Skip to main content
OpenTrials
Active, not recruiting

NCT Number: NCT07225959

A Study of Annual Doses of MK-1406/CD388 in Healthy Adults (MK-1406-006/CD388.SQ.2.07)

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.

Active, not recruiting

This study is active but is not currently recruiting participants.

Notify Me

Key information

Conditions

Healthy Participants Infections Influenza, Human Orthomyxoviridae Infections RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–66 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

hVIVO Serviced Limited, London, England, United Kingdom

Loading trial locations.

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

The main inclusion criteria include but are not limited to the following:

  • Be in stable health
  • Has previously completed participation in study CD388.SQ.2.05/MK-1406-004, and received a subcutaneous (SC) CD388/MK-1406 dose of either 150 mg, 300 mg or 450 mg.

Exclusion criteria

The main exclusion criteria include but are not limited to the following:

  • Have a contraindication to subcutaneous (SQ) injections and venipunctures (eg, bleeding disorders).
  • Has a known or suspected allergy or history of anaphylaxis or other serious adverse events (SAEs) to zanamivir (following administration of inhaled or intravenous formulations), monoclonal antibodies, or any of the components of CD388/MK-1406.

Treatment and study plan

MK-1406 Injection

Combination Product

MK-1406 liquid for injection administered subcutaneously

Other names: CD388

Primary outcomes

  1. Number of Participants with Treatment-Induced Anti-Drug Antibodies (ADAs)

    Time frame: Periods 1 and 2: Day 1, Day 29, Day 85, Day 169, and Day 197

    Participants are evaluated for the occurrence of treatment-induced ADAs following administration of each annual dose of MK-1406.

  2. Number of Participants with Treatment-Boosted ADAs

    Time frame: Periods 1 and 2: Day 1, Day 29, Day 85, Day 169, and Day 197

    Participants are evaluated for the occurrence of treatment-boosted ADAs following administration of each annual dose of MK-1406.

Secondary outcomes

  1. Number of participants with ≥1 Adverse Event (AE)

    Time frame: Period 1: Up to approximately Day 280. Period 2: Up to approximately Day 197.

    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.

  2. Number of Participants Who Discontinued from the Study Due to an AE

    Time frame: Period 1: Up to approximately Day 280. Period 2: Up to approximately Day 197.

    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.

  3. Number of Participants with a Solicited Injection-site AE

    Time frame: 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. The number of participants with a solicited injection-site AE will be assessed.

  4. Number of Participants with a Serious Adverse Event (SAE)

    Time frame: Period 1: Up to approximately Day 280. Period 2: Up to approximately Day 197.

    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.

  5. Plasma Concentration Following Administration of MK-1406

    Time frame: Periods 1 and 2: Pre-dose, Day 8, Day 29, Day 85, Day 169, Day 197

    Blood samples will be collected at multiple time points to assess the plasma concentrations of MK-1406.

  6. Plasma concentration of MK-1406 by anti-drug antibody (ADA) status.

    Time frame: Periods 1 and 2: Day 197

    Blood samples will be collected to assess the plasma concentration of MK-1406 where ADAs are present in participants administered MK-1406.

Sponsors and collaborators

Lead sponsor

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

Industry

Registry information

Official study title

A Phase 2, Open-Label, Long-Term Study to Evaluate the Safety, Pharmacokinetics, and Occurrence of Anti-Drug Antibodies in Healthy Participants Following Annual Doses of CD388, a Novel Long-Acting Antiviral Conjugate

Acronym: NAVIGATE-2

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Nov 10, 2025
Registry last updated
Aug 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.