What are the latest updates in the treatment of small‑cell lung carcinoma (SCLC)?

Latest Updates in Small Cell Lung Cancer Treatment

The most significant recent advance is the FDA approval of tarlatamab, a novel bispecific T-cell engager, for relapsed SCLC, which joins durvalumab consolidation for limited-stage disease and first-line chemoimmunotherapy for extensive-stage disease as the major treatment paradigm shifts in SCLC. 1

Limited-Stage SCLC (LS-SCLC)

Consolidation Immunotherapy - Major Update

Patients with LS-SCLC who complete concurrent chemoradiotherapy without disease progression should receive consolidation durvalumab for up to 2 years if no contraindications exist. 1

• This represents a strong recommendation with moderate evidence quality from the 2025 ASCO guideline update 1
• Durvalumab is administered as a single agent following completion of platinum-based chemotherapy and radiation therapy 2
• Even patients with ECOG performance status 3-4 due to SCLC may be offered durvalumab consolidation if their performance status improves after chemoradiotherapy, though this carries a conditional recommendation with low evidence quality 1

Standard Concurrent Treatment

• Cisplatin and etoposide remain the preferred chemotherapy backbone concurrent with radiation therapy 1
• Carboplatin and etoposide may substitute when cisplatin is contraindicated 1
• Chemotherapy should commence immediately and not be delayed waiting for radiation therapy to start 1

Extensive-Stage SCLC (ES-SCLC)

First-Line Treatment - Established Standard

First-line therapy must include platinum-etoposide chemotherapy combined with a PD-L1 inhibitor (atezolizumab or durvalumab) followed by maintenance immunotherapy. 1

• Atezolizumab is administered at 840 mg every 2 weeks, 1200 mg every 3 weeks, or 1680 mg every 4 weeks in combination with carboplatin and etoposide 3
• Durvalumab is dosed at 1500 mg every 3 or 4 weeks (for patients ≥30 kg) in combination with etoposide and platinum 2
• This combination should be administered prior to chemotherapy when given on the same day 3, 2
• This represents high-quality evidence with strong recommendation strength 1

Relapsed/Recurrent Disease - Major 2025 Update

For relapsed SCLC with chemotherapy-free interval <90 days, preferred single-agent options are now topotecan, lurbinectedin, OR tarlatamab. 1

Tarlatamab - The Newest Option

• Tarlatamab is a bispecific T-cell engager that represents the most significant new drug approval for relapsed SCLC 1
• Dosing schedule: 1 mg IV on day 1 of cycle 1, followed by 10 mg on days 8 and 15 of cycle 1, then 10 mg every 2 weeks thereafter until progression or unacceptable toxicity 1
• Requires 24-hour inpatient monitoring after the first two doses (days 1 and 8 of cycle 1) due to risk of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) 1
• Grade ≥3 treatment-related adverse events occur in 26% of patients, but grade ≥3 CRS and ICANS are rare (1% and 0%, respectively) 1
• Duration of response exceeds 9 months, substantially longer than other available agents 1
• Cross-trial comparisons suggest both tarlatamab and lurbinectedin are more effective than topotecan 1

Chemotherapy-Free Interval ≥90 Days

Patients may receive either rechallenge with platinum-based regimen OR single-agent therapy (topotecan, lurbinectedin, or tarlatamab). 1

Critical Caveats and Pitfalls

Sequencing Uncertainty

• No head-to-head data exist comparing tarlatamab, lurbinectedin, and topotecan - the optimal sequencing remains unknown 1
• The ongoing DeLLphi-304 trial is comparing tarlatamab with standard chemotherapy to address this question 1

Immunotherapy Contraindications

• Evaluate baseline liver enzymes, creatinine, and thyroid function before initiating immunotherapy 3
• Monitor for immune-mediated adverse reactions including pneumonitis, colitis, hepatitis, endocrinopathies, dermatologic reactions, and nephritis 3, 2
• These reactions may be severe or fatal and can occur in any organ system 3, 2

Single-Agent Preference in Relapsed Disease

Single-agent systemic therapy is preferred over multiagent therapies in the relapsed setting due to concerns about risk-benefit balance. 1

Emerging Considerations

Radiation Therapy Integration

• Consolidative thoracic radiotherapy combined with chemoimmunotherapy in ES-SCLC shows promising safety and efficacy data, with 1-year overall survival of 80.2% in small studies 4
• Radiation-related pneumonitis rates remain low (8%, grades 1-2) when combined with immunotherapy 4

Smoking Cessation

Smoking cessation must be strongly recommended for all SCLC patients, as it improves treatment tolerance, response rates, and overall survival. 1