Lapatinib appears safe in patients with breast cancer

July 14, 2008

NEW YORK (Reuters Health) - Pooled data from 44 studies indicate that the tyrosine kinase EGFR and HER2 inhibitor lapatinib exhibits low cardiotoxicity in cancer patients.

"This study," lead investigator Dr. Edith A. Perez told Reuters Health, "represents a thorough analysis of the prospectively collected data of more than 3,500 patients treated with lapatinib for HER2-positive breast cancer."

In the June issue of Mayo Clinic Proceedings, Dr. Perez of the Mayo Clinic in Jacksonville, Florida, and colleagues observe that HER2 pathway inhibitors can cause cardiac dysfunction.

However, cardiac events (i.e., decreases in left ventricular ejection fraction) were reported in only 60 (1.6%) of 3689 patients. Two patients had two such events. Fifty-three of the events were asymptomatic and these patients received no cardiac-related therapy.

In the 40 patients in whom cardiac outcome was determined, 35 (88%) had full or partial recovery, regardless of whether they continued or discontinued lapatinib. No cardiac deaths were attributed to lapatinib.

"The data," concluded Dr. Perez, "demonstrate a reassuringly low rate of clinically evident or asymptomatic cardiac effects. Further studies in comparative trials will allow us to place the data in the context of other anti-HER2 agents."