Phase II Study of Intravenous Tarlatamab for Patients with Asymptomatic Brain Metastases from Small Cell Lung Cancer

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What is this study about?

The condition being studied is small cell lung cancer that has spread to the brain, creating brain metastases that are currently not causing symptoms. The investigational medicine tested is tarlatamab, which is given by intravenous infusion.

The purpose of the trial is to find out how well tarlatamab can shrink or control the brain tumors. Participants will receive the medication on a regular schedule, and doctors will look at the brain with MRI scans after six weeks and then every six weeks, while chest and abdominal areas will be examined with CT scans at the same intervals. The study follows patients for several months to observe both short‑term and longer‑term effects.

At each clinic visit, safety checks are performed and any side effects are recorded, and the overall participation period may extend up to about a year, depending on continued treatment and follow‑up imaging.

1 baseline assessments

after joining the study, a series of initial tests are performed. a brain scan using mri is done to document the current condition of the brain metastases. a body scan using ct of the chest and upper abdomen is performed to assess disease outside the brain. these tests provide the reference point for later comparisons.

2 first administration of <b>tarlatamab</b>

the study drug tarlatamab is given by intravenous infusion. each dose contains 10 mg of the medication in a solution for injection. the infusion is performed in a clinical setting under observation.

3 regular follow‑up visits every six weeks

six weeks after the first dose, a follow‑up visit is scheduled. at each visit, a brain mri and a body ct are repeated to monitor changes in the metastases.

during the same visit, safety is evaluated using the standard toxicity grading system ctcae v5.0. any side effects are recorded and managed.

4 evaluation of intracranial response at twelve weeks

after the third visit (approximately twelve weeks from the start), the brain scans are examined to determine the confirmed intracranial objective response rate (orr) using the rano‑bm criteria. this measurement indicates whether the brain lesions have shrunk, remained stable, or progressed.

5 continued monitoring until study end

the pattern of six‑week visits continues for the duration of the study. each visit includes brain mri, body ct, and safety assessment.

additional outcomes such as intracranial disease control rate (dcr), central nervous system progression‑free survival (cns pfs), extracranial response, overall progression‑free survival, and overall survival are recorded according to the respective assessment systems (rano‑bm for brain lesions and recist 1.1 for other lesions).

Who Can Join the Study?

You must have a diagnosis of small cell lung cancer that has spread (metastasized) and this must be confirmed by tissue testing.
You must have already received at least one round of platinum‑doublet chemotherapy (two chemotherapy drugs, one of which contains platinum) with or without immunotherapy; there is no limit on how many previous treatments you have had.
You must have at least one brain metastasis (cancer spot in the brain) that is active (new or clearly growing) but asymptomatic (not causing symptoms), and it must be 5 mm or larger. Lesions between 5 mm and 10 mm are allowed if a detailed MRI scan is performed.
The brain lesion must be untreated, meaning it has not been treated before with focused radiation (SRS/SRT) or surgery. Prior whole‑brain radiation or surgery is allowed if the lesion has clearly progressed since then.
Your overall health must be good, with a WHO/ECOG performance status of 0 or 1 (fully active or able to do light work) and you are expected to live at least 12 weeks.
For at least 7 days before the study you must have no symptoms from the brain tumors and be on a stable dose of medicines to prevent seizures (anti‑epileptics) and steroids, with steroids not higher than 10 mg of prednisone (or equivalent) per day.
Your blood and organ tests must show adequate function, including: white‑blood‑cell (neutrophil) count ≥ 1.5 × 10⁹/L, platelet count ≥ 100 × 10⁹/L, hemoglobin ≥ 5.6 mmol/L; clotting tests (PT/INR and PTT/APTT) no more than 1.5 times the normal range unless you are on a stable blood‑thinner dose for 6 weeks; kidney function (eGFR) ≥ 30 mL/min/1.73 m²; liver enzymes (AST and ALT) less than three times normal (or less than five times if liver metastases are present) and bilirubin less than 1.5 times normal (or less than two times with liver metastases); no need for supplemental oxygen; and heart function with ejection fraction ≥ 50 % and no significant fluid around the heart or major ECG problems.
You must be 18 years of age or older.
You must sign a written informed consent form agreeing to take part in the study.

Who Cannot Join the Study?

Having symptoms from brain tumors that have spread to the brain (symptomatic brain metastases).
Having had a blood‑clot problem such as a stroke or a brief loss of brain blood flow (transient ischemic attack) within the last 6 months.
Having lung scarring disease (interstitial lung disease) or an active non‑infectious inflammation of the lungs (pneumonitis).
Having received a solid organ transplant (for example a kidney, liver or heart).
Having had a major surgery within 28 days before the first study dose.
Having an active HIV infection or an active hepatitis B or C infection (the virus is still present in the blood at high levels).
Having taken strong steroids or other medicines that suppress the immune system within 14 days before the first dose (low‑dose steroids are allowed).
Having a new or uncontrolled infection in the body within 7 days before the first dose (simple urinary‑tract infections that are improving are allowed).
Having received a live‑virus vaccine (or a certain non‑live vaccine) within 4 weeks (or 30 days for some vaccines) before the first dose.
Having used any drug that blocks the DLL3 pathway before.
Receiving another cancer treatment at the same time (except hormone therapy for early‑stage breast cancer).
Having cancer spread to the membranes covering the brain and spinal cord (leptomeningeal metastases) shown on MRI.
Having taken part in a different experimental trial within 28 days before joining this study.
Being a woman who could become pregnant and not willing to use the required birth‑control method during treatment and for 60 days after the last dose.
Being a woman who is breastfeeding or plans to breast‑feed during the study or for 60 days after the last dose.
Being a woman who plans to become pregnant or donate eggs while in the study or for 60 days after the last dose.
Being a woman of child‑bearing age who has a positive pregnancy test at screening.
Being a man whose female partner could become pregnant and who is not willing to avoid sex or use contraception during treatment and for 60 days after the last dose.
Being a man with a pregnant partner who is not willing to avoid sex or use a condom during treatment and for 60 days after the last dose.
Being a man who does not agree to refrain from donating sperm during treatment and for 60 days after the last dose.
Having a known allergy to tarlatamab or any of its ingredients.
Having any other serious medical problem that the doctor believes makes participation unsafe or would interfere with study procedures.
Having a brain tumor located in a critical (eloquent) area of the brain, as decided by a neuro‑oncologist.
Being unlikely to attend all required study visits or follow study procedures.
Having a condition that makes an MRI scan unsafe or impossible.
Having previously experienced a severe or life‑threatening reaction to any immune‑based therapy.
Having experienced moderate or worse side effects (grade 2 or higher) from prior cancer treatment, except for hair loss.
Having had another type of cancer in the past 2 years, except for certain low‑risk cancers such as treated non‑melanoma skin cancer, cervical cancer in situ, breast ductal carcinoma in situ, or non‑invasive bladder cancer.
Having an active or prior autoimmune or inflammatory disease (such as inflammatory bowel disease, lupus, sarcoidosis, rheumatoid arthritis, etc.), unless it is a mild condition like vitiligo, alopecia, well‑controlled hypothyroidism, or diet‑controlled celiac disease.
Having had a heart attack or having symptomatic heart failure that is worse than New York Heart Association class II within the last 6 months.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country	Status
University Hospital Maastricht	Maastricht	The Netherlands

Other Sites

Site Name	City	Country
Netherlands Cancer Institute	Amsterdam	The Netherlands
Evxnkpb Uxwizzmihcwd Mxeusyl Cbvrieb Rdzpfaboj (jzztngr Mbo	Rotterdam	The Netherlands
Uzlcxewlqsss Mmqkpcq Cuyxvbv Ggicivdst	Groningen	The Netherlands

Trial status

Country	Status	Recruitment Start
The Netherlands	Not yet recruiting	05.01.2026

Trial locations

Investigated drugs:

Tarlatamab

Tarlatamab is an experimental medicine being studied to see if it can shrink or control brain tumors that have spread from small cell lung cancer. In the trial, it is given through an IV (a needle placed into a vein) as a liquid that is mixed and infused into the bloodstream. The purpose of using this drug is to test how well it works inside the brain and whether it can reduce the size of these metastases, which are growths that have moved to the brain from the original lung cancer.

Investigated diseases:

Small cell lung cancer metastatic

Small cell lung carcinoma – a fast‑growing cancer that begins in the lining of the airways of the lung. It often spreads early to other organs such as lymph nodes, liver, bone, and brain. The tumor cells can form clusters that block airways and reduce breathing ability. As the disease expands, it may cause coughing, weight loss, and fatigue.

Brain metastasis from small cell lung carcinoma – the spread of cancer cells from the lung to the brain. These secondary tumors can develop without causing noticeable symptoms at first. As they enlarge, they may press on brain tissue and affect normal function. The lesions can increase in size and number, leading to changes in mood, balance, or vision. They are considered active when they are still growing and can be seen on imaging.

Trial ID:

2025-522162-75-00

Trial Phase:

Therapeutic exploratory (Phase II)

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Phase II Study of Intravenous Tarlatamab for Patients with Asymptomatic Brain Metastases from Small Cell Lung Cancer

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?