First in Human SAD and MAD Study of Inhaled TD-0903, a Potential Treatment for ALI Associated With COVID-19

Inclusion Criteria: * Body mass index (BMI) ≥ 18.0 and ≤ 32.0 kg/m2 at Screening and weighs at least 50 kg. * Medically healthy with no clinically significant medical history, physical examination, spirometry, vital signs or ECGs. * Forced expiratory volume in 1 second (FEV1) ≥80%. * No clinically significant abnormalities in the results of laboratory evaluations. * Female subjects must be either of non-childbearing potential or if of childbearing potential, subject must not be pregnant or breastfeeding, and must agree to use a highly effective birth control method. * Male subjects must agree to use condoms, in addition to the use of highly effective pregnancy prevention measures with female partners of childbearing potential. * Understands the correct technique for the use the nebulizer device(s). * Other inclusion criteria apply Exclusion Criteria: * History or presence of clinically significant medical or psychiatric condition. * Abnormal ECG measurements at Screening. * Any signs of respiratory tract infection within 6 weeks of Screening. * Subject who has a current bacterial, parasitic, fungal, or viral infection; any infection requiring hospitalization or intravenous antibiotics within 6 months prior to Screening. * Positive test for SARS-CoV-2 * Subject has any condition of the oro-laryngeal or respiratory tract. * Uses or has used tobacco or nicotine-containing products (e.g., cigarettes, cigars, chewing tobacco, snuff, patches etc.) within 6 months prior to screening * Additional exclusion criteria apply