RecruitingPhase IIIInterventional

A Phase III randomized, open-label study of pasritamig (JNJ-78278343), a T-cell-redirecting agent targeting human kallikrein 2, with docetaxel versus docetaxel for metastatic castration-resistant prostate cancer

This study is looking into a new treatment for advanced prostate cancer that has spread and is no longer responding to hormone therapy. It combines a new drug called pasritamig with a standard chemotherapy, docetaxel. Pasritamig is designed to help your immune system fight cancer cells. Researchers want to know if adding pasritamig to docetaxel can slow down the cancer's growth more effectively than docetaxel alone. Participants will be randomly assigned to receive either the combined treatment or docetaxel alone. This is for men over 18 whose cancer has worsened despite previous treatments but haven't yet had chemotherapy.

At a glance

Status

Recruiting

Phase

Phase III

Sponsor

Janssen-Cilag International NV

Enrolment target

800

Start

30 Jan 2026

Estimated completion

27 Aug 2027

Metastatic castration-resistant prostate cancer (mCRPC)

What is this study about?

This study is about a type of prostate cancer called metastatic castration-resistant prostate cancer (mCRPC). This means the cancer started in the prostate gland and has spread to other parts of the body, and it's also grown despite treatments that lower male hormones. Even though there are treatments, this kind of cancer can't currently be cured and can cause serious health problems.

Researchers are investigating a new drug called pasritamig. This drug is a special type of protein designed to make your own immune system fight the cancer cells. It works by targeting specific proteins on the cancer cells and also on your immune system's T-cells, bringing them together to attack the cancer. The study combines pasritamig with docetaxel, which is a common chemotherapy drug already used for advanced prostate cancer. The main aim is to see if this combination treatment can keep the cancer from growing or spreading for longer than docetaxel alone.

This is a 'Phase III' study, which means it’s a later stage of research involving a larger group of people. This helps determine if the new treatment is safe and effective compared to existing options. The study will last for about 3 years and 5 months overall, with careful monitoring of participants throughout.

Key takeaways

This study compares a new combination (pasritamig + docetaxel) against docetaxel alone for advanced prostate cancer.
Pasritamig aims to use your immune system to fight cancer.
Participation involves random assignment to one of two treatment groups.
It's for men whose prostate cancer has spread and has not responded to hormone therapy, who haven't had chemotherapy yet.
The study includes regular check-ups and monitoring for safety and effectiveness.
There's no guaranteed personal benefit, but it could help future patients.

Who may be eligible?

This study is for men aged 18 or older who have prostate cancer that has spread to other parts of the body (metastatic) and is no longer responding to hormone treatments. Your cancer must have gotten worse even after you've had certain hormone-based therapies, but you shouldn't have had chemotherapy yet.

To be suitable, a doctor must have confirmed that you have this specific type of prostate cancer. Your overall health and fitness will also be checked to make sure you can safely take part in the study. For example, your kidney and liver function, and blood tests will need to be within certain ranges, and you should be generally active.

There are also specific reasons why you might not be able to join, such as having certain other health conditions. Your study doctor will go through all the details with you, including any medications you're currently taking and your full medical history, to make sure 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 male and 18 years old or older?
Do you have prostate cancer that has spread to other parts of your body?
Has your prostate cancer continued to grow despite previous hormone treatments?
Have you NOT had chemotherapy for your prostate cancer yet?
Are you generally healthy enough for a clinical study (e.g., active, satisfactory organ function)?
Are you willing to use contraception if necessary during the study?

Answer every question to see your result.

What does participation involve?

If you decide to take part, the study will involve several stages. First, there's a screening phase (up to 28 days) to confirm you're eligible. Then, you'll enter the treatment phase. You'll be randomly assigned, like flipping a coin, to one of two groups: either you'll receive the new drug pasritamig alongside docetaxel, or you'll receive docetaxel alone. Both groups will also receive prednisolone.

During the treatment phase, you’ll have regular check-ups, including physical exams, monitoring of your vital signs, and blood tests, to make sure you're safe and to track your progress. Once your treatment finishes or you start a different cancer therapy, there will be a final visit within 42 days. After that, you'll enter a follow-up phase. If your cancer hasn't worsened, you'll have check-ups every 6 weeks. If your cancer has worsened, you'll have check-ups every 12 weeks to monitor your long-term health. The whole study is expected to last around 3 years and 5 months.

Potential risks and benefits

There's no guarantee that you will personally benefit from taking part in this study, as the combined treatment is still being tested. However, based on what scientists understand, it's hoped that combining pasritamig with docetaxel might slow down your cancer's growth more effectively than docetaxel alone. Even if you don't receive the new drug, you'll get docetaxel, which is a standard and effective treatment for advanced prostate cancer. Taking part may also mean you receive more regular health checks, and your participation could help future patients with prostate cancer. Every medical treatment carries risks, and you might experience side effects from the drugs or procedures. These can range from mild to severe and could be life-threatening. Common potential side effects include immune reactions, neurological issues like headaches, or infusion-related reactions. Docetaxel also has known side effects such as fatigue, hair loss, and effects on blood cells. Not all possible side effects are known yet, but the study team will monitor you closely for any issues and always inform you of new information. You are free to withdraw from the study at any time, for any reason.

Locations (7)

Royal Marsden Hospital
Approximate
Sutton, England
The Royal Marsden Hospital
Approximate
London, England
Freeman Road Hospital
City only
Newcastle upon Tyne, England
Royal Preston Hospital
Approximate
Preston, England
Beatson West of Scotland Cancer Centre
City only
Glasgow, Scotland
Velindre Cancer Centre
Approximate
Cardiff, Wales
St. Bartholomews Hospital
City only
London, England

Common questions

What is metastatic castration-resistant prostate cancer?

It's prostate cancer that has spread to other parts of your body and continues to grow even when hormone-lowering treatments are used.

What is pasritamig?

It's a new investigational drug designed to help your immune system's T-cells find and attack prostate cancer cells.

Will I get the new drug?

You will be randomly assigned to one of two groups: either you'll get pasritamig with docetaxel, or you'll get docetaxel alone. It's like flipping a coin.

How long will the study last for me?

The different stages of the study, including screening, treatment, and follow-up, could mean you are involved for a few years, depending on your individual progress. The overall study is planned for 3 years and 5 months.

Who is paying for this study?

The study is funded by Janssen-Cilag International NV, a pharmaceutical company, who is also providing the study drugs and covering study-related tests. You may also receive reimbursement for travel costs.

How to find out more

Peter Chatfield

Official trial record

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