Neoplasms, Breast
Conditions
Keywords
neo-adjuvant, letrozole, lapatinib, primary breast cancer
Brief summary
Evaluate the percentage of clinical objective responses (cOR) in patients with HER2 negative early breast cancer treated with pre operative (neoadjuvant)lapatinib and letrozole
Interventions
DRUGlapatinib
1500 mg administered orally daily
DRUGletrozole
2.5 mg administered orally daily
OTHERplacebo
1500 mg administered orally daily
Sponsors
GlaxoSmithKline
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Histologically confirmed infiltrating primary breast cancer of 2.0 cm or more in largest clinical diameter * ER and/or PgR positive cancer (\> 10% of positive cancer cell assessed by IHC) * Postmenopausal status, defined by at least one of the following: ≥ 60 years of age \< 60 years of age and amenorrheic for ≥ 12 months prior to day 1 \< 60 years of age and amenorrheic for \< 12 months prior to day, or without a uterus: luteinizing hormone (LH) and follicle stimulating hormone (FSH) values within postmenopausal range Prior bilateral oophorectomy Prior radiation castration with amenorrhea for at least 6 months * HER2 negative tumors (IHC 0-2+, or FISH negative) * Availability of tumor tissue suitable for biological and molecular examination before starting primary treatment * Age over 18 years * ECOG PS 0-1 * Normal organ and marrow function as defined below: leukocytes \> 3000/mL absolute neutrophil count \> 1,500/mL platelets \> 100,000/mL total bilirubin within normal institutional limits AST (SGOT)/ALT(SGPT)\< 2.5 X institutional upper limit of normal Creatinine within normal institutional limits * Cardiac ejection fraction within the institutional range of normal as measured by echocardiogram or MUGA scan. * Eligibility of patients receiving medications or substances known to affect, or with the potential to affect the activity or pharmacokinetics of lapatinib will be determined following review of their use by the Principal Investigator. A list of medications and substances known or with the potential to interact with CYP450 isoenzymes is provided * Ability to understand and the willingness to sign a written informed consent document. * Ability to swallow and retain oral medication.
Exclusion criteria
* Stage IIIB, IIIC, and inflammatory breast cancer * Stage IV breast cancer * Contraindication to the treatment with letrozole * Prior treatment with chemotherapy, endocrine therapy or radiotherapy. Prior treatment with EGFR targeting therapies * Treatment with any other investigational agents, or with all herbal (alternative) medicines * History of allergic reactions attributed to compounds of similar chemical or biologic composition to lapatinib * Uncontrolled inter-current 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 * HIV-positive patients receiving combination anti-retroviral therapy * GI tract disease resulting in an inability to take oral medication, malabsorption syndrome, a requirement for IV alimentation, prior surgical procedures affecting absorption, uncontrolled inflammatory GI disease (e.g., Crohn's, ulcerative colitis) * Concomitant requirement for medication classified as CYP3A4 inducers or inhibitors (See section 3.7.4.2 Other concomitant treatments)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants With Clinical Objective Response (cOR) in the Breast, Evaluated by an Independent Radiological Evaluation Monitoring Committee | From Baseline (Day 1) up to 6 months, evaluated every 12 weeks | cOR is defined as the documented evidence of complete response (CR) and partial response (PR) as assessed by ultrasound examination using Response Evaluation Criteria In Solid Tumors (RECIST). CR is defined as the disappearance of all target lesions (TLs) and non-TLs and the appearance of no new lesions (NLs). PR for TLs is defined as a \>=30% decrease in the sum of the longest diameter (LD) of TLs, taking as a reference the Baseline sum LD. For non-TLs, it is defined as the persistence of \>=1 non-TL and no new TLs or non-TLs. |
| Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | From Baseline (Day 1) up to 6 months, evaluated every 12 weeks | Complete clinical response=nodule not detectable; all ultrasound abnormalities detected at diagnosis have disappeared. Partial clinical response=the tumor's longest diameter (LD) is reduced by 50% or more; ultrasound characteristics of the tumor persist. Minimal response=the tumor's LD is reduced by 25%-49%. Stable disease=the tumor's LD is decreased by less than 25% and is increased by no more than 25% from the starting value. Progressive disease=the tumor's LD is increased by more than 25% from the starting value. Participants who were not evaluable did not have data available. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With the Indicated Nodal Status at Surgery | At the point of definitive surgery (up to 6 months after Baseline) | The nodal status of cancer indicates the involvement of lymph nodes in the participant with cancer. N0 indicates no involvement of lymph nodes, and N+ indicates involvement of lymph nodes. |
| Number of Participants With the Indicated Type of Surgery | At the point of definitive surgery (up to 6 months after Baseline 1) | Mastectomy is the medical term for the surgical removal of one or both breasts. Breast-conserving surgery (BCS) involves removing only the affected part of the breast tissue during surgery, as opposed to removal of the entire breast. |
| Percentage of Participants With Conversion From Planned Mastectomy at Baseline to BCS at Surgery | At the point of definitive surgery (up to 6 months after Baseline) | The percentage of participants who were planned to undergo a mastectomy at baseline but later underwent BCS was measured. |
| Percentage of Participants With Pathological Complete Response (pCR) in the Breast and Axillary Nodes, Evaluated Using Miller and Payne Criteria | At the point of definitive surgery (up to 6 months after Baseline) | pCR is defined as the complete absence of infiltrating tumor cells (TCs) in the breast and lymph nodes. Miller and Payne criteria: Grade 1, no change/some alteration to individual malignant cells, but no reduction in overall cellularity; Grade 2, up to a 30% loss in TCs; Grade 3, between an estimated 30% and 90% reduction in TCs; Grade 4, more than a 90% reduction in TCs, only small cluster/dispersed cells remaining; Grade 5, no malignant identifiable cells; carcinoma in the milk ducts may be present. Grades 1 and 2 = No response; Grades 3 and 4= PR; Grade 5 = CR. |
| Mean Left Ventricular Ejection Fraction (LVEF) | Baseline (Day 1), after 12 weeks, and after 24 weeks | Cardiac safety was evaluated as any signs or symptoms of deterioration in LVEF. LVEF is the measurement of how much blood is being pumped out of the left ventricle of the heart (the main pumping chamber) with each contraction. LVEF was evaluated using NCI CTCAE. |
| Time to Treatment Failure From the Start of the Primary Therapy | From Baseline (Day 1) up to study withdrawal (approx. 66 months) | Time to treatment failure is calculated as the interval between the date of randomization and the occurrence of local tumor progression (including ipsilateral \[on the same side\] and controlateral breast tumor progression), distant tumor progression, permanent treatment discontinuation (either for the experimental or conventional treatment arm), or death for any cause. |
| Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | From Baseline (Day 1) up to 6 months (until definitive surgery) | Toxicity was measured in grades (severity of the AE) as per National Cancer Institute Common Toxicity Criteria for Adverse Event (NCI CTCAE) version (v) 3.0. The CTCAE v3.0 displays Grades 1 through 5 with unique clinical descriptions of severity for each AE based on this general guideline: Grade 1, mild; Grade 2, moderate; Grade 3, severe; Grade 4, life-threatening/disabling; Grade 5, death related to the AE. Mucositis is the painful inflammation and ulceration of the mucous membranes lining the digestive tract, and hypertension is high blood pressure. |
| Number of Participants With Breast Tumors Per Pathological Stage at Surgery | At the point of definitive surgery (up to 6 months after Baseline) | Tumors were categorized as follows: T0, no evidence of primary tumor, but carcinoma of the milk ducts, accumulation of abnormal cells in the breast lobules, or Paget disease (cancer condition that appears like a skin disease involving the breast nipple) with no associated tumor mass; T1, tumor was \<=2 centimeters (cm) across; T2, tumor was \>2 cm but \<5 cm across; T3, tumor was \>5 cm across; T4, tumor of any size growing into the chest wall or skin, including inflammatory breast cancer. |
Countries
Italy, Spain
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Letrozole + Placebo Letrozole tablets in the dose of 2.5 milligrams (mg) plus matching placebo were administered orally once daily for 6 months prior to surgery. | 49 |
| Letrozole + Lapatinib Letrozole tablets in the dose of 2.5 mg plus lapatinib ditosylate monohydrate tablets in the dose of 1500 mg were administered orally once daily for 6 months prior to surgery | 43 |
| Total | 92 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Adverse Event | 0 | 2 |
| Overall Study | Disease Progression | 3 | 1 |
| Overall Study | Informed Consent Withdrawn | 1 | 2 |
Baseline characteristics
| Characteristic | Letrozole + Placebo | Letrozole + Lapatinib | Total |
|---|---|---|---|
| Age, Continuous | 70 Years | 70 Years | 70 Years |
| Sex: Female, Male Female | 49 Participants | 43 Participants | 92 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 20 / 49 | 36 / 43 |
| serious Total, serious adverse events | 1 / 49 | 3 / 43 |
Outcome results
Primary
Percentage of Participants With Clinical Objective Response (cOR) in the Breast, Evaluated by an Independent Radiological Evaluation Monitoring Committee
cOR is defined as the documented evidence of complete response (CR) and partial response (PR) as assessed by ultrasound examination using Response Evaluation Criteria In Solid Tumors (RECIST). CR is defined as the disappearance of all target lesions (TLs) and non-TLs and the appearance of no new lesions (NLs). PR for TLs is defined as a \>=30% decrease in the sum of the longest diameter (LD) of TLs, taking as a reference the Baseline sum LD. For non-TLs, it is defined as the persistence of \>=1 non-TL and no new TLs or non-TLs.
Time frame: From Baseline (Day 1) up to 6 months, evaluated every 12 weeks
Population: Intent-to-Treat (ITT) Population: all participants who entered the study and received at least one dose of letrozole. Three participants withdrew consent and were not included in the efficacy analysis.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Letrozole + Placebo | Percentage of Participants With Clinical Objective Response (cOR) in the Breast, Evaluated by an Independent Radiological Evaluation Monitoring Committee | CR | 2 percentage of participants |
| Letrozole + Placebo | Percentage of Participants With Clinical Objective Response (cOR) in the Breast, Evaluated by an Independent Radiological Evaluation Monitoring Committee | PR | 58 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Clinical Objective Response (cOR) in the Breast, Evaluated by an Independent Radiological Evaluation Monitoring Committee | CR | 12 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Clinical Objective Response (cOR) in the Breast, Evaluated by an Independent Radiological Evaluation Monitoring Committee | PR | 54 percentage of participants |
Primary
Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria
Complete clinical response=nodule not detectable; all ultrasound abnormalities detected at diagnosis have disappeared. Partial clinical response=the tumor's longest diameter (LD) is reduced by 50% or more; ultrasound characteristics of the tumor persist. Minimal response=the tumor's LD is reduced by 25%-49%. Stable disease=the tumor's LD is decreased by less than 25% and is increased by no more than 25% from the starting value. Progressive disease=the tumor's LD is increased by more than 25% from the starting value. Participants who were not evaluable did not have data available.
Time frame: From Baseline (Day 1) up to 6 months, evaluated every 12 weeks
Population: ITT Population. Three participants withdrew consent and were not included in the efficacy analysis.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Letrozole + Placebo | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Complete Response | 2 percentage of participants |
| Letrozole + Placebo | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Partial Response | 27 percentage of participants |
| Letrozole + Placebo | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Minimal Response | 40 percentage of participants |
| Letrozole + Placebo | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Stable Disease | 33 percentage of participants |
| Letrozole + Placebo | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Progressive Disease | 6 percentage of participants |
| Letrozole + Placebo | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Not Evaluable | 2 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Progressive Disease | 2 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Complete Response | 12 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Stable Disease | 20 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Partial Response | 34 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Not Evaluable | 7 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Various Responses in the Breast, Evaluated Using Per Protocol Criteria | Minimal Response | 24 percentage of participants |
Secondary
Mean Left Ventricular Ejection Fraction (LVEF)
Cardiac safety was evaluated as any signs or symptoms of deterioration in LVEF. LVEF is the measurement of how much blood is being pumped out of the left ventricle of the heart (the main pumping chamber) with each contraction. LVEF was evaluated using NCI CTCAE.
Time frame: Baseline (Day 1), after 12 weeks, and after 24 weeks
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Group | Value (MEAN) |
|---|---|---|---|
| Letrozole + Placebo | Mean Left Ventricular Ejection Fraction (LVEF) | Baseline | 61 Percent volume |
| Letrozole + Placebo | Mean Left Ventricular Ejection Fraction (LVEF) | After 12 weeks | 62 Percent volume |
| Letrozole + Placebo | Mean Left Ventricular Ejection Fraction (LVEF) | After 24 weeks | 61 Percent volume |
| Letrozole + Lapatinib | Mean Left Ventricular Ejection Fraction (LVEF) | Baseline | 61 Percent volume |
| Letrozole + Lapatinib | Mean Left Ventricular Ejection Fraction (LVEF) | After 12 weeks | 60 Percent volume |
| Letrozole + Lapatinib | Mean Left Ventricular Ejection Fraction (LVEF) | After 24 weeks | 59 Percent volume |
Secondary
Number of Participants With Breast Tumors Per Pathological Stage at Surgery
Tumors were categorized as follows: T0, no evidence of primary tumor, but carcinoma of the milk ducts, accumulation of abnormal cells in the breast lobules, or Paget disease (cancer condition that appears like a skin disease involving the breast nipple) with no associated tumor mass; T1, tumor was \<=2 centimeters (cm) across; T2, tumor was \>2 cm but \<5 cm across; T3, tumor was \>5 cm across; T4, tumor of any size growing into the chest wall or skin, including inflammatory breast cancer.
Time frame: At the point of definitive surgery (up to 6 months after Baseline)
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Letrozole + Placebo | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T1 | 20 participants |
| Letrozole + Placebo | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T3 | 2 participants |
| Letrozole + Placebo | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T2 | 24 participants |
| Letrozole + Placebo | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T4 | 0 participants |
| Letrozole + Placebo | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T0 | 1 participants |
| Letrozole + Lapatinib | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T4 | 2 participants |
| Letrozole + Lapatinib | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T0 | 0 participants |
| Letrozole + Lapatinib | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T1 | 26 participants |
| Letrozole + Lapatinib | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T2 | 12 participants |
| Letrozole + Lapatinib | Number of Participants With Breast Tumors Per Pathological Stage at Surgery | T3 | 2 participants |
Secondary
Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2
Toxicity was measured in grades (severity of the AE) as per National Cancer Institute Common Toxicity Criteria for Adverse Event (NCI CTCAE) version (v) 3.0. The CTCAE v3.0 displays Grades 1 through 5 with unique clinical descriptions of severity for each AE based on this general guideline: Grade 1, mild; Grade 2, moderate; Grade 3, severe; Grade 4, life-threatening/disabling; Grade 5, death related to the AE. Mucositis is the painful inflammation and ulceration of the mucous membranes lining the digestive tract, and hypertension is high blood pressure.
Time frame: From Baseline (Day 1) up to 6 months (until definitive surgery)
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Letrozole + Placebo | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Musculoskeletal pain | 4 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Diarrhea | 2 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Mucositis | 0 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Liver toxicity | 1 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Skin disorders | 1 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Hypertension | 1 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Skin disorders | 18 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Musculoskeletal pain | 2 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Liver toxicity | 4 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Diarrhea | 10 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Hypertension | 2 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Adverse Events With a Classification of >=Grade 2 | Mucositis | 8 participants |
Secondary
Number of Participants With the Indicated Nodal Status at Surgery
The nodal status of cancer indicates the involvement of lymph nodes in the participant with cancer. N0 indicates no involvement of lymph nodes, and N+ indicates involvement of lymph nodes.
Time frame: At the point of definitive surgery (up to 6 months after Baseline)
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Letrozole + Placebo | Number of Participants With the Indicated Nodal Status at Surgery | N0 | 19 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Nodal Status at Surgery | N+ | 28 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Nodal Status at Surgery | N0 | 21 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Nodal Status at Surgery | N+ | 21 participants |
Secondary
Number of Participants With the Indicated Type of Surgery
Mastectomy is the medical term for the surgical removal of one or both breasts. Breast-conserving surgery (BCS) involves removing only the affected part of the breast tissue during surgery, as opposed to removal of the entire breast.
Time frame: At the point of definitive surgery (up to 6 months after Baseline 1)
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Letrozole + Placebo | Number of Participants With the Indicated Type of Surgery | Mastectomy | 13 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Type of Surgery | BCS | 34 participants |
| Letrozole + Placebo | Number of Participants With the Indicated Type of Surgery | Not done | 2 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Type of Surgery | Mastectomy | 15 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Type of Surgery | BCS | 27 participants |
| Letrozole + Lapatinib | Number of Participants With the Indicated Type of Surgery | Not done | 1 participants |
Secondary
Percentage of Participants With Conversion From Planned Mastectomy at Baseline to BCS at Surgery
The percentage of participants who were planned to undergo a mastectomy at baseline but later underwent BCS was measured.
Time frame: At the point of definitive surgery (up to 6 months after Baseline)
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Letrozole + Placebo | Percentage of Participants With Conversion From Planned Mastectomy at Baseline to BCS at Surgery | 56 percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Conversion From Planned Mastectomy at Baseline to BCS at Surgery | 46 percentage of participants |
Secondary
Percentage of Participants With Pathological Complete Response (pCR) in the Breast and Axillary Nodes, Evaluated Using Miller and Payne Criteria
pCR is defined as the complete absence of infiltrating tumor cells (TCs) in the breast and lymph nodes. Miller and Payne criteria: Grade 1, no change/some alteration to individual malignant cells, but no reduction in overall cellularity; Grade 2, up to a 30% loss in TCs; Grade 3, between an estimated 30% and 90% reduction in TCs; Grade 4, more than a 90% reduction in TCs, only small cluster/dispersed cells remaining; Grade 5, no malignant identifiable cells; carcinoma in the milk ducts may be present. Grades 1 and 2 = No response; Grades 3 and 4= PR; Grade 5 = CR.
Time frame: At the point of definitive surgery (up to 6 months after Baseline)
Population: ITT Population
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Letrozole + Placebo | Percentage of Participants With Pathological Complete Response (pCR) in the Breast and Axillary Nodes, Evaluated Using Miller and Payne Criteria | 0 Percentage of participants |
| Letrozole + Lapatinib | Percentage of Participants With Pathological Complete Response (pCR) in the Breast and Axillary Nodes, Evaluated Using Miller and Payne Criteria | 0 Percentage of participants |
Secondary
Time to Treatment Failure From the Start of the Primary Therapy
Time to treatment failure is calculated as the interval between the date of randomization and the occurrence of local tumor progression (including ipsilateral \[on the same side\] and controlateral breast tumor progression), distant tumor progression, permanent treatment discontinuation (either for the experimental or conventional treatment arm), or death for any cause.
Time frame: From Baseline (Day 1) up to study withdrawal (approx. 66 months)
Population: ITT Population. Only those participants contributing data were analyzed.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Letrozole + Placebo | Time to Treatment Failure From the Start of the Primary Therapy | 32.2 Months |
| Letrozole + Lapatinib | Time to Treatment Failure From the Start of the Primary Therapy | 22.2 Months |