Study of Sodium Phenylbutyrate (ACER-001) for the Treatment of Patients With Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)

Inclusion Criteria:

• A diagnosis of MCADD and molecular confirmation of at least one copy of the commonc.985A>G mutation.

• ≥16 years of age for cohort 1 and ≥10-15 years of age for cohort 2.

• Able to perform and comply with study activities including overnight admission tothe PCTRC, placement of an IV catheter, and all blood draws.

• Negative pregnancy test for all female subjects of childbearing age.

• Signed informed consent by the subject or parent/guardian of minors.

• All females of childbearing age and all sexually active males must agree to use anacceptable method of contraception throughout the study. Appropriate contraceptivemethods include hormonal contraceptives (oral, injected, implanted, or transdermal),tubal ligation, intrauterine device, hysterectomy, vasectomy, or double barriermethods. Abstinence is an acceptable form of birth control, though appropriatecontraception must be used if the subject becomes sexually active.

Exclusion Criteria:

• Use of any investigational drug within 30 days of Day 1.

• Active infection (viral or bacterial) or any other intercurrent condition asreported by the subject or noted on physical exam at screening.

• Any clinical or laboratory abnormality of Grade 3 or greater severity according tothe CTCAE v5.0, or Grade 3 elevations in liver enzymes, defined as levels 5-20 timesULN in alanine aminotransferase (ALT/SGPT), aspartate aminotransferase (AST/SGOT),or gamma glutamyl transpeptidase (GGT) in a clinically stable subject.

• Any clinical or laboratory abnormality or medical condition that, at the discretionof the investigator, may put the subject at increased risk by participating in thisstudy.

• Use of any medication known to significantly affect renal clearance (e.g.,probenecid) or to increase protein catabolism (e.g., corticosteroids), or othermedication known to increase ammonia levels (e.g., valproic acid or haloperidol),within the 48 hours prior to Day 1 and throughout the study.

• Subjects with renal insufficiency will be excluded from the study. Cutoff eGFR <60mL/min/1.73m2 (GFR categories G3a-G5) will be used as measure of renalinsufficiency.

• Use of sodium benzoate within one week of Day 1.

• Known hypersensitivity to PAA or PBA.

• Breastfeeding or lactating females.

• Subjects at risk of hypokalemia due to pre-existing diagnosis or on medications thatcan cause hypokalemia.

• Subjects with type 1 or type 2 diabetes, or who take medications as part of theirroutine care that can cause hypoglycemia