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Abraxane® With or Without Mifepristone for Advanced, Glucocorticoid Receptor-Positive, Triple-Negative Breast Cancer

A Randomized, Placebo-Controlled, Double-Blind, Phase II Trial of Nanoparticle Albumin-Bound Paclitaxel (Nab-Paclitaxel, Abraxane®) With or Without Mifepristone for Advanced, Glucocorticoid Receptor-Positive, Triple-Negative Breast Cancer

Status
Active, not recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02788981
Enrollment
29
Registered
2016-06-02
Start date
2017-03-28
Completion date
2026-08-31
Last updated
2025-06-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast Cancer

Keywords

triple-negative breast cancer, advanced breast cancer, nab-paclitaxel, mifepristone, glucocorticoid receptor-positive breast cancer

Brief summary

This is a randomized, placebo-controlled, double-blind, phase II trial of nab-paclitaxel with or without mifepristone for advanced, glucocorticoid receptor-positive, triple-negative breast cancer. A total of 64 patients will receive nab-paclitaxel. Patients will be randomly assigned to either receive placebo or to receive mifepristone daily on the day prior to and day of each dose of nab-paclitaxel. Patients will be enrolled over 12 months and followed for 12 months following completion of study. To expand and follow up on the investigators understanding of a potential pharmacokinetic (PK) interaction between nab-paclitaxel and mifepristone, investigators will perform PK studies in the first 20 patients enrolled at pre-specified PK sites.

Detailed description

Primary Objective: To compare the progression free survival (PFS) of patients treated with nab-paclitaxel + placebo and patients treated with nab-paclitaxel + mifepristone. Secondary Objectives: 1. To correlate percentage glucocorticoid receptor (GR) positivity in the most recent metastatic tumor biopsy (or in primary tumor if only primary tumor is available) with PFS in mifepristone and placebo groups. 2. To perform an exploratory assessment of overall response rate in both groups. 3. To collect information regarding overall survival in both treatment cohorts.

Interventions

DRUGMifepristone

Patients will receive mifepristone 300 mg daily on the day prior to and day of each dose of nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle).

OTHERPlacebo

Patients will receive placebo and nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle).

DRUGNab-Paclitaxel

Patients will either receive placebo and nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle) or patients will receive mifepristone 300 mg daily on the day prior to and day of each dose of nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle). Patients will receive mifepristone and nab-paclitaxel, or placebo and nab-paclitaxel. Not all three.

Sponsors

University of Chicago
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Patients must have histologically or cytologically confirmed breast cancer with stage IV or unresectable stage III disease. 2. Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as ≥20 mm with conventional techniques or as ≥10 mm with spiral CT scan, MRI, or calipers by clinical exam. To be considered pathologically enlarged and measurable, a lymph node must be ≥15 mm in short axis when assessed by CT scan (CT scan slice thickness recommended to be no greater than 5 mm). 3. Triple-negative breast cancer (defined as estrogen receptor (ER) and progesterone receptor (PR) \<10% positive; HER2 0-1+ by immuno-histochemistry (IHC) or fluorescence in situ hybridization (FISH) ratio \<2.0) 4. Patients must have tumor block or slides available for testing, and tumor must be glucocorticoid receptor positive (defined as GR \>10% moderate to strong staining by central lab). A formalin-fixed, paraffin-embedded surgical or core needle biopsy obtained from the primary tumor or from a metastasis and containing viable tumor tissue is required for this evaluation. Fine needle aspirates or other alternative cytology samples are not acceptable. 5. Patients may have received adjuvant chemotherapy and up to two prior chemotherapy for metastatic or locally recurrent disease. No prior nab-paclitaxel or mifepristone therapy for metastatic disease will be allowed. 6. Age ≥ 18 years. Because no dosing or adverse event data are currently available on the use of Nab-Paclitaxel in combination with Mifepristone in patients \< 18 years of age, children are excluded from this study, but will be eligible for future pediatric trials. 7. Eastern Cooperative Oncology Group performance status ≤ 2 (Karnofsky ≥ 60%). 8. Patients must have normal organ and marrow function as defined below * absolute neutrophil count \>1,500 cells/mm3. * platelets ≥100,000/mcL * hemoglobin \> 9.0 g/dL * total bilirubin\< 1.5 mg/dL * alkaline phosphatase \< 2.5 X upper limit of normal (ULN) or \< 5 X ULN if bone mets are present * aspartate aminotransferase (AST) and Alanine transaminase (ALT) \< 2.5 ULN or \< 5 X ULN if liver mets are present * adequate renal function: creatinine ≤ institutional upper limit of normal OR creatinine clearance ≥ 60 mL/min/1.73 m2 for patients with creatinine levels above institutional normal. * international normalized ratio (INR) \< 1.5 9. Females of child-bearing potential (defined as a sexually mature woman who has not undergone hysterectomy, bilateral oophorectomy, or who has not been naturally postmenopausal for at least 24 consecutive months prior to study enrollment) must: * Commit to abstinence from heterosexual contact or agree to use effective contraception without interruption beginning at least 28 days prior to starting protocol therapy and while on study medication. * Have a negative serum pregnancy test result at screening and agree to ongoing pregnancy testing during the study dosing 10. Male subjects must practice true abstinence or agree to use a condom during sexual contact with a pregnant female or a female of childbearing potential while participating in the study, during dose interruptions and for 6 months following protocol discontinuation, even if he has undergone a successful vasectomy. 11. Patients must have \< Grade 2 pre-existing peripheral neuropathy (per CTCAE). 12. Ability to understand and the willingness to sign a written informed consent document.

Exclusion criteria

1. Patients who are receiving any other investigational agents. 2. Patients who have had chemotherapy or radiotherapy within 2 weeks prior to entering the study or those who have not recovered from adverse events due to agents administered more than 4 weeks earlier. 3. Patients with a currently active second malignancy other than non-melanoma skin cancers. Patients are not considered to have a currently active malignancy if they have completed therapy and are free of disease for ≥ 3 years. 4. Patients with known brain metastases will be eligible as long as they have completed radiation to the brain, and have been off of corticosteroid therapy for at least 7 days. 5. History of allergic reactions attributed to compounds of similar chemical or biologic composition to mifepristone or paclitaxel/nab-paclitaxel. Patients with a history of mild infusion reactions with paclitaxel who were able to continue to receive paclitaxel with corticosteroid premedication will be eligible to participate, as these cases were likely related to cremaphor and not paclitaxel. 6. Mifepristone can both inhibit CYP3A4 and induce CYP3A4. Addition of mifepristone to a pre-existing drug regimen may cause a mild and temporary increase in plasma drug concentration of drugs with significant CYP3A4 metabolism. Medications that are strong inducers of CYP3A4 such as carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone, rifabutin, rifampin, rifapentine, St. John's Wort may decrease plasma mifepristone levels. Strong CYP3A4 inhibitor medications are expected to cause the largest increases in plasma mifepristone concentrations. Mifepristone may increase the plasma drug concentration of concomitant medications with metabolism mediated by CYP2C9/CYP2C8. Drugs with the largest increases will be those whose metabolism is largely or solely mediated by CYP2C9/2C8 and include: Non-steroidal Anti-inflammatory drugs (NSAIDs) and warfarin. 7. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. 8. Pregnant women are excluded from this study because Mifepristone is an abortifacient agent with the potential for teratogenic effects. 9. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with Mifepristone, breastfeeding should be discontinued if the mother wishes to participate in this study. 10. HIV-positive patients on combination antiretroviral therapy are ineligible because of the potential for pharmacokinetic interactions with Mifepristone. In addition, these patients are at increased risk of lethal infections when treated with marrow-suppressive therapy. Appropriate studies will be undertaken in patients receiving combination antiretroviral therapy when indicated. 11. No history of long-term use of corticosteroids or concurrent short term use of corticosteroids is allowed.

Design outcomes

Primary

MeasureTime frameDescription
Progression-free Survival (PFS)12 monthsMeasured using the RECIST guideline v1.1

Secondary

MeasureTime frameDescription
Response Rate in Glucocorticoid Receptor (GR) Positivity12 monthsCompare the response rate in GR positivity between the placebo and mifepristone groups using the RECIST guideline v1.1
Response Rate12 monthsMeasured using the RECIST guideline v1.1
Overall Survival24 monthsCollected from date of randomization until death

Countries

United States

Participant flow

Participants by arm

ArmCount
Nab-Paclitaxel+Mifepristone
Patients will receive mifepristone 300 mg daily on the day prior to and day of each dose of nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle) Mifepristone: Patients will receive mifepristone 300 mg daily on the day prior to and day of each dose of nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle). Nab-Paclitaxel: Patients will either receive placebo and nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle) or patients will receive mifepristone 300 mg daily on the day prior to and day of each dose of nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle). Patients will receive mifepristone and nab-paclitaxel, or placebo and nab-paclitaxel. Not all three.
13
Nab-Paclitaxel+Placebo
Patients will receive placebo and nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle) Placebo: Patients will receive placebo and nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle). Nab-Paclitaxel: Patients will either receive placebo and nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle) or patients will receive mifepristone 300 mg daily on the day prior to and day of each dose of nab-paclitaxel (100 mg/m2 on days 1, 8 and 15 of each 28 day cycle). Patients will receive mifepristone and nab-paclitaxel, or placebo and nab-paclitaxel. Not all three.
16
Total29

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyPatient chose to pursue alternative treatment01

Baseline characteristics

CharacteristicNab-Paclitaxel+MifepristoneTotalNab-Paclitaxel+Placebo
Age, Continuous57 years
STANDARD_DEVIATION 13
53 years
STANDARD_DEVIATION 12
49 years
STANDARD_DEVIATION 10
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
1 Participants1 Participants0 Participants
Race (NIH/OMB)
Black or African American
6 Participants11 Participants5 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants3 Participants2 Participants
Race (NIH/OMB)
White
5 Participants14 Participants9 Participants
Region of Enrollment
United States
13 participants29 participants16 participants
Sex: Female, Male
Female
13 Participants29 Participants16 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
12 / 1314 / 15
other
Total, other adverse events
13 / 1312 / 15
serious
Total, serious adverse events
2 / 130 / 15

Outcome results

Primary

Progression-free Survival (PFS)

Measured using the RECIST guideline v1.1

Time frame: 12 months

ArmMeasureValue (MEDIAN)
Nab-Paclitaxel+MifepristoneProgression-free Survival (PFS)3.0 months
Nab-Paclitaxel+PlaceboProgression-free Survival (PFS)3.0 months
Secondary

Overall Survival

Collected from date of randomization until death

Time frame: 24 months

ArmMeasureValue (MEDIAN)
Nab-Paclitaxel+MifepristoneOverall Survival9.0 months
Nab-Paclitaxel+PlaceboOverall Survival6.0 months
Secondary

Response Rate

Measured using the RECIST guideline v1.1

Time frame: 12 months

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Nab-Paclitaxel+MifepristoneResponse RateResponder3 Participants
Nab-Paclitaxel+MifepristoneResponse RateNon-Responder10 Participants
Nab-Paclitaxel+PlaceboResponse RateResponder5 Participants
Nab-Paclitaxel+PlaceboResponse RateNon-Responder8 Participants
Secondary

Response Rate in Glucocorticoid Receptor (GR) Positivity

Compare the response rate in GR positivity between the placebo and mifepristone groups using the RECIST guideline v1.1

Time frame: 12 months

Population: Data on glucocorticoid receptor positivity was not collected.

Source: ClinicalTrials.gov · Data processed: Feb 9, 2026