Timber Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug designation to TMB-003, the company’s locally delivered formulation of sitaxsentan, for the treatment of systemic sclerosis. The Orphan Drug Designation program provides orphan status to drugs and biologics that are intended for the treatment, prevention or diagnosis of a rare disease or condition that affects less than 200,000 people in the U.S. Systemic sclerosis is a group of rare autoimmune connective tissue disorders (CTD) characterized by inflammation and thickening of the skin and other connective tissues from excessive collagen deposition. Systemic sclerosis leads to abnormalities in the skin, joints, and internal organs. Sitaxsentan is a highly selective endothelin (ET-A) receptor antagonist, which is a class of drugs previously developed in oral form for the treatment of pulmonary arterial hypertension (PAH). TMB-003 is a locally delivered formulation of sitaxsentan that has the potential to reduce collagen while addressing systemic safety concerns associated with oral administration. Timber is in the preclinical stages of evaluating TMB-003 for the treatment of scleroderma and expects to submit an Investigational New Drug (IND) application to the FDA in 2022.