Conditions: Neoplasms, Breast
Keywords: Adjuvant ErbB2-overexpressing Early stage breast cancer HER2/neu gene amplified
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 8381
Healthy volunteers: no

Brief summary:
This was a four-arm (parallel group) randomized, open-label, multicenter Phase 3 study to investigate the use of a combination of Lapatinib and Trastuzumab, a sequence of Trastuzumab followed by Lapatinib, and Lapatinib alone, compared to Trastuzumab alone in the adjuvant treatment of Human Epidermal Growth Factor Receptor 2 (HER2) positive early breast cancer.

Detailed description:
Treatment allocation was stratified by blocked randomization, with three stratification factors:

* Hormone receptor status: Estrogen Receptor (ER) and/or Progesterone Receptor (PgR) positive versus both negative.
* Axillary lymph node involvement: not assessed because of neoadjuvant chemotherapy versus node negative versus 1-3 positive nodes versus 4 or more positive nodes.
* Timing of adjuvant chemotherapy: concurrently with taxanes and targeted therapy (Design 2) and concurrently with non-anthracycline-based platinum chemotherapy and targeted therapy (Design 2B) versus all other chemotherapy completed before randomization (Design 1). Treatments delivered differed according to the timing and type of adjuvant chemotherapy.

The primary objective of this study was to compare disease-free survival (DFS) in subjects with HER2 overexpressing and/or amplified breast cancer randomized to trastuzumab for one year versus lapatinib for one year versus trastuzumab (12 or 18 weeks, according to assigned design) followed by a six week treatment-free interval followed by lapatinib (28 or 34 weeks, according to assigned design) versus trastuzumab in combination with lapatinib for one year (52 weeks).

Secondary objectives included treatment comparisons with respect to overall survival, time to recurrence, time to distant recurrence, safety and tolerability, and incidence of brain metastasis.

Based on the recommendation of the Independent Data Monitoring Committee (IDMC) at the first interim analysis (18-Aug-2011), the Lapatinib alone arm was discontinued prior to primary analysis due to futility. The IDMC also stated that the other three arms (trastuzumab alone, sequential trastuzumab/lapatinib arm and the combination arm) could continued as planned with no changes.

Arms:
arm 1: Design 1: Oral lapatinib 1000 mg daily concurrent with trastuzumab 8 mg/kg IV loading dose followed by 6mg/kg IV every 3 weeks (52 weeks total).

Design 2: Trastuzumab (4mg/kg loading dose followed by 2mg/kg IV weekly) concurrent with oral lapatinib 750 mg daily and either paclitaxel 80mg/m2 IV weekly for 12 weeks OR docetaxel 75mg/m2 every 21 days for 4 cycles (12 weeks). After completion of chemotherapy, the dose of lapatinib will be increased to 1000mg daily concurrently with trastuzumab every 3 weeks (6mg/kg without loading dose) for an additional 40 weeks (52 weeks total).

Design 2B: Docetaxel 75mg/m2 and carboplatin AUC 6 every 3 weeks for 6 cycles (18 weeks) administered concurrently with oral lapatinib 750mg plus weekly trastuzumab (4mg/kg IV loading dose followed by 2mg/kg IV. After the completion of chemotherapy, trastuzumab will be administered every 3 weeks (6mg/kg without loading dose) concurrent with lapatinib 1000mg daily for an additional 40 weeks (52 weeks total). arm 2: Design 1: Trastuzumab (4mg/kg IV loading dose followed by 2mg/kg IV weekly) for 12 weeks followed by a 6 week treatment-free interval followed by oral lapatinib 1500mg daily for 34 weeks (52 weeks total).

Design 2: Trastuzumab (4mg/kg IV loading dose followed by 2mg/kg IV weekly) for 12 weeks administered concomitantly and either paclitaxel 80mg/m2 IV weekly for 12 weeks OR docetaxel 75mg/m2 every 21 days for 4 cycles; followed by a 6 week treatment-free interval followed by oral lapatinib 1500mg daily for 34 weeks (52 weeks total).

Design 2B: Docetaxel 75mg/m2 and carboplatin AUC 6 every 3 weeks for 6 cycles (18 weeks) administered concomitantly with trastuzumab (4mg/kg IV loading dose followed by 2mg/kg IV weekly) followed by a 6 week treatment-free interval followed by oral lapatinib 1500 mg daily for 28 weeks (52 weeks total). arm 3: Design 1: Lapatinib 1500mg oral daily for a total of 52 weeks.

Design 2: Either paclitaxel 80mg/m2 IV weekly for 12 weeks OR docetaxel 75mg/m2 IV every 3 weeks for 4 cycles administered concomitantly with oral lapatinib at 750mg daily. After completion of chemotherapy, oral lapatinib administered at 1500mg daily for an additional 40 weeks (52 weeks total).

Design 2B: Docetaxel 75mg/m2 and carboplatin AUC 6 every 3 weeks for 6 cycles (18 weeks) administered concomitantly with oral lapatinib at 750mg daily. After completion of chemotherapy, the dose of lapatinib will be increased to 1500mg oral daily for an additional 40 weeks (52 weeks total). arm 4: Design 1: Trastuzumab 8mg/kg IV loading dose followed by 6mg/kg IV every 3 weeks for a total of 52 weeks.

Design 2: Either paclitaxel 80mg/m2 IV weekly for 12 weeks OR docetaxel 75mg/m2 IV every 3 weeks for 4 cycles administered concomitantly with trastuzumab 4mg/kg IV loading dose followed by 2mg/kg IV weekly. After completion of chemotherapy, trastuzumab administered every 3 weeks (6mg/kg IV without loading dose) for an additional 40 weeks (52 weeks total).

Design 2B: Docetaxel 75mg/m2 and carboplatin AUC 6 every 3 weeks for 6 cycles (18 weeks) administered concomitantly with trastuzumab 4mg/kg IV loading dose followed by 2mg/kg IV weekly. After completion of chemotherapy, trastuzumab (6mg/kg without loading dose) every 3 weeks for an additional 40 weeks (52 weeks total).

Interventions: intervention 1: Lapatinib intervention 2: Trastuzumab
Intervention descriptions: intervention 1: Small molecule inhibitor intervention 2: Antibody

Protocol document: