Study of CD388 for the Prevention of Influenza in Subjects Not at Risk for Influenza Complications

NCT06609460 | Completed Phase 2 DMC FDA Drug

• 1 other identifier: CD388.SQ.2.05
• Study Type: interventional
• Target: 5,071
• Locations: 2 countries
• Sites: 57

Brief Summary

The purpose of this study is to evaluate the effectiveness of CD388 in preventing symptomatic laboratory-confirmed influenza infections, as compared to placebo, and to select a dose of CD388 that is effective in preventing the same, when administered as a single dose via 3 subcutaneous (SQ) injections to adult participants in stable health, and to evaluate the safety and tolerability of CD388, as compared to placebo.

Conditions

Influenza

Outcome Measures

Primary Outcomes (2)

• Percentage of Participants Experiencing Protocol-defined Influenza-like Illness (ILI) Occurring ≥7 Days after and up to 24 Weeks after Administration of Study Drug

  Percentage of participants experiencing protocol-defined ILI occurring after administration of CD388, with central laboratory-confirmed reverse-transcriptase polymerase chain reaction positive (RT-PCR+) influenza infection based on the nasopharyngeal (NP) swab result, as compared to placebo.

  From Day 8 up to 24 weeks after study drug dosing

• Incidence and Severity of Treatment-Emergent Adverse Events (TEAEs) after Administration of Study Drug

  Safety and tolerability of CD388, as compared to placebo, will be evaluated by assessing the number of participants with incidences of TEAEs following the administration of study drug. TEAEs include but are not limited to adverse events (AEs), serious adverse events (SAEs), injection site reactions (ISRs), and any potentially clinically significant changes from baseline seen in vital signs, 12-lead electrocardiograms (ECGs), and clinical laboratory parameters.

  From Day 1 through Day 197/End of Study (EOS) after study drug dosing

Secondary Outcomes (14)

• Percentage of Participants Experiencing Protocol-defined ILI Occurring ≥7 Days after and up to 28 Weeks after Administration of Study Drug

  From Day 8 up to 28 weeks after study drug dosing

• Percentage of Participants Experiencing Protocol-defined ILI (as in Primary Endpoint 1) Except with a Lower Threshold for New Onset of Fever

  From Day 8 up to 24 weeks after study drug dosing

• Percentage of Participants Experiencing Protocol-defined ILI (as in Primary Endpoint 1) Except the Influenza Infection is Based on the Midturbinate (MT) Swab Result

  From Day 8 up to 24 weeks after study drug dosing

• Percentage of Participants Experiencing an Influenza Infection AND New Onset of Fever AND New Onset of ≥2 Respiratory Symptoms after Administration of Study Drug

  From Day 8 up to 24 weeks after study drug dosing

• Percentage of Participants Experiencing an Influenza Infection AND New Onset of ≥2 Respiratory Symptoms after Administration of Study Drug

  From Day 8 up to 24 weeks after study drug dosing

Study Arms (4)

CD388 Low Dose

EXPERIMENTAL

Participants are randomized to receive a low dose of CD388 by SQ injection. Participants are randomized at a 1:1:1:1 ratio across the 4 arms.

Combination Product: CD388 Injection

CD388 Medium Dose

EXPERIMENTAL

Participants are randomized to receive a medium dose of CD388 by SQ injection. Participants are randomized at a 1:1:1:1 ratio across the 4 arms.

Combination Product: CD388 Injection

CD388 High Dose

EXPERIMENTAL

Participants are randomized to receive a high dose of CD388 by SQ injection. Participants are randomized at a 1:1:1:1 ratio across the 4 arms.

Combination Product: CD388 Injection

Placebo

PLACEBO COMPARATOR

Participants are randomized to receive placebo by SQ injection. Participants are randomized at a 1:1:1:1 ratio across the 4 arms.

Combination Product: Placebo

Interventions

CD388 Injection COMBINATION_PRODUCT

CD388 liquid for injection

CD388 High Dose; CD388 Low Dose; CD388 Medium Dose

Placebo COMBINATION_PRODUCT

Placebo to match

Placebo

Eligibility Criteria

• Age: 18 Years - 63 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Willing and able to provide written informed consent and comply with scheduled visits, laboratory tests, and other study procedures.
• Males and females 18 to less than 64 years of age.
• In the Investigator's clinical judgment, is in stable health at the time of screening and randomization. Participants may not have underlying hematologic, oncologic, renal, autoimmune, and/or cardiopulmonary illnesses or be considered at risk of developing complications from influenza infection per the CDC guidelines (chronic obstructive pulmonary disease \[COPD\], asthma, immune compromised current cancer \[except non-melanomatous skin cancer\], or diabetes). Subjects will be included on the basis of medical history and vital signs taken between signing of the informed consent and randomization.
• Body mass index (BMI; calculated as weight in kilograms \[kg\] divided by height in meters \[m\] squared) of 18.0 kg/m\^2 to 35.0 kg/m\^2 (inclusive).
• Women of childbearing potential (WOCBP) must:
• Have a negative pregnancy test (beta-human chorionic gonadotropin \[β-hCG\]) at screening, AND
• Be practicing a highly effective, preferably user-independent method of contraception (failure rate of less than 1 percent per year when used consistently and correctly) from ≥2 weeks prior to randomization and agrees to remain on a highly effective method from Day 1 until 32 weeks after study drug administration, the end of relevant systemic exposure. The Investigator should evaluate the potential for contraceptive method failure (e.g., noncompliance, recently initiated) in relationship to the day of administration of study drug.
• A woman is considered of childbearing potential (i.e., fertile) following menarche and until becoming postmenopausal, unless permanently sterile. Permanent sterilization methods include hysterectomy, bilateral salpingectomy, and bilateral oophorectomy. A postmenopausal state is defined as no menses for 12 months without an alternative medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm a postmenopausal state in women not using hormonal contraception or hormonal replacement therapy. However, in the absence of 12 months of amenorrhea, a single FSH measurement is insufficient.
• Female participants must agree not to donate or freeze eggs (ova, oocytes) for future use for the purposes of assisted reproduction from Day 1 until 32 weeks after study drug administration.
• Male participants must wear a condom when engaging in any activity that allows for passage of ejaculate to another person from Day 1 until 32 weeks after study drug administration. Male participants should also be advised of the benefit for a female partner to additionally use a highly effective method of contraception, as condoms could break or leak.
• Note: Contraceptive (birth control) use by participants should be consistent with local regulations regarding the acceptable methods of contraception for those participating in clinical studies.
• Male participants must agree not to donate sperm from Day 1 until 32 weeks after study drug administration.
• Participant agrees not to donate blood from Day 1 until 32 weeks after study drug administration.
• Must be able to read, understand, and complete questionnaires in the electronic diary (eDiary), work with smartphones/tablets/computers, and be willing and able to adhere to the prohibitions and restrictions specified in this protocol. If an appropriate language version is not available for the eDiary assessments, the participant should not be enrolled.
• Must be willing to provide verifiable identification, has means to be contacted, and is able to contact the Investigator/study site and communicate reliably during participation in the study.

You may not qualify if:

• Known or suspected allergy or history of anaphylaxis or other serious adverse reactions to zanamivir (following administration of inhaled or intravenous formulations), monoclonal antibodies (including crystallizable fragment \[Fc\] domains), or any of the components of CD388 or placebo.
• Have been diagnosed with influenza (i.e., with medical history \[including verbal\] of influenza) within the past 6 months prior to randomization.
• Has received the current seasonal influenza vaccine prior to screening or is planning to receive the seasonal vaccine during trial participation.
• Has an acute illness (including acute respiratory illnesses) or body temperature ≥38.0ºC (≥100.4 degrees Fahrenheit \[ºF\]) within 7 days prior to study drug administration (Note: Enrollment at a later date, subsequent to resolution \[within the screening period\] is permitted).
• Has had close contact (including household contacts) with someone with laboratory-confirmed influenza or with someone who has been treated with antiviral therapies for influenza within the past 7 days prior to randomization.
• Has had close contact (including household contacts) with someone with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19) as defined by the US CDC or has had a positive SARS-CoV-2 test within 10 days prior to screening. Please note SARS-CoV-2 testing is NOT required during screening.
• Has a serious and/or clinically unstable condition such as psychiatric condition, including recent (within the past year) or active suicidal ideation/behavior, Alzheimer's disease, or any other condition for which, in the opinion of the Investigator, participation would not be in the participant's best interest or that could prevent, confound, or limit the protocol-specified assessments.
• Had major surgery (e.g., major cardiopulmonary or abdominal operations) per Investigator judgment within 4 weeks prior to randomization, or will not have fully recovered from surgery, or has major surgery planned during the time the participant is expected to participate in the study.
• Screening ECG findings of prolonged QT interval corrected for heart rate using Fridericias formula (QTcF) (greater than 450 milliseconds \[msec\] in males or greater than 470 msec in females), prolonged PR interval (greater than 220 msec), second- or third-degree heart block, or other clinically significant dysrhythmias.
• At the time of screening, any finding that may significantly increase the risk of participation in the study, affect the ability to participate in the study, or impair interpretation of the study data.
• Current or planned participation in another clinical study where study intervention is being administered while participating in the current study. Note: Concurrent enrollment is allowed during the follow-up phase of the other clinical study or in case the study intervention in the other clinical study is a marketed product already approved for another indication - exception being if the other study requires study interventions that could affect the safety assessments of the present study (e.g., clinical laboratory tests).
• Prior receipt within the past 30 days or 5 half-lives (whichever is longer) or anticipated receipt of any drug, vaccine, or other biologic agent (e.g., monoclonal antibodies) administered for the prevention or treatment of influenza.
• Prior receipt of any experimental drug, vaccine, or biologic agent within the past 90 days or 5 half-lives (whichever is longer).
• Contraindication to SQ injections and blood draws (e.g., bleeding disorders).
• Has donated ≥450 mL of blood product (1 unit) for any reason within 30 days of screening or plans to donate blood product during the study.

Sponsors & Collaborators

• Cidara Therapeutics Inc.: lead

Study Sites (57)

Pinnacle Research Group, LLC

Anniston, Alabama, 36207, United States

Location

Cullman Clinical Trials

Cullman, Alabama, 35055, United States

Location

Fiel Family and Sports Medicine/CCT Research

Tempe, Arizona, 85283, United States

Location

Del Sol Research Management, LLC

Tucson, Arizona, 85715, United States

Location

Baptist Health Center for Clinical Research

Little Rock, Arkansas, 72205, United States

Location

Velocity Clinical Research - Huntington Park

Huntington Park, California, 90255, United States

Location

Velocity Clinical Research - San Diego

La Mesa, California, 91942, United States

Location

Catalina Research Institute, LLC

Montclair, California, 91763, United States

Location

Profound Research LLC

Oceanside, California, 92058, United States

Location

Acclaim Clinical Research

San Diego, California, 92120, United States

Location

Lynn Institute of the Rockies

Colorado Springs, Colorado, 80918, United States

Location

Critical Care, Pulmonary & Sleep Associates, PLLP/CCT Research

Lakewood, Colorado, 80228, United States

Location

Alliance for Multispecialty Research, LLC

Fort Myers, Florida, 33912, United States

Location

Nature Coast Clinical Research

Inverness, Florida, 34452, United States

Location

Health Awareness, LLC

Jupiter, Florida, 33458, United States

Location

South Florida Research Center, Inc.

Miami, Florida, 33135, United States

Location

Clinical Site Partners, LLC dba Flourish Research

Miami, Florida, 33186, United States

Location

Floridian Clinical Research

Miami Lakes, Florida, 33016, United States

Location

Healthcare Clinical Data, Inc.

North Miami, Florida, 33161, United States

Location

DelRicht Research

Atlanta, Georgia, 30329, United States

Location

Velocity Clinical Research - Boise

Meridian, Idaho, 83642, United States

Location

Optimal Research, LLC

Peoria, Illinois, 61614, United States

Location

Velocity Clinical Research - Valparaiso

Valparaiso, Indiana, 46383, United States

Location

Velocity Clinical Research - Sioux City

Sioux City, Iowa, 51106, United States

Location

Johnson County Clin-Trials

Lenexa, Kansas, 66219, United States

Location

DelRicht Research

Louisville, Kentucky, 40205, United States

Location

IMA Clinical Research

Monroe, Louisiana, 71201, United States

Location

DelRicht Research

New Orleans, Louisiana, 70115, United States

Location

DelRicht Research

Prairieville, Louisiana, 70769, United States

Location

Profound Research LLC

Clarkston, Michigan, 48346, United States

Location

Profound Research LLC

Farmington Hills, Michigan, 48334, United States

Location

Profound Research LLC

Rochester Hills, Michigan, 48307, United States

Location

DelRicht Research

Gulfport, Mississippi, 39503, United States

Location

DelRicht Research

Springfield, Missouri, 65807, United States

Location

Sundance Clinical Research, LLC

St Louis, Missouri, 63141, United States

Location

Velocity Clinical Research - Norfolk

Norfolk, Nebraska, 68701, United States

Location

Velocity Clinical Research - Omaha

Omaha, Nebraska, 68134, United States

Location

Velocity Clinical Research - Albuquerque

Albuquerque, New Mexico, 87107, United States

Location

IMA Clinical Research

New York, New York, 10036, United States

Location

DelRicht Research

Charlotte, North Carolina, 28205, United States

Location

Velocity Clinical Research - Cleveland

Beachwood, Ohio, 44122, United States

Location

Velocity Clinical Research - Springdale

Cincinnati, Ohio, 45246, United States

Location

DelRicht Research

Tulsa, Oklahoma, 74133, United States

Location

Velocity Clinical Research - Medford

Medford, Oregon, 97504, United States

Location

Velocity Clinical Research - Anderson

Anderson, South Carolina, 29621, United States

Location

DelRicht Research

Charleston, South Carolina, 29407, United States

Location

Spartanburg Medical Research

Spartanburg, South Carolina, 29303, United States

Location

DelRicht Research

Hendersonville, Tennessee, 37075, United States

Location

Zenos Clinical Research

Dallas, Texas, 75230, United States

Location

Lonestar Clinical Research, LLC

Dallas, Texas, 75243, United States

Location

DelRicht Research

Prosper, Texas, 75078, United States

Location

Clinical Trials of Texas, LLC dba Flourish Research

San Antonio, Texas, 78229, United States

Location

Stephenville Medical & Surgical Clinic

Stephenville, Texas, 76401, United States

Location

Alliance for Multispecialty Research, LLC

Layton, Utah, 84041, United States

Location

Velocity Clinical Research - Salt Lake City

West Jordan, Utah, 84088, United States

Location

Clinical Research Partners, LLC

Richmond, Virginia, 23226, United States

Location

hVIVO

London, E1 1EQ, United Kingdom

Location

MeSH Terms

Conditions

Influenza, Human

Condition Hierarchy (Ancestors)

Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases

Study Officials

• Nicole Davarpanah, MD, JD

  Cidara Therapeutics Inc.

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 20, 2024
• First Posted: September 24, 2024
• Study Start: September 20, 2024
• Primary Completion: September 19, 2025
• Study Completion: September 19, 2025
• Last Updated: October 20, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1); US (56)