Metastatic Breast CancerPhase 2NCT03147287
Palbociclib After CDK and Endocrine Therapy (PACE)
A Phase 2 study testing Palbociclib, Fulvestrant and Avelumab in people with Metastatic Breast Cancer, run by Dana-Farber Cancer Institute at 22 sites in United States.
Trial summary
This research study is studying three combinations of drugs as treatments for breast cancer. The drugs involved in this study are: Fulvestrant Fulvestrant with Palbociclib Fulvestrant with Palbociclib and Avelumab Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Metastatic Breast Cancer
- What is being tested?
- Palbociclib, Fulvestrant and Avelumab
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 220 participants
- Where
- 22 sitesUnited States
- Study dates
- 5 Sep 2017to 30 Dec 2026
- 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
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Participants must have histologically confirmed hormone receptor positive (HR+) HER2 negative metastatic or locally recurrent unresectable invasive breast cancer. ER, PR and HER2 measurements should be performed according to institutional guidelines, in a CLIA-approved setting. 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.
- Men and pre- and postmenopausal women are eligible. Ongoing monthly GNRH agonist is required in pre-menopausal women or male participants for at least 4 weeks prior to study entry.
- Participants must have radiological or objective evidence of progression on an endocrine and CDK 4/6 inhibitor regimen in the metastatic setting, and/or relapse/progression during or within 12 months of completion of an endocrine and CDK4/6 inhibitor regimen in the adjuvant setting.
- Participants must have previously been exposed to CDK4/6 inhibitor therapy in combination with endocrine therapy. Exposure to any prior CDK4/6 inhibitor, (including palbociclib, abemaciclib, and ribociclib) is allowed. Patients may have a line of endocrine therapy after combination endocrine and CDK4/6 inhibitor exposure.
- Participants must have remained on prior endocrine and CDK4/6 therapy in the metastatic setting without progression for at least 6 months prior to study entry.
- It is not mandatory to have a CDK 4/6 inhibitor containing regimen as the most recent treatment.
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- Participants may have 0-1 prior lines of cytotoxic chemotherapy in the metastatic setting.
- Prior endocrine therapy in the metastatic setting may include any aromatase inhibitor (AI) or tamoxifen, but may not include prior fulvestrant. In the metastatic setting, 1-2 prior lines of endocrine therapy are allowed.
- Participants may have received radiotherapy for palliative purpose, but must not be experiencing > grade 1 treatment related toxicities, and must have completed treatment > 14 days prior to registration.
- Age ≥18 years. Because no dosing or adverse event data are currently available on the use of study agents in participants <18 years of age, children are excluded from this study.
- ECOG performance status 0-1 (see Appendix A).
- Participants must have normal organ and marrow function as defined below:
- Absolute neutrophil count > 1,500/µL
- Platelets > 100,000/µL
- Hemoglobin > 9g/dL
- Total bilirubin < 1.5 x institutional upper limit of normal (ULN) (participants with documented Gilbert's disease are allowed total bilirubin up to 1.5X ULN)
- AST (SGOT)/ALT (SGPT) < 2.5 x institutional ULN, or ≤ 5 x ULN for subjects with documented metastatic disease to the liver.
- Creatinine < institutional ULN or creatinine clearance > 60 mL/min/1.73 m2 for subjects with creatinine levels above institutional ULN.
- Baseline QTc < 480 ms
- The effects of palbociclib and avelumab on the developing human fetus are unknown. If, for any reason, a woman should become pregnant or suspect that she is pregnant while participating in this study, she should inform her treating physician immediately. Women of childbearing age, women who are made postmenopausal through use of GNRH agonists, and men must agree to use adequate contraception for the duration of protocol treatment and for at least 60 days after the last dose of study medication if the risk of contraception exists.
- Adequate contraception is defined as one highly effective non-hormonal form of contraception or two effective forms of non-hormonal contraception by the participant and/or partner.
- Highly Effective Non-Hormonal Contraception
- Methods of birth control which result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly are considered highly-effective forms of contraception.
- The following non-hormonal methods of contraception are acceptable:
- True abstinence when this is in line with the preferred and usual lifestyle of the participant. [Periodic abstinence (e.g., calendar, ovulation, symptothermal post-ovulation methods) and withdrawal are not acceptable methods of contraception].
- Male sterilization (with appropriate post-vasectomy documentation of the absence of sperm in the ejaculate). For female participants, the vasectomized male partner should be the sole partner.
- OR
- -Effective Non-Hormonal Contraception
- Alternatively two of the following effective forms of contraception may be used instead:
- Placement of non-hormonal intrauterine device (IUD) or intrauterine system (IUS). Consideration should be given to the type of device being used, as there is higher failure rates quoted for certain types, e.g., steel or copper wire.
- Condom with spermicidal foam/gel/film/cream/suppository.
- Occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/film/cream/suppository.
- The use of barrier contraceptives should always be supplemented with the use of spermicide. The following should be noted:
- Failure rates indicate that, when used alone, the diaphragm and condom are not highly effective forms of contraception. Therefore, the use of additional spermicides does confer additional theoretical contraceptive protection.
- However, spermicides alone are ineffective at preventing pregnancy when the whole ejaculate is spilled. Therefore, spermicides are not a barrier method of contraception and should not be used alone.
- It should be noted that two forms of effective contraception are required. A double barrier method is acceptable, which is defined as condom and occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/film/cream /suppository.
- Premenopausal women must have a negative serum or urine pregnancy test. Pregnancy testing does not need to be pursued in female participants who are:
- Age > 60 years; or
- Age < 60 with intact uterus and amenorrhea for 12 consecutive months or more AND estrogen (estradiol) levels within postmenopausal range; or
- Status-post bilateral oophorectomy, total hysterectomy, or bilateral tubal ligation.
- Participant must be able to swallow and retain oral medication.
- Ability to understand and the willingness to sign a written informed consent document
Who cannot join
- Participants who have had endocrine, chemotherapy, and/or biologic therapy within 14 days prior to entering the study or those who have not recovered from any prior treatment-related toxicities (must recover to no more than grade 1. Alopecia, sensory neuropathy Grade ≤ 2, or other Grade ≤ 2 toxicity not constituting a safety risk based on investigator's judgment are acceptable).
- Participants who are receiving concurrent therapy with other investigational agents.
- Rapidly progressive, symptomatic, visceral spread of disease placing participant at risk of life-threatening complications in the short term.
- Participants with active brain metastases. Stable treated brain metastases are allowed (this includes participants who have documented radiologic stability at least 4 weeks after radiotherapy, and do not require systemic steroids for management of symptoms from CNS metastatic lesions).
- Participants who have discontinued prior palbociclib for toxicity, or have needed more than one dose or schedule reduction for toxicity from prior palbociclib therapy. If a participant required a single dose reduction during prior palbociclib therapy and tolerated it well, for example prior dosing at 100 mg qd 3 weeks on 1 week off schedule, than that dose may be selected for this trial.
- History of allergic reactions to palbociclib or attributed to compounds of similar chemical or biologic composition to palbociclib.
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- Known prior severe hypersensitivity to investigational product or any component in its formulations, including known severe hypersensitivity reactions to monoclonal antibodies (NCI CTCAE v4.03 Grade ≥ 3)
- Participants receiving any medications or substances that are strong inhibitors or inducers of CYP3A isoenzymes are ineligible. Lists including medications and substances known or with the potential to interact with the CYP3A isoenzymes are provided in Appendix B, and can also be found within Section 5.4. Because the lists of these agents are constantly changing, it is important to regularly consult a frequently-updated list such as http://medicine.iupui.edu/clinpharm/ddis/table.aspx; medical reference texts such as the Physicians' Desk Reference may also provide this information. As part of the enrollment/informed consent procedures, the participant will be counseled on the risk of interactions with other agents, and what to do if new medications need to be prescribed or if the participant is considering a new over-the-counter medicine or herbal product.
- Current use of drugs listed in Appendix C that are known to prolong the QT interval (See Appendix C)
- Prior organ transplantation including allogenic stem-cell transplantation
- Current use of immunosuppressive medication, except for the following: a. intranasal, inhaled, topical steroids, or local steroid injection (e.g., intra-articular injection); b. Systemic corticosteroids at physiologic doses ≤ 10 mg/day of prednisone or equivalent; c. Steroids as premedication for hypersensitivity reactions (e.g., CT scan premedication).
- Uncontrolled intercurrent illness including, but not limited to: ongoing or active infection requiring systemic therapy, clinically significant cardiovascular disease including: cerebral vascular accident/stroke (< 6 months prior to enrollment), myocardial infarction (< 6 months prior to enrollment), unstable angina, congestive heart failure (≥ New York Heart Association Classification Class II), or serious cardiac arrhythmia requiring medication, uncontrolled diabetes mellitus, 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.
- Active autoimmune disease that might deteriorate when receiving an immuno-stimulatory agent. Participants with diabetes type I, vitiligo, psoriasis, or hypo- or hyperthyroid diseases not requiring immunosuppressive treatment are eligible.
- Known history of testing positive for HIV or known acquired immunodeficiency syndrome, or need to receive combination antiretroviral therapy for HIV
- Known history of immune-mediated conditions including colitis, inflammatory bowel disease requiring steroid or immunosuppressive therapy, pneumonitis, or pulmonary fibrosis.
- Hepatitis B virus (HBV) or hepatitis C virus (HCV) infection at screening (positive HBV surface antigen or HCV RNA if anti-HCV antibody screening test positive)
- Live vaccination within 4 weeks of the first dose of avelumab
- Pregnant women are excluded from this study because effect of palbociclib and avelumab on a developing fetus is unknown. Breastfeeding should be discontinued prior to entry onto the study.
- Individuals with a history of a different malignancy are ineligible except for the following circumstances. Individuals with a history of other malignancies are eligible if they have been disease-free for at least 3 years and are deemed by the investigator to be at low risk for recurrence of that malignancy. Individuals with the following cancers are eligible if diagnosed and treated within the past 5 years: ductal carcinoma in situ of the breast, cervical cancer in situ, and basal cell or squamous cell carcinoma of the skin
Trial locations and contacts
22 sites in 1 country.
22 sites in 1 country
United States22 sites
Emory University - Winship Cancer Institute
Atlanta, Georgia, 30322
Eastern Maine Medical Center
Bangor, Maine, 04401
Boston Medical Center
Boston, Massachusetts, 02188
Dana-Farber Cancer Institute
Boston, Massachusetts, 02215
Dana-Farber at St. Elizabeth's Medical Center
Brighton, Massachusetts, 02135
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, 27599
Northwestern University
Chicago, Illinois, 60611
Baylor University
Houston, Texas, 77030
Indiana University
Indianapolis, Indiana, 46202
The University of Kansas Cancer Center - North
Kansas City, Kansas, 64154
The University of Kansas Cancer Center - Lee's Summit
Lee's Summit, Missouri, 64064
Dana-Farber/New Hampshire Oncology-Hematology
Londonderry, New Hampshire, 03053
University of Louisville
Louisville, Kentucky, 40202
University of Miami
Miami, Florida, 33136
DF/BWCC at Milford Regional Medical Center
Milford, Massachusetts, 01757
Aurora Cancer Care
Milwaukee, Wisconsin, 53215
Vanderbilt University Medical Center
Nashville, Tennessee, 37232
The University of Kansas Cancer Center - Overland Park
Overland Park, Kansas, 66210
University of Pennsylvania
Philadelphia, Pennsylvania, 19104
DF/BWCC in clinical affiliation with South Shore Hospital
South Weymouth, Massachusetts, 02190
Washington University
St Louis, Missouri, 63110
The University of Kansas Cancer Center
Westwood, Kansas, 66205
About this study
Official title: Palbociclib After CDK and Endocrine Therapy (PACE): A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab for Endocrine Pre-treated ER+/HER2- Metastatic Breast Cancer
This research study is studying three combinations of drugs as treatments for breast cancer.
The drugs involved in this study are:
- Fulvestrant
- Fulvestrant with Palbociclib
- Fulvestrant with Palbociclib and Avelumab
Read the detailed description
This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational intervention to learn whether the intervention works in treating a specific disease. "Investigational" means that the intervention is being studied and the researchers are trying to find out more about it- for example, the side effects it may cause, and the activity of a drug, or combination of drugs, against a cancer.
In this research study, the investigators are evaluating the activity of fulvestrant alone, fulvestrant and palbociclib, or fulvestrant, palbociclib, and avelumab combined, in participants with metastatic hormone receptor positive HER2 negative breast cancer that has previously stopped responding to prior palbociclib and endocrine therapy.
The FDA (the U.S. Food and Drug Administration) has approved both palbociclib and fulvestrant as treatment options for this disease, however the use of palbociclib has not been studied in people who have previously been treated with palbociclib. The FDA has not approved avelumab as a treatment for any disease.
Palbociclib is a drug that may stop cancer cells from growing. Palbociclib blocks activity of two closely related enzymes (proteins that help chemical reactions in the body occur), called Cyclin Dependent Kinases 4 and 6 (CDK 4/6). These proteins are part of a pathway, or a sequence of steps, which is known to promote cancer cell growth. Laboratory testing has shown that palbociclib may stop the growth of hormone receptor positive breast cancer. Palbociclib is FDA-approved as therapy for metastatic hormone receptor positive HER2 negative breast cancer in combination with endocrine therapy in the first line setting, and in combination with fulvestrant for pre-treated disease. It is not known whether cancers that have grown despite prior palbociclib treatment are still sensitive to palbociclib.
Endocrine therapy prevents growth of hormone receptor positive breast cancer by blocking stimulation of cancer cells by estrogen. During this study, the endocrine therapy will be fulvestrant. Fulvestrant is a drug that is approved by the FDA for treatment of metastatic hormone receptor positive breast cancer.
The immune system is the body's natural defense against disease. The immune system sends a type of cells called T cells throughout the body to detect and fight infections and diseases-including cancers. One way the immune system controls the activity of T cells is through the PD-1 (programmed cell death protein-1) pathway. However, some cancer cells hide from T-cell attack by taking control of the PD-1 pathway and this stops T cells from attacking cancer cells.
Avelumab is an antibody designed to block the PD-1 pathway and helps the immune system in detecting and fighting cancer cells. An antibody is a protein produced by the body's immune system when it detects harmful substances. Previous studies show that the administration of antibodies which block the PD-1 pathway can lead to tumor destruction.
In the laboratory, adding avelumab to fulvestrant and palbociclib appears to improve effectiveness. It is not known whether this is true in humans
- Conditions
- Metastatic Breast Cancer
- Being tested
- Palbociclib, Fulvestrant, Avelumab
- Keywords
- Breast Cancer
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PalbociclibDrug
Also called Ibrance
Palbociclib is a drug that may stop cancer cells from growing
FulvestrantDrug
Also called Faslodex
Fulvestrant prevents growth of hormone receptor positive breast cancer by blocking stimulation of cancer cells by estrogen
AvelumabDrug
Also called Bavencio
Avelumab is an antibody designed to block the PD-1 pathway and helps the immune system in detecting and fighting cancer cells
| Study group | Role | What they receive |
|---|---|---|
| Fulvestrant | Active comparator | -Fulvestrant will be administered in the clinic as two IM injections on Cycle 1 Days 1, 15, then monthly Receives: Drug: Fulvestrant |
| Fulvestrant with Palbociclib | Experimental | * Palbociclib should be taken orally, once per day for 21 days on a 28 days cyclye
* Fulvestrant will be administered in the clinic as two IM injections on Cycle 1 Days 1, 15, then monthly Receives: Drug: Palbociclib; Drug: Fulvestrant |
| Fulvestrant with Palbociclib and Avelumab | Experimental | * Palbociclib should be taken orally, once per day for 21 days on a 28 days cyclye
* Fulvestrant will be administered in the clinic as two IM injections on Cycle 1 Days 1, 15, then monthly
* Avelumab will be administered intravebously once every 2 weeks Receives: Drug: Palbociclib; Drug: Fulvestrant; Drug: Avelumab |
What is being measured
The primary outcome is the main question the study is designed to answer.
Progression-Free Survival (PFS), According to RECIST v1.1 Criteria (Investigator Assessment)
Progression-Free Survival (PFS), according to RECIST v1.1 criteria (investigator assessment): the time from randomization to the earlier of progression or death due to any cause. Participants alive without disease progression were censored at date of last disease assessment (tumor assessments). The date of progression was the first date that recurrent or progressive disease was objectively documented; if death was the defining event, it must have happened within 2 intervals of the last disease assessment, otherwise PFS was censored at last disease assessment. The length of PFS was calculated as PFS time (months) =[progression/death date(censor date) - randomization date + 1]/30.4375.
Measured: Tumor were assessed every 8 weeks until 24 weeks, then every 12 weeks. The median PFS follow-up time at database lock was 12.1 months (range 1 day to 50.1 months).
Secondary outcomes (2)
Overall Response Rate, According to RECIST v1.1 Criteria (Investigator Assessment)
Objective Response (OR): best overall response of complete response or partial response. Response was primarily evaluated in this study using the criteria proposed by the Response Evaluation Criteria in Solid Tumors (RECIST) guideline (version 1.1). For example, target lesions: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), >=30% decrease in the sum of the longest diameter of target lesions. See RECIST 1.1 manuscript for further details on overall assessment based on target lesions, non-target lesions and new lesions. The Overall Response Rate (with 2-sided 90% CIs) were estimated according to treatment assignment and subgroup.
Measured: Tumor were assessed every 8 weeks until 24 weeks, then every 12 weeks. The median follow-up time for overall response rate at database lock was 12.1 months (range 1 day to 50.1 months).
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability)
The frequency (and %) of patients who are reported as having grade 3-5 treatment-related adverse events were summarized. From starting the first dose of study treatment to 30 days (90 days for arm C) after last dose administration of study treatment or study discontinuation, whichever was earlier. Afterwards only SAEs attributed to study treatment were reported.
Measured: The median follow-up time for adverse event was 5.4 months (range 1.6 months to 51.2 months).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 May 2017
- Study start5 Sep 2017
- Primary completion31 Dec 2022
- Study completion30 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Metastatic Breast CancerStudies of the same condition, open and under way.
- More trials run by Dana-Farber Cancer InstituteThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- 220 participants (actual)
Sponsor and investigators
- Lead sponsor
- Dana-Farber Cancer Institute
- Sponsor type
- University, hospital or other
- Collaborators
- Pfizer
- Responsible party
- Principal investigator, Erica Mayer, MD, MPH, Dana-Farber Cancer Institute
- Investigators
- Erica L Mayer, MD MPH, Principal investigator, Dana-Farber Cancer Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03147287
- Sponsor's protocol ID
- 17-101
- Status last verified
- Aug 2026
- First submitted
- 5 May 2017
- Last updated
- 11 Sep 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Mayer EL, Ren Y, Wagle N, Mahtani R, Ma C, DeMichele A, Cristofanilli M, Meisel J, Miller KD, Abdou Y, Riley EC, Qamar R, Sharma P, Reid S, Sinclair N, Faggen M, Block CC, Ko N, Partridge AH, Chen WY, DeMeo M, Attaya V, Okpoebo A, Alberti J, Liu Y, Gauthier E, Burstein HJ, Regan MM, Tolaney SM. PACE: A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab After Progression on Cyclin-Dependent Kinase 4/6 Inhibitor and Aromatase Inhibitor for Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor-Negative Metastatic Breast Cancer. J Clin Oncol. 2024 Jun 10;42(17):2050-2060. doi: 10.1200/JCO.23.01940. Epub 2024 Mar 21.
PubMed 38513188
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Palbociclib After CDK and Endocrine Therapy (PACE): A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab for Endocrine Pre-treated ER+/HER2- Metastatic Breast Cancer
- ClinicalTrials.gov ID
- NCT03147287
- Acronym / sponsor ID
- 17-101
- Conditions
- Metastatic Breast Cancer
- Keywords
- Breast Cancer
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 220 participants (actual)
- Lead sponsor
- Dana-Farber Cancer InstituteUniversity, hospital or other
- Collaborators
- Pfizer
- Study start
- 5 Sep 2017 (actual)
- Primary completion
- 31 Dec 2022 (actual)
- Study completion
- 30 Dec 2026 (estimated)
- First posted
- 10 May 2017 (actual)
- Results
- Posted 12 Dec 2023
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research study is studying three combinations of drugs as treatments for breast cancer.
The drugs involved in this study are:
- Fulvestrant
- Fulvestrant with Palbociclib
- Fulvestrant with Palbociclib and Avelumab
Detailed description
This research study is a Phase II clinical trial. Phase II clinical trials test the safety and effectiveness of an investigational intervention to learn whether the intervention works in treating a specific disease. "Investigational" means that the intervention is being studied and the researchers are trying to find out more about it- for example, the side effects it may cause, and the activity of a drug, or combination of drugs, against a cancer.
In this research study, the investigators are evaluating the activity of fulvestrant alone, fulvestrant and palbociclib, or fulvestrant, palbociclib, and avelumab combined, in participants with metastatic hormone receptor positive HER2 negative breast cancer that has previously stopped responding to prior palbociclib and endocrine therapy.
The FDA (the U.S. Food and Drug Administration) has approved both palbociclib and fulvestrant as treatment options for this disease, however the use of palbociclib has not been studied in people who have previously been treated with palbociclib. The FDA has not approved avelumab as a treatment for any disease.
Palbociclib is a drug that may stop cancer cells from growing. Palbociclib blocks activity of two closely related enzymes (proteins that help chemical reactions in the body occur), called Cyclin Dependent Kinases 4 and 6 (CDK 4/6). These proteins are part of a pathway, or a sequence of steps, which is known to promote cancer cell growth. Laboratory testing has shown that palbociclib may stop the growth of hormone receptor positive breast cancer. Palbociclib is FDA-approved as therapy for metastatic hormone receptor positive HER2 negative breast cancer in combination with endocrine therapy in the first line setting, and in combination with fulvestrant for pre-treated disease. It is not known whether cancers that have grown despite prior palbociclib treatment are still sensitive to palbociclib.
Endocrine therapy prevents growth of hormone receptor positive breast cancer by blocking stimulation of cancer cells by estrogen. During this study, the endocrine therapy will be fulvestrant. Fulvestrant is a drug that is approved by the FDA for treatment of metastatic hormone receptor positive breast cancer.
The immune system is the body's natural defense against disease. The immune system sends a type of cells called T cells throughout the body to detect and fight infections and diseases-including cancers. One way the immune system controls the activity of T cells is through the PD-1 (programmed cell death protein-1) pathway. However, some cancer cells hide from T-cell attack by taking control of the PD-1 pathway and this stops T cells from attacking cancer cells.
Avelumab is an antibody designed to block the PD-1 pathway and helps the immune system in detecting and fighting cancer cells. An antibody is a protein produced by the body's immune system when it detects harmful substances. Previous studies show that the administration of antibodies which block the PD-1 pathway can lead to tumor destruction.
In the laboratory, adding avelumab to fulvestrant and palbociclib appears to improve effectiveness. It is not known whether this is true in humans
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Fulvestrant | Active comparator | Drug: Fulvestrant-Fulvestrant will be administered in the clinic as two IM injections on Cycle 1 Days 1, 15, then monthly |
| Fulvestrant with Palbociclib | Experimental | Drug: Palbociclib, Drug: Fulvestrant* Palbociclib should be taken orally, once per day for 21 days on a 28 days cyclye * Fulvestrant will be administered in the clinic as two IM injections on Cycle 1 Days 1, 15, then monthly |
| Fulvestrant with Palbociclib and Avelumab | Experimental | Drug: Palbociclib, Drug: Fulvestrant, Drug: Avelumab* Palbociclib should be taken orally, once per day for 21 days on a 28 days cyclye * Fulvestrant will be administered in the clinic as two IM injections on Cycle 1 Days 1, 15, then monthly * Avelumab will be administered intravebously once every 2 weeks |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (42 listed)
- Participants must have histologically confirmed hormone receptor positive (HR+) HER2 negative metastatic or locally recurrent unresectable invasive breast cancer. ER, PR and HER2 measurements should be performed according to institutional guidelines, in a CLIA-approved setting. 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.
- Men and pre- and postmenopausal women are eligible. Ongoing monthly GNRH agonist is required in pre-menopausal women or male participants for at least 4 weeks prior to study entry.
- Participants must have radiological or objective evidence of progression on an endocrine and CDK 4/6 inhibitor regimen in the metastatic setting, and/or relapse/progression during or within 12 months of completion of an endocrine and CDK4/6 inhibitor regimen in the adjuvant setting.
- Participants may have 0-1 prior lines of cytotoxic chemotherapy in the metastatic setting.
- Prior endocrine therapy in the metastatic setting may include any aromatase inhibitor (AI) or tamoxifen, but may not include prior fulvestrant. In the metastatic setting, 1-2 prior lines of endocrine therapy are allowed.
Key exclusion criteria (19 listed)
- Participants who have had endocrine, chemotherapy, and/or biologic therapy within 14 days prior to entering the study or those who have not recovered from any prior treatment-related toxicities (must recover to no more than grade 1. Alopecia, sensory neuropathy Grade ≤ 2, or other Grade ≤ 2 toxicity not constituting a safety risk based on investigator's judgment are acceptable).
- Participants who are receiving concurrent therapy with other investigational agents.
- Rapidly progressive, symptomatic, visceral spread of disease placing participant at risk of life-threatening complications in the short term.
- Participants with active brain metastases. Stable treated brain metastases are allowed (this includes participants who have documented radiologic stability at least 4 weeks after radiotherapy, and do not require systemic steroids for management of symptoms from CNS metastatic lesions).
- Participants who have discontinued prior palbociclib for toxicity, or have needed more than one dose or schedule reduction for toxicity from prior palbociclib therapy. If a participant required a single dose reduction during prior palbociclib therapy and tolerated it well, for example prior dosing at 100 mg qd 3 weeks on 1 week off schedule, than that dose may be selected for this trial.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PalbociclibAlso: IbrancePalbociclib is a drug that may stop cancer cells from growing | Drug | Fulvestrant with Palbociclib, Fulvestrant with Palbociclib and Avelumab |
| FulvestrantAlso: FaslodexFulvestrant prevents growth of hormone receptor positive breast cancer by blocking stimulation of cancer cells by estrogen | Drug | Fulvestrant, Fulvestrant with Palbociclib, Fulvestrant with Palbociclib and Avelumab |
| AvelumabAlso: BavencioAvelumab is an antibody designed to block the PD-1 pathway and helps the immune system in detecting and fighting cancer cells | Drug | Fulvestrant with Palbociclib and Avelumab |
Primary outcome
Progression-Free Survival (PFS), According to RECIST v1.1 Criteria (Investigator Assessment)
Time frame: Tumor were assessed every 8 weeks until 24 weeks, then every 12 weeks. The median PFS follow-up time at database lock was 12.1 months (range 1 day to 50.1 months).
Progression-Free Survival (PFS), according to RECIST v1.1 criteria (investigator assessment): the time from randomization to the earlier of progression or death due to any cause. Participants alive without disease progression were censored at date of last disease assessment (tumor assessments). The date of progression was the first date that recurrent or progressive disease was objectively documented; if death was the defining event, it must have happened within 2 intervals of the last disease assessment, otherwise PFS was censored at last disease assessment. The length of PFS was calculated as PFS time (months) =[progression/death date(censor date) - randomization date + 1]/30.4375.
2 secondary outcomes
Overall Response Rate, According to RECIST v1.1 Criteria (Investigator Assessment)
Time frame: Tumor were assessed every 8 weeks until 24 weeks, then every 12 weeks. The median follow-up time for overall response rate at database lock was 12.1 months (range 1 day to 50.1 months).
Incidence of Treatment-Emergent Adverse Events [Safety and Tolerability)
Time frame: The median follow-up time for adverse event was 5.4 months (range 1.6 months to 51.2 months).
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 38513188Mayer EL, Ren Y, Wagle N, Mahtani R, Ma C, DeMichele A, Cristofanilli M, Meisel J, Miller KD, Abdou Y, Riley EC, Qamar R, Sharma P, Reid S, Sinclair N, Faggen M, Block CC, Ko N, Partridge AH, Chen WY, DeMeo M, Attaya V, Okpoebo A, Alberti J, Liu Y, Gauthier E, Burstein HJ, Regan MM, Tolaney SM. PACE: A Randomized Phase II Study of Fulvestrant, Palbociclib, and Avelumab After Progression on Cyclin-Dependent Kinase 4/6 Inhibitor and Aromatase Inhibitor for Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor-Negative Metastatic Breast Cancer. J Clin Oncol. 2024 Jun 10;42(17):2050-2060. doi: 10.1200/JCO.23.01940. Epub 2024 Mar 21.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Erica L Mayer, MD MPH principal investigator
Dana-Farber Cancer Institute
22 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Palbociclib, Fulvestrant and Avelumab in people with Metastatic Breast Cancer, run by Dana-Farber Cancer Institute at 22 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 42 inclusion and 19 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 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 22 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 12 Dec 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?
Progression-Free Survival (PFS), According to RECIST v1.1 Criteria (Investigator Assessment) (time frame: Tumor were assessed every 8 weeks until 24 weeks, then every 12 weeks. The median PFS follow-up time at database lock was 12.1 months (range 1 day to 50.1 months).). 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 NCT03147287, which also lists 1 linked publication.
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 11 Sep 2026.