
Jun 2026
First submitted
4 May 2016
Last updated
23 Jun 2026
Data monitoring committee
Yes
Individual data sharing
No

Publications

  • Grinshpun A, Dustin D, Cai M, Hughes M, DiLullo M, Moore M, Yardley D, Mayer IA, Symmans WF, Mayer EL, Winer EP, Lin NU, Tolaney SM, Metzger O, Jeselsohn R. Circulating tumor DNA in neoadjuvant endocrine therapy for early breast cancer. ESMO Open. 2026 Mar;11(3):106067. doi: 10.1016/j.esmoop.2026.106067. Epub 2026 Feb 10.

    PubMed 41672025

  • Weiss A, Jin Q, Tayob N, Wrabel E, DeMeo M, Carter J, Constantine M, Faggen M, Block C, Fenton MA, Lo KMS, Openshaw T, Yardley D, Kennedy L, Bedrosian I, Mittendorf EA, Jeselsohn R, Metzger Filho O, King TA. Axillary Management and Outcomes After Neoadjuvant Endocrine Therapy in the Randomized PELOPS Trial. Ann Surg Oncol. 2026 Mar;33(3):2275-2283. doi: 10.1245/s10434-025-18697-5. Epub 2025 Nov 23.

    PubMed 41276768

  • Weiss A, Revette A, Nava-Coulter B, Mittendorf EA, Filho OM, King TA. Surgeon Perspectives on Axillary Management Following Neoadjuvant Endocrine Therapy: Results from a Qualitative Substudy of the PELOPS Trial. Ann Surg Oncol. 2026 Mar;33(3):2267-2274. doi: 10.1245/s10434-025-18695-7. Epub 2025 Nov 21.

    PubMed 41272386

  • Hermida-Prado F, Xie Y, Sherman S, Nagy Z, Russo D, Akhshi T, Chu Z, Feit A, Campisi M, Chen M, Nardone A, Guarducci C, Lim K, Font-Tello A, Lee I, Garcia-Pedrero J, Canadas I, Agudo J, Huang Y, Sella T, Jin Q, Tayob N, Mittendorf EA, Tolaney SM, Qiu X, Long H, Symmans WF, Lin JR, Santagata S, Bedrosian I, Yardley DA, Mayer IA, Richardson ET, Oliveira G, Wu CJ, Schuster EF, Dowsett M, Welm AL, Barbie D, Metzger O, Jeselsohn R. Endocrine Therapy Synergizes with SMAC Mimetics to Potentiate Antigen Presentation and Tumor Regression in Hormone Receptor-Positive Breast Cancer. Cancer Res. 2023 Oct 2;83(19):3284-3304. doi: 10.1158/0008-5472.CAN-23-1711.

    PubMed 37450351

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Letrozole, Tamoxifen and Palbociclib in people with Breast Cancer, run by Dana-Farber Cancer Institute at 11 sites in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 25 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 23 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 11 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 31 Aug 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Difference in Anti-proliferative Activity of Patients Given Letrozole Versus Tamoxifen During the Window Phase (time frame: baseline to day 15). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02764541, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Jun 2026.

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