The Safety, Tolerability and Pharmacokinetic Study of HEC585 in Healthy Male and Female Subjects

This will be a double-blind, placebo-controlled, single, and multiple oral dose study
conducted in 2 parts.

Part A will comprise a single-dose, sequential-group study incorporating a food effect
evaluation. Up to 48 subjects will be studied in up to 6 groups (Groups A1 to A6), with each
group consisting of 8 subjects. Each subject will participate in 1 treatment period only and
reside at the clinical research unit (CRU) from Day -1 (the day before dosing) to Day 7 (144
hours postdose), except for Group A3, which will participate in a second treatment period for
a food effect evaluation. Each subject in Group A3 will participate in 2 treatment periods
separated by a minimum of 7 days. Dosing of subjects in the fed state in Group A3 can
commence after review of the safety data from Group A4.

Part B will comprise a multiple-dose, sequential-group study. Up to 36 subjects will be
studied in up to 3 groups (Groups B1 to B3), with each group consisting of 12 subjects. Part
B of the study may start after completion of Group A5, at a dose equal or less than given in
Groups A1 to A3.

Inclusion Criteria:

1. Males or females, of any race, between 18 and 60 years of age, inclusive, at
Screening.

2. Body mass index between 18.0 and 32.0 kg/m2, inclusive, at Screening.

3. In good health, determined by no clinically significant findings from medical history,
physical examination, 12-lead ECG, vital sign measurements, and clinical laboratory
evaluations (congenital nonhemolytic hyperbilirubinemia [eg, Gilbert's syndrome] is
not acceptable) at Screening and/or Check-in as assessed by the Investigator (or
designee).

4. Females will be nonpregnant and nonlactating. Females of childbearing potential and
male subjects will agree to use contraception.

5. Able to comprehend and willing to sign an informed consent form (ICF) and to abide by
the study restrictions.

Exclusion Criteria:

1. Significant history or clinical manifestation of any metabolic, allergic,
dermatological, hepatic, renal, hematological, pulmonary, cardiovascular,
gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder, as
determined by the Investigator (or designee).

2. History of significant hypersensitivity, intolerance, or allergy to any drug compound,
food, or other substance, unless approved by the Investigator (or designee).

3. History of stomach or intestinal surgery or resection that would potentially alter
absorption and/or excretion of orally administered drugs (uncomplicated appendectomy
and hernia repair will be allowed).

4. History of alcoholism or drug/chemical abuse within 2 years prior to Check-in.

5. Alcohol consumption of > 21 units per week for males and > 14 units for females. One
unit of alcohol equals 12 oz (360 mL) beer, 1½ oz (45 mL) liquor, or 5 oz (150 mL
wine), or a positive alcohol breath test at Check-in.

6. Positive urine drugs of abuse screen including cotinine at Screening or Check-in.

7. Positive hepatitis B surface antigen, hepatitis C virus antibody and/or positive human
immunodeficiency virus (HIV) test (Appendix 3).

8. Absolute lymphocyte count below the lower limit of normal which can be confirmed by
repeat.

9. Participation in a clinical study involving administration of an investigational drug
(new chemical entity) in the past 30 days or 5 half-lives (if known), whichever is
longer, prior to Check-in.

10. Use or intend to use any medications/products known to alter drug absorption,
metabolism, or elimination processes, including St. John's Wort, within 30 days prior
to Check-in, unless deemed acceptable by the Investigator (or designee). Strong CYP3A
inhibitors and inducers should be avoided.

11. Use or intend to use any prescription medications/products, within 14 days prior to
Check-in, unless deemed acceptable by the Investigator (or designee).

12. Use or intend to use any nonprescription medications/products including vitamins,
minerals, and phytotherapeutic/herbal/plant-derived preparations within 7 days prior
to Check-in, unless deemed acceptable by the Investigator (or designee).

13. Use of tobacco- or nicotine-containing products within 3 months prior to Check-in.

14. Consumption of foods and beverages containing poppy seeds, grapefruit, or Seville
oranges within 7 days prior to Check-in, consumption of caffeine-containing foods and
beverages within 72 hours prior to Check-in, or consumption of alcohol within 48 hours
prior to Check-in.

15. Receipt of blood products within 2 months prior to Check-in.

16. Donation of blood from 56 days prior to Screening, plasma from 2 weeks prior to
Screening, or platelets from 6 weeks prior to Screening.

17. Poor peripheral venous access.

18. Have previously completed or withdrawn from this study, and have previously received
the investigational product.

19. Subjects who, in the opinion of the Investigator (or designee), should not participate
in this study.