Phase 2b Trial Comparing HDV-Insulin Lispro to Insulin Lispro in Adults With Type 1 Diabetes Receiving Insulin Degludec

Inclusion Criteria: * clinical diagnosis Type 1 diabetes with C-peptide \<=0.6 ng/mL and using insulin for at least 6 months * willing to use study provided insulin as the only bolus insulin and insulin degludec as the basal insulin * willing to use CGM device throughout the study * screening A1C \>= 6.5% and \<= 10.0% daily insulin dose \<= 1.25 U/kg/day Exclusion Criteria: * known or specific allergy to any component of the study drug, the active comparator * pregnant or breast-feeding, or plans to become pregnant at any time during duration of study * current use of hydroxyurea * use of noninsulin glucose-lowering medications other than metformin, weight loss medications or dietary supplements for weight loss within 30 days, or anticipated use during the course of the study * received any investigational drug within prior 30 days * Clinically significant abnormalities on screening laboratory testing including liver enzymes * Presence of a medical condition or use of a medication that could compromise the results of the study or the safety of the subject (eg. alcohol or drug abuse, uncontrolled hypertension, history of transient ischemic attack or stroke within the last 12 months) * employed by or having immediate family members employed by the sponsor or directly involved in conducting the clinical trial.