RecruitingPhase 3NCT07159763

A Study to Evaluate the Safety and Efficacy of CD388 for Prevention of Influenza

A Phase 3 Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Evaluate the Safety and Efficacy of CD388, a Novel Long-Acting Antiviral Conjugate, for the Prevention of Influenza in Adults and Adolescents at Higher Risk of Developing Influenza Complications


Sponsor

Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)

Enrollment

7,500 participants

Start Date

Sep 25, 2025

Study Type

INTERVENTIONAL

Conditions

Summary

The purpose of this study is to evaluate how well CD388 works in preventing symptomatic laboratory-confirmed influenza infections, as compared to placebo, when given as a single dose via 3 subcutaneous (SQ) injections to adult and adolescent participants who are at higher risk of developing influenza complications, and to evaluate the safety and tolerability of CD388, as compared to placebo.


Eligibility

Min Age: 12 Years

Inclusion Criteria42

  • Must be 12 years of age or older at the time of signing the informed consent.
  • Written informed consent and any locally required authorization (e.g., Health Insurance Portability and Accountability Act \[HIPAA\] in the US) obtained from the participant before performing any protocol-related procedures, including screening evaluations. For participants under the legal age of consent as defined by local regulations, the parent(s) or legal guardian(s) may be required to give their signed written informed consent and participants may sign an assent form as specified by local law.
  • Has negative rapid antigen tests for influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) prior to dosing at Day 1.
  • Weight is ≥ 40 kilograms (kg) at screening.
  • Body Mass Index (BMI; calculated as weight in kg divided by height in meters \[m\] squared)) is ≥ 18 kg/m\^2 at screening.
  • In the opinion of the Investigator, must be able to comply with the requirements of the protocol and be able to read, understand, and complete questionnaires in the electronic diary (eDiary), work with smartphones/tablets/computers (if applicable, with assistance by a caregiver, surrogate, or legally authorized representative), 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 assessed by the Investigator as medically stable and not requiring significant change in maintenance therapy and has not been hospitalized for worsening disease or any significant medical event during the 2 months before screening
  • Must agree to the following contraception requirements:
  • a. Females of childbearing potential must use 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 agree to remain on a highly effective method from Day 1 until 32 weeks after study intervention administration, the end of relevant systemic exposure. Note: 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.
  • 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.
  • Must agree not to donate blood or blood products from Day 1 until 32 weeks after study intervention administration.
  • 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.
  • Has a history of pulmonary disease; specifically:
  • Chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema, graded as follows using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) Categories A, B, and E (ABE) (i.e., GOLD ABE) assessment tool:
  • Gold Grade 2 (moderate) or Grade 3 (severe) with following exacerbation history, within 1 year of screening
  • At least 2 moderate exacerbations (i.e., not leading to hospitalization), or
  • At least 1 exacerbation leading to hospitalization OR
  • Gold Grade 4 regardless of exacerbation history
  • Bronchiectasis, cystic fibrosis, interstitial lung disease, pneumoconiosis, or past or active bronchopulmonary dysplasia.
  • Has moderate to severe asthma, as defined by the Global Initiative for Asthma (GINA) Treatment Steps 3-5.
  • Has existing cardiac disease; specifically:
  • Congenital heart disease
  • Congestive heart failure New York Heart Association (NYHA) Class II-IV
  • Coronary artery disease requiring regular medication and/or follow-up for ischemic heart disease (i.e., participants who, through interventional procedure\[s\] and/or active medical treatment, have attained an established state of chronic stability of a duration of no less than 6 months)
  • Hypertension with cardiac complications (NOTE: Hypertension alone without cardiac complications will be excluded). Acceptable cardiac complications of hypertension include, but are not limited to, heart failure, cardiac arrhythmias (e.g., atrial fibrillation), ischemic heart disease, coronary artery disease, enlarged left heart, metabolic syndrome, left ventricular hypertrophy, systolic or diastolic myocardial dysfunction, angina, and myocardial infarction.
  • Has insulin-dependent diabetes.
  • Has moderate renal impairment (Stage 3 Chronic Kidney Disease \[CKD\], equivalent to an estimated glomerular filtration rate \[eGFR\] 30 to 59 milliliter per minute \[mL/min\] per 1.73 m\^2 as calculated by the Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] equation for adults or the Chronic Kidney Disease in Children under 25 \[CKiD U25\] equation for adolescents) with or without micro-macroproteinuria and within 3 months prior to screening; examples include, but are not limited to, any history of glomerulosclerosis, diabetic nephropathy, lupus nephritis, glomerular nephritis, immunoglobulin A (IgA) nephropathy, and Goodpasture syndrome. NOTE: Participants with chronic renal disease who meet the criteria for immune compromised (immunosuppressive therapy) should be enrolled in Stratum B.
  • Is ≥ 65 years of age at the time of randomization but does not meet any of criteria 11a through 11e, and is otherwise healthy as determined by the Investigator.
  • Has a solid tumor diagnosis AND has received chemotherapy and/or immunotherapy within 1 year of screening.
  • Has a diagnosis of a hematologic malignancy within 5 years of screening AND has received any chemotherapy or biologic therapy within 1 year of screening.
  • NOTE: Participants with multiple myeloma may be enrolled regardless of duration of time from diagnosis to screening.
  • Participants who have had a solid organ transplant (SOT) must satisfy all of the following:
  • Has received a kidney, liver, heart, or lung transplant more than 6 months prior to screening
  • Is currently receiving at least two immunosuppressive medications
  • Participants who have had a hematopoietic stem cell transplant (HSCT) must satisfy at least one of the following:
  • Has a history of HSCT (i.e., autologous, allogeneic, bone marrow, peripheral blood stem cell, tandem \[peripheral blood and marrow\]) within 1 year of screening
  • Has a history of non-autologous HSCT with graft-versus-host disease (GvHD) requiring active treatment with immunosuppressants (e.g., systemic corticosteroids ≥1 mg/kg at screening), regardless of the duration of time since HSCT
  • Is receiving immunosuppressive medicines (e.g., corticosteroids \[i.e., at least 20 mg prednisone or equivalent per day\], alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive \[e.g., Bruton's tyrosine kinase inhibitors\], tumor- necrosis blockers, or other immunosuppressive biologic agents \[e.g., for rheumatic diseases\]). NOTE: The regimen must be stable (same agents and doses, or clinically equivalent doses) for ≥2 months prior to Screening to ensure clinical stability (see Inclusion Criterion 7).
  • Has received chimeric antigen receptor-modified T-cell therapy.
  • Has received B-cell depleting therapies (e.g., rituximab, ocrelizumab, ofatumumab, alemtuzumab) within the 12 months prior to screening.
  • Has a diagnosis of any primary or secondary immunodeficiency except IgA deficiency.
  • Has advanced or untreated human immunodeficiency virus (HIV) infection manifested by a cluster of differentiation 4 (CD4) cell count less than 350/cubic millimeter (mm\^3) within 6 months of screening.

Exclusion Criteria18

  • A female who is pregnant or lactating.
  • 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.
  • Has been diagnosed with influenza (i.e., with medical history \[including verbal\] of influenza) within 6 months prior to randomization.
  • Has received the current seasonal inactivated influenza vaccine or live attenuated influenza vaccine within the 14 days prior to dosing on Day 1. (NOTE: Participant may have received recombinant influenza vaccine up to the day of dosing on Day 1.)
  • Has an acute (time-limited) or febrile (temperature ≥38.0 degrees Celsius \[ºC\] \[≥100.4 degrees Fahrenheit {ºF}\]) illness within 7 days prior to planned dosing on Day 1.
  • Has had close contact (including household contact) with someone with laboratory-confirmed influenza or SARS-CoV-2 or with someone who has been treated with antiviral therapies for influenza or SARS-CoV-2 within the 7 days prior to randomization.
  • Has a clinically unstable condition including, but not limited to, a psychiatric condition, including recent (within the past year) or active suicidal ideation/behavior, or any other condition for which, in the opinion of the Investigator, may lead to hospitalization or death within the study period and that suggests that study enrollment would not be in the participant's best interest and/or that could prevent, confound, or limit the protocol-specified assessments.
  • Has any history of alcohol or drug abuse that, in the opinion of the Investigator, would adversely impact the conduct of the study.
  • Had major surgery (e.g., major cardiac, pulmonary or abdominal operation) 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.
  • Has severe CKD (equivalent to an eGFR less than 30 mL/min/1.73 m\^2 as calculated by CKD-EPI equation for adults or the CKiD U25 equation for adolescents), or is receiving hemodialysis.
  • Current or planned participation in another clinical study in which study intervention is being administered during participation 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).
  • Receipt within the past 30 days or 5 half-lives (whichever is longer) or anticipated receipt of any drug or other biologic agent (e.g., monoclonal antibodies) administered for the prevention or treatment of influenza.
  • Receipt of any formulation of immunoglobulin within 14 days prior to planned study intervention administration.
  • Receipt of any experimental drug, vaccine, or biologic agent within the 90 days or 5 half-lives (whichever is longer) prior to study intervention administration.
  • Has a clinically significant bleeding disorder (e.g., factor deficiency, coagulopathy, or platelet disorder) or medical history of significant bleeding or bruising following intramuscular or SQ injections or venipuncture. NOTE: Participants receiving apixaban or warfarin may be enrolled if the Investigator determines risk of SQ treatment with study intervention on Day 1 is minimal.
  • Has donated ≥450 mL of blood product (1 unit) for any reason within 30 days of screening.
  • Has direct involvement in the proposed study or other studies under the direction of the Investigator, sub-investigators, or at the study site; or is a family member of an individual with such direct involvement; or is an employee of the Sponsor; or was previously enrolled and dosed in a CD388 clinical trial.
  • In the Investigator's judgment, the participant has any condition or circumstance present that significantly increases risk, affects the ability to participate, impairs interpretation of study data, or indicates a likelihood of non-adherence to study requirements.

Interested in this trial?

Get notified about updates and connect with the research team.

Interventions

COMBINATION_PRODUCTCD388 Injection

CD388 liquid for injection

COMBINATION_PRODUCTPlacebo

Placebo to match


Locations(157)

Pinnacle Research Group, LLC

Anniston, Alabama, United States

Cullman Clinical Trials

Cullman, Alabama, United States

HOPE Research Institute

Glendale, Arizona, United States

Desert Clinical Research, LLC / Avacare

Mesa, Arizona, United States

Foothills Research Center / Avacare

Phoenix, Arizona, United States

Fiel Family and Sports Medicine / Avacare

Tempe, Arizona, United States

HOPE Research Institute

Tempe, Arizona, United States

Arizona Clinical Trials

Tucson, Arizona, United States

Del Sol Research Management, LLC

Tucson, Arizona, United States

Triallogix Medical Corporation

Fullerton, California, United States

National Institute of Clinical Research, Inc.

Garden Grove, California, United States

Eximia Research-CA, LLC

La Mesa, California, United States

Kinetic Clinical Research, LLC dba Long Beach Clinical Trials

Long Beach, California, United States

Seaside Medical Group

Oceanside, California, United States

Profound Research, LLC

Pasadena, California, United States

Paradigm Clinical Research

Redding, California, United States

Artemis Institute for Clinical Research

San Diego, California, United States

Acclaim Clinical Research

San Diego, California, United States

Diablo Clinical Research, Inc.

Walnut Creek, California, United States

Tekton Research, LLC

Denver, Colorado, United States

Tekton Research, LLC

Fort Collins, Colorado, United States

Critical Care, Pulmonary and Sleep Associates PLLP / Avacare

Lakewood, Colorado, United States

Tekton Research, LLC

Longmont, Colorado, United States

New England Research Associates

Bridgeport, Connecticut, United States

Stamford Therapeutics Consortium

Stamford, Connecticut, United States

Emerson Clinical Research Institute

Washington D.C., District of Columbia, United States

Imagine Research - Palm Beach County

Boynton Beach, Florida, United States

Innovative Research of West Florida, Inc.

Clearwater, Florida, United States

Hillcrest Medical Research, LLC

DeLand, Florida, United States

Health Awareness, Inc.

Jupiter, Florida, United States

Columbus Clinical Services, LLC

Miami, Florida, United States

Flourish Research - Miami, LLC DBA Flourish Research

Miami, Florida, United States

South Florida Research Center, Inc.

Miami, Florida, United States

Floridian Clinical Research, LLC

Miami Lakes, Florida, United States

Healthcare Clinical Data, Inc.

North Miami, Florida, United States

Clinical Neuroscience Solutions, Inc.

Orlando, Florida, United States

Progressive Medical Research

Port Orange, Florida, United States

Health Awareness, Inc.

Port Saint Lucie, Florida, United States

Global Clinical Professionals

St. Petersburg, Florida, United States

Clinical Site Partners, LLC dba Flourish Research

Winter Park, Florida, United States

Agile Clinical Research Trials, LLC

Atlanta, Georgia, United States

DelRicht Research

Atlanta, Georgia, United States

Clinical Research Atlanta

Stockbridge, Georgia, United States

Paradigm Clinical Research

Boise, Idaho, United States

Velocity Clinical Research - Boise

Meridian, Idaho, United States

Great Lakes Clinical Trials, LLC dba Flourish Research

Chicago, Illinois, United States

Velocity Clinical Research - Valparaiso

Valparaiso, Indiana, United States

Integrated Clinical Trial Services, LLC

West Des Moines, Iowa, United States

Johnson County Clin-Trials, LLC

Lenexa, Kansas, United States

AMR Clinical

Newton, Kansas, United States

DelRicht Research

Louisville, Kentucky, United States

Elevate Clinical Research

Lake Charles, Louisiana, United States

DelRicht Research

New Orleans, Louisiana, United States

DelRicht Research

Prairieville, Louisiana, United States

Annapolis Internal Medicine / Avacare

Annapolis, Maryland, United States

Jadestone Clinical Research, LLC

Silver Spring, Maryland, United States

Skylight Health Research

Burlington, Massachusetts, United States

Profound Research, LLC

Clarkston, Michigan, United States

Profound Research, LLC

Dearborn, Michigan, United States

Profound Research, LLC

Farmington Hills, Michigan, United States

Javara, Inc.

Mankato, Minnesota, United States

DelRicht Research

Gulfport, Mississippi, United States

Clay Platte Family Medicine, PC / Avacare

Kansas City, Missouri, United States

DelRicht Research

Springfield, Missouri, United States

Sundance Clinical Research, LLC

St Louis, Missouri, United States

Montana Medical Research, Inc.

Missoula, Montana, United States

Methodist Physicians Clinic / Avacare

Fremont, Nebraska, United States

Velocity Clinical Research - Omaha

Omaha, Nebraska, United States

Midwest Regional Health Services, LLC / Avacare

Omaha, Nebraska, United States

Henderson Clinical Trials

Henderson, Nevada, United States

Excel Clinical Research

Las Vegas, Nevada, United States

Santa Rosa Medical Centers of Nevada / Avacare

Las Vegas, Nevada, United States

Las Vegas Clinical Trials, LLC

North Las Vegas, Nevada, United States

IMA Clinical Research

Warren Township, New Jersey, United States

Brooklyn Clinical Research

Brooklyn, New York, United States

Finger Lakes Medical Research, PLLC dba Certified Research Associates

Cortland, New York, United States

Drug Trials America

Hartsdale, New York, United States

Rochester Clinical Research

Rochester, New York, United States

CHEAR Center, LLC

The Bronx, New York, United States

DelRicht Research

Charlotte, North Carolina, United States

Eximia EquiHealth Research, LLC

Durham, North Carolina, United States

Monroe Biomedical Research

Monroe, North Carolina, United States

West Clinical Research, Inc.

Morehead City, North Carolina, United States

OnSite Clinical Solutions, LLC

Salisbury, North Carolina, United States

Wilmington Health

Wilmington, North Carolina, United States

Wake Forest University Health Sciences

Winston-Salem, North Carolina, United States

Velocity Clinical Research - Cleveland

Beachwood, Ohio, United States

Velocity Clinical Research - Springdale

Cincinnati, Ohio, United States

Centricity Research Columbus Ohio Multispecialty

Columbus, Ohio, United States

PriMed Clinical Research

Dayton, Ohio, United States

Tekton Research, LLC

Edmond, Oklahoma, United States

Lynn Health Science Institute East

Oklahoma City, Oklahoma, United States

DelRicht Research

Tulsa, Oklahoma, United States

Tekton Research, LLC

Yukon, Oklahoma, United States

Altoona Center for Clinical Research

Duncansville, Pennsylvania, United States

Central Erie Primary Care

Erie, Pennsylvania, United States

Hatboro Medical Associates / Avacare

Horsham, Pennsylvania, United States

DM Clinical Research

Philadelphia, Pennsylvania, United States

DelRicht Research

Charleston, South Carolina, United States

Tribe Clinical Research, LLC

Greenville, South Carolina, United States

Spartanburg Medical Research

Spartanburg, South Carolina, United States

Velocity Clinical Research - Spartanburg

Spartanburg, South Carolina, United States

DelRicht Research

Hendersonville, Tennessee, United States

DCT-HCWC, LLC dba Discovery Clinical Trials

Dallas, Texas, United States

Zenos Clinical Research

Dallas, Texas, United States

Lonestar Clinical Research, LLC

Dallas, Texas, United States

Laguna Clinical Research Associates, LLC

Laredo, Texas, United States

Epic Clinical Research

Lewisville, Texas, United States

Elevate Clinical Research

McAllen, Texas, United States

Pearland Physicians

Pearland, Texas, United States

Research Your Health

Plano, Texas, United States

Clinical Trials of Texas, LLC dba Flourish Research

San Antonio, Texas, United States

Elevate Clinical Research

Seabrook, Texas, United States

Javara, Inc.

Stephenville, Texas, United States

DM Clinical Research

Tomball, Texas, United States

Cope Family Medicine / Avacare

Bountiful, Utah, United States

Olympus Family Medicine / Avacare

Salt Lake City, Utah, United States

Charlottesville Medical Research Center, LLC

Charlottesville, Virginia, United States

Clinical Research Partners, LLC

Richmond, Virginia, United States

Rainier Clinical Research Center

Renton, Washington, United States

Equipo Ciencia

Buenos Aires, Argentina

Emeritus Research Sydney

Botany, New South Wales, Australia

Australian Clinical Research Network Pty Ltd

Maroubra, New South Wales, Australia

AIM Research

Merewether, New South Wales, Australia

Momentum Clinical Research St Leonards

Saint Leonards, New South Wales, Australia

Momentum Clinical Research Taringa

Taringa, Queensland, Australia

Emeritus Research Camberwell

Camberwell, Victoria, Australia

Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust

Birmingham, England, United Kingdom

Fylde Coast Clinical Research at Layton Medical Centre

Blackpool, England, United Kingdom

Southmead Hospital, North Bristol NHS Trust - Clinical Research Centre

Bristol, England, United Kingdom

Velocity Clinical Research - Bristol

Bristol, England, United Kingdom

Eynsham Medical Centre

Eynsham, England, United Kingdom

Velocity Clinical Research - High Wycombe

High Wycombe, England, United Kingdom

HMC Health, The Meadows Centre for Health, The Great West Surgery

Hounslow, England, United Kingdom

Leeds Teaching Hospitals NHS Trust - St. James's University Hospital

Leeds, England, United Kingdom

University Hospitals of Leicester NHS Trust - Leicester Royal Infirmary

Leicester, England, United Kingdom

hVIVO Services Limited

London, England, United Kingdom

Panthera Enfield

London, England, United Kingdom

Velocity Clinical Research - North London

London, England, United Kingdom

North Manchester General Hospital

Manchester, England, United Kingdom

The University of Nottingham Health Service

Nottingham, England, United Kingdom

Wansford Research LTD

Peterborough, England, United Kingdom

University Hospitals Plymouth NHS Trust

Plymouth, England, United Kingdom

Panthera Preston

Preston, England, United Kingdom

Panthera Rochdale

Rochdale, England, United Kingdom

Velocity Clinical Research - Romford

Romford, England, United Kingdom

Warrington and Halton Teaching Hospitals NHS Foundation Trust

Runcorn, England, United Kingdom

Salford Royal Hospital

Salford, England, United Kingdom

Panthera Sheffield

Sheffield, England, United Kingdom

University Hospital Southampton NHS Foundation Trust, NIHR Southampton Clinical Research Facility

Southampton, England, United Kingdom

Royal Cornwall Hospitals NHS Trust

Truro, England, United Kingdom

Windrush Medical Practice

Witney, England, United Kingdom

Panthera York

York, England, United Kingdom

Aberdeen Royal Infirmary

Aberdeen, Scotland, United Kingdom

NHS Lothian - Western General Hospital

Edinburgh, Scotland, United Kingdom

Queen Elizabeth University Hospital, Glasgow Clinical Research Facility

Glasgow, Scotland, United Kingdom

Cardiff and Vale UHB - University Hospital of Wales

Cardiff, Wales, United Kingdom

View Full Details on ClinicalTrials.gov

For the most up-to-date information, visit the official listing.

Visit

NCT07159763


Related Trials