Lapatinib In Combination With Trastuzumab Versus Lapatinib Monotherapy In Subjects With HER2-positive Metastatic Breast Cancer

Phase 3

Completed

Conditions: Neoplasms, Breast

Interventions: Drug: Lapatinib
Biological: Trastuzumab

Registration Number: NCT00320385

Lead Sponsor: GlaxoSmithKline

Brief Summary: This study will evaluate and compare the safety and efficacy of lapatinib in combination with trastuzumab versus lapatinib monotherapy in subjects with HER2-positive metastatic breast cancer.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 296

Inclusion Criteria

Signed informed consent.
Female ≥18 years. Women of childbearing potential must have a negative serum pregnancy test at screening and must use an approved contraceptive method, if appropriate (for example, intrauterine device [IUD], birth control pills, or barrier device) beginning 2 weeks before the first dose of investigational product and for 28 days after the final dose of investigational product.
Metastatic breast cancer, histologically/cytologically confirmed. If the disease is restricted to a solitary lesion, its neoplastic nature must be confirmed by cytology or histology.
Subjects must have stage IV breast cancer whereby their disease has progressed in either the adjuvant or metastatic setting. Prior therapies must include, but are not limited to:
Taxane-containing regimen for at least 4 cycles, or 2 cycles provided disease progression occurred while on taxane.
Anthracycline-containing regimen for at least 4 cycles, or 2 cycles provided disease progression occurred while on anthracycline.
Subjects must have documented progression following at least ONE trastuzumab plus cytotoxic chemotherapy or anti-hormonal regimen in the metastatic setting.
Note: The most recent treatment must have contained trastuzumab, either alone or in combination with other therapy in the metastatic setting, and subjects must have progressed while on this regimen. Progression is defined as either new lesions or a ≥20% increase in the sum of longest diameter (LD) on the progression radiologic scan.
Subjects must have archived tumor tissue available for testing.
Documented amplification of the ErbB2 gene by fluorescence in situ hybridization (FISH) or documented overexpression of the ErbB2 protein by IHC in primary or metastatic tumor tissue. The IHC or FISH amplification may be documented by a local or central laboratory for randomization into the study. Subjects may be randomized on the basis of ErbB2 positivity by IHC 3+ overexpression or FISH amplification.
Lesion eligibility is as follows:
at least one measurable lesion(s) according to Response Evaluation Criteria in Solid Tumors [RECIST; Therasse, 2000], or
bone-only disease.
Note: Tumor lesions which are situated in a previously irradiated field, and have well-defined margins which are located in soft tissue will be defined as measurable disease.
Subjects with stable CNS metastases defined as asymptomatic and off systemic steroids and anticonvulsants for at least 1 month. Treatment with prophylactic anticonvulsants is permitted, unless listed within the Prohibited Medications (Section 8.2).
Radiotherapy if received within 2 weeks prior to initiation of investigational product to a limited area (e.g., palliative treatment for painful disease) other than the sole site of measurable disease is allowed; however, subject must have completed treatment and recovered from all treatment-related toxicities prior to administration of the first dose of investigational product.
With the single exception of prior trastuzumab treatment, all prior chemotherapy, immunotherapy, biologic therapy, or surgery (except for minor surgical procedures) must be discontinued at least 3 weeks prior to the first dose of investigational product. Subjects must have recovered or stabilized sufficiently from treatment-related toxicities prior to administration of the first dose of investigational product.
Bisphosphonate therapy for bone metastases is allowed; however, treatment must be initiated prior to the first dose of investigational product. Prophylactic use of bisphosphonates is permitted only for the treatment of osteoporosis.
ECOG Performance Status of 0 to 2.
Able to swallow and retain oral medication.
Cardiac ejection fraction within institutional range of normal as measured by echocardiogram. MUGA scans will be accepted in cases where an echocardiogram cannot be performed or is inconclusive. Same modality used at baseline must be used for repeat assessments throughout study.
Subject must have adequate organ function as defined in Table 1 :
Table 1 (Definitions for Adequate Hematologic and Hepatic Function)
SYSTEM (LABORATORY VALUES)
Hematologic:
ANC (absolute neutrophil count) (≥ 1x10^9/ L)
Hemoglobin (≥ 9 g / dL)
Platelets (≥75x10^9/ L)
Hepatic
Albumin (≥ 2.5 g / dL)
Serum bilirubin (≤ 2 mg / dL)
AST and ALT (≤ 3 x ULN without liver metastases) (≤ 5 xULN if documented liver metastases)
Renal
Serum Creatinine (≤1.5 mg / dL)
OR -
Calculated Creatinine Clearance1 (≥40 mL / min)
Calculated by the Cockcroft and Gault Method.
Subjects may continue anti-estrogen therapy only if treatment was initiated at least 1 month prior to the first dose of investigational product (IP). After randomization, no anti-hormonal therapy may be initiated.

Exclusion Criteria

Pregnant or lactating females.
Prior therapy with an ErbB1 and/or ErbB2 inhibitor other than trastuzumab.
Malabsorption syndrome, disease significantly affecting gastrointestinal function, or resection of the stomach or small bowel. Subjects with ulcerative colitis are also excluded.
History of other malignancy. However, 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.
Concurrent disease or condition that would make the subject inappropriate for study participation or any serious medical disorder that would interfere with the subject's safety.
Unresolved or unstable, serious toxicity from prior administration of another investigational drug and/or of prior cancer treatment.
Active or uncontrolled infection.
Dementia, altered mental status, or any psychiatric condition that would prohibit the understanding or rendering of informed consent.
Known history of uncontrolled or symptomatic angina, arrhythmias, or congestive heart failure.
Known history or clinical evidence of leptomeningeal carcinomatosis.
Concurrent cancer therapy (chemotherapy, radiation therapy, immunotherapy, biologic therapy).
Concurrent treatment with an investigational agent or participation in another clinical trial.
Used an investigational drug within 3 weeks or 5 half-lives, whichever is longer, preceding the first dose of investigational product.
Known immediate or delayed hypersensitivity reaction or idiosyncrasy to drugs chemically related to trastuzumab or lapatinib or their excipients.
Have current active hepatic or biliary disease (with exception of patients with Gilbert's syndrome, asymptomatic gallstones, liver metastases or stable chronic liver disease per investigator assessment).

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Arm 1: Lapatinib plus Trastuzumab	Lapatinib	Lapatinib 1000mg once daily in combination with trastuzumab 4mg/kg loading dose followed by 2mg/kg weekly
Arm 1: Lapatinib plus Trastuzumab	Trastuzumab	Lapatinib 1000mg once daily in combination with trastuzumab 4mg/kg loading dose followed by 2mg/kg weekly
Arm 2: Lapatinib	Lapatinib	Lapatinib 1500mg once daily

Primary Outcome Measures

Name	Time	Method
Progression-Free Survival (PFS)	Baseline to disease progression or death due to any cause or 30 days after last dose (up to 216 weeks)	PFS was defined as the time from randomization until the first documented sign of disease progression or death due to any cause.

Secondary Outcome Measures

Name	Time	Method
Clinical Benefit Response (CBR)	Baseline to disease progression or death or discontinuation from study or 30 days after last dose (up to 216 weeks)	CBR: percentage of participants with confirmed CR or PR or stable disease (SD) for at least 24 weeks according to RECIST criteria. CR: disappearance of all lesions (target and/or non-target). PR: at least a 30% decrease in the sum of the LD of target lesions taking as reference baseline sum LD, with non-target lesions not increased or absent. SD: neither had sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD) in target lesions, taking as reference the smallest sum LD since treatment started; persistence of 1 or more non-target lesions.
Overall Survival (OS)	Baseline to death or 30 days after last dose for the last participant (up to 216 weeks)	OS was defined as the time from randomization until death due to any cause. For participants who did not die, OS was censored at the time of last contact.
Duration of Response (DR)	Time from first documented evidence of CR or PR until the first documented sign of disease progression or death or 30 days after last dose (up to 216 weeks)	DR was defined for the subset of participants who showed a confirmed CR or PR, as the time from the first documented evidence of CR or PR until the first documented sign of disease progression or death. Because of the low number of participants experiencing a confirmed response in both treatment arms, analysis for this outcome measure was not performed.
Overall Tumor Response (OR)	Baseline to disease progression or death or discontinuation from study or 30 days after last dose (up to 216 weeks)	OR was defined as the percentage of participants experiencing either a confirmed complete response (CR) or a confirmed partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria 1.0. CR was defined as the disappearance of all lesions (target and/or non-target). PR was defined as at least a 30% decrease in the sum of the longest dimensions (LD) of target lesions taking as a reference the baseline sum LD, with non-target lesions not increased or absent.
Change From Baseline in Functional Assessment of Cancer Therapy-Breast (FACT-B) Scores at Week 4, Week 12, Week 16, Week 24, and Conclusion or Withdrawal From Study	Baseline, Week 4, Week 12, Week 16, Week 24, and conclusion or withdrawal from study (up to Week 108)	Quality of Life (QOL) was assessed using the FACT-B questionnaire, which was a 37-item (27 general and 10 breast cancer-specific questions) self-reporting instrument consisting of 5 dimensions: physical-, social/family-, emotional-, functional-well being, and a breast cancer subscale. Higher scores on the FACT-B scales indicate a higher QOL; each ranging from 0 (not at all) to 4 (very much). The score is transformed for FACT-B and results in a total score ranging from 0 to 144.
Time to Response (TTR)	Baseline until first documented evidence of CR or PR or 30 days after last dose (up to 216 weeks)	TTR was defined as the time from randomization until the first documented evidence of CR or PR (whichever status was recorded first). TTR could not be analyzed because too few participants experienced a confirmed CR or PR.
Time to Progression (TTP)	Baseline to disease progression or death or 30 days after last dose (up to 216 weeks)	TTP was defined as the interval between the date of randomization and the earlier of the date of disease progression or death due to breast cancer. Because this outcome measure was confounded by death due to other causes and was similar to PFS, it was not analyzed.