A tumor test may show who does well on tarlatamab
Original title: DLL3 expression predicts response and long-term outcome in small cell lung cancer patients treated with tarlatamab
How far along is this research?
This is a preprint. Other scientists have not checked it yet, so treat it as an early signal rather than an answer.
Doctors looked back at past patient records, so this test is not yet proven for choosing treatment.
The short version
A lab test on tumor tissue may help predict who benefits from the drug tarlatamab.
What was studied. Doctors reviewed records from 138 people with small cell lung cancer at one center. They measured a protein called DLL3 in tumor samples. 54 of these people had been treated with the drug tarlatamab.
What they found. In the 54 treated people, the middle DLL3 level was 75%. People with DLL3 above 75% stayed on the drug 10.1 months. People at 75% or below stayed on it 2.9 months. Of 41 people checked for tumor shrinkage, 51% (21) had tumors shrink and 27% (11) got worse.
What this means, and what it doesn't
What it could mean: A test doctors already run on tumor tissue might help guess who will benefit. That could help doctors and patients talk about whether this drug is a good fit. It may also point out who needs a different plan.
What it doesn't mean: This is not a new treatment, and it is not a cure. Doctors looked back at past records at one center. That is a weaker kind of study than a trial. The test is not yet a proven way to pick treatment. DLL3 level also did not match how brain spots responded. Larger studies are needed before this changes everyday care.
Source: bioRxiv (preprint), September 7, 2026 · Read the original
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