A Phase 2 interventional study of Cabozantinib and Fulvestrant in Breast Cancer, sponsored by Massachusetts General Hospital. Completed at 4 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-05-25.
Sponsored by Massachusetts General Hospital · Phase 2, Interventional, and Treatment
The study drug cabozantinib works by inhibiting several different proteins which are believed to be involved in breast cancer tumor growth, its ability to spread, and its ability to form new blood vessels. This drug has been used in other research studies and information from those other research studies suggests that this drug may help to prevent cancer growth.
The single agent portion of this study is now closed to accrual. This research study is now examining the efficacy of cabozantinib in combination with fulvestrant for treatment of hormone-receptor-positive breast cancer that has spread to bone.
Cabozantinib will be taken orally once a day in cycles of 28 days (4 weeks). Fulvestrant will be given intramuscularly on days 1 and 15 of cycle 1 and on day 1 of all subsequent cycles.
On Day 1 of each cycle subjects will have the following tests and procedures:
Subjects will also have the following additional tests and procedures:
12,547 studies on the registry are indexed under Breast Neoplasms; 2,892 are open to participants now.
This study's enrollment of 68 is close to the median of 72 across 9,305 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Massachusetts General Hospital is the lead sponsor of 2,537 studies on the registry; 447 are open to participants now.
Of its 214 completed or terminated interventional studies of FDA-regulated products, 161 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Oral cabozantinib therapy daily
Drug: Cabozantinib
Combination therapy with oral cabozantinib daily plus fulvestrant monthly Intramuscularly (IM)
Drug: Cabozantinib · Drug: Fulvestrant
Given orally daily with a starting dose of 40 mg
Also known as: XL184
Given intramuscularly 500 mg on Days 1 and 15 of the first 28 day cycle, then on Day 1 only each cycle after
Also known as: Faslodex
Bone Scan Response Rate
Bone scan response rate will be defined as the percentage of patients experiencing a complete resolution of bone lesions or partial response in the isotope bone scan per Bone Scan Time Point Response Criteria, as defined in the protocol. Complete resolution is defined as the disappearance of all areas of radiotracer uptake attributable to metastatic disease, and a partial response is defined as significant improvement in radiotracer uptake in areas attributable to metastatic disease, but not meeting the criteria for CR.
Time frame: 2 years
Overall Response Rate by RECIST v 1.1
The overall response rate (ORR) is defined as the percentage of patients experiencing a complete response or partial response on PET imaging per mRECIST (modified response evaluation criteria in solid tumors), as defined in the protocol. A complete response is defined as resolution of all areas of FDG uptake attributable to metastatic disease. A partial response is defined as significantly decreased FDG uptake in areas attributable to metastatic disease, but not meeting the criteria for a complete response.
Time frame: 2 years
Overall Survival
Overall Survival (OS) is defined as the difference between the date of a patient's enrollment onto this study until the date of death. Patients who are alive at last contact will be censored for OS at this date.
Time frame: 5 years
Progression Free Survival
Progression Free Survival (PFS) is defined as the difference between the date of a patient's enrollment onto this study until the earlier of the date of progression or the date of death. Patients who are alive and progression-free at last contact will be censored for PFS at this date.
Time frame: 5 years
| Milestone | Cabozantinib | Cabozantinib Plus Fulvestrant |
|---|---|---|
| Started | 55 | 13 |
| Completed | 52 | 13 |
| Not completed | 3 | 0 |
| Withdrew: Withdrawal by subject | 3 | 0 |
Bone scan response rate will be defined as the percentage of patients experiencing a complete resolution of bone lesions or partial response in the isotope bone scan per Bone Scan Time Point Response Criteria, as defined in the protocol. Complete resolution is defined as the disappearance of all areas of radiotracer uptake attributable to metastatic disease, and a partial response is defined as significant improvement in radiotracer uptake in areas attributable to metastatic disease, but not meeting the criteria for CR.
| percentage of participants | Cabozantinib |
|---|---|
| Bone Scan Response Rate | 38.5 (27.1 to 51.0) |
The overall response rate (ORR) is defined as the percentage of patients experiencing a complete response or partial response on PET imaging per mRECIST (modified response evaluation criteria in solid tumors), as defined in the protocol. A complete response is defined as resolution of all areas of FDG uptake attributable to metastatic disease. A partial response is defined as significantly decreased FDG uptake in areas attributable to metastatic disease, but not meeting the criteria for a complete response.
| Participants | Cabozantinib |
|---|---|
| Overall Response Rate by RECIST v 1.1 | 0 |
Overall Survival (OS) is defined as the difference between the date of a patient's enrollment onto this study until the date of death. Patients who are alive at last contact will be censored for OS at this date.
| months | Cabozantinib |
|---|---|
| Overall Survival | 19.6 (18.0 to 26.8) |
Progression Free Survival (PFS) is defined as the difference between the date of a patient's enrollment onto this study until the earlier of the date of progression or the date of death. Patients who are alive and progression-free at last contact will be censored for PFS at this date.
| units on a scale | Cabozantinib |
|---|---|
| Progression Free Survival | 4.3 (2.8 to 5.5) |
Collected over Adverse event reporting will begin from the time of the first dose of study treatment, through the study and until the final study visit (up to 5 years). Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Cabozantinib | 35/52 (67.3%) | 13/52 (25%) | 51/52 (98.1%) |
| Cabozantinib Plus Fulvestrant | 12/13 (92.3%) | 3/13 (23.1%) | 13/13 (100%) |
| Event | Cabozantinib | Cabozantinib Plus Fulvestrant |
|---|---|---|
| Shortness of BreathRespiratory, thoracic and mediastinal disorders | 1/52 | 1/13 |
| DysphoniaRespiratory, thoracic and mediastinal disorders | 0/52 | 1/13 |
| Bilateral pulmonary embolismRespiratory, thoracic and mediastinal disorders | 0/52 | 1/13 |
| Vascular access complicationVascular disorders | 0/52 | 1/13 |
| ColitisGastrointestinal disorders | 0/52 | 1/13 |
| DeathGeneral disorders | 3/52 | 0/13 |
| Urinary Tract InfectionInfections and infestations | 2/52 | 0/13 |
| HyponatremiaMetabolism and nutrition disorders | 2/52 | 0/13 |
| PneumoniaInfections and infestations | 2/52 | 0/13 |
| Pathologic left femur fractureInjury, poisoning and procedural complications | 1/52 | 0/13 |
| Event | Cabozantinib | Cabozantinib Plus Fulvestrant |
|---|---|---|
| FatigueGeneral disorders | 37/52 | 10/13 |
| AnorexiaMetabolism and nutrition disorders | 19/52 | 8/13 |
| Alanine aminotransferase increasedInvestigations | 28/52 | 5/13 |
| Aspartate aminotransferase increasedInvestigations | 28/52 | 5/13 |
| PainGeneral disorders | 17/52 | 7/13 |
| DiarrheaGastrointestinal disorders | 26/52 | 6/13 |
| Palmar-plantar erythrodysesthesia syndromeSkin and subcutaneous tissue disorders | 25/52 | 3/13 |
| NauseaGastrointestinal disorders | 24/52 | 6/13 |
| Gastroesophageal reflux diseaseGastrointestinal disorders | 2/52 | 5/13 |
| HypothyroidismEndocrine disorders | 12/52 | 5/13 |
| Age, Continuous(years) | Cabozantinib | Cabozantinib Plus Fulvestrant | Total |
|---|---|---|---|
| Median | 55 (33 to 79) | 63 (51 to 78) | 56 (33 to 79) |
| Sex: Female, Male(Participants) | Cabozantinib | Cabozantinib Plus Fulvestrant | Total |
|---|---|---|---|
| Female | 55 | 13 | 68 |
| Male | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | Cabozantinib | Cabozantinib Plus Fulvestrant | Total |
|---|---|---|---|
| Hispanic or Latino | 0 | 0 | 0 |
| Not Hispanic or Latino | 44 | 12 | 56 |
| Unknown or Not Reported | 11 | 1 | 12 |
| Race (NIH/OMB)(Participants) | Cabozantinib | Cabozantinib Plus Fulvestrant | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 1 | 0 | 1 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 1 | 1 | 2 |
| White | 45 | 12 | 57 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 8 | 0 | 8 |
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Massachusetts General Hospital