This is a prospective, single-center, open-label, randomized controlled clinical trial evaluating whether the addition of a nutritional therapy regimen (Spirulina-Bifidobacterium capsules, fish oil-grape seed-blueberry soft capsules, and Ganoderma spore oil) to standard glucocorticoid therapy improves outcomes in patients with Grade 3-4 immune checkpoint inhibitor-related pneumonitis (CIP), compared with standard glucocorticoid therapy alone.

A total of 60 patients with malignancies who develop Grade 3-4 CIP (per CTCAE v5.0) after at least one cycle of immune checkpoint inhibitor therapy will be randomized 1:1 to the experimental or control arm. The primary endpoints are time to pneumonitis downgrading and the proportion of patients achieving downgrading at 3 months.

BACKGROUND:

Immune checkpoint inhibitor-related pneumonitis (CIP) accounts for the largest proportion of fatal immune-related adverse events. Approximately 30% of patients respond poorly to corticosteroid therapy, and long-term high-dose steroids increase the risk of secondary infection. Oxidative stress plays a key role in pulmonary fibrosis. The investigational nutritional products have demonstrated antioxidant and immunomodulatory properties in preclinical and clinical studies.

OBJECTIVES:

Primary: To evaluate the efficacy of nutritional therapy combined with glucocorticoids versus glucocorticoids alone in treating CIP, as measured by time to pneumonitis downgrading and the 3-month downgrading rate.

Secondary: To evaluate safety (AE/SAE incidence, severity), total steroid dose and duration, and changes in 6-minute walk distance (6MWD), modified Medical Research Council dyspnea scale (mMRC), St George's Respiratory Questionnaire (SGRQ), and Leicester Cough Questionnaire (LCQ).

Exploratory: To analyze the relationship between treatment response and changes in T-cell subsets, inflammatory cytokines (IL-1 beta, IL-6, IL-10), KL-6, ALC, CD4+ Th1/Th17, Tregs, NLR, AEC, and gut microbiome.

STUDY DESIGN:

Sixty eligible participants will be randomized 1:1 to:

• Experimental arm: Spirulina-Bifidobacterium capsules 1080 mg twice daily orally, fish oil-grape seed-blueberry soft capsules 1200 mg twice daily orally, and Ganoderma spore oil 800 mg twice daily orally, plus methylprednisolone (dose and tapering per investigator assessment, referencing NCCN Guidelines 2025 v1).
• Control arm: Matching placebo orally plus methylprednisolone (per NCCN Guidelines 2025 v1), tapered until symptoms and imaging improve and then discontinued.

Pneumonitis imaging (chest X-ray or CT) will be assessed at baseline and on Days 3, 7, 14, 28, 42, and 56, and at 2-3 months post-treatment, with additional imaging as clinically indicated. Pneumonitis grade will be determined by an Independent Radiologic Review Committee (IRRC) blinded to treatment allocation.

PARTICIPANTS:

Adults 18-75 years of age with histologically or cytologically confirmed malignancy, who have received at least one cycle of immune checkpoint inhibitor therapy, and who develop Grade 3-4 CIP per CTCAE v5.0 and radiologic grading.

FOLLOW-UP:

All participants will be followed for 2 years or until death, with contacts every 90 (plus or minus 7) days.

Inclusion Criteria:

1. Voluntary participation with full understanding of the study and signed informed consent form.
2. Age 18 to 75 years (inclusive) on the day of informed consent signing.
3. Histologically or cytologically confirmed malignancy.
4. Received at least one cycle of immune checkpoint inhibitor therapy.
5. Grade 3-4 immune-related pneumonitis (per CTCAE v5.0 and radiologic grading).
6. ECOG performance status 0-2, with expected survival of more than 3 months.
7. Adequate organ function based on laboratory results (without transfusion, apheresis, erythropoietin, or granulocyte colony-stimulating factor support within 14 days before the first dose). Women of childbearing potential must have a negative serum pregnancy test within 7 days before first dose.

Exclusion Criteria:

1. Severe cardiac, cerebrovascular, renal, hematologic, or other serious systemic disease, including: NYHA Class III-IV heart failure; acute myocardial infarction or unstable angina within 6 months; severe post-stroke functional impairment (mRS greater than or equal to 3); progressive neurodegenerative disease; Child-Pugh Class B or C liver disease or acute liver failure; CKD stage 4-5 (eGFR less than 30 mL/min/1.73 m2) or requiring dialysis; absolute neutrophil count less than 1.5 x 10^9/L, platelet count less than 50 x 10^9/L, or Grade 3 or higher anemia (Hb less than 8 g/dL).
2. Severe allergic constitution or contraindications to the study treatment.
3. Significant psychiatric or psychological disorder, or doubts about the treatment plan.
4. Investigator judgment that the patient is unsuitable for the trial (e.g., poor follow-up adherence, refusal of supportive care).
5. Use of anti-tumor traditional Chinese medicine within 14 days before first dose.
6. History of or active inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis).
7. Severe acute or chronic infection.
8. Known alcohol or drug abuse history.
9. Pregnancy or breastfeeding.
10. Use of antibiotics, probiotic food, or microecological preparations within 2 weeks before enrollment.
11. Prior treatment-related lung injury: (a) targeted-therapy-related pulmonary toxicity (prior EGFR-TKI, ALK inhibitor, VEGF inhibitor, or antibody-drug conjugate causing interstitial lung disease or pneumonitis that has not fully resolved, with radiologic fibrosis or persistent functional impairment); (b) thoracic radiation-related lung injury (radiation pneumonitis or radiation fibrosis with irreversible CT findings).
12. Use of another investigational drug within 28 days before first dose that, per investigator judgment, would interfere with evaluation of study treatment.
13. Gastrointestinal disorder precluding oral administration.

The decision regarding sharing of individual participant data has not yet been made. A plan will be provided before publication of study results.

The control arm receives matching placebo capsules identical in appearance, color, shape, size, odor, taste, packaging, label, route, and dosing frequency to the investigational nutritional products. Pneumonitis imaging is assessed by an Independent Radiologic Review Committee blinded to treatment allocation.