Background: Lymphangioleiomyomatosis (LAM) is characterized by cystic lung destruction, kidney angiomyolipomas (AMLs), and LAM cell growth within the axial lymphatics and multiple other organs and surfaces. LAM occurs both sporadically and in association with tuberous sclerosis complex (TSC). Sirolimus (rapamycin), an mTORC1 inhibitor, has been shown to stabilize lung function decline and decrease angiomyolipoma tumor size in both TSC and sporadic LAM patients. However, cessation of rapamycin therapy results in recurrent decline in lung function, and regrowth of angiomyolipoma, suggesting that continuous use may be required to maintain its beneficial effects. Recently the investigators have discovered that cyclo-oxygenase (COX) function is altered in cells lacking TSC2, including in a LAM patient-derived angiomyolipoma cell line. COX-2 levels are increased, prostaglandin metabolite levels are increased, and treatment with COX-2 inhibitors are effective in reducing tumor size in two different Tsc mouse models, one a native tumor, and the other a xenograft model. Furthermore, rapamycin does not affect these differences in COX-2 expression or prostaglandin metabolites.
Objectives/Hypothesis: Our preclinical studies indicate that celecoxib (a COX-2 specific inhibitor) decreases the size of TSC2-deficient tumors in Tsc models. Hence the investigators propose this Pilot Clinical Trial to test the safety and tolerability of celecoxib in patients with LAM, with preliminary assessment of potential benefit using multiple approaches.
Specific aims: The primary endpoint of this pilot trial is to test the safety and tolerability of treatment with celecoxib in patients with mild-to-moderate LAM, who are not currently on sirolimus; and to assess the potential benefit of this treatment using the following: 1. Spirometry, 2. MRI measurement of angiomyolipoma size, 3. St. George's Respiratory Questionnaire, 4. VEGF-D serum levels. The investigators will assess Exhaled breath condensate prostaglandin metabolites to confirm effects of celecoxib. The investigators will also develop a novel biomarker of LAM to assess response, quantitative measurement of the number of TSC2 mutant circulating LAM cells, by next generation sequencing.
Study design: The investigators will perform a pilot clinical trial to investigate the safety and tolerability of celecoxib therapy as a single agent for patients with LAM. LAM subjects who are not taking everolimus or rapamycin will be treated with celecoxib at 200mg PO QD for 6 months. They will be monitored for respiratory function and angiomyolipoma size. At the end of the 6 month period, celecoxib will be discontinued, and subjects will be monitored for another 6 months.
Clinical Impact: Sirolimus is the only medical therapy shown to reduce tumor size and stabilize lung function in patients with LAM and TSC-LAM. Although sirolimus has clear benefits, results from the MILES trial suggest that continuous therapy in some form is required, as the rate of decline in lung function resumed when sirolimus was discontinued. The investigators hope that celecoxib will show benefit with minimal toxicity in this trial, and provide an alternative approach for the long term prophylactic/preventive treatment of patients with mild-to-moderate LAM. Our study will include patients with TSC LAM, which often appears to be more slowly progressive than sporadic LAM, and hence long term therapy with celecoxib may have particular benefit in the TSC LAM population. In addition, the investigators will develop a quantitative measure of circulating LAM cell levels as part of this trial.
