A Study Evaluation the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Patients With Primary Hypothyroidism

The North Star study is a multi-center, Phase 2, double-blind, randomized, parallel group clinical study to evaluate the safe and effective dose conversion from Levothyroxine to North Star therapy.

Inclusion Criteria:Diagnosed with primary hypothyroidismOn continuous thyroid replacement therapy for at least 6 months before Study EntryOn a stable daily dose of LT4 for a minimum of 12 weeks prior to ScreeningAgree to practice a method of contraceptionFemale patients not pregnant or lactating at ScreeningAgree to practice a method of contraception of greater than 90% reliabilityWilling to give written informed consent for the StudyProvide written authorization for use and disclosure of protected health informationExclusion Criteria:Any clinical condition or previous surgery that might affect the absorption, distribution, biotransformation or excretion of North Star or levothyroxineHospitalization for a major illness within 4 weeks prior to ScreeningAnticipated initiation or change in concomitant medicationsConcomitant use of prohibited medications or supplementsParticipated in another investigational new drug study within 30 days or 5 half-lives of the IMP, whichever is longer, prior to the first study drug administration.For female subjects, be pregnant, nursing or planning to become pregnant during the study