BACKGROUND:

The global lapatinib expanded access programme (LEAP) provided access to lapatinib (L) combined with capecitabine (C) for women with HER2- positive metastatic breast cancer (MBC) who were previously treated with an anthracycline (A), taxane (T) and trastuzumab (TRAS) in 45 countries. The eligibility criteria and the dose of given drugs resembled that used in the phase III clinical trial EGF 100151, with the exception that patients (pts)previously exposed to C and pts with an ECOG performance status of 2 could be included as well. L is a dual tyrosine kinase inhibitor of EGFR and HER2. L plus C is an effective treatment option in T-refractory HER2-positive MBC. 148 Canadian pts were enrolled. METHODS:

LEAP enrolled patients with ErbB2-positive, locally advanced and MBC showing progressive disease following prior therapies with A, T, TRAS-containing regimens. Pts received L (1,250 mg/day) and C (2,000 mg/m2/day, days 1-14, every 21 days). We analyzed 148 Canadian LEAP pts recruited from seven centres for demographics, duration of therapy, L compliance, left ventricular function, progression-free survival (PFS), and overall survival (OS). RESULTS:

Data cut off for these analyses was Jan 10, 2010. [Data were not available for all 148 pts. The median age was 52 y (range 29-80 y) for 147 pts (145 women, 2 men). Ninety-five pts (64.6%) had no prior C and 52 (35.4%) had prior C (n=147). Study medication was discontinued for 142 pts (96.6%): 110 (74.8%) for progressive disease; 17 (11.6%) for adverse events; 8 (5.4%) for patient preference; and 3 (2%) were transitioned to the commercial supply of L. The median duration of therapy was 18.95 wk, ranging 0.1 to 96 wk (n=137). L compliance data showed that 73.7% of pts received ≥80% of the L dose (n=122). Median baseline left ventricular function (LVF) was 60%, ranging 50% to 81% (n=142). The median LVF at study end was 61%, ranging 37% to 83% (n = = 96). There was an amendment in June 2008 to end the collection of disease progression and/or death dates. Median PFS and OS were 22.1 wk (95% CI: 18.9-26.7), and 48 wk (95% CI: 42.3-…), respectively (n=71). CONCLUSIONS:

L combined with C is an effective option for women with refractory HER2-positive MBC. The results seen in the Canadian subset enrolled in LEAP were similar to the results of EGF 100151 and the Global LEAP in the efficacy and safety data.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-15.

2010