ALTTO – Randomisierte, mulitzentrische, offene Phase III-Studie zur Untersuchung der adjuvanten Therapie mit Lapatinib, Trastuzumab sowie deren sequentieller Gabe bzw. in Kombination bei Patienten mit HER2-/ErbB2-positivem primärem Brustkrebs

ALTTO – Randomisierte, mulitzentrische, offene Phase III-Studie zur Untersuchung der adjuvanten Therapie mit Lapatinib, Trastuzumab sowie deren sequentieller Gabe bzw. in Kombination bei Patienten mit HER2-/ErbB2-positivem primärem Brustkrebs

This is a randomised, open label multi-centre phase III study comparing the activity of lapatinib alone versus trastuzumab alone versus trastuzumab followed by lapatinib versus lapatinib concomitantly with trastuzumab in the adjuvant treatment of patients with ErbB2 overexpressing and/or amplified breast cancer. Patients will be enrolled according to one of two design schemas, with Design 2 having two chemotherapy options (Design 2 and 2B), and will be randomised to one of four treatment regimens within each design schema. The primary objective of this study is to compare disease-free survival (DFS) in patients with HER2 overexpressing and/or amplified breast cancer randomised 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 include treatment comparisons with respect to overall survival, time to recurrence, time to distant recurrence, safety and tolerability, incidence of brain metastasis, and analyses conducted separately for cohorts of patients defined by presence or absence of cMyc oncogene amplification, expression level of PTEN and presence or absence of the p95HER2 receptor. On August 18, 2011, the ALTTO Independent Data Monitoring Committee (IDMC) met to review the first planned interim analysis. The IDMC reported that the comparison of lapatinib alone versus trastuzumab alone crossed the futility boundary, indicating that the lapatinib alone arm was unlikely to meet the pre-specified criteria to demonstrate non-inferiority to trastuzumab alone with respect to disease-free survival (DFS). The IDMC also stated that the other three arms (trastuzumab alone, sequential trastuzumab/lapatinib arm and the combination arm) should continue as planned with no changes.