DLTs were defined as specific events that are considered to be probably or definitely related to CA4P. Major DLTs included QTc interval ≥ 500 msec (based on measurements provided by the core laboratory for ECG analysis), Grade-2 or greater ventricular arrhythmia, unexplained syncope, Grade-3 or greater toxicity, delayed recovery postponing re-treatment by >14 days, and ocular toxicity such as keratopathy, uveitis, optic neuropathy, and retinopathy, at the discretion of the investigator.