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 thesubject has been informed of all pertinent aspects of the study and is willing andable to participate.

• Have diagnosis of X-linked adrenoleukodystrophy (X-ALD) by genetic testing andelevated 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 performedwithin the last 12 months or MRI at screening

• Have been treated with any drug targeting TRβ or with any drug being tested astherapy 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 oroncological that in the opinion of the investigator would pose a significant riskfor the subject

• Subject has untreated primary adrenal insufficiency based on morning plasma cortisoland ACTH at screening

• Lorenzo's Oil. Currently taking Lorenzo's Oil or erucic acid containing product, orother lipid lowering agent known to effect VLCFA levels