CDI-988 Safety Study in Healthy Participants

A Phase 1, Randomized, Double-Blinded, Placebo-Controlled, First-in-Human Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of Single-Ascending and Multiple-Ascending Doses of Oral CDI-988 in Healthy Adult Participants

The goal of this clinical trial is to learn about the safety and pharmacokinetics (PK, the amount of drug in the blood) of a new drug called CDI-988 in healthy volunteers.

The main questions it aims to answer are:

• Are there any side effects of the drug?
• What is the amount of drug that reaches the bloodstream? Participants will be assigned by chance to take either CDI-988 or placebo by mouth and have physical exams, electrocardiograms (ECGs), vital signs, and blood tests to look for any side effects.

Study Overview

• Status: Completed
• Conditions: Healthy Volunteers
• Intervention / Treatment: Drug: Placebo; Drug: CDI-988

Detailed Description

CDI-988 is a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) 3-chymotrypsin-like (3CL) protease inhibitor for oral administration. This study is being conducted in 2 parts to examine the safety, tolerability, and PK of CDI-988 in healthy participants. Part 1 will entail escalating single doses in sequential cohorts and Part 2 will enroll escalating multiple-dose cohorts. Participants will be monitored for adverse events, vital signs, laboratory values, and electrocardiograms (ECGs).

• Study Type: Interventional
• Enrollment (Actual): 116
• Phase: Phase 1

Contacts and Locations

Study Locations

• Australia
  • New South Wales
    • Randwick, New South Wales, Australia, 2031
      • Scientia Clinical Research Pty Ltd

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy males or non-pregnant, non-lactating females
• Body weight of at least 45 kg.
• Body mass index ≥18.0 and ≤32.0 kg/m2
• Good state of mental and physical health
• Negative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test

Exclusion Criteria:

• Received an investigational drug within 30 days
• Received a coronavirus disease 2019 (COVID-19) vaccine within 7 days
• Drug or alcohol abuse in the past 12 months
• Clinically significant abnormal biochemistry, hematology, coagulation, urinalysis test results
• Clinically significant abnormal ECG or vital signs

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Quadruple

Number of Arms

12

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SAD Cohort 1A; first single-dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: SAD Cohort 1B; second single-dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: SAD Cohort 1C; third single-dose level; food-effect cohort	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: SAD Cohort 1D; fourth single-dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: MAD Cohort 2A; first multiple-dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: MAD Cohort 2B; second multiple-dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: MAD Cohort 2C; third multiple-dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: SAD Cohort 1E; fifth dose level; food effect cohort	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: SAD Cohort 1F; sixth dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: MAD Cohort 2D; 4th multiple dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: MAD Cohort 2E; 5th multiple dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor
Experimental: MAD Cohort 2F; 6th multiple dose level	Drug: Placebo; matching placebo; Drug: CDI-988; SARS-CoV-2 3CL protease inhibitor

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse events	number of participants with treatment-emergent adverse events	Day 1 to 7 days after last dose
Laboratory abnormalities	number of participants with clinically significant laboratory abnormalities	Day 1 to 7 days after last dose
Vital signs	number of participants with clinically significant changes from baseline in vital signs	Day 1 to 7 days after last dose
ECGs	number of participants with clinically significant changes from baseline in ECGs	Day 1 to 7 days after last dose

Secondary Outcome Measures

Outcome Measure	Time Frame
Maximum plasma concentration (Cmax)	Day 1 to 3 days after last dose
Time of maximum plasma concentration (Tmax)	Day 1 to 7 days after last dose
Area under the plasma concentration-time curve (AUC)	Day 1 to 3 days after last dose
Elimination rate constant (lambda Z)	Day 1 to 3 days after last dose
Terminal elimination half-life (t1/2)	Day 1 to 3 days after last dose

Collaborators and Investigators

• Sponsor: Cocrystal Pharma, Inc.
• Collaborators: Cocrystal Pharma Australia Pty Ltd.; Beyond Drug Development Pty Ltd.; Resolutum Global Pty Ltd.; Scientia Clinical Research Pty Ltd
• Investigators: Principal Investigator: Christopher Argent, MD, Scientia Clinical Research

Study record dates

Study Major Dates

• Study Start (Actual): September 27, 2023
• Primary Completion (Actual): May 23, 2025
• Study Completion (Actual): July 23, 2025

Study Registration Dates

• First Submitted: July 28, 2023
• First Submitted That Met QC Criteria: July 28, 2023
• First Posted (Actual): August 4, 2023

Study Record Updates

• Last Update Posted (Actual): August 17, 2025
• Last Update Submitted That Met QC Criteria: August 14, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: SARS-CoV-2; Coronavirus
• Other Study ID Numbers: CDI-988-P1-001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No