RecruitingPhase IIInterventional

A long-term study testing the safety and effects of a new yearly antiviral treatment (CD388) in healthy people

This study is for healthy people aged 18-66 who have already taken part in a previous CD388 study. It's designed to see how safe and effective a new yearly flu treatment called CD388 is over a longer period. Participants will receive two annual doses of 450mg of CD388 for two years. The main goal is to check its long-term safety and how the body handles it. You'll have screening visits, treatment, and follow-up appointments over about 18 months. This research helps us understand if CD388 could be a useful long-term treatment for preventing influenza infections.

At a glance

Status

Recruiting

Phase

Phase II

Sponsor

hVIVO Limited Services

Enrolment target

400

Start

01 Nov 2025

Estimated completion

06 Aug 2027

Influenza infection

What is this study about?

This study is looking into a new treatment called CD388, which is designed to help prevent flu infections. If you've already been part of an earlier study for CD388, this next step is for you. We want to understand how safe this treatment is and how well it works over a longer period when taken once a year.

Participants will receive a 450mg dose of CD388 once a year for two years. The main things we'll be checking are any side effects and how your body reacts to the treatment over time. This kind of research is vital because it helps doctors and scientists learn more about new medicines and whether they could be a good option for people in the future.

By taking part, you'll be contributing to important medical research that could one day help many people avoid getting the flu. This study is a 'Phase II' trial, which means we're still in the relatively early stages of testing this treatment in a larger group of people to gather more safety and effectiveness information.

Key takeaways

This study is for healthy people aged 18-66 who were in a previous CD388 flu treatment study.
It tests a new yearly treatment (CD388) over two years to check its long-term safety and effects.
Participation involves screening, two yearly doses, and regular follow-up visits for about 18 months.
Common side effects might include injection site reactions, muscle aches, headaches, or tiredness.
Your involvement helps gather important information on new flu treatments.

Who may be eligible?

This study is looking for healthy adults between 18 and 66 years old. Most importantly, you must have already taken part in a specific previous study called 'CD388.SQ.2.05' and received a dose of CD388 during that time.

To join, you need to be generally healthy and not have certain long-term health problems like heart, lung, kidney, or immune system issues, or specific blood or cancer conditions. Your doctor will carefully check your health to make sure it's safe for you to participate. You also need to have a body mass index (BMI) of 18 or higher.

You should be able to attend all scheduled appointments, provide your consent, and follow all instructions. If you're a woman who could become pregnant, you'll need to agree to use certain birth control methods. Also, you must not donate blood during the study and for 40 weeks after each dose.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you between 18 and 66 years old?
Did you take part in the previous CD388.SQ.2.05 study?
Are you generally healthy and don't have serious long-term health conditions?
Are you able to attend all clinic visits over about 18 months?
Are you willing to use specific birth control methods if you are a woman who could become pregnant?

Answer every question to see your result.

What does participation involve?

If you take part, your total time in the study will be around 18 months. It starts with one visit to make sure you're suitable (the 'screening visit'). If you qualify, you'll then come for the main 'treatment visit' on Day 1 where you'll receive your first yearly dose of CD388. You'll be watched for at least 30 minutes after getting the treatment before you can leave.

After your first dose, you'll have several follow-up visits to the study site to check your health and how you're reacting to the treatment. These visits are on Day 8, 29, 85, 169, 197, and 280. For the second year's dose, you'll receive it and then have follow-up visits on Day 8, 29, 85, 169, and 197. During these visits, the study team will monitor your progress and may take blood samples.

Potential risks and benefits

Taking part in a study like this helps us learn more about new treatments, which could potentially benefit others in the future. While there isn't a direct guaranteed personal benefit to you, your involvement is very valuable to medical science. As with any treatment, there are potential risks. You might experience common side effects like pain, swelling, or redness where you got the injection, or feel muscle pain, joint pain, headache, tiredness, chills, fever, or have diarrhoea. Although not seen before in previous studies, there's a small chance of an allergic reaction to the treatment, which could cause symptoms like rash, swelling, shortness of breath, nausea, or vomiting. The study team will watch you closely for any of these reactions. Blood tests, which are part of the study, can sometimes cause minor pain, bruising, or light-headedness. You are free to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

hVIVO Services Limited
City only
London, England

Common questions

What is CD388?

CD388 is a new yearly treatment being tested to see if it can help prevent flu infections.

How long will I be in the study?

The total time you'd be in the study is about 18 months.

Do I have to pay to join this study?

No, you do not have to pay to join the study. All study-related care and treatment are provided at no cost.

What are the common side effects?

Common side effects can include pain, swelling, or redness at the injection site, muscle pain, headache, tiredness, chills, fever, or diarrhoea.

Can I leave the study if I change my mind?

Yes, you can choose to leave the study at any time without giving a reason, and it won't affect your regular medical care.

How to find out more

Sumreen Aftab

projectadmin@hvivo.com +44 (0) 20 7756 1300 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.