Evidence Hub

Early Pseudoprogression After Tarlatamab in Small‐Cell Lung Cancer: A Case Report

Yoshio Nakano, Hiroka Serizawa, Yuri Enomoto, Yusuke Kuze, Norio Okamoto, I. Gohma

Respirology Case Reports, 2025

5 citations

Abstract

Pseudoprogression, a transient radiographic flare caused by immune infiltration, is common after immune‐checkpoint inhibitors but has not been reported with tarlatamab, a bispecific T‐cell engager approved for third‐line small‐cell lung cancer (SCLC). A 57‐year‐old woman with extensive‐stage SCLC and syndrome of inappropriate antidiuretic hormone secretion (SIADH) received tarlatamab. Within hours, she developed bone pain; Day 7 imaging showed marked tumour swelling and pleural effusion despite negative cytology and rising serum sodium. Therapy continued. By Day 13, computed tomography demonstrated regression of thoracic and hepatic lesions and falling pro–gastrin‐releasing peptide (pro‐GRP). Early pseudoprogression and paraneoplastic biomarker improvement may predict efficacy.

How strong is the evidence?

Evidence Hub reads this as a case report, done in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free