Study assessments
toxicity, Rijswijk, SAD
INFECTIOUS DISEASES, EVENTS, ACQUIRED IMMUNODEFICIENCY SYNDROME
Clinical laboratory variables, including hematology and serum biochemistry, were assessed at screening and periodically during the study as indicated in the protocol. AEs, including pre-treatment events, were recorded from the time of consent through the completion visit. AEs were reported using Medical Dictionary for Regulatory Activities (MedDRA) Version 16.1 or higher. Severity was graded using either the Division of Acquired Immunodeficiency Syndrome Grading Version 1.0 (Study 1) or the Division of Microbiology and Infectious Diseases toxicity scale (Study 2).Nasal aspirates (except for the 40/20 mg/kg and 60/40 mg/kg groups in Study 1) or mid-turbinate nasal swab specimens (used for the 40/20 mg/kg and 60/40 mg/kg groups in Study 1 and Study 2) were collected at the baseline, during treatment, and post-treatment through day 7 (Study 1 SAD only) or day 28. The RSV RNA viral load in the nasal specimens was determined through day 28 using qRT-PCR assays performed at the University of Tennessee Children’s Foundation Research Institute for Study 1 (reported in plaque-forming-unit equivalents per milliliter [PFUe/mL]) or the DDL Diagnostic Laboratory (Rijswijk, The Netherlands) for Study 2 (RSV viral load lower limit of quantification (LLOQ) = 3.00 logPost-dose whole blood samples were collected from infants in all dosing cohorts in both studies at specified time points (twice in the first 24 hours’ post-dose, and a random sample at any time on the last day of dosing for multiple dose cohorts) for determining PK parameters. Whole blood concentrations of ALS-008112 and ALS-008144 and other metabolites were determined by a liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The population PK model was developed to derive PK parameters following a single dose or at steady-state.Next-generation sequencing (NGS; using 1% read-frequency cut-off) of the RSV L-gene was performed at DDL Diagnostic Laboratory on the baseline and post-baseline samples of patients in Study 1 (MAD) and Study 2. Post-baseline samples were selected from the last evaluable on-treatment time point with the RSV RNA levels above the sequencing limit. Sequencing analyses focused on the RSV L-amino acid positions 628, 789, 795, and 796, at which resistance-associated substitutions were identified in 