Study to Assess Amphotericin B Cystetic for Inhalation (ABCI) Doses in Healthy Volunteers & People with Cystic Fibrosis

Inclusion Criteria: Part A and Part B: Each subject must meet the following criteria to be enrolled in Part A and Part B of this study. * Subject has signed, dated, and received a copy of the IRB/IEC-approved written ICF. * Subject is male or female aged ≥18 to ≤55 years. * Subject has a BMI between 18 and 32 kg/m2 * Subject has an FEV1 of \>90% of predicted normal value * Subject has normal or clinically acceptable physical examination, vital signs, clinical laboratory values, and ECG at Screening. * Female subjects must be of non-childbearing potential or male/female subjects of childbearing potential agree to use highly effective contraception/preventive exposure measures Part C: Each subject must meet the following criteria to be enrolled in Part C of this study. * Subject has signed, dated, and received a copy of the IRB/IEC-approved written ICF. * Age 16 years or older * Confirmed diagnosis of CF, including sweat chloride \>60 mM. * Subject is either: Being treated with an approved CFTR modulator for at least 28 days prior to Screening, or Not being treated with a CFTR modulator * FEV1: * For subjects on CFTR modulators: FEV1 ≥40% and ≤90% * For subjects not on CFTR modulators: FEV1 ≥40% and ≤100% * Stable CF disease and treatment regiment * Female subjects must be of non-childbearing potential or male/female subjects of childbearing potential agree to use highly effective contraception/preventive exposure measures Exclusion Criteria: Part A and Part B: Any subject who meets any of these criteria must be excluded from Part A and Part B of this study: * Subject has history or evidence of any clinically significant pulmonary condition * Subject has history or evidence of any clinically significant diseases or conditions * Subject has history of malignancy of any type * Subject has an active COVID-19 infection within 4 weeks * Subject is positive for human immunodeficiency virus antibodies, hepatitis B surface antigen, or hepatitis C antibodies, or has a positive QuantiFERON®-tuberculosis Gold (QFT-G) test for tuberculosis at Screening * Subject has a self-reported lower respiratory tract infection within 6 weeks * Subject has evidence of any active or suspected bacterial, viral, fungal or parasitic infections within the past 4 weeks * A subject who is an active smoker or a former smoker * Subject has history of alcohol or drug abuse in the past year * Subject has tested positive for drugs (including cannabis), nicotine/cotinine, and/or alcohol use at Screening, subject has consumed alcohol within 24 hours prior to Visit 3 * Subject has participated in any clinical study or had been treated with any investigational drugs within 28 days or 5 half-lives * Female subject who is pregnant or breastfeeding. * Subject has any episode of paradoxical bronchospasm in the past 12 months. * Subject has pacemaker; is not in sinus rhythm; has a corrected QT interval (QTc; using Fridericia's \[QTcF\] formula) of \>450 ms (for males) and \>470 ms (for females); or has a left bundle branch block or bifascicular block. * Subject has a pulse \<40 or \>100 bpm; systolic blood pressure \>140 mmHg, or diastolic blood pressure \>90 mmHg at Screening * Subject has Type I or II diabetes requiring medication. * Subject has received any vaccine within 30 days prior to Day 1. * Subject has received any of the following immunosuppressant therapies within 6 months prior to Screening: imatinib, ambrisentan, azathioprine, cyclophosphamide, cyclosporine A, bosentan, or methotrexate. * Subject has received any antibody or therapeutic biologic product during the 6 months prior to Screening. * Subject has received any oral, intravenous, or intramuscular steroid within 4 weeks prior to Screening. Intrathecal or intraarticular steroids are permitted. * A subject who is not vaccinated with the COVID-19 vaccine with appropriate window from last dose of vaccine to Screening per local guidelines, policies, and availability within 30 days prior to Day 1. Part C: Any subject who meets any of these criteria must be excluded from Part C of this study: * History of any illness or any clinical condition that might confound the results of the study or pose an additional risk in administering study drug(s) to the subject. * Any of the following abnormal laboratory tests: Hemoglobin, Total bilirubin, liver enzymes or creatine clearance * An acute upper or lower respiratory infection, pulmonary exacerbation, or changes in therapy for sinopulmonary disease within 28 days before the screening visit. * An acute illness not related to CF within 14 days before the first dose of study drug. * Subject has an active COVID-19 infection within 4 weeks prior to screening. * Ongoing or prior participation in a study of an investigational treatment within 28 days or 5 terminal half-lives (whichever is longer) before screening. * Female subject who is pregnant or breastfeeding. Please refer to study protocol for the complete inclusion/exclusion criteria list.