Adebrelimab + Apatinib in SCLC Maintenance Therapy

Inclusion criteria

• Voluntary participation with signed informed consent and good compliance for follow-up.
• Age between 18 and 75 years old.
• Histologically or cytologically confirmed extensive-stage small cell lung cancer (LS-SCLC) according to the AJCC 8th edition or VALG phase II staging criteria.
• ECOG performance status score: 0 to 2.
• Absence of disease progression after receiving 4-6 cycles of platinum-based chemotherapy combined with Atezolizumab induction therapy.
• Recovery of non-hematologic adverse reactions to grade 1 (except for alopecia, skin pigment changes, or as determined by the investigator) following induction therapy.
• Time from the end of induction treatment (last dose) to initiation of maintenance treatment ≤ 6 weeks.
• At least one measurable lesion assessed by the investigator according to RECIST 1.1.
• Expected life expectancy of at least 3 months.
• Normal function of major organs, meeting the following criteria:

• Bone marrow function: Absolute neutrophil count (ANC) ≥ 1.5×10^9/L (grade 1 according to CTCAE 5.0); platelets ≥ 100×10^9/L; hemoglobin > 80g/L.
• Renal function: Creatinine ≤ 1.5 times the upper limit of normal (ULN), grade 1 according to CTCAE. Note: If creatinine is greater than 1.5 times the ULN, creatinine clearance must be > 50ml/min.
• Liver function: Bilirubin ≤ 1.5 times ULN (grade 1 according to CTCAE), patients with Gilbert's syndrome bilirubin ≤ 3.0 times ULN; AST and ALT ≤ 3.0×ULN.
• Coagulation indicators: International normalized ratio (INR) ≤ 1.55 (if the patient is receiving a stable dose of therapeutic warfarin or low molecular weight heparin, INR is usually between 2 and 3), PTT < 1.2 times ULN.
• Women of childbearing potential must agree to use contraception during the study and for 6 months after the end of the study (such as an intrauterine device, contraceptive pills, or condoms); serum or urine pregnancy test must be negative within 1 week before enrollment, and must be non-lactating patients; men must agree to use contraception during the study and for 6 months after the end of the study.

Exclusion criteria

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Exclusion criteria

• Limited-stage small cell lung cancer (SCLC).
• Histologically or cytologically confirmed mixed-type SCLC.
• Prior use of anti-angiogenic drugs or deemed unsuitable for anti-angiogenic therapy by the investigator.
• Central tumors invading major blood vessels with assessed bleeding risks.
• Factors affecting oral medication (e.g., dysphagia, chronic diarrhea, intestinal obstruction).
• Major surgical procedures, incisional biopsies, or significant traumatic injuries within 4 weeks prior to enrollment.
• Participation in another investigational drug clinical trial within the past 4 weeks.
• Medical history including:

• Untreated or symptomatic brain metastases or spinal cord compression.
• Concurrent active malignant tumors requiring treatment.
• History of immunodeficiency, including HIV positivity, other acquired or congenital immunodeficiency diseases, or organ transplant recipients.
• History of substance abuse disorders not amenable to treatment or psychiatric disorders.
• Presence of any severe and/or uncontrolled diseases including:

• Poorly controlled hypertension (systolic blood pressure ≥ 150 mmHg, diastolic blood pressure ≥ 100 mmHg).
• Ischemic heart disease or myocardial infarction of grade I or higher, arrhythmias (including QTc ≥ 450ms for males, QTc ≥ 470ms for females), and ≥ grade 2 congestive heart failure (New York Heart Association [NYHA] functional classification); or left ventricular ejection fraction (LVEF) < 50% based on echocardiography.
• Decompensated diabetes or other contraindications to high-dose corticosteroid therapy.
• Worsening chronic obstructive pulmonary disease (COPD) or other severe respiratory diseases requiring hospitalization.
• Active or uncontrolled severe infections (≥ CTC AE grade 2).
• Uncontrolled pleural effusion, pericardial effusion, or ascites requiring repeated drainage.
• Liver cirrhosis, decompensated liver disease, active hepatitis, or chronic hepatitis requiring antiviral therapy.
• Renal insufficiency: Urine protein ≥ ++ on urinalysis, and confirmed 24-hour urine protein quantitation > 1.0 g.
• Clinically significant hemoptysis (>1/2 teaspoon of fresh blood) or significant bleeding symptoms within the past 3 months prior to enrollment, or evidence of bleeding tendency such as gastrointestinal bleeding, bleeding gastric ulcers, baseline fecal occult blood test ≥ ++, or non-healed wounds, ulcers, or fractures.
• Occurrence of venous or arterial thrombotic events within the past 6 months prior to enrollment, such as cerebrovascular accidents (including transient ischemic attacks, cerebral hemorrhages, cerebral infarctions), deep vein thrombosis, and pulmonary embolism.
• Abnormal coagulation function (INR > 1.5 or prothrombin time PT > ULN + 4 seconds or APTT > 1.5 ULN), bleeding tendency, or undergoing thrombolysis or anticoagulant therapy. Use of low-dose heparin (adult daily dose of 0.6-1.2 x 104U) or low-dose aspirin (daily dose ≤ 100 mg) is permitted for prophylactic purposes with INR ≤ 1.5.
• Patients unable to comply with study procedures, restrictions, and requirements as judged by the investigator are ineligible for participation.