Abstract OT1-1-08: Clinical outcomes among ErbB2+ MBC patients treated with lapatinib-capecitabine after trastuzumab progression: Role of early switch to lapatinib (TYCO study).
Authors: Abulkhair O , Uslu R , Sezgin C , Büyükberber S , Darwish T , Isikdogan A , Gumus M , Dane F , Sevinc A , Halawani H , Uncu D , Marrero N , Tobler J , Soares C , Landis S , Moraes E , Gidekel R , Santillana S , Nunez P , Cagnolati S , Rodriguez JG 
Published: August 2014

Background: Lapatinib in combination with capecitabine is a standard of care treatment for ErbB2+ metastatic breast cancer (MBC) patients who have progressed after anthracyclines, taxanes and trastuzumab treatment. Results from the lapatinib pivotal trial showed that the addition of lapatinib to capecitabine increased median time to progression (TTP) even among heavily pre-treated patients (median of 4 prior lines of therapy). A post-hoc exploratory sub-group analysis of this trial suggested that earlier administration of lapatinib-capecitabine in MBC patients who progress after trastuzumab may produce better clinical outcomes. The TYCO study was designed to evaluate if early initiation of lapatinib-capecitabine in patients with ErbB2+ MBC who have progressed on trastuzumab-containing regimen improves TTP in comparison with a delayed start of the therapy.

Trial design: TYCO is an international, multicenter, prospective, observational study in 269 ErbB2+ MBC patients whose disease has progressed after treatment with trastuzumab in the metastatic setting. Two cohorts will be compared; Group 1: patients receiving lapatinib-capecitabine just after the first trastuzumab progression, and Group 2: patients receiving lapatinib-capecitabine after two or more lines of treatment after first trastuzumab progression. The study duration is of 12 months with data collection at baseline and approximately every 3 months thereafter.

Major Eligibility Criteria: 1. Females ≥18y with confirmed ErbB2+ MBC who have progressed after a previous trastuzumab-containing regimen,2. Pts eligible for standard therapy with lapatinib-capecitabine at approved conventional doses, as per local approved label.3. Pts eligible to start standard treatment with Lapatinib-capecitabine at conventional doses, or receiving standard treatment with Lapatinib-capecitabine at conventional doses, for no longer than 10 weeks from the start of the treatment to the date of inclusion in the study;

Aims: Primary objective of this study is to determine if early switch to lapatinib-capecitabine in patients with ErbB2+ metastatic breast cancer who have progressed on trastuzumab containing regimen improves time to disease progression as determined by treating physician either clinically or radiologically. Secondary objectives include overall response rate and overall survival.

Statistical Methods: Kaplan-Meier plots will be used to describe the median TTP after start of lapatinib-capecetabine. Cox proportional hazard model will be developed to estimate the adjusted hazard ratio (and 95% confidence intervals) comparing TTP for the two treatment group using propensity score methods (trimmed sample, adjustment for the continuous propensity score measure, and doubly robust adjustment) to adjust for potential confounding by indication that may arise due to the non-randomised design.

Present and Target Accrual: Enrollment began in February 2010, and as per May 2012, 266 patients have been included from Turkey, Venezuela, Argentina, Saudi Arabia and Colombia.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-08.