Initial results from phase I trial of a novel oncolytic adenovirus Ad-TD-nsIL12 in recurrent glioblastoma connecting to ventricular system.

2057 Background: Glioma is the most common primary central nervous system malignancy in adults, of which glioblastoma (GBM) accounts for more than 50% of the incidence and is the most aggressive subtype of glioma, with a median survival of about 15 months. Oncolytic virus emerges as a promising therapy for recurrent GBM (rGBM), but its safety and efficacy are not evaluated in patients with rGBM connecting to ventricular system. Methods: This is a dose-escalating trial to study the safety and efficacy of Ad-TD-nsIL12, a novel oncolytic adenovirus, in patients with rGBM connecting to the ventricular system. The assigned dose levels of Ad-TD-nsIL12 were 5x10 9 vp, 1x10 10 vp, and 5x10 10 vp. Adverse events (AEs) associated with the virus were graded using the Common Terminology Criteria for Adverse Events (CTCAE, version 5.0), and Grade ≥ 3 AEs identified the dose-limiting toxicity (DLT). Tumor response was evaluated based on the Response Assessment in Neuro-Oncology (RANO) criteria. Results: Eight patients, aged from 45 to 71 years, were enrolled between December 2019 and September 2022, with treatment doses ranging from 5x10 9 to 5x10 10 vp. Grade 3 seizure according to CTCAE occurred in two patients from Cohort 3 (5x10 10 vp) after AD-TD-nsIL12 injection. Minimal adverse events were observed at a treatment dose of 1x10 10 vp, even after multiple injections. Complete response (CR) was demonstrated in one patient, partial response (PR) in one patient, stable disease (SD) in four patients and progressive disease (PD) in two patients. Immunohistochemical staining showed higher infiltrations of CD3 + , CD4 + and CD8 + T cells and positivity of E1A and Hexon in virus post-treated tissues. Inflammation associated cytokines in the blood were not significantly elevated by Ad-TD-nsIL12. Conclusions: AD-TD-nsIL12 treatment was safe and effective in patients with rGBM and warrants examination in a phase II clinical study. Clinical trial information: ChiCTR2000032402.