A Study to Assess the Safety, Tolerability and Pharmacokinetics of Viaca (Sildenafil + Cabergoline) Compared With Sildenafil and Cabergoline

NCT07732387 | Not Yet Recruiting Phase 1 DMC

• 3 other identifiers: CR-067-001EC00372462/26
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This is a Phase 1, open-label, single-ascending-dose study evaluating the safety, tolerability, and pharmacokinetics (PK) of Viaca - a fixed-dose oral combination of sildenafil (a PDE5 inhibitor) and cabergoline (a dopamine D2 agonist) - versus sildenafil monotherapy and cabergoline monotherapy in healthy adult male volunteers. Approximately 30 participants are enrolled across 5 sequential cohorts (6 each). Each participant receives a single oral dose. The combination targets erectile dysfunction through both vascular and neuroendocrine pathways, aiming for efficacy at lower component doses.

Conditions

Erectile Dysfunctions; Healthy Volunteer

Keywords

viaca; sildenafil; cabergoline; erectile dysfunction; PDE5 inhibitor; dopamine agonist; fixed-dose combination; single ascending dose; pharmacokinetics; healthy volunteers; Phase 1

Outcome Measures

Primary Outcomes (9)

• Participants with AEs/SAEs

  Number of participants with treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs). Unit: participants (summarised by severity and relatedness).

  Day 1 (dosing) through Day 8

• Blood pressure

  Change from Baseline in systolic and diastolic blood pressure. Unit: mmHg.

  Baseline through Day 8.

• Pulse rate

  Change from Baseline in pulse rate. Unit: beats/min.

  Baseline through Day 8.

• Respiratory rate

  Change from Baseline in respiratory rate. Unit: breaths/min.

  Baseline through Day 8.

• Body temperature

  Change from Baseline in body temperature. Unit: °C.

  Baseline through Day 8.

• ECG heart rate

  Change from Baseline in 12-lead ECG heart rate. Unit: beats/min.

  Baseline through Day 8.

• ECG intervals

  Change from Baseline in 12-lead ECG intervals (QTcF, PR, QRS). Unit: milliseconds.

  Baseline through Day 8.

• Laboratory tests

  Number of participants with clinically significant safety laboratory abnormalities. Unit: participants.

  Baseline through Day 8.

• Physical examination

  Number of participants with clinically significant physical examination findings. Unit: participants.

  Baseline through Day 8.

Secondary Outcomes (14)

• Cmax

  Predose (Day 1) through 168 hours post-dose (Day 8).

• Tmax

  Predose (Day 1) through 168 hours post-dose (Day 8).

• AUC0-t

  Predose (Day 1) through 168 hours post-dose (Day 8)

• AUC0-24

  Predose (Day 1) through 168 hours post-dose (Day 8).

• AUC0-inf

  Predose (Day 1) through 168 hours post-dose (Day 8).

Study Arms (5)

Cohort 1: Viaca 25/0.25 mg

EXPERIMENTAL

Single oral dose of Viaca (sildenafil 25 mg / cabergoline 0.25 mg; one low-dose tablet) in 6 healthy male participants.

Drug: Viaca

Cohort 2: Viaca 50/0.5 mg

EXPERIMENTAL

Single oral dose of Viaca (sildenafil 50 mg / cabergoline 0.5 mg; one high-dose tablet

Drug: Viaca

Cohort 3: Viaca 75/0.75 mg

EXPERIMENTAL

Single oral dose of Viaca (sildenafil 75 mg / cabergoline 0.75 mg; one low + one high tablet

Drug: Viaca

Cohort 4: Sildenafil 50 mg

ACTIVE COMPARATOR

Single oral dose of sildenafil 50 mg (two 25 mg tablets).

Drug: Sildenafil 50 mg

Cohort 5: Cabergoline 0.5 mg

ACTIVE COMPARATOR

Single oral dose of cabergoline 0.5 mg (one 0.5 mg tablet).

Drug: Cabergoline 0.5 MG

Interventions

Viaca DRUG

fixed-dose oral tablet of sildenafil + cabergoline (low-dose 25/0.25 mg; high-dose 50/0.5 mg). Single oral dose.

Cohort 1: Viaca 25/0.25 mg; Cohort 2: Viaca 50/0.5 mg; Cohort 3: Viaca 75/0.75 mg

Sildenafil 50 mg DRUG

single oral dose

Cohort 4: Sildenafil 50 mg

Cabergoline 0.5 MG DRUG

single oral dose

Cohort 5: Cabergoline 0.5 mg

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male participants, aged 18 to 65 years (inclusive) at the time of informed consent.
• In good general health (Investigator judgement) with no significant medical history and no clinically significant abnormalities on physical examination, vital signs, or 12-lead ECG - including systolic blood pressure 110-140 mmHg (inclusive) at Screening and Day -1 - at Screening and/or before first IP administration.
• BMI ≥ 18.0 and ≤ 32.0 kg/m² and weight ≥ 50 kg.
• Nonsmoker or casual smoker (\< 5 cigarettes/week equivalent) with no tobacco use within 2 months prior to Screening (Investigator discretion).
• Clinical laboratory values within normal range (or not clinically significant per Investigator).
• Fertile men agree to acceptable contraception from Screening until 90 days after last IP dose, and no sperm donation from first dose until ≥ 90 days after last dose.
• Able and willing to attend required study visits.
• Able and willing to provide written informed consent before any study procedures.

You may not qualify if:

• Physical or psychological condition that would impair protocol compliance or study completion (Investigator judgement).
• History of, or condition that would contraindicate study medication or interfere with study evaluations (Investigator judgement).
• Previous history of any of: myocardial infarction; cerebrovascular accident; arrhythmia; congestive heart failure; unstable angina; recent (\<6 months) need for calcium-channel/beta-blocker/nitrate/anti-epileptic therapy; uncontrolled hypertension (SBP \>140 or DBP \>100 mmHg); hypotension (SBP \<90 or DBP \<60 mmHg) incl. syncope/orthostatic/vasovagal; pulmonary/pericardial/retroperitoneal fibrotic disorders; sickle-cell disease or trait; cardiac valve disease; severe psychiatric disorders; Raynaud's/vasospastic disorders; bariatric surgery (cholecystectomy acceptable).
• Blood/plasma donation or significant blood loss (450 mL) within 30 days prior to first IP dose.
• Fever (\>38°C) or symptomatic viral/bacterial infection within 2 weeks prior to Screening.
• Infections requiring parenteral antibiotics within 1 month prior to Screening.
• Concomitant use of an indwelling urethral catheter.
• Concomitant nitrates/nitric-oxide donors, potent CYP3A4 inhibitors (e.g. ritonavir, indinavir, ketoconazole) or moderate inhibitors (e.g. erythromycin); unwilling to avoid St. John's wort and CYP3A4-active herbals (e.g. grapefruit) within 14 days prior and throughout the study.
• Medications that significantly affect BP: nitrates (any form), alpha-blockers (e.g. doxazosin, terazosin, tamsulosin), guanylate cyclase stimulators (e.g. riociguat).
• Positive HCV antibody, HBsAg, or HIV antibody.
• Live vaccine within 4 weeks prior to first IP dose.
• Poor pill-swallowing ability or poor venous access.
• History of severe allergic/anaphylactic reactions or sensitivity to IP or constituents.
• History of malignancy (except non-melanoma skin cancer excised \>5 years prior to Screening).
• Clinically significant abnormal Screening ECG (e.g. QRS ≥ 120 msec and/or QTcF \> 450 msec, per Investigator).

Sponsors & Collaborators

• Yanping Kong: lead
• Novotech (Australia) Pty Limited: collaborator

Study Sites (1)

Nucleus Network Brisbane

Herston, Queensland, 4006, Australia

Location

MeSH Terms

Conditions

Erectile Dysfunction

Interventions

Sildenafil Citrate; Cabergoline

Condition Hierarchy (Ancestors)

Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Sexual Dysfunction, Physiological; Male Urogenital Diseases; Sexual Dysfunctions, Psychological; Mental Disorders

Intervention Hierarchy (Ancestors)

Sulfonamides; Amides; Organic Chemicals; Sulfones; Sulfur Compounds; Piperazines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Purines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Ergolines; Ergot Alkaloids; Alkaloids; Heterocyclic Compounds, 4 or More Rings

Study Officials

• Emma Trowbridge, MD

  Nucleus Network Brisbane

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Clinical Research Coordinator at Nucleus Network Brisbane

CONTACT

1800 243 733; brisbane@nucleusnetwork.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: MD, PhD, President, Kong's Pharmaceutical Co.

Study Record Dates

• First Submitted: July 13, 2026
• First Posted: July 28, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): September 19, 2026
• Study Completion (Estimated): September 19, 2026
• Last Updated: July 28, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

AU (1)