P17.15.A THANK PHASE I TRIAL OF DNX-2440 ONCOLYTIC ADENOVIRUS IN PATIENTS WITH FIRST OR SECOND RECURRENCE OF GLIOBLASTOMA: PRELIMINARY RESULTS

Abstract

Abstract BACKGROUND Oncolytic immunovirotherapy is emerging as a potential therapeutic approach in neuro-oncology. The oncolytic adenovirus DNX-2401, genetically engineered for selective replication and enhanced infectivity in tumor cells, has shown efficacy in adult patients with recurrent glioblastoma (GBM). In order to overcome the immunosuppressive brain-tumor microenvironment and thus enhance its antiglioma effect, DNX-2440 is a new armed virus which contains the same modifications but additionally incorporates OX40 ligand to induce the expression of such molecule in tumor cells and so increase the antitumor immune response. MATERIAL AND METHODS We are conducting a phase I open-label single-center study to investigate the safety and efficacy of a single intratumoral injection of DNX-2440 in patients with first or second recurrence of GBM. This is a dose escalation study, with a 3 + 3 design, evaluating an initial dose of 4x10e9 viral particles (vp) and a target dose of 4x10e10 vp. A single measurable lesion bigger than 10 mm in two perpendicular diameters and smaller than 25 cc is required for inclusion in the study. RESULTS To date 16 patients (6 [37.5%] female, 10 [62.5%] male) have been enrolled and treated with DNX-2401. Median age is 55 years (range, 39-80) and median KPS is 80 (range 70-90). As per protocol, surgery consisted of biopsy in all patients followed by intratumoral injection of DNX-2440. No dose limiting toxicity has been registered during the dose escalation phase (first cohort of 3 patients receiving 4x10e9 vp, and second cohort of 3 patients receiving 4x10e10 vp), and the remainder patients have received the target dose of 4x10e10 vp in the dose expansion cohort. Safety profile is acceptable with no serious adverse events related to DNX-2440 reported to date. Clinical benefit with tumor size reduction and prolonged survival have already been confirmed in 3 patients. Correlative analyses evaluating immune response in blood samples are ongoing. CONCLUSION Our current data suggest that intratumoral injection of DNX-2440 is feasible and safe, and seems to provide a clinical benefit in some patients with recurrent GBM. Furthermore, this trial illustrates the potential of oncolytic virus platforms to reshape the brain-tumor microenvironment and its interesting role in combination strategies with other immune-oncology agents for treating this disease.