Low-dose Thoracic Radiotherapy Followed by Adebrelimab Plus Chemotherapy, and Then Sequential Maintenance Therapy With Adebrelimab for Extensive-stage Small Cell Lung Cancer

NCT07583550 | Not Yet Recruiting Phase 2

• 1 other identifier: 2026 049 A
• Study Type: interventional
• Target: 43
• Locations: 0 countries
• Sites: N/A

Brief Summary

This multicenter, prospective study aims to investigate the efficacy and safety of low-dose radiotherapy (15Gy/1.5 Gy bid × 10 fractions) combined with 4-6 cycles of systemic chemotherapy plus anti-PD-L1 antibody, followed by anti-PD-L1 antibody maintenance for up to two years, in participants with extensive-stage small cell lung cancer (ES-SCLC). Additionally, dynamic monitoring using next-generation sequencing (NGS) technology will be performed to assess ctDNA levels, genetic information, and mutation abundance at the following time points: before and after low-dose radiotherapy, after 4-6 cycles of chemotherapy plus anti-PD-L1 antibody (chemotherapy-immunotherapy), and before the initiation of anti-PD-L1 maintenance therapy. This approach aims to guide efficacy and prognosis prediction, as well as to identify potential biomarkers associated with treatment response.

Conditions

Radiotherapy; Lung

Outcome Measures

Primary Outcomes (1)

• Progression-Free Survival（PFS）

  Time from first radiotherapy to first occurrence of disease relapse/progression (RECIST 1.1), metastasis, or death from any cause.

  From the date of first radiotherapy to the date of first documented disease progression, metastasis, or death from any cause, assessed up to 24 months.

Secondary Outcomes (5)

• Overall Survival (OS)

  From date of first radiotherapy to date of death from any cause, assessed up to 36 months.

• Overall Response Rate (ORR)

  At 3 months after completion of low-dose thoracic radiotherapy.

• Disease Control Rate (DCR)

  At 3 months and 6 months after completion of low-dose thoracic radiotherapy.

• Incidence of Treatment-Emergent Adverse Events

  From date of first low-dose radiotherapy to 30 days after last dose.

• Peripheral Blood ctDNA Level

  Within 48 hours pre-first low-dose RT (at SCLC diagnosis); within 48 hours post-low-dose RT; within 48 hours pre-anti-PD-L1 maintenance (post 4-6 cycles EP/EC + adebrelimab); and within 48 hours post-confirmed PD.

Study Arms (1)

Low-Dose Radiotherapy + EP/EC + Adebrelimab

EXPERIMENTAL

All patients will first receive low-dose radiotherapy. Within one week after completion of radiotherapy, patients will receive concurrent systemic chemotherapy (either EP or EC regimen) combined with adebrelimab for 4-6 cycles. Following the 4-6 cycles of chemo-immunotherapy, patients will continue maintenance therapy with adebrelimab for up to two years.

Drug: Etoposide; Drug: Cisplatin; Drug: Carboplatin; Drug: Adebrelimab; Radiation: Thoracic Radiotherapy

Interventions

Etoposide DRUG

Etoposide 100 mg/m² intravenously on days 1-3, plus Cisplatin 75 mg/m² intravenously on day 1, repeated every 21 days (q3w).

Low-Dose Radiotherapy + EP/EC + Adebrelimab

Cisplatin DRUG

Etoposide 100 mg/m² intravenously on days 1-3, plus Cisplatin 75 mg/m² intravenously on day 1, repeated every 21 days (q3w).

Low-Dose Radiotherapy + EP/EC + Adebrelimab

Carboplatin DRUG

Etoposide 100 mg/m² intravenously on days 1-3, plus Carboplatin area under the curve (AUC) 5 intravenously on day 1, repeated every 21 days (q3w).

Low-Dose Radiotherapy + EP/EC + Adebrelimab

Adebrelimab DRUG

20 mg/kg intravenously on day 1, repeated every 21 days (q3w). Administered concurrently with chemotherapy for 4-6 cycles, followed by maintenance monotherapy for up to 2 years.

Low-Dose Radiotherapy + EP/EC + Adebrelimab

Thoracic Radiotherapy RADIATION

Radiotherapy will be delivered to the primary tumor in the lung, involved regional lymph nodes, and metastatic pleural lesions.

Low-Dose Radiotherapy + EP/EC + Adebrelimab

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥18 years and ≤75 years.
• Histologically or cytologically confirmed extensive-stage small cell lung cancer (SCLC).
• No prior systemic anti-tumor therapy.
• ECOG performance status 0-2 and life expectancy ≥12 weeks.
• At least one measurable lesion per RECIST version 1.1.
• No brainstem metastasis and no significant neurological symptoms from brain metastases.
• All participants must undergo routine contrast-enhanced CT of the chest and upper abdomen, as well as brain MRI, before enrollment. Whole-body PET-CT plus brain MRI is preferred. For participants with limited financial resources who also have significant obstructive pneumonia or atelectasis, an additional chest MRI is recommended.
• No malignant pleural effusion or pericardial effusion.
• All participants must provide written informed consent.

You may not qualify if:

• Presence of interstitial pneumonia or infectious fever prior to treatment.
• Comorbid autoimmune diseases or long-term oral corticosteroid use (including those who received oral corticosteroids within 14 days prior to treatment).
• Prior history of thoracic radiotherapy or thoracic surgery.
• Presence of Grade ≥3 hematologic toxicity or hepatic/renal impairment.
• Hypersensitivity to adebrelimab.
• Significant respiratory symptoms that preclude tolerance to radiotherapy.
• Active hepatitis B or hepatitis C infection with ongoing antiviral therapy. Subjects with a documented history of HBV infection who have achieved undetectable HBV levels after prior active treatment at the time of enrollment may be included.
• Presence of pleural effusion or pericardial effusion.

Sponsors & Collaborators

• Jiangmen Central Hospital: lead

MeSH Terms

Interventions

Etoposide; Cisplatin; Carboplatin

Intervention Hierarchy (Ancestors)

Podophyllotoxin; Tetrahydronaphthalenes; Naphthalenes; Polycyclic Aromatic Hydrocarbons; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Hydrocarbons; Organic Chemicals; Polycyclic Compounds; Glucosides; Glycosides; Carbohydrates; Chlorine Compounds; Inorganic Chemicals; Nitrogen Compounds; Platinum Compounds; Coordination Complexes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Deputy Director of the Oncology Department

Study Record Dates

• First Submitted: April 21, 2026
• First Posted: May 13, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): October 30, 2027
• Study Completion (Estimated): January 1, 2028
• Last Updated: May 13, 2026

Record last verified: 2026-05