Effect of lapatinib on meningioma growth in adults with neurofibromatosis type 2
INTRODUCTION/BACKGROUND:Epidermal growth factor receptors EGFR and ErbB2 are overexpressed in schwannomas and meningiomas. Preclinical and clinical data indicate that lapatinib, an EGFR/ErbB2 inhibitor, has antitumor activity against vestibular schwannomas in neurofibromatosis type 2 (NF2) patients. Its antitumor activity against meningiomas, however, is unknown. METHODS:) who received at least five 28-day courses of treatment. Patients received lapatinib 1500Â mg daily. Meningioma response was assessed using 3-dimensional MRI volumetrics. Progressive meningioma growth and response were defined as +â€‰20 and -â€‰20% change in tumor volume from baseline, respectively. Off-treatment was defined as any periodâ€‰>â€‰5Â months without lapatinib. RESULTS:Eight patients (ages: 20-58Â years) who met criteria had 17 evaluable meningiomas with a combined volume of 61.35Â cc at baseline, 61.17Â cc during treatment, and 108.86Â cc (+â€‰77.44% change) off-treatment, pâ€‰=â€‰0.0033. Median time on-treatment and off-treatment was 15.5 and 16.7Â months, respectively. On-treatment mean and median annualized growth rates were 10.67 and 1.32%, respectively. Off-treatment mean and median annualized growth rates were 20.05 and 10.42%, respectively. The best volumetric response was -â€‰26.1% after 23Â months on lapatinib. Two tumors increasedâ€‰>â€‰20% volumetrically on-treatment, compared to eight tumors off-treatment. CONCLUSIONS:These data suggest that lapatinib may have growth-inhibitory effects on meningiomas in NF2 patients, and support prospective studies of lapatinib for NF2 patients with progressive meningiomas.