Dabrafenib and Lapatinib in Treating Patients With Refractory Thyroid Cancer That Cannot Be Removed by Surgery

Description

PRIMARY OBJECTIVE:

I. To determine the maximum tolerated dose of lapatinib that can be used in combination of dabrafenib.

SECONDARY OBJECTIVES:

I. To observe and record anti-tumor activity. II. Evaluate potential mechanisms of primary resistance of BRAF mutant thyroid cancer to dabrafenib by performing pathway profiling of tumor biopsies before and while on therapy.

III. Obtain preliminary data on the activity of the combination of lapatinib and dabrafenib in BRAF mutant thyroid cancer through imaging.

OUTLINE: This is a dose-escalation study of lapatinib.

Patients receive dabrafenib orally (PO) twice daily (BID) on days 1-28 of each cycle. After two weeks of single agent dabrafenib, patients also start receiving lapatinib PO once daily (QD) on days 1-28 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. Additionally, patients undergo tumor biopsy, blood sample collection, echocardiography (ECHO) or multigated acquisition scan (MUGA), as well as positron emission tomography (PET), computed tomography (CT), or magnetic resonance imaging (MRI) during screening and on study.

After completion of study treatment, patients are followed up for 4 weeks and then annually thereafter.