PET imaging and treatment of pancreatic cancer peritoneal carcinomatosis after subcutaneous intratumoral administration of a novel oncolytic virus, CF33-hNIS-antiPDL1

Using Oncolytic Virus to Retask CD19-Chimeric Antigen Receptor T Cells for Treatment of Pancreatic Cancer: Toward a Universal Chimeric Antigen Receptor T-Cell Strategy for Solid Tumor

BACKGROUND

Chimeric antigen receptor (CAR) T cells targeting the B-cell antigen CD19 are standard therapy for relapsed or refractory B-cell lymphoma and leukemia. CAR T cell therapy in solid tumors is limited due to an immunosuppressive tumor microenvironment and a lack of tumor-restricted antigens. We recently engineered an oncolytic virus (CF33) with high solid tumor affinity and specificity to deliver a nonsignaling truncated CD19 antigen (CD19t), allowing targeting by CD19-CAR T cells. Here, we tested this combination against pancreatic cancer.

STUDY DESIGN

We engineered CF33 to express a CD19t (CF33-CD19t) target. Flow cytometry and ELISA were performed to quantify CD19t expression, immune activation, and killing by virus and CD19-CAR T cells against various pancreatic tumor cells. Subcutaneous pancreatic human xenograft tumor models were treated with virus, CAR T cells, or virus+CAR T cells.

RESULTS

In vitro, CF33-CD19t infection of tumor cells resulted in >90% CD19t cell-surface expression. Coculturing CD19-CAR T cells with infected cells resulted in interleukin-2 and interferon gamma secretion, upregulation of T-cell activation markers, and synergistic cell killing. Combination therapy of virus+CAR T cells caused significant tumor regression (day 13): control (n = 16, 485 ± 20 mm 3 ), virus alone (n = 20, 254 ± 23 mm 3 , p = 0.0001), CAR T cells alone (n = 18, 466 ± 25 mm 3 , p = NS), and virus+CAR T cells (n = 16, 128 ± 14 mm 3 , p < 0.0001 vs control; p = 0.0003 vs virus).

CONCLUSIONS

Engineered CF33-CD19t effectively infects and expresses CD19t in pancreatic tumors, triggering cell killing and increased immunogenic response by CD19-CAR T cells. Notably, CF33-CD19t can turn cold immunologic tumors hot, enabling solid tumors to be targetable by agents designed against liquid tumor antigens.

Oncolytic Viruses in the Era of Omics, Computational Technologies, and Modeling: Thesis, Antithesis, and Synthesis

Oncolytic viruses (OVs) are the frontier therapy for refractory cancers, especially in integration with immunomodulation strategies. In cancer immunovirotherapy, the many available "omics" and systems biology technologies generate at a fast pace a challenging huge amount of data, where apparently clashing information mirrors the complexity of individual clinical situations and OV used. In this review, we present and discuss how currently big data analysis, on one hand and, on the other, simulation, modeling, and computational technologies, provide invaluable support to interpret and integrate "omic" information and drive novel synthetic biology and personalized OV engineering approaches for effective immunovirotherapy. Altogether, these tools, possibly aided in the future by artificial intelligence as well, will allow for the blending of the information into OV recombinants able to achieve tumor clearance in a patient-tailored way. Various endeavors to the envisioned "synthesis" of turning OVs into personalized theranostic agents are presented.

Current perspectives on Vaxinia virus: an immuno-oncolytic vector in cancer therapy

Viruses are being researched as cutting-edge therapeutic agents in cancer due to their selective oncolytic action against malignancies. Immuno-oncolytic viruses are a potential category of anticancer treatments because they have natural features that allow viruses to efficiently infect, replicate, and destroy cancer cells. Oncolytic viruses may be genetically modified; engineers can use them as a platform to develop additional therapy modalities that overcome the limitations of current treatment approaches. In recent years, researchers have made great strides in the understanding relationship between cancer and the immune system. An increasing corpus of research is functioning on the immunomodulatory functions of oncolytic virus (OVs). Several clinical studies are currently underway to determine the efficacy of these immuno-oncolytic viruses. These studies are exploring the design of these platforms to elicit the desired immune response and to supplement the available immunotherapeutic modalities to render immune-resistant malignancies amenable to treatment. This review will discuss current research and clinical developments on Vaxinia immuno-oncolytic virus.

Development of the oncolytic virus, CF33, and its derivatives for peritoneal-directed treatment of gastric cancer peritoneal metastases

BACKGROUND

Gastric cancer (GC) that metastasizes to the peritoneum is fatal. CF33 and its genetically modified derivatives show cancer selectivity and oncolytic potency against various solid tumors. CF33-hNIS and CF33-hNIS-antiPDL1 have entered phase I trials for intratumoral and intravenous treatments of unresectable solid tumors (NCT05346484) and triple-negative breast cancer (NCT05081492). Here, we investigated the antitumor activity of CF33-oncolytic viruses (OVs) against GC and CF33-hNIS-antiPDL1 in the intraperitoneal (IP) treatment of GC peritoneal metastases (GCPM).

METHODS

We infected six human GC cell lines AGS, MKN-45, MKN-74, KATO III, SNU-1, and SNU-16 with CF33, CF33-GFP, or CF33-hNIS-antiPDL1 at various multiplicities of infection (0.01, 0.1, 1.0, and 10.0), and performed viral proliferation and cytotoxicity assays. We used immunofluorescence imaging and flow cytometric analysis to verify virus-encoded gene expression. We evaluated the antitumor activity of CF33-hNIS-antiPDL1 following IP treatment (3×105 pfu × 3 doses) in an SNU-16 human tumor xenograft model using non-invasive bioluminescence imaging.

RESULTS

CF33-OVs showed dose-dependent infection, replication, and killing of both diffuse and intestinal subtypes of human GC cell lines. Immunofluorescence imaging showed virus-encoded GFP, hNIS, and anti-PD-L1 antibody scFv expression in CF33-OV-infected GC cells. We confirmed GC cell surface PD-L1 blockade by virus-encoded anti-PD-L1 scFv using flow cytometry. In the xenograft model, CF33-hNIS-antiPDL1 (IP; 3×105 pfu × 3 doses) treatment significantly reduced peritoneal tumors (p<0.0001), decreased amount of ascites (62.5% PBS vs 25% CF33-hNIS-antiPDL1) and prolonged animal survival. At day 91, seven out of eight mice were alive in the virus-treated group versus one out of eight in the control group (p<0.01).

CONCLUSIONS

Our results show that CF33-OVs can deliver functional proteins and demonstrate effective antitumor activity in GCPM models when delivered intraperitoneally. These preclinical results will inform the design of future peritoneal-directed therapy in GCPM patients.

Oncolytic virus: A catalyst for the treatment of gastric cancer

Gastric cancer (GC) is a leading contributor to global cancer incidence and mortality. According to the GLOBOCAN 2020 estimates of incidence and mortality for 36 cancers in 185 countries produced by the International Agency for Research on Cancer (IARC), GC ranks fifth and fourth, respectively, and seriously threatens the survival and health of people all over the world. Therefore, how to effectively treat GC has become an urgent problem for medical personnel and scientific workers at this stage. Due to the unobvious early symptoms and the influence of some adverse factors such as tumor heterogeneity and low immunogenicity, patients with advanced gastric cancer (AGC) cannot benefit significantly from treatments such as radical surgical resection, radiotherapy, chemotherapy, and targeted therapy. As an emerging cancer immunotherapy, oncolytic virotherapies (OVTs) can not only selectively lyse cancer cells, but also induce a systemic antitumor immune response. This unique ability to turn unresponsive 'cold' tumors into responsive 'hot' tumors gives them great potential in GC therapy. This review integrates most experimental studies and clinical trials of various oncolytic viruses (OVs) in the diagnosis and treatment of GC. It also exhaustively introduces the concrete mechanism of invading GC cells and the viral genome composition of adenovirus and herpes simplex virus type 1 (HSV-1). At the end of the article, some prospects are put forward to determine the developmental directions of OVTs for GC in the future.