A Phase 2 interventional study of MK-1406 Injection in Healthy Participants, sponsored by Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA). Active, not recruiting at 6 sites in 2 countries. Open to participants aged 18 Years to 66 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-20.
Sponsored by Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) (part of Merck & Co., Inc) · Phase 2, Interventional, and Prevention
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Among 966 studies in Influenza, Human with a site in United States — 60 open to participants now, 85 under way, 7 of them phase 3. Influenza, Human · United States.
Among the 966 studies in Influenza, Human with a site in United States, this one is the 343rd largest by planned enrollment of the 843 interventional ones that give a count, is one of 29 that started in 2025, is one of 161 in phase 2, reaches primary completion later than 41 of the 83 other live ones, and was the 942nd registered.
2,358 studies on the registry are indexed under Influenza, Human; 184 are open to participants now.
Browse Influenza, Human studies →60 of the 966 studies in Influenza, Human with a site in United States are open now. Recruiting first, the newest first:
National Institute of Allergy and Infectious Diseases (NIAID) · Sites in United States
Ages 18–55 · Healthy volunteers
ModernaTX, Inc. · Sites in United States
Ages 65+ · Healthy volunteers
ModernaTX, Inc. · Sites in United States
Ages 9–17 · Healthy volunteers
National Institute on Deafness and Other Communication Disorders (NIDCD) · Sites in United States
Ages 18–99 · Healthy volunteers
David Moss · Sites in United States
Ages 18+ · Healthy volunteers
A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →
Of the 121 Influenza, Human studies recruiting now, 66 (55%) set no upper age limit and 45 (37%) stop at 75 or younger; 33 take children under 18; 67 take healthy volunteers.
This study: 18 Years to 66 Years · all sexes · healthy volunteers too.
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966 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 249 · Phase 2 244 · Phase 3 127 · Phase 4 147
First in 1997; this study’s year is marked. 29 started in 2025.
By drug class, each counting the studies that test any of its medicines:
This study's planned enrollment of 400 is above the median of 227 across 1,957 interventional studies indexed under Influenza, Human.
Median enrollment 270 across the 843 interventional studies, 261 across the 122 observational. Of the 841 that completed or were terminated, 433 (51%) have results posted.
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435 of 966 have an industry lead sponsor. The 10 most frequent:
This study is registered under Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA), one of the names counted as Merck & Co., Inc. Under that name alone:
Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) is the lead sponsor of 4 studies on the registry; 2 are open to participants now.
Merck & Co., Inc has 7 studies filed under Influenza, Human — fewer than ten, so there is no comparison to draw.
41 of the studies in Influenza, Human with a site in United States that are under way reach primary completion within a year, 5 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07496450Phase 3ModernaTX, Inc.A Study of mRNA-1018-H5 Pandemic Influenza Vaccine in Healthy Adults | 2027-01-28 |
| NCT06094010Phase 3Hoffmann-La RocheA Surveillance Study of Susceptibility to Baloxavir Marboxil in Pediatric Participants With Influenza and Transmission of Influenza to Household Contacts | 2027-05-11 |
| NCT07159763Phase 3Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA)A Study to Evaluate the Safety and Efficacy of MK-1406/CD388 for Prevention of Influenza (MK-1406-005/CD388.SQ.3.06) | 2027-07-02 |
| NCT07851246Phase 3GlaxoSmithKlineA Study to Evaluate the Immune Response and Safety of a Vaccine Against Influenza in Adults 18-64 Years of Age | 2027-07-09 |
| NCT05624450Phase 3AstraZenecaEfficacy and Safety of Tozorakimab in Patients Hospitalised for Viral Lung Infection Requiring Supplemental Oxygen | 2027-11-04 |
Add all 41 to your calendar (.ics) → With an account.
Among the 966 studies in Influenza, Human with a site in United States, from their registry updates:
This tab as a report to print or save as PDF → With an account.
The goal of this clinical study is to learn if giving repeated annual doses of MK-1406 (CD388) is safe and how the body reacts to it in healthy adults who have already received one dose without serious side effects. The study aims to determine if the body makes antibodies against MK-1406 after repeated doses, which might affect how the drug works or how safe it is, and to better understand the safety and tolerability of repeated doses. Participants will receive two doses of MK-1406 over two years and be monitored for 18 months. Researchers will check for immune responses against the drug, watch for any side effects, and measure how the drug behaves in the body over time. This study is based on the idea that people who tolerated MK-1406 well before will likely continue to tolerate it safely with repeated annual dosing, and that the risk of immune reactions will remain low.
This is a Phase 2, open-label, long-term study to evaluate the occurrence anti-drug antibodies (ADAs) directed to MK-1406 (CD388) following administration of 2 annual doses of MK-1406 in healthy participants during an 18-month period. All participants previously completed study CD388.SQ.2.05/MK-1406-004, having received a dose of the active drug without experiencing any serious adverse events (SAEs) during that study. This study will also evaluate the safety and tolerability of MK-1406 and the pharmacokinetics (PK) of MK-1406 following repeated annual dosing.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The main inclusion criteria include but are not limited to the following:
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participant will receive 450 mg dose of MK-1406 (CD388) by subcutaneous (SC) injection followed 1 year later by a repeat single 450 mg dose of MK-1406 administered by SC injection.
Combination Product: MK-1406 Injection
MK-1406 liquid for injection administered subcutaneously
Also known as: CD388
Number of Participants with Treatment-Induced Anti-Drug Antibodies (ADAs)
Participants are evaluated for the occurrence of treatment-induced ADAs following administration of each annual dose of MK-1406.
Time frame: Periods 1 and 2: Day 1, Day 29, Day 85, Day 169, and Day 197
Number of Participants with Treatment-Boosted ADAs
Participants are evaluated for the occurrence of treatment-boosted ADAs following administration of each annual dose of MK-1406.
Time frame: Periods 1 and 2: Day 1, Day 29, Day 85, Day 169, and Day 197
Number of participants with ≥1 Adverse Event (AE)
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 number of participants with ≥1 AE will be assessed.
Time frame: Period 1: Up to approximately Day 280. Period 2: Up to approximately Day 197.
Number of Participants Who Discontinued from the Study Due to an AE
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 number of participants who discontinued the study because of an AE will be assessed.
Time frame: Period 1: Up to approximately Day 280. Period 2: Up to approximately Day 197.
Number of Participants with a Solicited Injection-site AE
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. The number of participants with a solicited injection-site AE will be assessed.
Time frame: Up to approximately Day 8 post dose
Number of Participants with a Serious Adverse Event (SAE)
An SAE is an AE that results in death, is life threatening, results in a persistent or significant disability or incapacity, results in or prolongs an existing hospitalization, is a congenital anomaly or birth defect, is a cancer, is an overdose, or is another important medical event. The number of participants with an SAE will be assessed.
Time frame: Period 1: Up to approximately Day 280. Period 2: Up to approximately Day 197.
Plasma Concentration Following Administration of MK-1406
Blood samples will be collected at multiple time points to assess the plasma concentrations of MK-1406.
Time frame: Periods 1 and 2: Pre-dose, Day 8, Day 29, Day 85, Day 169, Day 197
Plasma concentration of MK-1406 by anti-drug antibody (ADA) status.
Blood samples will be collected to assess the plasma concentration of MK-1406 where ADAs are present in participants administered MK-1406.
Time frame: Periods 1 and 2: Day 197
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
Started Oct 2025 (actual). Primary completion is estimated for Jul 2027, 21 months after the start.
Of 86 industry-sponsored phase 2 interventional studies under Influenza, Human, half reached primary completion within 7 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 14. This study's planned 21 months is above that.
Counting every sponsor, half of 122 studies reached it within 10 months; a quarter within 5 and three quarters within 19.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: MK-1406
Cidara Therapeutics Inc., a subsidiary of Merck & Co., Inc. (Rahway, New Jersey USA) →