Statement: the percentage of participants achieving complete response (CR) or partial response (PR) was much lower in the HER2-positive group in the primary trial,than in the ER+ and/or PR+ group.
Primary_evidence: Outcome Measurement:    CNS Objective Response Rate (ORR)   The central nervous system (CNS) ORR was defined as the percentage of participants achieving complete response (CR) or partial response (PR) based on RECIST 1.1 criteria in the evaluation CNS lesions on treatment: CR is complete disappearance of all target lesions and PR is at least a 30% decrease in the sum of longest diameter (LD) of target lesions, taking as reference baseline sum LD. PR or better overall response assumes at a minimum incomplete response/stable disease (SD) for the evaluation of non-target lesions and absence of new lesions.   Time frame: Disease assessments occurred every 6 cycles. Patients with stable or responsive disease after completion of 6 cycles could reduce frequency of assessments to every 3 cycles. Response was evaluated up to 25 months. Results 1:    Arm/Group Title: Cohort 1 - Cabozantinib, Trastuzumab for HER2+   Arm/Group Description: HER2-positive   Cabozantinib- orally administered daily per treatment cycle   Trastuzumab- IV administered once per cycle   MRI- Baseline, Cycle 2 Day 1, and every 2 cycles   Magnetic Resonance Angiography (MRA ), Baseline, Cycle 2 Day 1,   Cabozantinib: One, 60 mg tablet daily of each 21 day cycle. Number of Cycles: until progression or unacceptable toxicity develops.   Trastuzumab: For HER2-Positive participants only. Administered by IV on day 1 of each 21 day cycle. Number of Cycles: until progression or unacceptable toxicity develops.   Overall Number of Participants Analyzed: 21   Measure Type: Number   Unit of Measure: percentage of participants  5        (.2 to 24) Results 2:    Arm/Group Title: Cohort 2 - Cabozantinib for ER+ and/or PR+   Arm/Group Description: Hormone receptor-positive (ER+ and/or PR+)   Cabozantinib- orally administered daily per treatment cycle   MRI- Baseline, Cycle 2 Day 1, and every 2 cycles   Magnetic Resonance Angiography (MRA ), Baseline, Cycle 2 Day 1,   Cabozantinib: One, 60 mg tablet daily of each 21 day cycle. Number of Cycles: until progression or unacceptable toxicity develops.   Overall Number of Participants Analyzed: 7   Measure Type: Number   Unit of Measure: percentage of participants  14        (.4 to 58)