Combining low dose radiotherapy with immunotherapy for resistant metastatic tumors

Efficacy and Safety of Combining Intestinal Low Dose Radiotherapy and PD-1/PD-L1 Inhibitors for Metastatic Malignant Solid Tumors After Acquired Resistance to Anti-PD1/PD-L1 Treatment

This study is testing if combining low dose radiation with a type of immunotherapy can help people with stubborn metastatic tumors that didn't respond to earlier treatments.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 16 (estimated)
• Ages: 18 Years to 80 Years
• Sex: All
• Sponsor: Shantou University Medical College (Academic / other)
• Drugs / interventions: chemotherapy, immunotherapy, radiation
• Locations: 1 site (Shantou, Guangdong)
• Trial ID: NCT06076135 on ClinicalTrials.gov

What this trial studies

This phase 2 trial evaluates the effectiveness of intestinal low dose radiotherapy (ILDR) combined with PD-1/PD-L1 inhibitors in patients with metastatic solid tumors that have not responded to previous immunotherapy. The study aims to assess primary endpoints such as objective response rate, disease control rate, and progression-free survival while receiving the combined therapy. It will also monitor secondary endpoints including adverse events and cancer-specific survival. The trial is designed as a two-stage prospective study, enrolling patients who have progressed after immunotherapy.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18-80 with advanced metastatic solid tumors that have progressed after immunotherapy and have no standard treatment options available.

Not a fit: Patients with tumors that are amenable to surgical treatment or those who have not previously received immunotherapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could provide a new treatment option for patients with metastatic tumors that are resistant to current immunotherapy.

How similar studies have performed: While the combination of ILDR and immunotherapy is a novel approach, preclinical studies suggest potential benefits, but clinical evidence is still emerging.

Eligibility criteria

Inclusion Criteria:

1. Age ≥18 years, ≤80 years, regardless of gender.
2. ECOG level 0-2.
3. Expected life span\>3 months.
4. At least one accessible and measurable lesion should be selected as the target lesion for observation according to RECIST criteria.
5. Patients with metastatic solid tumors (of any histology) without standard therapy options, who have previously received immunotherapy, immunotherapy combined with chemotherapy, or immunotherapy combined with anti-angiogenesis treatment and have shown disease progression.
6. The patient is considered ineligible for surgical treatment.
7. Patients with brain metastases assessed as clinically stable after treatment through repeated CT and/or MRI scans are eligible.
8. Patients have complete clinical and pathological information.
9. Any psychological, family, social or geographical conditions may hinder compliance with the research protocol.
10. Patients are able to understand the informed consent form, voluntarily participate, and sign the informed consent form.
11. Other indicators accord with the general inclusion criteria for clinical trials.

Exclusion Criteria:

1. Patients with contraindications to radiation therapy and immunotherapy.
2. Previous occurrence of unacceptable immune related toxic side effects (immune myocarditis, pneumonia, etc.).
3. Patients who were assessed as hyperprogressive disease (HPD).
4. Patients who have received pelvic and abdominal radiation therapy within 6 months prior to enrollment.
5. The adverse reactions from prior treatment have not yet recovered to a CTCAE5.0 rating of ≤ 1 (excluding toxicity that has been determined to be risk-free, such as fatigue or hair loss).
6. Accompanied by severe infections.
7. Serious liver disease (such as cirrhosis), kidney disease, respiratory disease, or chronic system diseases such as uncontrollable diabetes and hypertension; Patients who cannot tolerate radiation therapy.
8. Clinical symptoms of brain metastases or meningeal metastasis.
9. The patients with known allergies or allergies to the test drug ingredients.
10. Substance/alcohol abuse.
11. Patients who are pregnant or planning to.
12. Patients participating in other clinical studies that may affect the efficacy/safety of this clinical study.
13. Patients who have undergone major surgical procedures within 30 days.
14. Patients who have received antibiotics, antifungal drugs, antiviral, antiparasitic drugs, or probiotics within 4 weeks.

Where this trial is running

Shantou, Guangdong

• Cancer Hospital, Shantou University Medical College — Shantou, Guangdong, China (Recruiting)

Study contacts

• Study coordinator: Chuangzhen Chen, MD

Conditions Metastatic Malignant Solid Neoplasm; Radiotherapy; Immune Checkpoint Blockade; Resistance to Immunotherapy