# Extensive-stage small-cell lung cancer

Source: https://onco.cc/cancers/extensive-stage-sclc/  
OnCo record `extensive-stage-sclc` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Small-cell lung cancer that has spread responds fast to chemotherapy but almost always returns within a year. Adding an immunotherapy antibody to first-line chemotherapy helps a minority live for years, and the T-cell engager tarlatamab, which points immune cells at the DLL3 protein on the cancer, has for the first time lengthened life after relapse.

## Summary

Extensive-stage small-cell lung cancer has been treated with platinum plus etoposide since the 1980s, with response rates of 60 to 70 percent but relapse within months, and thirty years of trials of added drugs, maintenance and dose intensity failed. IMpower133 (2018) was the first success: adding atezolizumab to carboplatin-etoposide lengthened median overall survival from 10.3 to 12.3 months (hazard ratio 0.70), and CASPIAN (2019) did the same with durvalumab (13.0 versus 10.3 months, hazard ratio 0.73); both were approved in 2019 and 2020 and a long tail of about 15 percent of patients alive at three years appeared. Chinese trials followed with serplulimab (ASTRUM-005, 15.4 versus 10.9 months, hazard ratio 0.63), adebrelimab and benmelstobart. IMforte (2025) then showed that adding lurbinectedin to atezolizumab maintenance after induction extended survival from 10.6 to 13.2 months (hazard ratio 0.73), approved in October 2025.

Second-line treatment was topotecan, with response rates around 20 percent, until lurbinectedin received accelerated approval in 2020 on a 35 percent response rate. Tarlatamab, a bispecific T-cell engager that binds DLL3 on small-cell cells and CD3 on T cells, produced a 40 percent response rate in DeLLphi-301 (2023) with cytokine release syndrome in about half, mostly mild, and received accelerated approval in May 2024; DeLLphi-304 (2025) then showed it lengthened median overall survival to 13.6 months against 8.3 months with chemotherapy (hazard ratio 0.60), the first randomised survival gain after relapse in this disease, and it is now the standard second-line treatment. The B7-H3 antibody-drug conjugate ifinatamab deruxtecan (IDeate-Lung02) and further DLL3 engagers are in phase 3.

Radiotherapy still has roles: prophylactic cranial irradiation improved survival when brain imaging was not routine (Slotman 2007) but not in the Japanese trial with MRI surveillance (Takahashi 2017), so MRI surveillance is increasingly preferred, and thoracic consolidation radiotherapy helps patients with residual chest disease. Open questions are why only a minority benefit durably from immunotherapy, whether the transcription factor subtypes (ASCL1, NEUROD1, POU2F3, inflamed) can direct treatment, and how to move tarlatamab and other DLL3 agents into first line.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: ES-SCLC; Extensive-disease small-cell lung cancer; Metastatic small-cell lung cancer; Stage IV small-cell lung cancer
- Tags: subtype-page; lung
- Group: lung
- Burden: About 70 percent of small-cell lung cancers are extensive stage at diagnosis, spread beyond one side of the chest, most often to liver, bone, brain and adrenal glands; median survival was about 10 months with chemotherapy alone and is now 12 to 15 months with chemoimmunotherapy, with about one in eight patients alive at three years.
- Subtypes: Extensive-stage small-cell lung cancer, first line (platinum-etoposide plus atezolizumab or durvalumab); Extensive-stage small-cell disease with brain metastases at diagnosis; Relapsed small-cell lung cancer, platinum-sensitive (relapse more than 90 days after chemotherapy); Relapsed small-cell lung cancer, platinum-resistant or refractory; Small-cell lung cancer transformed from EGFR-mutated adenocarcinoma; Neuroendocrine subtypes SCLC-A, SCLC-N, SCLC-P and SCLC-I (research)
- Biomarkers: Stage by PET-CT and brain MRI; Platinum-free interval at relapse (sensitive versus resistant); DLL3 expression (nearly universal; not required for tarlatamab); B7-H3 (ifinatamab deruxtecan trials); Transcription factor subtype and SLFN11 (research); PD-L1 and tumour mutational burden (not predictive in small-cell disease)

## Standard of care

- First line: Four cycles of carboplatin or cisplatin plus etoposide with atezolizumab (IMpower133) or durvalumab (CASPIAN), then maintenance immunotherapy until progression; lurbinectedin added to atezolizumab maintenance (IMforte); serplulimab, adebrelimab or benmelstobart in China. ([Platinum + etoposide (EP / CE)](https://onco.cc/drugs/platinum-etoposide/), [Carboplatin](https://onco.cc/drugs/carboplatin/), [Cisplatin](https://onco.cc/drugs/cisplatin/), [Etoposide](https://onco.cc/drugs/etoposide/), [Atezolizumab](https://onco.cc/drugs/atezolizumab/), [IMpower133](https://onco.cc/trials/impower133/), [Durvalumab](https://onco.cc/drugs/durvalumab/), [CASPIAN](https://onco.cc/trials/caspian/), [Lurbinectedin](https://onco.cc/drugs/lurbinectedin/), [IMforte](https://onco.cc/trials/imforte/), [Serplulimab](https://onco.cc/drugs/serplulimab/), [ASTRUM-005](https://onco.cc/trials/astrum-005/), [Adebrelimab](https://onco.cc/drugs/adebrelimab/), [Benmelstobart](https://onco.cc/drugs/benmelstobart/), [Maintenance therapy](https://onco.cc/terms/maintenance-therapy/))
- Second line: Tarlatamab (DeLLphi-304) with inpatient monitoring for cytokine release syndrome during the first doses; lurbinectedin or topotecan as alternatives; platinum-etoposide rechallenge if relapse is more than six months after first line. ([Tarlatamab](https://onco.cc/drugs/tarlatamab/), [DeLLphi-304](https://onco.cc/trials/dellphi-304/), [T-cell engagers (bispecific)](https://onco.cc/technologies/t-cell-engager/), [Cytokine release syndrome (CRS)](https://onco.cc/terms/crs/), [ICANS (neurotoxicity)](https://onco.cc/terms/icans/), [Step-up dosing (T-cell engagers)](https://onco.cc/terms/step-up-dosing/), [Lurbinectedin](https://onco.cc/drugs/lurbinectedin/), [Topotecan](https://onco.cc/drugs/topotecan/), [Platinum + etoposide (EP / CE)](https://onco.cc/drugs/platinum-etoposide/))
- Brain: MRI surveillance every three months or prophylactic cranial irradiation after response to first-line treatment; whole-brain or stereotactic radiotherapy for metastases. ([Prophylactic cranial irradiation vs MRI surveillance](https://onco.cc/technologies/prophylactic-cranial-irradiation/), [Prophylactic cranial irradiation (PCI)](https://onco.cc/terms/pci-term/), [EORTC 08993 (Slotman): prophylactic cranial irradiation in extensive-stage small-cell lung cancer](https://onco.cc/trials/slotman-pci-es-sclc/), [Takahashi trial: prophylactic cranial irradiation with MRI surveillance in extensive-stage small-cell lung cancer](https://onco.cc/trials/takahashi-pci/), [MRI](https://onco.cc/technologies/mri/), [Whole-brain radiotherapy (WBRT)](https://onco.cc/terms/wbrt/), [Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)](https://onco.cc/technologies/radiosurgery-srs/))
- Thoracic consolidation: Consolidative thoracic radiotherapy (30 Gy in 10 fractions) for patients with residual chest disease after chemotherapy. ([IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Hypofractionated radiotherapy](https://onco.cc/technologies/hypofractionated-radiotherapy/), [Consolidation therapy](https://onco.cc/terms/consolidation-therapy/))

## State of the art

- Chemoimmunotherapy first line (IMpower133, CASPIAN) with a tail of about 15 percent alive at three years.
- Tarlatamab second line: median survival 13.6 versus 8.3 months against chemotherapy in DeLLphi-304, the first randomised gain after relapse.
- Lurbinectedin plus atezolizumab maintenance (IMforte) approved in 2025.
- B7-H3 antibody-drug conjugates and further DLL3 engagers in phase 3; subtype-directed therapy in research.

## Open problems

- No biomarker identifies the minority who gain long-term benefit from immunotherapy; PD-L1 and mutational burden do not work in small-cell disease.
- Tarlatamab needs inpatient monitoring for cytokine release syndrome, which limits access outside specialist centres.
- Whether the transcription factor subtypes can direct treatment is unproven.
- Brain metastases remain common and prophylactic irradiation trades cognition for a benefit that is uncertain with MRI surveillance.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Small-cell_carcinoma
- Wikipedia: https://en.wikipedia.org/wiki/Small-cell_carcinoma
- NCCN Guidelines: Small Cell Lung Cancer: https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1462

## Connected records

- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/), [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/), [Hypofractionated radiotherapy](https://onco.cc/technologies/hypofractionated-radiotherapy/), [Immune checkpoint inhibitors](https://onco.cc/technologies/checkpoint-inhibitor/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [MRI](https://onco.cc/technologies/mri/), [PET/CT](https://onco.cc/technologies/pet-ct/), [Platinum agents](https://onco.cc/technologies/platinum/), [Prophylactic cranial irradiation vs MRI surveillance](https://onco.cc/technologies/prophylactic-cranial-irradiation/), [Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)](https://onco.cc/technologies/radiosurgery-srs/), [T-cell engagers (bispecific)](https://onco.cc/technologies/t-cell-engager/), [Targeted alpha therapy](https://onco.cc/technologies/targeted-alpha-therapy/), [Topoisomerase-I inhibitors (and ADC payloads)](https://onco.cc/technologies/topoisomerase-inhibitors/)
- targets: [B7-H3](https://onco.cc/targets/b7h3/), [DLL3](https://onco.cc/targets/dll3/), [PD-1](https://onco.cc/targets/pd1/), [PD-L1](https://onco.cc/targets/pdl1/), [TP53](https://onco.cc/targets/tp53/)
- drugs: [Actinium-225 DOTATATE](https://onco.cc/drugs/ryz101/), [Adebrelimab](https://onco.cc/drugs/adebrelimab/), [Atezolizumab](https://onco.cc/drugs/atezolizumab/), [Benmelstobart](https://onco.cc/drugs/benmelstobart/), [Carboplatin](https://onco.cc/drugs/carboplatin/), [Cisplatin](https://onco.cc/drugs/cisplatin/), [Durvalumab](https://onco.cc/drugs/durvalumab/), [Etoposide](https://onco.cc/drugs/etoposide/), [Ifinatamab deruxtecan](https://onco.cc/drugs/ifinatamab-deruxtecan/), [Lurbinectedin](https://onco.cc/drugs/lurbinectedin/), [Platinum + etoposide (EP / CE)](https://onco.cc/drugs/platinum-etoposide/), [Serplulimab](https://onco.cc/drugs/serplulimab/), [Tarlatamab](https://onco.cc/drugs/tarlatamab/), [Topotecan](https://onco.cc/drugs/topotecan/), [ZL-1310](https://onco.cc/drugs/zl-1310/)
- companies: [Amgen](https://onco.cc/companies/amgen/), [AstraZeneca](https://onco.cc/companies/astrazeneca/), [Daiichi Sankyo](https://onco.cc/companies/daiichi-sankyo/), [Jazz Pharmaceuticals](https://onco.cc/companies/jazz/), [Merck & Co. (MSD)](https://onco.cc/companies/merck/), [PharmaMar](https://onco.cc/companies/pharmamar/), [Roche / Genentech](https://onco.cc/companies/roche-genentech/), [Shanghai Henlius Biotech](https://onco.cc/companies/henlius/)
- institutions: [MD Anderson Cancer Center](https://onco.cc/institutions/md-anderson/), [Memorial Sloan Kettering Cancer Center](https://onco.cc/institutions/mskcc/)
- pathways: [Intrinsic apoptosis (BCL-2 family)](https://onco.cc/pathways/apoptosis-bcl2/), [p53 / RB / cell-cycle checkpoint](https://onco.cc/pathways/p53-cell-cycle/), [PD-1 / PD-L1 immune checkpoint & T-cell activation](https://onco.cc/pathways/pd1-checkpoint/), [Small cell lung cancer (KEGG map)](https://onco.cc/pathways/sclc-signalling/)
- terms: [Brain metastases (intracranial disease)](https://onco.cc/terms/brain-metastases/), [Consolidation therapy](https://onco.cc/terms/consolidation-therapy/), [Cytokine release syndrome (CRS)](https://onco.cc/terms/crs/), [ICANS (neurotoxicity)](https://onco.cc/terms/icans/), [Limited-stage vs extensive-stage (small-cell lung cancer)](https://onco.cc/terms/limited-extensive-stage/), [Maintenance therapy](https://onco.cc/terms/maintenance-therapy/), [Platinum-sensitive / platinum-resistant](https://onco.cc/terms/platinum-sensitivity/), [Prophylactic cranial irradiation (PCI)](https://onco.cc/terms/pci-term/), [Step-up dosing (T-cell engagers)](https://onco.cc/terms/step-up-dosing/), [Whole-brain radiotherapy (WBRT)](https://onco.cc/terms/wbrt/)
- trials: [A Study of ZL-1310 Versus Investigator's Choice of Therapy in Participants With Relapsed Small Cell Lung Cancer (DLLEVATE)](https://onco.cc/trials/dllevate/), [ASTRUM-005](https://onco.cc/trials/astrum-005/), [CASPIAN](https://onco.cc/trials/caspian/), [DeLLphi-304](https://onco.cc/trials/dellphi-304/), [DeLLphi-305](https://onco.cc/trials/dellphi-305/), [EORTC 08993 (Slotman): prophylactic cranial irradiation in extensive-stage small-cell lung cancer](https://onco.cc/trials/slotman-pci-es-sclc/), [IDeate-Lung02](https://onco.cc/trials/ideate-lung02/), [IMforte](https://onco.cc/trials/imforte/), [IMpower133](https://onco.cc/trials/impower133/), [Takahashi trial: prophylactic cranial irradiation with MRI surveillance in extensive-stage small-cell lung cancer](https://onco.cc/trials/takahashi-pci/)
- people: [Charles M. Rudin](https://onco.cc/people/charles-rudin/), [Luis Paz-Ares](https://onco.cc/people/luis-paz-ares/), [Martin Reck](https://onco.cc/people/martin-reck/), [Ying Cheng](https://onco.cc/people/cheng-ying/)
- key papers: [DeLLphi-301: tarlatamab, a DLL3-targeting T-cell engager, in previously treated small-cell lung cancer](https://onco.cc/key-papers/paper-dellphi-301-nejm-2023/)
- ideas: [MRI surveillance replaces prophylactic cranial irradiation in SCLC](https://onco.cc/ideas/idea-mri-surveillance-replaces-pci/), [Subtype-directed therapy for SCLC (ASCL1 / NEUROD1 / POU2F3 / inflamed)](https://onco.cc/ideas/idea-sclc-subtype-directed/)
- pairings: [Chemo-immunotherapy induction → maintenance intensification (SCLC)](https://onco.cc/pairings/chemo-io-then-maintenance-sclc/), [Sequencing DLL3 engager and B7-H3 ADC in relapsed SCLC](https://onco.cc/pairings/tarlatamab-vs-idxd-sequence/)
- cancers: [Small-cell lung cancer](https://onco.cc/cancers/sclc/)

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