Intestinal Low Dose Radiotherapy Combined With Immunotherapy in Immune-resistant Metastatic Solid Tumors

ABSTRACT: Preclinical and clinical studies have shown that intestinal low dose radiotherapy (ILDR) can enhance antitumor immunity and response to immune checkpoint blockade (ICB) by regulating intestinal flora. Therefore, the investigators design a phase II trial to validate the clinical value of combining ILDR and programmed cell death-1 (PD-1) inhibitors in patients with metastatic malignant solid tumors who have failed immunotherapy. The primary endpoints of this analysis are disease control rate (DCR), progression free survival while receiving second-line therapy (PFS2), and objective response rate (ORR). The secondary endpoints are the incidence of adverse events (AEs) and the overall response rate. This study is a researcher-initiated, prospective clinical study. The target population is patients with advanced metastatic malignant solid tumors who have progressed after immunotherapy. Thirty participants will be enrolled in this study. The primary objective of the study is to evaluate the efficacy and safety of ILDR combined with PD-1 inhibitors in immune-resistant metastatic malignant solid tumors, and the effect of ILDR combined with PD-1 inhibitors on the intestinal flora. Treatment will be given to patients who meet the eligibility criteria after obtaining their written informed consent. Subjects will be allocated into 3 groups. The jejunum and ileum will be selected and performed with low dose radiation of 1Gy/F, 1F/W, 1Gy-3Gy. The immunotherapy regimen is determined by the doctor in charge based on the patient’s clinical status, original immunotherapy regimen, radiological findings, and pathological results. Immunotherapy is administered in combination with radiotherapy, with a treatment frequency of once every 3 weeks until progression. Assess the occurrence rates of DCR, PFS2, ORR, and AEs in accordance with the guidelines for response criteria for use in trials testing immunotherapeutics (iRECIST) to determine the extent of benefit for patients participating in this trial. At least one accessible and measurable lesion should be selected as the target lesion for observation. Furthermore, tissue samples, stool samples, and peripheral blood samples will be collected to assess the effect of this treatment on immune status and intestinal flora.

DISEASE(S): Immune Checkpoint Blockade,Resistance To Immunotherapy,Radiotherapy,Metastatic Extracranial Malignant Solid Neoplasm

PROVIDER: 108718 | ecrin-mdr-crc |

REPOSITORIES: ECRIN MDR