Adenoviral P53 Research Articles

Abstract 7241: Combination of CDK4/6 inhibitor promotes the antitumor effect of oncolytic adenovirus against canine breast cancer cells

Abstract Background: Oncolytic virotherapy has emerged as a novel antitumor platform to induce tumor-specific cytopathic effect against human cancer cells. However, whether oncolytic virotherapy is effective to canine cancer cells remains unclear. We developed telomerase-specific oncolytic adenoviruses OBP-301 and a p53-armed OBP-702 based on human adenovirus serotype 5. OBP-301 and OBP-702 have therapeutic potential against various types of human cancer cells. As recent report has suggested that human adenovirus serotype 5 induces cytopathic effect against canine cancer cells, OBP-301 and OBP-702 are expected to have therapeutic effects against canine cancer cells. Furthermore, it has been reported that CDK4/6 inhibitors clinically used for human breast cancers promote the replication of oncolytic adenoviruses, suggesting that combination of CDK4/6 inhibitors promote the therapeutic potential of oncolytic adenoviruses. In this study, we investigated the therapeutic potential of OBP-301 and OBP-702 against canine breast cancer cells in monotherapy and combination therapy with CDK4/6 inhibitor. Methods: Two canine breast cancer cell lines (CMT-U27, AZA-CB) were used in this study. The antitumor effect of OBP-301 and OBP-702 against canine breast cancer cells was analyzed using the XTT assay. The therapeutic potential of combination therapy with CDK4/6 inhibitor (palibociclib) was further analyzed. Virus-mediated induction of adenovirus E1A and p53 expression was analyzed by Western blotting. The in vivo antitumor effects of OBP-301 and OBP-702 were assessed using CMT-U27 subcutaneous tumor model. Results: OBP-301 and OBP-702 had cytopathic effect against CMT-U27 and AZA-CB cells. The antitumor activity of OBP-702 was superior to that of OBP-301. The combination of palbociclib and OBP-301 showed a more profound antitumor effect compared with monotherapy against CMT-U27 and AZA-CB cells. The expression of E1A and p53 was increased in virus-treated CMT-U27 and AZA-CB cells in a dose-dependent manner. Intratumoral administration of OBP-301 and OBP-702 significantly suppressed the growth of subcutaneous CMT-U27 tumors compared with mock treatment. Conclusion: Our results suggest that telomerase-specific oncolytic adenoviruses have cytopathic effect against canine breast cancer cells via virus infection and replication. Furthermore, combination of CDK4/6 inhibitor may be a promising strategy for promoting the antitumor effect of oncolytic adenovirus against canine breast cancers. Citation Format: Naoyuki Hashimoto, Hiroshi Tazawa, Satoru Kikuchi, Shinji Kuroda, Yasuo Urata, Shunsuke Kagawa, Toshiyoshi Fujiwara. Combination of CDK4/6 inhibitor promotes the antitumor effect of oncolytic adenovirus against canine breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7241.

Recombinant human adenovirus p53 combined with transcatheter arterial chemoembolization for liver cancer: A meta-analysis.

To compare the clinical curative effects, survival and complications of recombinant human adenovirus-p53 (rAd-p53) combined with transcatheter arterial chemoembolization (TACE) versus TACE for the treatment of liver cancer. We searched all the eligible studies of rAd-p53 plus TACE versus control group had only TACE in the treatment of liver cancer, which were retrieved from CNKI, Wanfang database, CBM, VIP, PubMed, EMBase, The Chrance of Library, Web of Science from its inception to august 2022. A total of 17 studies were included, which involved 1045 patients. The results of the meta analysis indicated that the the rAd-p53combined with TACE markedly improved the patients' complete remission(OR = 2.19, 95% CI:1.13-4.22, P = 0.02), partial remission (OR = 2.22, 95% CI:1.67-2.94, P<0.00001), objective tumor response rate (OR = 2.58, 95% CI:1.95-3.41, P<0.00001) and disease control rate(OR = 2.39, 95% CI:1.65-3.47, P<0.00001) compared with TACE alone. And our results showed that rAd-p53combined with TACE had better survival benefit [6-month OS (OR = 3.41, 95% CI: 1.62-7.14, p = 0.001); 1-year OS (OR = 1.95, 95% CI: 1.28-2.96, p = 0.002)] and better quality of life(MD = 5.84, 95% CI:2.09-9.60, P = 0.002). In addition, the immunity of the patients was enhanced by the combination therapy, as demonstrated by the increase in the ratio of CD4+ to CD4+/CD8+. In adverse effects, except for fever in the TACE combined with rAd-p53 group, which was higher than that in the TACE group(OR = 2.62, 95% CI:2.02-3.49, P<0.00001), all other adverse effects were lower in the TACE combined with rAd-p53 group than in the TACE group. RAd-p53 combined with TACE for liver cancer showed significant advantages in terms of clinical efficacy, survival rate, and safety compared to the TACE alone, and effectively improved patient quality of life and immune function. https://inplasy.com/inplasy-2022-9-0127/.

Recombinant human p53 adenovirus injection combined with Bortezomib inhibits proliferation and promotes apoptosis in multiple myeloma

BackgroundMultiple myeloma (MM) is a B-cell malignancy characterized by abnormal proliferation of clonal plasma cells in the bone marrow, the incidence of which has further increased in recent years. In multiple myeloma, wild-type functional p53 is often inactivated or dysregulated. Therefore, this study aimed to investigate the role of p53 knockdown or overexpression in multiple myeloma and the therapeutic effect of recombinant adenovirus-p53 (rAd-p53) in combination with Bortezomib. MethodsSiRNA p53 and rAd-p53 were used to knock down and overexpress p53. RT-qPCR was used to detect gene expression, and western blotting (WB) was used to detect protein expression levels. We also constructed wild-type multiple myeloma cell line-MM1S cell xenograft tumor models and explored the effects of siRNA-p53, rAd-p53, and Bortezomib on multiple myeloma in vivo and in vitro. H&E staining and KI67 immunohistochemical staining were used to assess the anti-myeloma effects of recombinant adenovirus and Bortezomib in vivo. ResultsThe designed siRNA p53 effectively led to the knockdown of the p53 gene, while rAd-p53 could significantly achieve p53 overexpression. p53 gene inhibited MM1S cell proliferation and promoted apoptosis of wild-type multiple myeloma cell line MM1S. P53 gene inhibited tumor proliferation in vitro by promoting p21 expression and reducing cell cycle protein B1 expression of MM1S. P53 gene overexpression could inhibit tumor growth in vivo. Injection of rAd-p53 in tumor models inhibited tumor development through p21- and cyclin B1-mediated cell proliferation and apoptosis regulation. ConclusionsWe found that overexpression of p53 inhibits MM tumor cell survival and proliferation in vivo and in vitro. Furthermore, the combination of rAd-p53 and Bortezomib significantly improved the efficacy, which provides a new possibility for more effective treatment of MM.

Tumor suppressor immune gene therapy to reverse immunotherapy resistance

BackgroundWhile immune checkpoint inhibitors are becoming a standard of care for multiple types of cancer, the majority of patients do not respond to this form of immunotherapy. New approaches are required to overcome resistance to immunotherapies.MethodsWe investigated the effects of adenoviral p53 (Ad-p53) gene therapy in combination with immune checkpoint inhibitors and selective IL2 or IL15 CD122/132 agonists in the aggressive B16F10 tumor model resistant to immunotherapies. To assess potential mechanisms of action, pre- and post- Ad-p53 treatment biopsies were evaluated for changes in gene-expression profiles by Nanostring IO 360 assays.ResultsThe substantial synergy of “triplet” Ad-p53 + CD122/132 + anti-PD-1 therapy resulted in potential curative effects associated with the complete tumor remissions of both the primary and contralateral tumors. Interestingly, contralateral tumors, which were not injected with Ad-p53 showed robust abscopal effects resulting in statistically significant decreases in tumor size and increased survival (p < 0.001). None of the monotherapies or doublet treatments induced the complete tumor regressions. Ad-p53 treatment increased interferon, CD8+ T cell, immuno-proteosome antigen presentation, and tumor inflammation gene signatures. Ad-p53 treatment also decreased immune-suppressive TGF-beta, beta-catenin, macrophage, and endothelium gene signatures, which may contribute to enhanced immune checkpoint inhibitor (CPI) efficacy. Unexpectedly, a number of previously unidentified, strongly p53 downregulated genes associated with stromal pathways and IL10 expression identified novel anticancer therapeutic applications.ConclusionsThese results imply the ability of Ad-p53 to induce efficacious local and systemic antitumor immune responses with the potential to reverse resistance to immune checkpoint inhibitor therapy when combined with CD122/132 agonists and immune checkpoint blockade. Our findings further imply that Ad-p53 has multiple complementary immune mechanisms of action, which support future clinical evaluation of triplet Ad-p53, CD122/132 agonist, and immune checkpoint inhibitor combination treatment.

Analysis of Adenoviral p53 Gene Therapy Clinical Trials in Recurrent Head and Neck Squamous Cell Carcinoma.

BackgroundWe conducted an analysis of previous adenoviral p53 (Ad-p53) treatment data in recurrent head and neck squamous cell carcinoma (HNSCC) patients to identify optimal Ad-p53 treatment methods for future clinical trials.MethodsThe analysis involved recurrent HNSCC patients treated with Ad-p53 for whom p53 genotyping and immunohistochemistry tumor biomarker studies had been performed (n = 70). Ad-p53 tumor treatment responses defined by RECIST 1.1 criteria were correlated with Ad-p53 dose and tumor p53 biomarkers. Gene expression profiles induced by Ad-p53 treatment were evaluated using the Nanostring IO 360 panel.ResultsAd-p53 dose based upon the injected tumor volume had a critical effect on tumor responses. All responders had received Ad-p53 doses greater than 7 × 1010 viral particles/cm3 of tumor volume. There was a statistically significant difference in tumor responses between patients treated with greater than 7 × 1010 viral particles/cm3 compared to patients treated at lower Ad-p53 doses (Tumor Response 31% (9/29) for Ad-p53 > 7 × 1010 viral particles/cm3 versus 0% (0/25) for Ad-p53 < 7 × 1010 viral particles/cm3; p = 0.0023). All responders were found to have favorable p53 biomarker profiles defined by less than 20% p53 positive tumor cells by immunohistochemistry (IHC), wild type p53 gene sequence or p53 deletions, truncations, or frame-shift mutations without functional p53 tetramerization domains. Preliminary gene expression profiling results revealed that Ad-p53 treatment increased interferon signaling, decreased TGF-beta and beta-catenin signaling resulting in an increased CD8+ T cell signature which are associated with increased responses to immune checkpoint blockade.ConclusionsOur findings have important implications for future p53 targeted cancer treatments and identify fundamental principles to guide Ad-p53 gene therapy. We discovered that previous Ad-p53 clinical trials were negatively impacted by the inclusion of patients with unfavorable p53 biomarker profiles and by under dosing of Ad-p53 treatment. Future Ad-p53 clinical trials should have favorable p53 biomarker profiles inclusion criteria and Ad-p53 dosing above 7 × 1010 viral particles/cm3 of injected tumor volume. Preliminary gene expression profiling identified p53 mechanisms of action associated with responses to immune checkpoint blockade supporting evaluation of Ad-p53 in combination with immune checkpoint inhibitors.

Dynamic Changes in Plasma Urotensin II and Its Correlation With Plaque Stability.

Urotensin II (UII) is involved in the formation of atherosclerosis, but its role in the stability of atherosclerotic plaques is unknown. The purpose of this study was to observe the dynamic changes in plasma UII and analyze its relationship to the stability of atherosclerotic plaques. One hundred thirty-five consecutive patients with acute coronary syndrome (ACS) were enrolled. The plasma UII levels were measured immediately after admission and during three-month follow-up. A vulnerable plaque model was established using local transfection of a recombinant P53 adenovirus into plaques in rabbits fed with a high-cholesterol diet and subjected to balloon arterial injury. The levels of plasma UII were measured weekly. The changes in plasma UII during the formation of atherosclerotic plaques and before and after plaque transfection were observed. The morphology of the plaques and the expression, distribution, and quantitative expression of UII in the plaques also were observed. Our results showed that the levels of plasma UII in patients with ACS at admission were lower than levels observed at the three-month follow-up. UII dynamic changes and its correlation with plaque stabilities were further verified in rabbits with atherosclerotic vulnerable plaques. The UII levels in rabbits were significantly decreased immediately after the P53 gene transfection, which led to plaque instability and rupture. These results suggested that UII expression was down-regulated in ACS, which may be related to its ability to modulate mechanisms involved in plaque stability and instability.

Applications of Recombinant Adenovirus-p53 Gene Therapy for Cancers in the Clinic in China.

Suppression of TP53 function is nearly ubiquitous in human cancers, and a significant fraction of cancers have mutations in the TP53 gene itself. Therefore, the wild-type TP53 gene has become an important target gene for transformation research of cancer gene therapy. In 2003, the first anti-tumor gene therapy drug rAd-p53 (recombinant human p53 adenovirus), trade name Gendicine™, was approved by the China Food and Drug Administration (CFDA) for treatment of head and neck squamous cell carcinoma (HNSCC) in combination with radiotherapy. The recombinant human TP53 gene is delivered into cancer cells by an adenovirus vector constructed to express the functional p53 protein. Although the only currently approved used of Gendicine is in combination with radiotherapy for treatment of HNSCC, clinical studies have been carried out for more than 20 other applications of Gendicine in treating cancer, including treatment of advanced lung cancer, advanced liver cancer, malignant gynecological tumors, and soft tissue sarcomas. Currently more than 30,000 patients have been treated with Gendicine. This review provides an overview of the clinical applications of Gendicine in China. We summarize a total of 48 studies with 2,561 patients with solid tumors, including 34 controlled clinical studies and 14 open clinical studies, i.e., clinical studies without a control group. There are 11 studies for head and neck cancer, 10 for liver cancer, 6 for malignant gynecological tumors, 4 for non-small cell lung cancer, 4 for soft tissue sarcoma, 4 for malignant effusion, 2 for gastrointestinal tumors, and 7 for other types of cancer. In all the reported clinical studies, the most common side effect was self-limited fever. Intratumoral injection and intra-arterial infusion were the most common routes of administration. Overall, Gendicine combined with chemotherapy, radiotherapy, or other conventional treatment regimens demonstrated significantly higher response rates compared to standard therapies alone. Some of the published studies also showed that Gendicine combination regimens demonstrated longer progression-free survival times than conventional treatments alone. To date, Gendicine has been clinically used in China for treatment of cancers other than HNSCC for more than ten years, mainly for patients with advanced or unresectable malignant tumors. However, the establishment of standard treatment regimens using TP53 gene therapy is still needed in order to advance its use in clinical practice.

Combined effect of recombinant human adenovirus p53 and curcumin in the treatment of liver cancer.

The development of an effective therapeutic intervention for liver cancer is a worldwide challenge that remains to be adequately addressed. Of note, TP53, which encodes the p53 protein, is an important tumor suppressor gene, 61% of TP53 is functionally inactivated in liver cancer. Recombinant human adenovirus p53 (rAd-p53) is the first commercial product that has been used for gene therapy. In the present study, the combined mechanistic effects of rAd-p53 and curcumin, a naturally occurring compound with previously reported anti-inflammatory, antioxidant and anti-cancer properties, were assessed in liver cancer cells, using HepG2 cells as the model cell line. The administration of either curcumin or rAd-p53 promoted apoptosis, suppressed epithelial-mesenchymal transition (EMT) and blocked G2/M phase progression in HepG2 cells, which were potentiated further when both agents were applied together. Combined rAd-p53 and curcumin treatment resulted in higher p53 (P<0.01) and p21 (P<0.01) expression compared with rAd-p53 or curcumin were added alone, suggesting an additive effect on TP53 expression. Additionally, curcumin and rAd-p53 were demonstrated to regulate the activation of mitogen-activated protein kinases (MAPKs) ERK1/2, p38 MAPK and JNK. These results indicated that the combination of rAd-p53 with curcumin synergistically potentiates apoptosis and inhibit EMT compared with either rAd-p53 or curcumin treatment alone via the regulation of TP53 regulation. Mechanistically, this effect on TP53 expression may involve the ERK1/2, p38 MAPK and JNK signaling pathways. The current study provides new insights that can potentially advance the development of therapeutic strategies for liver cancer treatment.

Adenovirus oncoprotein E4orf6 triggers Cullin5 neddylation to activate the CLR5 E3 ligase for p53 degradation

The human adenovirus oncoprotein E4orf6 hijacks intracellular Cullin 5-based E3 ubiquitin ligases (CRL5s) to induce the degradation of host proteins, including p53, that impede efficient viral replication. The complex also relies on another viral protein, E1B55K, to recruit substrates for ubiquitination. However, the determinants of adenoviral E4orf6-CRL5 E3 ligase-mediated p53 degradation in the scaffolding protein Cullin5 remain rarely investigated. Here, we demonstrated that the viral protein E4orf6 triggered relocalization of the Cullin5 protein from the cytoplasm to the nucleus and induced activation of the CRL5 E3 ligase via facilitating neddylation. The expression of the deneddylase SENP8/Den1 was significantly downregulated by E4orf6. We then identified SENP8 as a natural restriction factor for E4orf6-induced p53 degradation. Furthermore, our results indicated that the NEDD8-conjugating E2 enzyme UBE2M was essential for E4orf6-mediated p53 degradation and that its dominant negative mutant UBE2M C111S dramatically blocked E4orf6 functions. The Nedd8-activating enzyme inhibitor MLN4924 decreased E4orf6-induced neddylation of the cullin5 protein and subsequently suppressed p53 degradation. Collectively, our findings illuminate the strategy by which this viral oncoprotein specifically utilizes the neddylation pathway to activate host CRL E3 ligases to degrade host restriction factors. Disrupting this post-translational modification is an attractive pharmacological intervention against human adenoviruses.

In Vitro and Clinical Studies of Gene Therapy with Recombinant Human Adenovirus-p53 Injection for Malignant Melanoma.

Malignant melanoma is an aggressive tumor with high fatality rates and poor prognosis, mainly due to the lack of efficient treatment methods. The present study investigated the potential antitumor effects of recombinant adenovirus p53 (rAd-p53) on human malignant melanoma. The optimal viral titer on a human malignant melanoma (A-375) cell line was determined for the rAd-p53 treatment. The invasive abilities, apoptosis, variations in the cell cycle, and molecular expression levels of A-375 cells were detected after infection by rAd-p53. A tumor growth curve and hematoxylin and eosin staining were carried out for experiments in nude mice. Twenty-one patients with malignant melanoma were evaluated, including 12 cases without gene therapy and nine cases with rAd-p53 gene therapy. The overall survival rate and the median survival time were analyzed between the two groups of patients. When the multiplicity of infection was 100, the cells showed the best transfection efficiency. The invasive ability, apoptosis, cycle changes of the cells, and the expression of the p53, p21, and Bax genes and proteins were significantly changed in the experimental group. In nude mice, the tumor growth curve and the tumor size in the experimental group were significantly smaller than those of the control group. Hematoxylin and eosin staining revealed tumor metastasis in the blank group and the control group but not in the experimental group. Between the two groups of patients, the median survival of the gene therapy group (38 months) was greater than that of the group without gene therapy (27 months). In this study, high expression of the p53 gene could regulate the gene expression and reduce the invasive and metastatic abilities of the tumor cells. Furthermore, rAd-p53 effectively improved the survival of patients with malignant melanoma. Therefore, rAd-p53 may be a potential treatment method for human malignant melanoma.

Recombinant adenovirus p53 combined with radiotherapy improves efficacy and safety in the treatment of head and neck lymphoma.

Lymphoma is considered to be a kind of malignant tumour. Gene therapy and radiotherapy have been reported as treatment methods for head and neck lymphoma. This study aims to evaluate the efficacy and safety for the treatment of head and neck lymphoma by a combination of recombinant adenovirus p53 (rAd-p53) and radiotherapy. A total of 156 patients with head and neck lymphoma were selected. All patients received an intratumor injection of rAd-p53 of four different doses, namely, 0, 1 × 1010 VP, 1 × 1011 VP and 1 × 1012 VP, once a week for 8 weeks, and radiotherapy was administered 3 days after the rAd-p53 injection using the same dosage and method. Four, eight and twelve weeks after treatment, tumor reduction and complete response (CR) rates, special laboratory examination and adverse reaction assessment were detected to evaluate the efficacy and safety of combined treatment with rAd-p53 injection and radiotherapy for head and neck lymphoma. At week 4, 8 and 12 of treatment with rAd-p53 at the 1 × 1010 VP, 1 × 1011 VP and 1 × 1012 VP doses, the average tumour reduction and CR rates were evidently elevated, the anti rAd-p53 antibody in the serum of patients was expressed positively, and the T cell subsets (CD3/CD4/CD8) increased and interleukin 2 receptor (IL-2R) level decreased markedly. Additionally, rAd-p53 was proven to be clinically safe in the treatment. Altogether, we conclude that rAd-p53 combined with radiotherapy improves the efficacy and safety in treating head and neck lymphoma, which has a broad scope in future clinical application.

P53 introduction enhances chemotherapy-induced apoptosis in Hela cells

Background: Cervical cancer remains a global health-related issue with over half a million new cases reported annually. However, despite different therapeutic regimens being utilized, over a million women die of cervical cancer each year. This makes it the most lethal cancer and indicates the urgent need for novel therapeutic strategies. This study was to investigate the functional roles of p53 over-expression in enhancing Lobaplatin (loba)-induced cell growth inhibition and apoptosis in cervical carcinoma cells. Methods: Hela cells were treated with recombinant p53 adenovirus (rAdp53), lobaplatin (loba), or rAdp53 plus loba combination. Subsequently, morphology, Hoechst staining, flow cytometry, and cell proliferation assay were conducted to measure apoptosis and cell growth inhibition in vitro . Western blotting was performed to assess protein expression. Xenograft tumor mouse model was used to detect the combined anti-cancer effects of rAdp53 and loba in vivo . Results: In vitro assays demonstrated that neither sub-lethal rAdp53 nor loba have any apparent apoptotic effect on Hela cells. The combination of rAdp53 and loba induced significant apoptosis and cell growth inhibition. P53 over-expression up-regulated the proapoptotic proteins Bax and Bak. Xenograft cervical tumors derived from Hela cells demonstrated that co-treatment with rAdp53 and loba effectively inhibited tumor growth in vivo . Conclusions: P53 restoration can sensitize cervical cancer cells to loba to induce apoptosis and cell growth inhibition.

Reversing immune checkpoint inhibitor resistance with adenoviral IL-24 and p53 tumor suppressor immune gene therapy.

64 Background: Immune checkpoint inhibitors represent an important advance in cancer therapeutics. However, most cancer patients either do not respond or become resistant to this therapy. Methods: We evaluated the ability of tumor suppressors p53 and IL-24, delivered via adenoviral vectors, to reverse immune checkpoint inhibitor resistance and induce abscopal therapeutic effects in the highly immune therapy resistant murine B16F10 melanoma tumor model. To mimic clinical conditions of immune checkpoint inhibitor resistance, animals with established tumors were treated with anti-PD-1 before intra-tumoral delivery of adenoviral vectors encoding tumor suppressors p53 (Ad-p53) or IL-24 (Ad-IL24). Results: Anti-PD-1 had minimal or no therapeutic efficacy when compared to PBS controls. However, there was a reversal of anti-PD-1 resistance in animals treated with Ad-p53, or Ad-IL24, in combination with anti-PD-1. Evaluation of primary tumor growth using ANOVA confirmed synergistic effects of the combination treatments over either agent used as monotherapy (p = 0.0001 for p53, p = 0.002 for IL-24). We also observed statistically significant decreases in contralateral abscopal tumor growth in animals whose primary tumors were treated with either Ad- p53 or Ad-IL24 (p = 0.046, and p = 0.0021, respectively) or in combination with anti-PD-1 (p = 0.02 p53, and p &lt; 0.0001 for IL-24) as compared to animals treated with anti-PD-1 alone. With respect to survival, combined tumor suppressor + anti-PD-1 therapy resulted in a statistically significant increase in survival compared to: a) tumor suppressor therapy alone (p = 0.01 for either Ad-p53 and or IL-24) and b) anti-PD-1 therapy alone (p &lt; 0.001 for p53, and p = x for IL-24). Conclusions: Overall, these results indicate that IL-24 and p53 tumor suppressor immune gene therapy can reverse immune checkpoint inhibitor resistance in primary tumors, and induce abscopal effects inferring the activation of systemic anti-tumor immune responses that reverse resistance to immune checkpoint inhibitor therapy.

The First Approved Gene Therapy Product for Cancer Ad-p53 (Gendicine): 12 Years in the Clinic.

Gendicine (recombinant human p53 adenovirus), developed by Shenzhen SiBiono GeneTech Co. Ltd., was approved in 2003 by the China Food and Drug Administration (CFDA) as a first-in-class gene therapy product to treat head and neck cancer, and entered the commercial market in 2004. Gendicine is a biological therapy that is delivered via minimally invasive intratumoral injection, as well as by intracavity or intravascular infusion. The wild-type (wt) p53 protein expressed by Gendicine-transduced cells is a tumor suppressor that is activated by cellular stress, and mediates cell-cycle arrest and DNA repair, or induces apoptosis, senescence, and/or autophagy, depending upon cellular stress conditions. Based on 12 years of commercial use in >30,000 patients, and >30 published clinical studies, Gendicine has exhibited an exemplary safety record, and when combined with chemotherapy and radiotherapy has demonstrated significantly higher response rates than for standard therapies alone. In addition to head and neck cancer, Gendicine has been successfully applied to treat various other cancer types and different stages of disease. Thirteen published studies that include long-term survival data showed that Gendicine combination regimens yield progression-free survival times that are significantly longer than standard therapies alone. Although the p53 gene is mutated in >50% of all human cancers, p53 mutation status did not significantly influence efficacy outcomes and long-term survival rate for Ad-p53-treated patients. To date, Shenzhen SiBiono GeneTech has manufactured 41 batches of Gendicine in compliance with CFDA QC/QA requirements, and 169,571 vials (1.0 × 1012 vector particles per vial) have been used to treat patients. No serious adverse events have been reported, except for vector-associated transient fever, which occurred in 50-60% of patients and persisted for only a few hours. The manufacturing accomplishments and clinical experience with Gendicine, as well as the understanding of its cellular mechanisms of action and implications, could provide valuable insights for the international gene therapy community and add valuable data to promote further developments and advancements in the gene therapy field.

A phase-1/2 study of adenovirus-p53 transduced dendritic cell vaccine in combination with indoximod in metastatic solid tumors and invasive breast cancer.

BackgroundIndoleamine 2, 3-dioxygenase is an enzyme that causes immunosuppression in tumors. Indoximod inhibits the indoleamine 2, 3-dioxygenase pathway and enhances immunologic responses to dendritic cell (DC) vaccines preclinically. Adenovirus p53 (Ad.p53) is used to generate DC vaccines against p53. A phase-1/2 trial of indoximod with Ad.p53-DC vaccine was conducted.Materials and MethodsThe phase-1 study combined 7 indoximod dose levels with < 6 Ad.p53-DC vaccinations every 2 weeks. Primary endpoints were maximum-tolerated dose in phase 1 and objective response in phase 2. Flow cytometry measured immune responses.ResultsThirty-nine patients were treated. In combination with Ad.p53-DC vaccine, the maximum-tolerated dose of indoximod was 1600 mg twice daily. Attributable toxicities were grade 1–2. Best response was stable disease in 4 patients. Immunologic responses were detected in 7 out of 23 evaluable patients. Median progression-free survival was 13.3 weeks (95% confidence interval, 12.97–21.85) and median overall survival was 20.71 weeks (95% confidence interval, 25.75–46.15). Nine out of 22 patients (40%) benefitted from chemotherapy after vaccination. Median overall survival in chemotherapy responders was 69.4 weeks (30.1–122.1).ConclusionsIndoximod 1600 mg twice daily with Ad.p53-DC was well tolerated. There may have been a chemosensitization effect. Future trials should explore combining this treatment with chemotherapy.

The effects of interleukin 2 and rAd-p53 as a treatment for glioblastoma.

Interleukin 2 (IL-2) is an anti-cancer cytokine that stimulates T cell propagation, triggering innate and adaptive immunity. IL-2 has been used for cancer therapy and has achieved curative effects. Recombinant adenovirus p53 injection (rAd‑p53) is a gene therapeutic agent that may improve the prognosis of patients with glioblastoma (GBM). In the present study, the effect of combined IL‑2 and rAd‑p53 treatment was studied. The ability of IL‑2 to stimulate immunoregulation and the ability of p53 to induce apoptosis for GBM was researched in the GBM tumor model. In addition, the activity of IL‑2 was analyzed. The antitumor potential of IL‑2 and rAd‑p53 was studied using xenograph mice carrying GBM cells. Tumor‑specific CD4+ and CD8+ T cells were also analyzed in the GBM‑bearing models. The results demonstrated that IL‑2 and rAd‑p53 not only stimulated tumor‑specific cytotoxic T‑lymphocyte responses and increased regulatory CD4+ and cytotoxic CD8+ T cell proliferation, however additionally increased expression of apoptosis‑associated genes. The treatment with IL‑2 and rAd‑p53 resulted in tumor regression and prolonged the survival of glioma‑bearing mice. Taken together, a combination of IL‑2 and rAd‑p53 treatment combines the effects of immunotherapy and oncolytic therapy and may be a comprehensive therapeutic schedule for clinical application in future cancer therapies.

Surgery combined with adenoviral p53 gene therapy for treatment of non-small cell lung cancer: a phase II study.

ObjectiveTo assess the efficacy of radical surgery combined with recombinant adenoviral human p53 (rAd-p53) gene therapy in treatment of resectable non-small cell lung cancer.MethodA total of 163 patients with resectable NSCLC meeting the inclusion criteria were randomly assigned to two groups: radical surgery alone (S) and radical surgery plus surgical wound surface injection of 2 x 1012 rAd-p53 units (SP). All patients were followed up for at least 3 years for efficacy and safety. Study endpoints were loco-regional recurrence or distant metastasis (Rec-Met) rate as primary endpoints, and progression free survival (PFS), overall survival (OS) and safety assessments as secondary endpoints.ResultsRecurrence or metastasis (Rec/Met) after surgery were 24/82 (29.27%) in SP group and 37/81 (45.68%) in S group. The difference in the Rec/Met rate was statistically significant (p = 0.0304) by chi-square test. The hazard ratios after adjusting of age and disease stage (S vs. SP) of PFS and OS are 1.772 (95% CI, 1.102 to 2.848) and 2.047 (95% CI, 1.109 to 3.377), respectively. The 3 years PFS and OS for SP vs. S were 71.9% vs. 46.9%, and 88.4% vs. 67.0%, respectively. Differences in PFS and OS between two treatment groups were significant with the p values of 0.0165 and 0.0191, respectively, using Log-Rank test.ConclusionsThe wound surface injection of rAd-p53 showed efficacious effects in preventing recurrence or metastasis and improving PFS and OS after a radical surgery in patients with NSCLC.

Effect of adenoviral p53 (Ad-p53) tumor suppressor immune gene therapy on checkpoint inhibitor resistance and abscopal therapeutic efficacy.

e14610 Background: Immune checkpoint inhibitors represent an important advance in cancer therapeutics. However, most cancer patients do not respond or become resistant to this form of immune therapy. Methods: We evaluated the ability of Ad-p53 to reverse immune checkpoint inhibitor resistance and induce abscopal effects in the immune therapy resistant murine B16F10 melanoma tumor model. To mimic clinical conditions of checkpoint inhibitor resistance, animals with established tumors were treated with anti-PD-1 before initiating Ad-p53 intra-tumoral therapy. Results: Anti-PD-1 had minimal therapeutic efficacy compared to control treatment. A statistical analysis of variance (ANOVA) comparison of tumor volumes revealed that the combined effect of Ad-p53 and anti-PD-1 treatment was synergistic and superior to either therapy alone (p = 0.0001). Surprisingly, there was a statistically significant abscopal effect with decreased growth of contralateral tumors not injected with Ad -p53. The Ad- p53 alone (p = 0.046) and Ad- p53 + anti-PD-1 (p = 0.0243) treatment groups both demonstrated a statistically significant decreased abscopal tumor growth compared to treatment with anti-PD-1 alone. Combined Ad- p53 and anti-PD-1 therapy demonstrated a statistically significant increase in survival compared to Ad- p53 therapy alone (p = 0.0167) and anti-PD-1 therapy alone (p &lt; 0.001) by the log rank test. We have initiated a Phase 1 clinical trial of Ad-p53 intra-hepatic arterial therapy in combination with capecitabine for patients with solid tumor liver metastases. In the first cohort of patients at a dose of 2 x 1012viral particles, treatment has been well tolerated with transient fever, chills and rigors. In one patient, decreased SUV uptake on PET scans of distant lymph node metastases suggested possible abscopal effects. Conclusions: These results suggest that Ad-p53 tumor suppressor immune gene therapy may reverse immune checkpoint inhibitor resistance and induce abscopal effects supporting the planned clinical evaluation of combined Ad-p53 and anti-PD-1 therapy in patients resistant to immune checkpoint inhibitor therapy. Clinical trial information: NCT02842125.

Amphiregulin impairs apoptosis-stimulating protein 2 of p53 overexpression-induced apoptosis in hepatoma cells.

Overexpression of apoptosis-stimulating protein 2 of p53 (ASPP2) induces apoptotic cell death in hepatoma cells (e.g. HepG2 cells) by enhancing the transactivation activity of p53, but long-term ASPP2 overexpression fails to induce more apoptosis since activation of the epidermal growth factor/epidermal growth factor receptor/SOS1 pathway impairs the pro-apoptotic role of ASPP2. In this study, in recombinant adenovirus-ASPP2-infected HepG2 cells, ASPP2 overexpression induces amphiregulin expression in a p53-dependent manner. Although amphiregulin initially contributes to ASPP2-induced apoptosis, it eventually impairs the pro-apoptotic function of ASPP2 by activating the epidermal growth factor/epidermal growth factor receptor/SOS1 pathway, leading to apoptosis resistance. Moreover, blocking soluble amphiregulin with a neutralizing antibody also significantly increased apoptotic cell death of HepG2 cells due to treatment with methyl methanesulfonate, cisplatin, or a recombinant p53 adenovirus, suggesting that the function of amphiregulin involved in inhibiting apoptosis may be a common mechanism by which hepatoma cells escape from stimulus-induced apoptosis. Thus, our data elucidate an apoptosis-evasion mechanism in hepatocellular carcinoma and have potential implications for hepatocellular carcinoma therapy.

Efficacy and safety of recombinant human adenovirus p53 combined with chemoradiotherapy in the treatment of recurrent nasopharyngeal carcinoma.

This study aims to explore the efficacy and safety of recombinant human adenovirus p53 (rAd-p53) combined with chemoradiotherapy (CRT) in the treatment of recurrent nasopharyngeal carcinoma (NPC). A total of 162 recurrent NPC patients were selected and divided randomly into the rAd-p53+CRT, CRT, and rAd-p53 groups. An electrochemical luminescence immune analyzer was used to detect serum levels of tumor markers (carcinoembryonic antigen, cancer antigen 199, and cancer antigen 153). Efficacy evaluation was in accordance with Response Evaluation Criteria in Solid Tumor. Toxicity evaluation was performed according to the WHO grading standard. A 3-year follow-up was performed. A Kaplan-Meier curve was drawn to calculate progression-free survival and the 3-year survival rate. The complete response rate and effective rate (complete response+partial response) of recurrent NPC patients in the rAd-p53+CRT group were higher than those in the CRT and rAd-p53groups. After treatment, compared with the CRT and rAd-p53 groups, the rAd-p53+CRT group had lower serum levels of carcinoembryonic antigen, cancer antigen 199, and cancer antigen 153. The incidences of leukopenia and oral mucositis in the rAd-p53+CRT group were lower than those in the CRT group, but no differences were found between the rAd-p53+CRT and rAd-p53 groups. The progression-free survival and 3-year survival rate of recurrent NPC patients in the rAd-p53+CRT group were higher than the than those in the CRT and rAd-p53 groups. Our study supports that rAd-p53 combined with CRT may provide better efficacy and lower toxicity than rAd-p53 or CRT alone for the treatment of recurrent NPC patients.