Neoadjuvant endobronchial delivery of gene mediated cytotoxic immunotherapy (GMCI) for non-small cell lung cancer (NSCLC): Safety and immunologic activity.

Abstract

9050 Background: GMCI is a tumor-specific immuno-oncology approach implemented through local delivery of aglatimagene besadenovec(AdV-tk) followed by anti-herpetic prodrug. This leads to immunogenic tumor cell death, antigen presenting cell activation, and T cell stimulation resulting in CD8+ T cell dependent protection, as demonstrated in preclinical models and clinical trials in other tumor types. This is the first study to assess endobronchial delivery of AdV-tk for NSCLC. Methods: This Phase I dose escalation trial enrolled patients with suspected NSCLC who were candidates for surgery. A single AdV-tk injection was performed by endobronchial ultrasound (n = 11) or mediastinoscopy (n = 1) during the diagnostic staging procedure 3 weeks prior to surgery. Three dose levels were evaluated: 2.5x 1011, 5x1011, and 1x1012 vector particles (vp) in a 3+3 design. Valacyclovir was administered for 14 days, starting the day after AdV-tk injection. To assess the local and systemic effects of GMCI, immune biomarkers were evaluated in blood and tumor samples before and after GMCI. Results: From 2017-2019, 12 patients (9 men, 3 women, median age 65 [range 55-80]) received GMCI followed by surgery. Average tumor size was 5.1 cm (largest diameter) and final pathologic stage was I (n = 4), II (n = 3), and III (n = 5). Treatment-related adverse events were CTC grade 1 fever (n = 1), flu-like symptoms (n = 1) and nausea/vomiting/diarrhea (n = 1). The only > grade 2 lab abnormality was transient grade 3 lymphopenia (n = 2). A measurable reduction in tumor size was observed in one patient. The average amount of tumor necrosis was 29.4%. Significant infiltration of CD8+T cells (5.2-fold compared to baseline, p = 0.001) was found in tumor 19-22 days after AdV-tk injection. Within the CD8+tumor infiltrating lymphocytes, there was increased expression of CD38 (2.5-fold, p = 0.002), Ki67 (4.8-fold, p = 0.02), PD1 (1.9-fold, p = 0.002), CD39 (2.9-fold, p = 0.04) and CTLA-4 (4.8-fold, p < 0.001), without significant detected differences in Tim3 or TIGIT. Simultaneously, peripheral blood CD8+ cells displayed significant increases in CD38 (3.4-fold, p = 0.006), HLA-DR (4.2-fold, p = 0.002), and Ki67 (5.8-fold, p = 0.017). Conclusions: Intratumoral injection of AdV-tk into lung tumors was safe and feasible. Further, AdV-tk effectively induced peripheral blood and intra-tumoral CD8 T cell activation. Consequent upregulation of inhibitory receptors suggests a potential benefit for combination therapies. Clinical trial information: NCT03131037.