Efficacy and Safety of HB-1 for Panic Disorder

Inclusion Criteria:

1. Male or female aged 18 to 65 years old, inclusive, at the time of informed consent.

2. Meets Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-V)Criteria for Panic Disorder.

3. Minimum of one full, unexpected panic attack in week prior to screening (viaDiagnostic and Statistical Manual of Mental Disorders 5th edition [DSM-V] basedstructured interview).

4. Medically stable on current medication regimen for at least 3 months (including asneeded [PRN] medications), as determined by Investigator.

5. Willing to remain on current doses of other psychiatric medications throughout thelength of the trial.

6. Willing and able to safely stop / avoid any of the following prior to study trial:Inhibitors or inducers of CYP3A4 (grapefruit juice, erythromycin, ritonavir,telithromycin, rifampin), HMG-CoA Reductase Inhibitors (Simvastatin, Lovastatin,Atorvastatin), Beta Blockers (Timolol eyedrops, Metoprolol), Neuromuscular BlockingAgents (curare-like and depolarizing), Antihypertensive Agents (Prazosin andvasodilators, angiotensin-converting enzyme inhibitors, diuretics, beta blockers),Inhalation Anesthetics, Disopyramide, Flecainide, Quinidine, Cimetidine, Lithium,Carbamazepine, Phenobarbital, Cyclosporine, Digitalis, Aliskiren, Ramipril andRamiprilat, aspirin, propranolol.

7. Willing and able to safely stop / avoid sensitive P-glycoprotein inhibitors.

8. Willing to take HB-1, telmisartan, verapamil, or placebo.

9. Willing and able to provide informed consent indicating an understanding of therequirements of the study and a willingness to comply with scheduled visits and allstudy procedures.

10. Female subjects must be surgically sterile (or have a monogamous partner who issurgically sterile) or be at least 2 years postmenopausal or commit to use 2acceptable forms of birth control (defined as the use of an intrauterine device, abarrier method with spermicide, condoms, any form of hormonal contraceptives, orabstinence) for the duration of the study and for 4 months following the last doseof study treatment. Male subjects must be sterile (biologically or surgically) orcommit to the use of a reliable method of birth control (condoms ± spermicide) forthe duration of the study and for 4 months following the last dose of studytreatment. Individuals who are involved exclusively in same-sex relationships areexempt from the birth control requirements but must agree to abide by therecommendations if they do engage in a heterosexual relationship.

11. Female subjects who are women of childbearing potential (WOCBP) must have a negativepregnancy test at Screening, within 7 days of dosing with study treatment.

Exclusion Criteria:

1. Any concomitant disease, condition, or treatment that could interfere with theconduct of the study, or that would, in the opinion of the Investigator or Sponsor,pose an unacceptable risk to the participant in the study or interfere with theinterpretation of study data.

2. Concurrent treatment with benzodiazepines (e.g. alprazolam, diazepam, clonazepam,lorazepam) as assessed by clinical interview and urine toxicology testing.

3. Severe Agoraphobia (Panic Disorder Symptom Severity Scale (PDSS) Item 4 "agoraphobicfear/avoidance" > 2).

4. Severe Generalized Anxiety (Hamilton Anxiety Rating Scale [HAM-A] Total Score > 23).

5. Prior lifetime history of suicide attempt, Columbia Suicide Severity Rating Scale (C-SSRS) ≥ 4 in the past 6 months or prior lifetime history of hospitalization fordepression.

6. Diagnosis of Substance Use Disorder, Obsessive-Compulsive Disorder (OCD), Bipolar I,Bipolar II disorder or schizoaffective or other psychotic disorders (per StructureClinical Interview for Diagnostic and Statistical Manual of Mental Disorders 5thEdition (DSM-V) [SCID-V].

7. Severe uncontrolled cardiac disease within 6 months of Screening, including but notlimited to uncontrolled hypertension, hypotension (defined as below 90/60); unstableangina; myocardial infarction (MI) or cerebrovascular accident (CVA).

8. Any clinically significant electrocardiogram (ECG) abnormalities at screening.

9. Inadequate hepatic function defined as total bilirubin > 1.5 × the upper limit ofnormal (ULN) ranges of each institution, aspartate aminotransferase (AST) andalanine aminotransferase (ALT) > 3 × the ULN range of each institution.

10. Inadequate renal function defined as serum creatinine > 1.5 × the upper limit ofnormal (ULN) range of each institution and/or estimated glomerular filtration rate (eGFR) < 60.

11. Any clinically significant abnormalities in clinical laboratory assessments asassessed by the Investigator.

12. Any other systemic conditions or organ abnormalities that in the opinion of theInvestigator may interfere with the conduct and/or interpretation of the currentstudy.

13. Unable to complete neuropsychological testing.

14. Already on treatment with either telmisartan or verapamil or both.

15. Has a history of hypersensitivity or severe allergic reaction to either telmisartanor verapamil, or any component of either licensed drug.

16. Documented contraindication to taking telmisartan or verapamil: (e.g., Duchenne'smuscular dystrophy, myasthenia gravis).

17. Pregnant or breastfeeding.

18. Participation in another current clinical trial or prior trial within the last threemonths.

19. Urinalysis evidence of exposure to substances that may interfere with HB-1 testing (per investigator discretion).