A Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of CB06-036 in Subjects With Chronic Hepatitis B

Inclusion Criteria:

1. Provide written informed consent before any study assessment is performed. 2.Male or nonpregnant, nonlactating female between the ages of 18 and 65 years (inclusive) at screening.

Females of childbearing potential (as defined in Appendix 3) must have a negative serum pregnancy test at screening and a negative urine or serum pregnancy test at baseline prior to enrollment and agree to use 2 methods of birth control. Methods must include 1 highly effective method with a secondary method of birth control during the study and for 3 months following the last dose of CB06-036. These methods are defined in Appendix 3.

Note: Females must agree not to breastfeed during the study and 30 days after receiving the last administration of CB06-036 and not to donate eggs (ova, oocytes) for assisted reproduction during the study and 90 days after receiving the last administration of CB06-036. Females of nonchildbearing potential defined as permanently sterile (ie, due to hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) or postmenopausal, as defined in Appendix 3.

Males with a female partner(s) of childbearing potential will agree to use contraception as detailed in Appendix 3. Male subjects must not donate sperm during the study and for at least 90 days after the last administration of CB06-036.

3. Documented evidence of chronic HBV infection (eg, HBsAg positive for more than 6months) with detectable HBsAg level at screening. Cohort 4 only: qHBsAg should be <3000 IU/mL.

4. Have been on commercially available HBV NA treatment(s) (tenofovir alafenamide,tenofovir disoproxil fumarate, entecavir, either as a single agent or incombination) for at least 6 months with no change in regimen for 3 months prior toscreening.

5. HBV DNA <90 IU/mL; measured at least once by local laboratory assessment within 6months prior to screening.

6. HBV DNA <90 IU/mL at screening. 7. Body mass index (BMI) of 18.0 to 32.0 kg/m2 (inclusive), and a total body weight ≥50.0 kg for males and ≥45.0 kg for females atscreening.

7. Electrocardiogram (ECG) without clinically significant abnormalities and with QTinterval corrected using Fridericia's formula (QTcF) ≤450 msec for males and ≤470msec for females at screening.

8. Willing and able to comply with scheduled visits, treatment plan, laboratory tests,and other study procedures as specified in the protocol.

Exclusion Criteria:

1. CHB patients with extensive bridging fibrosis or cirrhosis (METAVIR ≥3 or Ishak ≥4 by a liver biopsy within 5 years, FibroTest score >0.48 and APRI >1, or ahistoric FibroScan >9 kPa within 6 months prior to screening).

2. Subjects met any of the following laboratory parameters at screening:

3. hemoglobin <12 g/dL (for males) or <11 g/dL (for females)

4. white blood cell count <2500 cells/mm3 Protocol CONFIDENTIAL Labcorp DrugDevelopment Study: 000000244098 Protocol Reference: CB06-036-102 ProtocolVersion 1.0, 24 January 2023 Page 8 of 68

5. neutrophil count <1500 cells/mm3 (or <1000 cells/mm3 if considered aphysiological variant in a subject of African descent)

6. ALT >2 × ULN

7. INR >ULN unless the subject is stable on an anticoagulant regimen affecting INR

8. albumin <3.5 g/dL

9. direct bilirubin >1.5 × ULN

10. platelet Count <100,000/μL

11. estimated creatinine clearance (CrCl) <60 mL/min (using the Cockcroft-Gaultmethod). 3.Active systemic infections (other than common cold) within 2 weeks beforerandomization. 4.At screening, known history of lymphoma, leukemia, or malignancy within thepast 5 years, except for squamous epithelial carcinomas of the skin that havebeen resected with no evidence of metastatic disease for 3 years. 5.History or suspicion of hepatocellular carcinoma (ie, elevated alphafetoprotein (AFP) >50 ng/mL; suggestive lesions on abdominal ultrasound orother imaging). 6.History or presence of a medical condition associated with liver diseaseother than HBV infection (eg, hemochromatosis, autoimmune hepatitis, alcoholicliver disease, toxin exposure, thalassemia, moderate to severe nonalcoholicsteatohepatitis). Other known clinically significant hepatic or biliaryabnormalities (with the exception of Gilbert's syndrome or asymptomaticgallstones). 7.History of transaminase (ALT and/or AST) flare in the previous 6 months priorto study enrollment. 8.Personal or familial history or symptomatology indicative of a risk of immunemediated disease (eg, inflammatory bowel disease, idiopathic thrombocytopenicpurpura, lupus erythematosus, autoimmune hemolytic anemia, scleroderma, severepsoriasis, rheumatoid arthritis, autoimmune uveitis, multiple sclerosis). 9.Received a solid organ or bone marrow transplant. 10.Received prolongedsystemic therapy with immunomodulators (eg, corticosteroids) or biologics (eg,monoclonal antibody, interferon) within 3 months of screening. 11.Blood donation of approximately 500 mL within 56 days prior to firstadministration of study drug, plasma from 2 weeks prior to screening, orplatelets from 6 weeks prior to screening. 12.Have a known history of asthma. Note: Subjects with resolved childhoodasthma with no history of hospitalization due to asthma are allowed. 13.Current use of strong and moderate CYP3A4 inhibitors or inducers; please seeAppendix 6 for a list. 14.Are currently enrolled in, or discontinued from, a clinical trial involvingan investigational product or non-approved drug within the last 4 weeks or atleast 5 half-lives of the last dosing, if the half-life of the investigationalproduct or non-approved drug is greater than 5 days; or concurrently enrolledin any other types of medical research judged not to be scientifically ormedically compatible with this study. 15.live vaccination during the course of the study, or have participated in avaccine clinical trial within 12 weeks prior to randomization. Investigatorsshould review the vaccination status of the subjects and follow the localguidelines for adult vaccination with non-live vaccines intended to preventinfectious disease prior to administration of study drug. 16.Co-infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV) or hepatitis D virus (HDV). • Subjects who are HCV Ab positive, but have a documented negative HCV RNA, areeligible. 17.Abnormal clinical laboratory values at screening that, in the opinion of theinvestigator, pose an unacceptable risk to the subject or of interfering withthe interpretation of study results if participating in the study. 18.Pregnant or nursing (lactating) women, where pregnancy is defined as thestate of a female after conception and until the termination of gestation,confirmed by a positive human chorionic gonadotropin laboratory test atscreening or at Days -7 to -4. 19.Have any other condition that precludes the subject from following andcompleting the protocol in the opinion of the investigator. 20.Significant history or clinical manifestation of any metabolic, allergic,dermatologic, hepatic, renal, hematologic, pulmonary, cardiovascular,gastrointestinal, neurological, respiratory, endocrine, retinal, or psychiatricdisorder, as determined by the investigator (or designee). 21.History of stomach or intestinal surgery or resection that would potentiallyalter absorption and/or excretion of orally administered drugs (uncomplicatedappendectomy and hernia repair will be allowed). 22.Use or intend to use any nonprescription medications or products includingvitamins, minerals, and herbal supplements (ie, traditional Chinese medicine),protein powders or fish oils preparations within 7 days prior to screening,considered to potentially impact subject safety or the objectives of the study,as determined by the investigator (or designee). 23.Alcohol consumption of >21 units per week for males and >14 units forfemales. One unit of alcohol equals 12 oz (360 mL) beer, 1½ oz (45 mL) liquor,or 5 oz (150 mL) wine. 24.Ingestion of Seville orange or grapefruit-containing foods or beverageswithin 7 days prior to screening.