AuthorisedPhase I and Phase II (Integrated)- First administration to humansInterventional

A multicenter, non-therapeutic, interventional, long-term follow-up clinical trial to evaluate the safety of autologous PRAME-directed TCR T cell therapy IMA203 or IMA203CD8 in patients with previously treated, advanced and/or metastatic solid tumors

This long-term follow-up study is designed for adults who have already received an experimental cancer treatment known as IMA203 or IMA203CD8. These treatments use genetically modified versions of a patient's own immune cells (T cells) to help recognise and fight advanced solid tumours. In this study, participants do not receive any new medicines. Instead, doctors closely monitor their health over an extended period. Because cell therapies are relatively new, it is vital to check for any late-appearing side effects and to see how long the modified cells stay in the body. Participants will have scheduled check-ups, blood tests, and physical health reviews. By taking part, patients help doctors understand the long-term safety of modern immune therapies, which will help guide safer, more effective cancer care for future patients.

At a glance

Status

Authorised

Phase

Phase I and Phase II (Integrated)- First administration to humans

Sponsor

Immatics US Inc.

Enrolment target

Start

21 Aug 2026

Solid tumors

What is this study about?

In recent years, scientists have developed new ways to fight cancer using the body's own immune defences. One promising approach is T-cell receptor (TCR) therapy. In earlier trials of treatments called IMA203 and IMA203CD8, doctors took immune cells from patients with advanced solid tumours, modified them in a laboratory to help them target a specific cancer protein, and returned them to the body.

Because these altered cells can remain in the body for a very long time, medical safety rules require doctors to keep a close eye on patients long after the treatment ends. This study is a dedicated follow-up programme. Its main aim is to make sure participants remain safe and to detect any late or unexpected side effects that might only appear months or years down the line.

Taking part does not involve receiving new cancer treatments. Instead, doctors track each person's recovery, monitor their general wellbeing, and test blood samples to see if the modified cells are still active. This information is vital for ensuring current patients stay healthy and for helping researchers design safer cell therapies for others in the future.

Key takeaways

This study tracks the long-term safety of the cell therapies IMA203 and IMA203CD8.
It is only for people who have already received one of these treatments in a previous trial.
No new cancer drugs are given during this study.
Participation involves routine health checks, symptom reviews, and blood tests over several years.
You are free to leave the study at any point without impacting your standard medical care.

Who may be eligible?

This study is specifically for adults aged 18 and over who have already taken part in an earlier clinical trial where they received the cell therapy IMA203 or IMA203CD8 for an advanced or spreading (metastatic) solid tumour.

People who have not previously received one of these specific treatments cannot take part, as the study is solely designed to monitor the long-term effects of these exact therapies. Both men and women are eligible.

Participants must be willing and able to attend routine follow-up appointments and have regular health assessments, such as blood tests, over an extended period.

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.

I am aged 18 or older.
I have been treated for an advanced or metastatic solid tumour.
I have already received the experimental cell therapy IMA203 or IMA203CD8 in a clinical trial.
I am able and willing to attend regular hospital check-ups and give blood samples over time.

Answer every question to see your result.

What does participation involve?

Taking part in this study involves attending regular hospital visits for health check-ups. Because this is a follow-up study, you will not receive any new cancer medications or infusions as part of this trial. During visits, the medical team will carry out physical examinations, check your vital signs, and ask how you are feeling. You will have routine blood tests to look for any delayed side effects and to check whether any of the modified T cells are still present in your blood. These visits usually happen every few months at first and become less frequent over time. Because cell therapies can last a long time, the total follow-up period can extend over several years.

Potential risks and benefits

You will not receive any new medical treatment in this study, so there is no direct physical cure or tumour shrinkage expected from taking part. However, you will benefit from ongoing, expert medical monitoring by cancer specialists who will quickly notice and manage any late health issues. The physical risks of this study are very low and mainly relate to routine procedures, such as mild bruising or discomfort from blood tests. You have the right to leave the study at any time without giving a reason, and doing so will not affect your normal NHS care or relationship with your medical team.

Locations (1)

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

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Unverified
Germany

Common questions

Will I receive any new cancer medicine in this study?

No. This is a follow-up safety study only. Its purpose is to check on your health after your previous treatment with IMA203 or IMA203CD8, not to give you a new drug.

Why do doctors need to follow me for so long?

Cell therapies involve living cells that can stay in your body for years. Long-term monitoring helps doctors make sure that no late or delayed side effects appear over time.

How often will I need to visit the hospital?

Visits are typically more frequent in the first year or two and then become further apart, such as once or twice a year. Your doctor will give you an exact schedule.

Can I have other cancer treatments while in this study?

Yes, if your cancer progresses or changes, your doctor can prescribe other treatments. Taking part in this follow-up study will not stop you from receiving necessary care.

What happens if I decide I no longer want to take part?

You are completely free to leave the study whenever you choose. Your decision will be fully respected and will not change your regular healthcare in any way.