A phase II study of capecitabine and lapatinib in advanced refractory colorectal adenocarcinoma: A Wisconsin Oncology Network study.

BACKGROUND: Prognosis remains poor after progression on first-line chemotherapy for colorectal adenocarcinoma, and inactivation of the EGFR pathway with monoclonal antibodies is an effective treatment strategy in selected patients with metastatic disease. Lapatinib is an oral EGFR and HER-2 dual tyrosine kinase inhibitor that has not shown significant activity in metastatic colorectal cancer. However, lapatinib may act synergistically with capecitabine in anticancer effects.
METHODS: This was an open-label, non-randomized phase II study of lapatinib 1,250 mg orally daily and capecitabine 2,000 mg/m(2) by mouth split into twice-daily dosing for 14 days of a 21 days cycle. Inclusion criteria included metastatic or locally advanced adenocarcinoma of the colon or rectum with progression by RECIST on or within six months of receiving a fluoridopyrimidine-, oxaliplatin- or irinotecan-containing regimen. Prior EGFR monoclonal antibody was permitted. K-ras testing was not routinely performed and was not a part of the study protocol.
RESULTS: Twenty nine patients (16 M; 13 F) were enrolled in this study. There were no complete or partial responses. 41.4% of patients achieved stable disease as a best response. Median overall survival was 6.8 months, with a 1-year survival rate of 22%, and median progression-free survival was 2.1 months. The combination produced few grade 3 and no grade 4 toxicities. No grade 3 toxicity occurred in more than 10% of patients.
CONCLUSIONS: Although capecitabine and lapatinib is well tolerated, it is not an effective regimen in patients with refractory colorectal adenocarcinoma.