Lymphangioleiomyomatosis (LAM) is a rare lung disease that is caused by genetic mutations. It results in the uncontrolled growth and proliferation of an atypical smooth muscle cells in the lung. These cells invade airways, blood vessels, and lymph vessels, and limit the flow of air, blood, and lymph, respectively. The source of the cells is unknown, but available evidence indicates they arise from an extrapulmonary source. Their aberrant behavior is due to mutations in tuberous sclerosis genes that results in mTOR activation. Respiratory failure, lung collapse (pneumothorax), and pleural effusions (chylothorax) are hallmarks of the disease. This study will evaluate the safety and durability of the mTOR inhibitors sirolimus and everolimus, which are FDA approved medications for prevention of rejection of transplanted organs, in stabilizing or improving lung function in people in LAM.

The purpose of this medical research study is to evaluate the safety and effectiveness of a new medication called imatinib mesylate in the treatment of Lymphangioleiomyomatosis (LAM). LAM is a rare disease in which abnormal cells (called LAM cells) grow out of control. Over time, LAM cells destroy healthy lung tissue and cause respiratory disease or failure.

Many patients with LAM are currently treated with a medication called sirolimus (rapamycin). Sirolimus slows the growth of LAM cells.

Imatinib mesylate (hereafter called imatinib) is approved by the Food and Drug Administration (FDA) for the treatment of some cancers that share common pathways with LAM cells. Laboratory studies suggest that imatinib could completely block the growth of LAM cells through initiation of targeted cell death.

An important purpose of this research is to determine the safety of imatinib in people with LAM. This study will also evaluate the short-term effectiveness of imatinib. Participants will be randomized to receiving imatinib (study medication) or placebo (no treatment) for the 180 day duration of participation. The study is being conducted at the Medical University of South Carolina and at Columbia University in New York (CUMC). Each site will enroll 10 participants.