Side Effects by Body System

Side Effects by Body System

General

All clinical trial data were from trials of lapatinib in combination with capecitabine.

To report suspected adverse reactions, contact GlaxoSmithKline at 1-888-825-5249 or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Gastrointestinal

Gastrointestinal side effects including diarrhea (65%), nausea (44%), vomiting (26%), stomatitis (14%), and dyspepsia (11%) have been reported.

Diarrhea was the most common adverse reaction resulting in discontinuation of study medication.

Hematologic

Hematologic side effects have included laboratory abnormalities in hemoglobin (56%), neutrophils (22%), and platelets (18%).

Dermatologic

Dermatologic side effects including palmar plantar erythrodysesthesia (53%) (also called hand-foot syndrome or acral erythema), rash (28%), and dry skin (10%) have been reported.

Hepatic

Hepatic side effects have included laboratory abnormalities in AST (49%), total bilirubin (45%), and ALT (37%).

Cardiovascular

Due to potential cardiac toxicity with HER2 (ErbB2) inhibitors, left ventricular ejection fraction (LVEF) was monitored in clinical trials at approximately eight-week intervals. LVEF decreases were defined as signs or symptoms of deterioration in left ventricular cardiac function that are grade 3 (NCI CTCAE), or a 20% decrease in left ventricular cardiac ejection fraction relative to baseline which is below the institution's lower limit of normal. Among 198 patients who received lapatinib/capecitabine combination treatment, three experienced Grade 2 and one had Grade 3 LVEF adverse reactions (NCI CTC 3.0).

The QT prolongation potential of lapatinib was assessed as part of an uncontrolled, open-label dose escalation study in advanced cancer patients. Eighty-one patients received daily doses of lapatinib ranging from 175 mg/day to 1800 mg/day. Serial ECGs were collected on day 1 and day 14 to evaluate the effect of lapatinib on QT intervals. Thirteen of the 81 subjects were found to have either QTcF (corrected QT by the Friedericia method) greater than 480 msec or an increase in QTcF greater than 60 msec by automated machine-read evaluation of ECG. Analysis of the data suggested a relationship between lapatinib concentration and the QTc interval.

Cardiovascular side effects including decreases in left ventricular ejection fraction and QT prolongation have been reported.

Other

Other side effects including mucosal inflammation (15%), pain in the extremity (12%), dyspnea (12%), back pain (11%), and insomnia (10%) have been reported.

Oncologic

Oncologic side effects including genotoxicity have been reported. An impurity in the drug product was genotoxic when tested alone in both in vitro and in vivo assays.

Respiratory

It is recommended that patients be monitored for pulmonary symptoms indicative of interstitial lung disease or pneumonitis. Lapatinib should be discontinued in patients who experience pulmonary symptoms indicative of interstitial lung disease/pneumonitis which are greater than or equal to grade 3 (NCI CTCAE).

Respiratory side effects have been reported including interstitial lung disease and pneumonitis in monotherapy or in combination with other chemotherapies