The Influence of ANS-6637 on Midazolam Pharmacokinetics in Healthy Volunteers

Opioid use causes a myriad of effects which contribute to significant morbidity and early
mortality, and is associated with risky sexual behavior and injection drug use (IDU), two
major forms of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) transmission in
urban and suburban United States. Through these high-risk behaviors, persons with opioid use
disorder (OUD) develop both direct comorbidities (e.g. blood stream infections and infectious
endocarditis), as well as risk-associated illnesses (e.g. sexually transmitted infections,
HCV and hepatitis B virus [HBV]) which have considerable downstream health care effects. As
such, there is a need for pharmacologic agents in the treatment of OUD that go beyond
avoidance of withdrawal and facilitate decreased frequency or complete cessation of opioid
use.

The biologic mechanism of OUD, common to all forms of addiction, is a conditioned drug
cue-related response in the CNS, causing a dopamine surge. If effective, a central
pharmacologic strategy targeting the aberrant reward circuitry seen in OUD could potentially
reduce drug craving and result in opioid abstinence.

In the SEARCH Pharmacokinetic (PK) investigation, we aim to understand the pharmacokinetic
signal of the novel, oral agent ANS-6637, an aldehyde dehydrogenase 2 (ALDH-2) inhibitor that
has the potential to reduce dopamine surge in the CNS and inhibit opioid craving. In
preclinical studies, the active metabolite of ANS-6637, GS-548351, showed substrate dependent
inhibition of CYP3A in vitro, with little or no inhibitory effect on the activities of other
cytochrome P450 (CYP) enzymes. As such, the current investigation seeks to explore the
potential inhibition of CYP3A by ANS-6637 with the FDA-recommended CYP3A probe substrate,
midazolam.

-INCLUSION CRITERIA:

1. Must have the ability to understand and must personally sign a written informed
consent form, which must be obtained prior to initiation of study procedures.

2. Must be between 18 and 65 years of age, inclusive.

3. Must have discontinued use of nicotine and nicotine containing products including
vaping or juuling from 90 days prior to study drug dosing and throughout the study
duration.

4. Must be willing to abstain from any food or beverages containing alcohol 72 hours
prior to first dose and through follow-up visit.

5. Must be willing to abstain from cannabis 72 hours prior to first dose and through
follow-up visit.

6. Must be willing to abstain from caffeine (including tea, coffee, chocolate) or
grapefruit, Seville orange juice or other methyl xanthine containing foods (e.g.
theophylline, theobromine, tea leaves, yerba mate, kola nuts and guarana berries) 72
hours prior to the first dose and through follow- up visit.

7. Must have a body mass index (BMI) from 19 to 30 kg/m^2 (inclusive) at screening.

8. Must be human immunodeficiency virus type 1 (HIV-1) antibody negative at screening.

9. Must be hepatitis B (HBV) surface antigen negative at screening.

10. Must be hepatitis C (HCV) antibody or RNA negative at screening.

11. Male subjects must refrain from sperm donation from clinic admission, throughout the
study period, and continuing for at least 90 days following the last dose of study
drug.

12. Subjects must refrain from blood donation from clinic admission, throughout the study
period, and continuing for at least 30 days following the last dose of study drug.

13. Must be willing to comply with contraception guidelines below Contraception:

The fetal risks associated with ANS-6637 are not known, but pre- clinical animal data
demonstrate some risk. Subjects must agree not to become pregnant or impregnate a
female. Females of childbearing potential must have a reproductive risk assessment
done to determine the risk of undetectable pregnancy at study start [i.e. sexual and
contraceptive history for 30 days preceding screening] pregnancy test at screening and
baseline (Day 0). For the duration of the study, subject and their partners must
practice must use two non-hormonal methods of birth control, having begun no less than
30 days, without interruption, prior to screening. They must continue to use both
methods until 3 months after stopping the study drug. Two of the three methods of
birth control listed below MUST be used, or an alternative combination offering very
high efficacy, per the PI, in consultation with the Sponsor Medical Monitor may be
considered:

- Male or female condoms [but not both] with a spermicide

- Diaphragm with a spermicide

- Intrauterine device (IUD)

If pregnancy is suspected or should occur, subjects must notify the study staff
immediately.

14. Must, in the opinion of the Investigator, be in good health based upon medical history
and physical examination, and screening laboratory evaluations.

15. Judged to be healthy based on medical history, physical examination, vital signs, and
clinical laboratory tests at screening and Day 0: liver function tests (AST, ALT,
Tbili) less than or equal to upper limit of normal [ULN], platelets (PLT) >150,000/
microliter, hemoglobin (Hgb) >13 g/dL (males); >12 g/dL (females), CK less than or
equal to 2x ULN, Amylase/lipase < ULN, thyroid function tests [TSH and T4] within
normal range, fasting total cholesterol <240 mg/dL, or fasting triglycerides <240
mg/dL, per DAIDS AE table and Toxicity Grading Scale for Healthy Adult and Adolescent
Volunteers Enrolled in Preventive Vaccine Trials AE table for total bilirubin [Tbili]
only.

16. Must be willing and able to comply with all study requirements.

EXCLUSION CRITERIA:

1. Therapy with any prescription, over-the-counter (OTC), herbal, or holistic
medications, including hormonal contraceptives by any route, within 5 half- lives of
the agent prior to receipt of any study medications will not be permitted with the
following exception: Intermittent or short-course therapy (<14 days) with prescription
or OTC medications, herbals, or holistic medications within the screening period prior
to starting study drugs may be permitted after review by the investigators on a
case-by-case basis for potential drug interactions. Receipt of influenza vaccination
will be allowed prior to, during, and/or after the study.

2. Have any serious or active medical, surgical, or psychiatric conditions which, in the
opinion of the Investigator, would interfere with subject treatment, assessment, or
compliance with the protocol.

3. Have previously participated in an investigational trial involving administration of
any investigational compound within 30 days prior to screening.

4. Have current, or a history of mild to severe alcohol use, cannabis or other substance
use disorder including any use of illicit drugs as defined by DSM-5 criteria, within
12 months of first study dose

5. Renal impairment (chronic renal insufficiency of any chronic kidney disease stage, or
acute renal failure not induced by drug therapy defined as eGFR <90 ml/min)

6. Have a positive urine drug test (ethanol, cannabis, barbiturates, cocaine,

opiates, or amphetamines) at Screening or Day 0.

7. History of flushing or intolerance related to alcohol consumption using the NIAAA
screening assessment questionnaire tool for alcohol flushing

8. Inability to obtain venous access for sample collection.

9. Have a history of significant drug sensitivity or drug allergy to any benzodiazepines.

10. Known hypersensitivity to formulation excipients: microcrystalline cellulose,
croscarmellose sodium, magnesium stearate, polyvinyl alcohol, titanium dioxide,
polyethylene glycol, and talc.

11. Have been treated with systemic steroids, immunosuppressant therapies or
chemotherapeutic agents within 3 months of study screening or expected to receive
these agents during the study (e.g., corticosteroids, immunoglobulins, and other
immune- or cytokine-based therapies).

12. Presence or history of clinically significant cardiovascular disease, cardiomyopathy,
and/or cardiac conduction abnormalities.

13. Have clinically significant ECG abnormalities or any of the following ECG
abnormalities at Screening: PR >220 msec; QRS >120 msec; QTcF >450 msec; HR <40 beats
per minute; second or third degree heart block.

14. Have a history or family history of Long QT Syndrome, Brugada syndrome,
Wolfe-Parkinson-White Syndrome, or have a family history of sudden cardiac death or
unexplained death in an otherwise healthy individual between the ages of 1 and 30
years.

15. Have history of syncope, palpitations, unexplained dizziness or chronic nausea or
headaches.

16. Have an implanted defibrillator or pacemaker.

17. Have a history of liver disease, including Gilbert's Disease.

18. Any clinically significant electrolyte abnormality (outside of NIH normal reference
ranges) at screening (e.g., hypokalemia, hypocalcemia, hypomagnesemia) or any
condition that could lead to abnormal electrolyte disturbances (eg, eating disorder).

19. Have a history of taking dopamine antagonists/anti-psychotics.

20. Are unable to comply with study requirements.

21. Positive urine toxicology screen