A Study to Assess the Pharmacodynamics of VK0214 in Male Subjects With AMN

Inclusion Criteria: * Provide a personally signed and dated informed consent document indicating that the subject has been informed of all pertinent aspects of the study and is willing and able to participate. * Have diagnosis of X-linked adrenoleukodystrophy (X-ALD) by genetic testing and elevated VLCFAs. * Present clinical features of AMN, or adrenal insufficiency. * Subjects must be 18 years of age and older. Exclusion Criteria: * Have the cerebral form of X-ALD, based on medical records, or based on MRI performed within the last 12 months or MRI at screening * Have been treated with any drug targeting TRβ or with any drug being tested as therapy for X-ALD AMN form within the past 30 days before screening * History or presence of clinically significant acute or unstable hepatic, renal, gastrointestinal, pulmonary, immunological, endocrine, diabetes, hematological or oncological that in the opinion of the investigator would pose a significant risk for the subject * Subject has untreated primary adrenal insufficiency based on morning plasma cortisol and ACTH at screening * Lorenzo's Oil. Currently taking Lorenzo's Oil or erucic acid containing product, or other lipid lowering agent known to effect VLCFA levels