A Trial to Evaluate the Effect of CD388/MK1406 on the Immunogenicity of Fluzone® HD Vaccine (CD388.SQ.1.08/MK-1406-007)
- Summary
- Approximately one billion cases of seasonal influenza occur annually. Of these, 3 to 5 million illnesses are severe and responsible for up to 650,000 deaths per year (WHO 2025). Yearly administration of an influenza vaccine for the prevention of influenza is currently recommended. However, the real-world vaccine effectiveness varied from 10% to 60% in the general population across the years of 2004 to 2024, with effectiveness in most years below 50% (CDC 2025) and decreasing to as low as 5% in immunocompromised individuals (Hughes 2021). Researchers are looking for other ways to prevent severe illness from the influenza virus. The goals of this study are to learn if: * MK-1406 (formerly CD388) is safe to take with Fluzone® * MK-1406 affects the immune response to Fluzone®
- Short title
- A Trial to Evaluate the Effect of CD388/MK1406 on the Immunogenicity of Fluzone® HD Vaccine (CD388.SQ.1.08/MK-1406-007)
- Official title
- A Phase 1, Double-blind, Randomized Trial to Evaluate Safety and Immunogenicity of Fluzone® High-Dose Influenza Vaccine When Concomitantly Administered With CD388, a Novel Long-Acting Antiviral Conjugate for the Prevention of Influenza
- Control arm
- Placebo
- Registry reports results
- Listing at source
- Listed
- Recruitment status
- Active, not recruiting
- Phase
- Phase 1
- Study type
- Interventional
- Completion date
- 2026-12-31
- First posted
- 2025-12-23
- Registry last updated
- 2026-08-19
- Primary completion date
- 2026-12-31
- Start date
- 2025-11-08
- Participants
- Participant count basis
- Estimated
- Planned participants
- Protocol amendments
- Number of sites
- Data monitoring committee
- Registry sponsor category
- Industry
- Lead sponsor
- Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)
- Source registry
- ClinicalTrials.gov
- Registry ID
- NCT07300085
- ClinicalTrials.gov ID
- NCT07300085
- Registry record
- Open registry record
- Allocation
- Randomised
- Model
- Parallel groups
- Purpose
- Prevention
- Masking
- Quadruple masking
- Masked roles
- Participants, Care providers, Investigators, Outcome assessors
Geometric Mean of Hemagglutinin Inhibition (HAI) Titers Against the Influenza Strains Contained in the Vaccine Among Participants Receiving Concomitant Fluzone® High-Dose (HD) and MK-1406 Compared to Participants Who Receive Fluzone® HD and Placebo
Timeframe: Predose (Day 1), Day 15 and Day 29
Geometric mean of HAI titers at 2-weeks and 4-weeks post-trial intervention against the influenza virus strains contained in the vaccine among participants receiving concomitant Fluzone® HD influenza vaccine and MK-1406 compared to participants who receive Fluzone® HD and placebo will be determined. HAI testing will be performed using validated methods in accordance with applicable Good Clinical Laboratory Practice (GCLP) and laboratory Standard Operating Procedures (SOPs). Geometric Mean Titers (GMTs) will be summarized by treatment group and influenza strain.
Percentage of Participants with Seroconversion Rates against the Influenza Strains Contained in the Vaccine Among Participants Receiving Concomitant Fluzone® HD and MK-1406 Compared to Participants Who Receive Fluzone® HD and Placebo
Timeframe: Predose (Day 1), Day 15 and Day 29
Seroconversion is defined as a 4-fold increase in influenza titer as measured by HAI assay at each visit compared to baseline. Seroconversion rates at 2-weeks and 4-weeks post-trial intervention against the influenza virus strains contained in the vaccine among participants receiving concomitant Fluzone® HD influenza vaccine and MK-1406 compared to participants who receive Fluzone® HD and placebo will be determined. Seroconversion rates will be summarized by treatment group and influenza strain.
Percentage of participants with ≥1 Adverse Event (AE)
Timeframe: Up to approximately Day 29
An AE is defined as any untoward medical occurrence in a participant administered a pharmaceutical product temporally associated with the use of study treatment, whether or not considered related to the study treatment.
Percentage of Participants Who Discontinued from the Study Due to an Adverse Event
Timeframe: Up to approximately Day 29
An AE is defined as any untoward medical occurrence in a participant administered a pharmaceutical product temporally associated with the use of study treatment, whether or not considered related to the study treatment. The percentage of participants who discontinued the study because of an AE (as defined above) will be assessed.
Percentage of Participants with a Solicited Injection-site Adverse Event
Timeframe: Up to approximately Day 8 post-dose
An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The solicited injection-site AEs assessed are redness/erythema, swelling, and tenderness/pain.
Percentage of Participants with a Solicited Systemic Adverse Event
Timeframe: Up to approximately Day 29
An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study treatment, whether or not considered related to the study treatment. The solicited systemic AEs assessed are muscle pain/myalgia, joint pain/arthralgia, headache, and tiredness/fatigue.
- Sex
- All
- Age groups
- Adults
- Minimum age
- 18 Years
- Maximum age
- 49 Years
- Healthy volunteers
- Yes
The main inclusion criteria include but are not limited to the following:
- Be ≥18 to ≤49 years of age
- Be deemed healthy by the Investigator
- Have not received any seasonal influenza vaccine and have not had a diagnosed or suspected influenza infection within 12 months prior to Day 1 of the trial
The main exclusion criteria include but are not limited to the following:
- Had an active malignancy within 5 years prior to screening, except basal cell or squamous cell skin cancer. Any history of breast cancer or melanoma is exclusionary.
- Has previously been diagnosed with Guillain-Barre Syndrome following a previous influenza vaccination.
- California Clinical Trials Medical Group (CCTMG) managed by ParexelGlendale, United States
- Parexel ( Site 0001)Glendale, United States
- Parexel ( Site 0002)Baltimore, United States
- Parexel International - EPCU BaltimoreBaltimore, United States
- MK-1406-007
- CD388.SQ.1.08
- NCT07770061