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A Study to Compare the Safety and Efficacy of an Aromatase Inhibitor in Combination With Lapatinib, Trastuzumab or Both for the Treatment of Hormone Receptor Positive, HER2+ Metastatic Breast Cancer

A Phase III Trial to Compare the Safety and Efficacy of Lapatinib Plus Trastuzumab Plus an Aromatase Inhibitor (AI) vs. Trastuzumab Plus an AI vs. Lapatinib Plus an AI as 1st- or 2nd- Line Therapy in Postmenopausal Subjects With Hormone Receptor+, HER2-positive Metastatic Breast Cancer (MBC) Who Received Prior Trastuzumab and Endocrine Therapies

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01160211
Enrollment
369
Registered
2010-07-12
Start date
2011-05-05
Completion date
2022-06-06
Last updated
2025-03-07

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

Conditions

Neoplasms, Breast

Keywords

1st line MBC, MBC, hormone receptor positive, lapatinib, trastuzumab, HER2 positive, aromatase inhibitor

Brief summary

A study to compare the safety and efficacy of an aromatase inhibitor in combination with lapatinib, trastuzumab or both for the treatment of hormone receptor positive, HER2+ metastatic breast cancer (MBC).

Detailed description

This Phase III, multicenter, open-label study randomized subjects to one of the three treatment arms: 1. Treatment group A: lapatinib 1000 mg PO once daily + trastuzumab (loading dose of 8 mg/kg) followed by the maintenance dose of 6 mg/kg IV q3weeks + an AI (either letrozole, anastrozole, or exemestane) of Investigator's choice PO once daily. 2. Treatment group B: trastuzumab (loading dose of 8 mg/kg) followed by maintenance dose of 6 mg/kg IV q3weeks + an AI (either letrozole, anastrozole, or exemestane) of Investigator's choice PO once daily. 3. Treatment group C: lapatinib 1500 mg PO once daily + an AI (either letrozole, anastrozole, or exemestane) of Investigator's choice PO once daily. Treatment continued until disease progression, death, or unacceptable toxicities, whichever came first. Subjects who discontinued study treatment for reasons other than disease progression were followed-up every 12 weeks until disease progression or death, until the start of post-study treatment anti-cancer therapy (including radiotherapy and surgery), withdrawal of consent, or lost to follow-up, whichever came first.

Interventions

DRUGLapatinib

1000 mg by mouth once a day

DRUGTrastuzumab

Loading dose of 8 mg/kg IV followed by the maintenance dose of 6 mg/kg IV every 3 weeks (q3weeks)

DRUGAromatase Inhibitor

Aromatase inhibitor (either letrozole, anastrozole, or exemestane) of investigator's choice given by mouth once daily

Sponsors

GlaxoSmithKline
CollaboratorINDUSTRY
Novartis Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

Subjects eligible for enrollment in the study must meet all of the following criteria: 1. Signed written informed consent. In Korea and Japan, subjects between \>=18 and \<20 years of age must also have a legal representative sign the written informed consent. 2. Post-menopausal female subjects \>=18 years of age. Post-menopausal as defined by any of the following: * Subjects at least 60 years of age. * Subjects under 60 years of age and amenorrhic for at least 12 consecutive months AND follicle-stimulating hormone (FSH) and estradiol levels in postmenopausal range (utilizing ranges from the local laboratory facility). * Prior bilateral oophorectomy. * Prior radiation castration with amenorrhea for at least 6 months 3. Subjects must have a history of histologically confirmed breast cancer, with a clinically confirmed diagnosis of metastatic disease \[confirmed by histology, cytology or other clinical means (e.g. CT, MRI)\]. Subjects may have either measurable or non-measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) 4. Tumors that are ER+ and/or PgR+ by local laboratory 5. Documentation of HER2 overexpression or gene amplification, in the invasive component of either the primary tumor or metastatic disease site as defined as: * 3+ by Immunohistochemistry (IHC) and/or * HER2/neu gene amplification by fluorescence, chromogenic or silver in situ hybridization \[FISH, CISH or SISH; \>6 HER2/neu gene copies per nucleus or a FISH, CISH or SISH test ratio (HER2 gene copies to chromosome 17 signals) of ≥2.0\] 6. Subject must have received at least one prior regimen containing trastuzumab in combination with chemotherapy for breast cancer:. * Subject has ONLY received prior trastuzumab in combination with chemotherapy as neoadjuvant and/or adjuvant treatment. OR * Subject has received ONE prior trastuzumab-containing regimen for metastatic disease (and has progressed), and may or may not have received prior trastuzumab in combination with chemotherapy as neoadjuvant and/or adjuvant treatment. 7. Subject must have received prior endocrine therapy (such as aromatase inhibitors or selective estrogen receptor modulators). 8. Subjects who have a life expectancy of \> 6 months as assessed by the treating investigator 9\. Subjects must have baseline Left Ventricular Ejection Fraction (LVEF) ≥50% measured by echocardiography (ECHO) or multi-gated acquisition scan (MUGA) 10. Subject must have an ECOG performance status of 0-1 11. All prior treatment related toxicities must be CTCAE (Version 4.0) ≤ Grade 1 at the time of randomization 12. Completion of screening assessments 13. Adequate baseline organ function. 14. Subjects must meet all of the following criteria: * QTc \<450msec or * QTc \<480msec for subjects with bundle branch block The QTc is the QT interval corrected for heart rate according to either Bazett's formula (QTcB) or to Fridericia's formula (QTcF), machine or manual over read, for males and females. The specific formula that will be used in a protocol should be determined prior to initiation of the study, and the formula used to determine inclusion and discontinuation should be the same throughout the study. The QTc should be based on single or averaged QTc values of triplicate electrocardiograms (ECGs) obtained over a brief recording period

Exclusion criteria

1. History of another malignancy. Exception: Subjects who have been disease-free for 5 years, or subjects with a history of completely resected non-melanoma skin cancer or successfully treated in situ carcinoma are eligible. 2. Subjects with extensive symptomatic visceral disease including hepatic involvement and pulmonary lymphangitic spread of tumor, or the disease is considered by the investigator to be rapidly progressing or life threatening (subjects who are intended for chemotherapy) 3. Serious cardiac illness or medical condition including but not confined to: * Uncontrolled arrhythmias * Uncontrolled or symptomatic angina * History of congestive heart failure (CHF) * Documented myocardial infarction \<6 months from study entry 4. Known history of, or clinical evidence of, central nervous system (CNS) metastases or leptomeningeal carcinomatosis 5. Have acute or currently active/requiring anti-viral therapy hepatic or biliary disease (with the exception of subjects with Gilbert's syndrome, asymptomatic gallstones, liver metastases or stable chronic liver disease per investigator assessment) 6. Have a concurrent disease or condition that may interfere with study participation, or any serious medical disorder that would interfere with the subject's safety (for example, active or uncontrolled infection or any psychiatric condition prohibiting understanding or rendering of informed consent) 7. Have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels 8. Have a known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to any of the study agents or their excipients that, in the opinion of the Investigator or GSK medical monitor, contraindicates their participation 9. Any prohibited medication. 10. Administration of an investigational drug within 30 days or 5 half-lives, whichever is longer, preceding the first dose of study treatment.

Design outcomes

Primary

MeasureTime frameDescription
Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)From date of randomization until date of progression or date of death from any cause, whichever comes first, assessed up approximately 5 yearsThe Number of Participants with Progression free survival (PFS) events in the Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) arm vs. Trastuzumab + Aromatase Inhibitor (AI) arm was based on assessments by the Investigator.
Median Kaplan Meier Estimates for PFS in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)From date of randomization until date of progression or date of death from any cause, whichever comes first, assessed up approximately 5 yearsProgression free survival (PFS) was defined as the interval of time between the date of randomization and the earliest date of disease progression (with radiological evidence) or death from any cause, or to the date of censor. Disease progression was based on assessments by the Investigator.

Secondary

MeasureTime frameDescription
Overall Response Rate (ORR)Up approximately 11 yearsOverall Response Rate (ORR) was defined as the proportion of participants achieving either a Complete Response (CR) or Partial Response (PR). The ORR was calculated from the Investigator's assessment of response based on RECIST 1.1. Subjects with an unknown or missing response were treated as non-responders; i.e. they were included in the denominator when calculating the percentages. Subjects who do not have measurable disease contributed to the Response Rate based analyses, for the evaluation of CR, SD and PD.
Clinical Benefit Rate (CBR)Up approximately 11 yearsClinical Benefit Rate (CBR) was defined as the percentage of patients with evidence of Complete Response (CR), Partial Response (PR), or maintaining Stable Disease (SD) for at least 6 months while on study, according to the investigator assessment of response per RECIST 1.1 criteria.
Progression Free Survival (PFS)From date of randomization until date of progression or date of death from any cause, whichever comes first, assessed up approximately 11 yearsProgression free survival (PFS) was defined as the interval of time between the date of randomization and the earliest date of disease progression (with radiological evidence) or death from any cause, or to the date of censor. Disease progression was based on assessments by the Investigator.
Duration of Response (DoR)From first documented evidence of CR or PR (the response prior to confirmation) until time of documented disease progression or death due to any cause, whichever comes first, assessed up approximately 11 yearsDuration of Response (DOR) was defined as the duration between the date of first documented Complete Response (CR) or Partial Response (PR) and the date of first documented sign of Progressive Disease or Death, or to the date of censor.
Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentDay 1 (pre-dose), up approximately 11 yearsQuality of life was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire. It is a 37-item (27 general questions and 10 breast cancer specific questions) self-reporting instrument consisting of 5 dimensions: physical well-being (PWB), social well-being (SWB), emotional well-being (EWB), functional well-being (FWB), and a breast cancer subscale (BCS). The followings were the score ranges for each self-reporting subscale: • PWB : 0-28 • SWB : 0-28 • EWB : 0-24 • FWB : 0-28 • BCS : 0-40 FACT-B Total Outcome Index (TOI) = PWB + FWB + BCS (range:0 - 96) FACT-B Total Score = PWB + SWB + EWB + FWB + BCS (range:0-148) FACT-G Total Score = PWB + SWB + EWB + FWB (range:0-108). For all the FACIT scales and symptom indices, the higher the score the better QoL
Time to ResponseFrom date of randomization until the earliest date of Complete Response (CR) or Partial Response (PR), assessed up approximately 11 yearsTime to Response (TTR) was defined as the time from randomization to the earliest date of Complete Response (CR) or Partial Response (PR)
Overall Survival (OS)From date of randomization until date of death from any cause, assessed up approximately 11 yearsThe Number of Participants with Overall Survival (OS) events was based on assessments by the Investigator.

Countries

Argentina, Australia, Belgium, Brazil, Bulgaria, China, Croatia, France, Germany, Greece, Hong Kong, Hungary, India, Israel, Italy, Japan, Peru, Poland, Portugal, Russia, Serbia, Singapore, South Korea, Spain, Taiwan, Turkey (Türkiye), Ukraine, United Kingdom, United States

Participant flow

Recruitment details

This study was conducted at 113 centers in 29 countries worldwide (Argentina, Australia, Belgium, Brazil, Bulgaria, China, Croatia, France, Germany, Greece, Hong Kong, Hungary, India, Israel, Italy, Japan, Peru, Poland, Portugal, Republic of Korea, Russia, Serbia, Singapore, Spain, Taiwan, Turkey, UK, Ukraine and USA)

Participants by arm

ArmCount
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)
Lapatinib 1000 mg PO once daily + Trastuzumab (loading dose of 8 mg/kg) followed by the maintenance dose of 6 mg/kg IV every 3 weeks (q3weeks) + an Aromatase Inhibitor (AI) of Investigator's choice PO once daily.
124
Lapatinib + Aromatase Inhibitor (AI)
Lapatinib 1500 mg PO once daily + an Aromatase Inhibitor (AI) of Investigator's choice PO once daily.
123
Trastuzumab + Aromatase Inhibitor (AI)
Trastuzumab (loading dose of 8 mg/kg) followed by maintenance dose of 6 mg/kg IV every 3 weeks (q3weeks) + an Aromatase Inhibitor (AI) of Investigator's choice PO once daily.
122
Total369

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Overall StudyData unavailable due to regulatory issues202
Overall StudyLost to Follow-up484
Overall StudyPhysician Decision100
Overall StudySubject Reached Protocol-Defined Stopping Criteria494959
Overall StudyWithdrawal by Subject422

Baseline characteristics

CharacteristicLapatinib + Trastuzumab + Aromatase Inhibitor (AI)Lapatinib + Aromatase Inhibitor (AI)Trastuzumab + Aromatase Inhibitor (AI)Total
Age, Continuous56.9 Years
STANDARD_DEVIATION 11.15
57.1 Years
STANDARD_DEVIATION 9.98
54.9 Years
STANDARD_DEVIATION 10.1
56.3 Years
STANDARD_DEVIATION 10.45
Race (NIH/OMB)
American Indian or Alaska Native
1 Participants1 Participants1 Participants3 Participants
Race (NIH/OMB)
Asian
31 Participants31 Participants32 Participants94 Participants
Race (NIH/OMB)
Black or African American
3 Participants4 Participants3 Participants10 Participants
Race (NIH/OMB)
More than one race
0 Participants2 Participants2 Participants4 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
89 Participants85 Participants84 Participants258 Participants
Sex: Female, Male
Female
124 Participants123 Participants122 Participants369 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
EG003
affected / at risk
EG004
affected / at risk
EG005
affected / at risk
deaths
Total, all-cause mortality
5 / 1248 / 1235 / 12233 / 11837 / 11434 / 116
other
Total, other adverse events
113 / 123107 / 12386 / 1210 / 00 / 00 / 0
serious
Total, serious adverse events
27 / 12323 / 12314 / 1210 / 00 / 00 / 0

Outcome results

Primary

Median Kaplan Meier Estimates for PFS in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)

Progression free survival (PFS) was defined as the interval of time between the date of randomization and the earliest date of disease progression (with radiological evidence) or death from any cause, or to the date of censor. Disease progression was based on assessments by the Investigator.

Time frame: From date of randomization until date of progression or date of death from any cause, whichever comes first, assessed up approximately 5 years

Population: Participants in the Intent-to-Treat (ITT) Population with available data for the outcome measure.

ArmMeasureValue (MEDIAN)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Median Kaplan Meier Estimates for PFS in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)11.0 Months
Trastuzumab + Aromatase Inhibitor (AI)Median Kaplan Meier Estimates for PFS in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)5.6 Months
Primary

Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)

The Number of Participants with Progression free survival (PFS) events in the Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) arm vs. Trastuzumab + Aromatase Inhibitor (AI) arm was based on assessments by the Investigator.

Time frame: From date of randomization until date of progression or date of death from any cause, whichever comes first, assessed up approximately 5 years

Population: Participants in the Intent-to-Treat (ITT) Population with available data for the outcome measure.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)Disease progression or died (event)62 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)Censored, follow-up for disease progression ended7 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)Censored, f/p for disease progression ongoing51 Participants
Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)Disease progression or died (event)75 Participants
Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)Censored, follow-up for disease progression ended3 Participants
Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS) Events in Lapatinib + Trastuzumab + Aromatase Inhibitor (AI) vs. Trastuzumab + Aromatase Inhibitor (AI)Censored, f/p for disease progression ongoing39 Participants
Comparison: Null hypothesis H0: λ ≥ 1 or to reject it in favor of the alternative hypothesis HA: λ \<1, where λ is the hazard ratio (HR) between Treatment Group A and Treatment Group B for progression-free survival.p-value: 0.006395% CI: [0.45, 0.88]Log Rank
Secondary

Clinical Benefit Rate (CBR)

Clinical Benefit Rate (CBR) was defined as the percentage of patients with evidence of Complete Response (CR), Partial Response (PR), or maintaining Stable Disease (SD) for at least 6 months while on study, according to the investigator assessment of response per RECIST 1.1 criteria.

Time frame: Up approximately 11 years

Population: Intent-to-Treat (ITT) Population

ArmMeasureValue (NUMBER)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Clinical Benefit Rate (CBR)51.6 Percentage of Participants
Trastuzumab + Aromatase Inhibitor (AI)Clinical Benefit Rate (CBR)43.1 Percentage of Participants
Trastuzumab + Aromatase Inhibitor (AI)Clinical Benefit Rate (CBR)34.4 Percentage of Participants
Secondary

Duration of Response (DoR)

Duration of Response (DOR) was defined as the duration between the date of first documented Complete Response (CR) or Partial Response (PR) and the date of first documented sign of Progressive Disease or Death, or to the date of censor.

Time frame: From first documented evidence of CR or PR (the response prior to confirmation) until time of documented disease progression or death due to any cause, whichever comes first, assessed up approximately 11 years

Population: Intent-to-Treat (ITT) Population. Only participants achieving either a confirmed complete response (CR) or partial response (PR)

ArmMeasureValue (MEDIAN)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Duration of Response (DoR)22.5 Months
Trastuzumab + Aromatase Inhibitor (AI)Duration of Response (DoR)11.1 Months
Trastuzumab + Aromatase Inhibitor (AI)Duration of Response (DoR)11.8 Months
Secondary

Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment Assessment

Quality of life was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire. It is a 37-item (27 general questions and 10 breast cancer specific questions) self-reporting instrument consisting of 5 dimensions: physical well-being (PWB), social well-being (SWB), emotional well-being (EWB), functional well-being (FWB), and a breast cancer subscale (BCS). The followings were the score ranges for each self-reporting subscale: • PWB : 0-28 • SWB : 0-28 • EWB : 0-24 • FWB : 0-28 • BCS : 0-40 FACT-B Total Outcome Index (TOI) = PWB + FWB + BCS (range:0 - 96) FACT-B Total Score = PWB + SWB + EWB + FWB + BCS (range:0-148) FACT-G Total Score = PWB + SWB + EWB + FWB (range:0-108). For all the FACIT scales and symptom indices, the higher the score the better QoL

Time frame: Day 1 (pre-dose), up approximately 11 years

Population: Participants in the Intent-to-Treat (ITT) Population with available data for the outcome measure.

ArmMeasureGroupValue (LEAST_SQUARES_MEAN)Dispersion
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-B total score-4.2 score on a scaleStandard Error 1.48
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-G total score-4.3 score on a scaleStandard Error 1.22
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-B trial outcome Index (TOI)-3.3 score on a scaleStandard Error 1.05
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentPhysical well-being (PWB)-2.0 score on a scaleStandard Error 0.48
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentSocial family wellbeing (SWB)-0.5 score on a scaleStandard Error 0.5
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentEmotional wellbeing (EWB)-0.4 score on a scaleStandard Error 0.4
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFunctional wellbeing (FWB)-1.3 score on a scaleStandard Error 0.45
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentBreast cancer subscale (BCS)0.0 score on a scaleStandard Error 0.47
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-B trial outcome Index (TOI)-4.2 score on a scaleStandard Error 1.07
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFunctional wellbeing (FWB)-1.7 score on a scaleStandard Error 0.46
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentPhysical well-being (PWB)-2.1 score on a scaleStandard Error 0.49
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentSocial family wellbeing (SWB)-1.5 score on a scaleStandard Error 0.5
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentEmotional wellbeing (EWB)-0.6 score on a scaleStandard Error 0.4
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-B total score-6.3 score on a scaleStandard Error 1.51
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-G total score-5.9 score on a scaleStandard Error 1.24
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentBreast cancer subscale (BCS)-0.5 score on a scaleStandard Error 0.47
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-B trial outcome Index (TOI)-0.6 score on a scaleStandard Error 1.07
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-G total score-2.8 score on a scaleStandard Error 1.24
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFACT-B total score-2.4 score on a scaleStandard Error 1.51
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentPhysical well-being (PWB)-0.5 score on a scaleStandard Error 0.49
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentFunctional wellbeing (FWB)-0.3 score on a scaleStandard Error 0.46
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentEmotional wellbeing (EWB)-1.0 score on a scaleStandard Error 0.41
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentSocial family wellbeing (SWB)-0.9 score on a scaleStandard Error 0.51
Trastuzumab + Aromatase Inhibitor (AI)Mean Change in the Quality of Life (QoL) Status Relative to Baseline FACT-B Overall and Subscale Scores at Last On Treatment AssessmentBreast cancer subscale (BCS)0.4 score on a scaleStandard Error 0.48
Comparison: FACT-B total score95% CI: [-5.95, 2.36]
Comparison: FACT-B total score95% CI: [-8.09, 0.29]
Comparison: FACT-G total score95% CI: [-4.92, 1.92]
Comparison: FACT-G total score95% CI: [-6.55, 0.34]
Comparison: FACT-B trial outcome index (TOI)95% CI: [-5.66, 0.25]
Comparison: FACT-B trial outcome index (TOI)95% CI: [-6.59, -0.64]
Comparison: Physical well-being (PWB)95% CI: [-2.82, -0.11]
Comparison: Physical well-being (PWB)95% CI: [-2.9, -0.18]
Comparison: Social family wellbeing (SWB)95% CI: [-1.01, 1.79]
Comparison: Social family wellbeing (SWB)95% CI: [-1.96, 0.86]
Comparison: Emotional wellbeing (EWB)95% CI: [-0.57, 1.66]
Comparison: Emotional wellbeing (EWB)95% CI: [-0.72, 1.53]
Comparison: Functional wellbeing (FWB)95% CI: [-2.26, 0.28]
Comparison: Functional wellbeing (FWB)95% CI: [-2.6, -0.04]
Comparison: Breast cancer subscale (BCS)95% CI: [-1.66, 0.95]
Comparison: Breast cancer subscale (BCS)95% CI: [-2.14, 0.48]
Secondary

Overall Response Rate (ORR)

Overall Response Rate (ORR) was defined as the proportion of participants achieving either a Complete Response (CR) or Partial Response (PR). The ORR was calculated from the Investigator's assessment of response based on RECIST 1.1. Subjects with an unknown or missing response were treated as non-responders; i.e. they were included in the denominator when calculating the percentages. Subjects who do not have measurable disease contributed to the Response Rate based analyses, for the evaluation of CR, SD and PD.

Time frame: Up approximately 11 years

Population: Intent-to-Treat (ITT) Population.

ArmMeasureValue (NUMBER)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Overall Response Rate (ORR)32.3 Percentage of Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Response Rate (ORR)22.8 Percentage of Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Response Rate (ORR)17.2 Percentage of Participants
Secondary

Overall Survival (OS)

The Number of Participants with Overall Survival (OS) events was based on assessments by the Investigator.

Time frame: From date of randomization until date of death from any cause, assessed up approximately 11 years

Population: Intent-to-Treat (ITT) Population

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Censored, follow-up ended86 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Death38 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Censored, follow-up ongoing0 Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Censored, follow-up ended78 Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Death45 Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Censored, follow-up ongoing0 Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Death39 Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Censored, follow-up ongoing0 Participants
Trastuzumab + Aromatase Inhibitor (AI)Overall Survival (OS)Censored, follow-up ended83 Participants
Secondary

Progression Free Survival (PFS)

Progression free survival (PFS) was defined as the interval of time between the date of randomization and the earliest date of disease progression (with radiological evidence) or death from any cause, or to the date of censor. Disease progression was based on assessments by the Investigator.

Time frame: From date of randomization until date of progression or date of death from any cause, whichever comes first, assessed up approximately 11 years

Population: Intent-to-Treat (ITT) Population

ArmMeasureValue (MEDIAN)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS)11.1 Months
Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS)8.3 Months
Trastuzumab + Aromatase Inhibitor (AI)Progression Free Survival (PFS)5.7 Months
95% CI: [0.44, 0.79]
95% CI: [0.66, 1.15]
95% CI: [0.51, 0.92]
Secondary

Time to Response

Time to Response (TTR) was defined as the time from randomization to the earliest date of Complete Response (CR) or Partial Response (PR)

Time frame: From date of randomization until the earliest date of Complete Response (CR) or Partial Response (PR), assessed up approximately 11 years

Population: Intent-to-Treat (ITT) Population. Only participants achieving either a confirmed complete response (CR) or partial response (PR)

ArmMeasureValue (MEDIAN)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)Time to Response85.0 Days
Trastuzumab + Aromatase Inhibitor (AI)Time to Response86.5 Days
Trastuzumab + Aromatase Inhibitor (AI)Time to Response86.0 Days
Post Hoc

All Collected Deaths

Pre-treatment deaths were collected from day of participant's informed consent to the day before first dose of study medication. On-treatment deaths were collected from first dose of study medication to 30 days after last dose of study medication (on-treatment), up to approximately 131 months. Deaths were collected in the post treatment survival follow up from 31 days after last dose of study medication until the end of the study, up to approximately 132 months.

Time frame: Pre-treatment deaths: Up to 28 days prior to treatment. On-treatment deaths: Up to 131 months. Post-treatment deaths: up to 132 months.

Population: Intent-to-Treat (ITT) Population.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsPre-treatment deaths0 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsAll deaths38 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsPost-treatment deaths33 Participants
Lapatinib + Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsOn-treatment deaths5 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsPost-treatment deaths37 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsOn-treatment deaths8 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsAll deaths45 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsPre-treatment deaths0 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsAll deaths39 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsPre-treatment deaths0 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsOn-treatment deaths5 Participants
Trastuzumab + Aromatase Inhibitor (AI)All Collected DeathsPost-treatment deaths34 Participants

Source: ClinicalTrials.gov · Data processed: Mar 10, 2026