RecruitingPHASE2INTERVENTIONAL

Prevention of Recurrent C. Difficile Infection Study With AZD5148 Monoclonal Antibody

This study is looking into a new medicine called AZD5148. The main goal is to find out if it can effectively prevent Clostridioides difficile (C. diff) infections from returning in adults aged 18 and over. C. diff is a type of gut infection that can come back after treatment. Participants will be randomly assigned to receive either AZD5148 or a placebo (a dummy treatment like saline solution) as a single dose. Researchers will then check if the new medicine works and if it's safe. This is a Phase 2 study, meaning it's still in the early stages of testing. The study aims to involve about 230 people.

At a glance

Status

Recruiting

Phase

PHASE2

Sponsor

AstraZeneca

Enrolment target

230

Start

10 Dec 2025

Estimated completion

18 Jan 2028

Clostridioides Difficile Infection

What is this study about?

You might be reading this because you, or someone you know, has had a Clostridioides difficile (C. diff) infection. This is a common gut infection that can cause unpleasant symptoms like severe diarrhoea. While there are treatments for C. diff, it can sometimes come back, which can be very frustrating and difficult.

This study is testing a new medicine called AZD5148. The main purpose is to see if this medicine can help stop C. diff infections from returning after you've been treated for an active infection. Researchers also want to make sure the medicine is safe. By preventing C. diff from coming back, we hope to improve the health and well-being of people who suffer from this condition.

About 230 people will take part in this study. Half will receive the new medicine, AZD5148, and the other half will receive a 'placebo', which is a dummy treatment like a saltwater solution. This allows researchers to compare the effects of the new medicine against no active treatment. You won't know whether you're getting the active medicine or the placebo, and neither will your doctor involved in the study, to ensure the results are as fair as possible.

Key takeaways

The study tests a new medicine (AZD5148) to stop C. diff infections from coming back.
It's for adults 18+ who recently had a C. diff infection.
You'll either get the new medicine or a dummy treatment (placebo).
Participation involves clinic visits, contacts, and an electronic diary.
The study aims to see if the medicine works and if it's safe.
You can withdraw from the study at any time.

Who may be eligible?

To join this study, you need to be at least 18 years old and have recently had a C. diff infection that has been confirmed by a test. You should also be receiving standard treatment (like antibiotics) for your C. diff infection at the time you join, and this treatment should be planned to last between 10 and 25 days. Your body weight must be at least 40 kg (about 6 stone 4 pounds).

There are also some reasons why you might not be able to join. For example, if you have certain bowel conditions like Crohn's disease or ulcerative colitis, or if you've recently had major gut surgery. You also can't take part if you've had certain treatments for C. diff recently, such as a faecal transplant, or if you're planning to have one. If you've been diagnosed with a severe form of C. diff that requires immediate surgery, you wouldn't be able to join either.

It's important to discuss your full medical history with the study team to see if this study is right for you.

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 18 years old or older?
Have you recently had a confirmed C. diff infection?
Are you currently receiving treatment for your C. diff, lasting 10-25 days?
Do you weigh at least 40 kg (about 6 stone 4 pounds)?
Have you ever had inflammatory bowel disease (like Crohn's or ulcerative colitis)? (If yes, you might not be eligible)
Have you had a faecal transplant in the last 6 months or plan to have one?

Answer every question to see your result.

What does participation involve?

If you decide to take part, your involvement would generally include:

* **Initial visits:** You'll have up to two visits to confirm you're suitable for the study and to receive the study medicine (either AZD5148 or the placebo). During these visits, a stool sample will also be collected. * **Dose administration:** The study medicine will be given as a single dose, either into a muscle (like your arm) or directly into a vein (like through a drip). * **Follow-up visits:** After the initial visits, you'll have up to seven more planned visits to the clinic or hospital. * **Regular contact:** The study staff will also contact you weekly at first, and then monthly, to check on your health and any symptoms. * **Daily diary:** You'll be asked to complete an electronic diary regularly to record how you're feeling and any changes in your health.

The overall duration of your participation in the study, from your first visit to your last follow-up, could be several months.

Potential risks and benefits

Taking part in any clinical study has potential benefits and risks. For this study, a potential benefit is that AZD5148 *might* help prevent your C. diff infection from returning, which could improve your health and quality of life. However, it's also possible that the medicine may not work or could cause new side effects. Because this is a new medicine, all possible risks aren't fully known, but the study team will monitor you closely for any issues. There's always the chance you might receive the placebo and not the active medicine. You are free to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (114)

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

Research Site
Verified postcode
Phoenix, United States· Withdrawn
Research Site
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Chula Vista, United States· Withdrawn
Research Site
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Sacramento, United States· Not yet recruiting
Research Site
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Torrance, United States· Recruiting
Research Site
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Hamden, United States· Recruiting
Research Site
Verified postcode
Gainesville, United States· Recruiting
Research Site
Verified postcode
Hialeah, United States· Not yet recruiting
Research Site
Verified postcode
Homestead, United States· Recruiting
Research Site
Verified postcode
Jacksonville, United States· Recruiting
Research Site
Verified postcode
Miami Lakes, United States· Withdrawn
Research Site
Verified postcode
Miramar, United States· Recruiting
Research Site
Verified postcode
Port Orange, United States· Withdrawn

Common questions

What is C. difficile infection?

C. difficile is a type of germ that can cause an infection in your gut, leading to symptoms like tummy pain and severe diarrhoea.

What is AZD5148?

AZD5148 is an investigational medicine being tested to see if it can prevent C. difficile infections from returning.

What is a placebo?

A placebo is a substance that looks exactly like the study medicine but doesn't contain any active drug. It helps researchers compare the effects of the active medicine fairly.

How long will I be in the study?

Your involvement could last several months, including initial visits, receiving the medicine, and follow-up checks.

Can I leave the study if I change my mind?

Yes, you can choose to leave the study at any time, for any reason, and it won't affect your ongoing medical care.

How to find out more

AstraZeneca Clinical Study Information Center

information.center@astrazeneca.com 1-877-240-9479 Official trial record

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