This is an ongoing Phase 2, open-label, single-center, non-randomized study of sintilimab (one anti-PD-1 antibody same as nivolumab approved in China) plus bevacizumab administered in a low dosage schedule in adult (≥ 18 years) participants with a clinical relapse or circulating tumor DNA (ctDNA)-level relapse of Oligodendroglioma(WHO III).
This study has three non-comparative study groups. Cohort 1 and Cohort 2 will receive the same study drug sintilimab 200mg and bevacizumab 3mg/kg every 3 weeks. Cohort 3 will take only standard treatment. A stringent three-step non-randomized process will be used to assign participants to one of the study groups. Neither participants nor doctors but the researcher can choose which group participants are in. No one knows if one study group is better or worse than the other. 80 total participants are expected to participate in this study (30 participants in Cohort 1 and Cohort 2).
Grouping process: After enrollment, under the standard of care, participants will receive regular tumor in situ fluid (fluid within the surgical cavity, TISF) sampling for ctDNA analysis and recceive regular MRI. The researcher will study the TISF ctDNA and imaging dynamics to determine whether the tumor reaches to ctDNA-level (Cohort 1) or clinical relapse (Cohort 2). At the first step, all timely identified as ctDNA-level relapse tumors will be assigned into the Cohort 1 and receive the study drug immediately, those failed to be timely identified will be assigned into the Cohort 2 and receive the study drug after the clinical relapse. At the second step, once Cohort 1 or Cohort 2 reaches the target number, the new participants will be all assigned into the other Cohort. In the third step, if no CTDNA-level or clinical relapse was observed within 60 months after surgery, patients were assigned to Cohort 3 and further analyzed for prognostic biomarkers compared with Cohort 1 and Cohort 2.
Written informed consent and HIPAA authorization obtained from the subject/legal representative prior to performing any protocol-related procedures, including screening evaluations
Subjects must be willing and able to comply with scheduled visits, treatment schedule, laboratory testing, and other requirements of the study, including disease assessment by MRI and tumor in situ fluid (TISF) collection
Histologically confirmed diagnosis of oligodendroglioma(WHO III)
Resection surgery done at the study center (Henan Provincial People's Hospital), with an reservoir intraoperatively implanted connecting the surgical cavity and the subscalp for postoperative noninvasive TISF collection
More than two recurrences of oligodendroglioma
Presence of extracranial metastatic, significant leptomeningeal disease or tumors primarily localized to the brainstem or spinal cord
Any serious or uncontrolled medical disorder that, in the opinion of the investigator, may increase the risk associated with study participation or study drug administration, impair the ability of the subject to receive protocol therapy, or interfere with the interpretation of study results
Subjects with active, known or suspected autoimmune disease. Subjects with vitiligo, type I diabetes mellitus, residual hypothyroidism due to autoimmune condition only requiring hormone replacement, psoriasis not requiring chronic and systemic immunosuppressive treatment, or conditions not expected to recur in the absence of an external trigger are permitted to enroll. Subjects have any other condition requiring systemic treatment with corticosteroids or other immunosuppressive agents within 14 days. Inhaled or topical steroids and adrenal replacement doses >10mg daily prednisone equivalent are permitted in absence of active autoimmune disease