BackgroundOvarian cancers often contain significant numbers of tumor-infiltrating lymphocytes (TILs) that can be readily harnessed for adoptive T-cell therapy (ACT). However, the immunosuppressive ...ovarian tumor microenvironment and lack of tumor reactivity in TILs can limit the effectiveness of the therapy. We hypothesized that by using an oncolytic adenovirus (Ad5/3-E2F-D24-hTNFa-IRES-hIL2; TILT-123) to deliver tumor necrosis factor alpha (TNFa) and interleukin-2 (IL-2), we could counteract immunosuppression, and enhance antitumor TIL responses in ovarian cancer (OVCA).MethodsWe established ex vivo tumor cultures freshly derived from patients with advanced OVCA and evaluated the effects of Ad5/3-E2F-D24-hTNFa-IRES-hIL2 or Ad5/3-E2F-D24 (the control virus without TNFa and IL-2) on TILs, cytokine response and tumor viability. Tumor reactivity was assessed by determining interferon gamma (IFNg) response of clinically relevant TILs towards autologous T-cell-depleted ex vivo tumor cultures pretreated with or without the aforementioned oncolytic adenoviruses.ResultsTreatment of ex vivo tumor cultures with Ad5/3-E2F-D24-hTNFa-IRES-hIL2 caused a substantial rise in proinflammatory signals: increased secretion of IFNg, CXCL10, TNFa and IL-2, and concomitant activation of CD4+ and CD8+ TILs. Potent tumor reactivity was seen, as clinically relevant TIL secreted high levels of IFNg in response to autologous T-cell-depleted ovarian ex vivo tumor cultures treated with Ad5/3-E2F-D24-hTNFa-IRES-hIL2. This phenomenon was independent of PD-L1 expression in tumor cells, a factor that determined the variability of IFNg responses seen in different patient samples.ConclusionsOverall, oncolytic adenovirus Ad5/3-E2F-D24-hTNFa-IRES-hIL2 was able to rewire the ovarian tumor microenvironment to accommodate heightened antitumor TIL reactivity. Such effects may improve the clinical effectiveness of ACT with TILs in patients with advanced OVCA.
Adoptive cell therapy holds much promise in the treatment of cancer but results in solid tumors have been modest. The notable exception is tumor-infiltrating lymphocyte (TIL) therapy of melanoma, but ...this approach only works with high-dose preconditioning chemotherapy and systemic interleukin (IL)-2 postconditioning, both of which are associated with toxicities. To improve and broaden the applicability of adoptive cell transfer, we constructed oncolytic adenoviruses coding for human IL-2 (hIL2), tumor necrosis factor alpha (TNF-α), or both. The viruses showed potent antitumor efficacy against human tumors in immunocompromised severe combined immunodeficiency (SCID) mice. In immunocompetent Syrian hamsters, we combined the viruses with TIL transfer and were able to cure 100% of the animals. Cured animals were protected against tumor re-challenge, indicating a memory response. Arming with IL-2 and TNF-α increased the frequency of both CD4+ and CD8+ TILs in vivo and augmented splenocyte proliferation ex vivo, suggesting that the cytokines were important for T cell persistence and proliferation. Cytokine expression was limited to tumors and treatment-related signs of systemic toxicity were absent, suggesting safety. To conclude, cytokine-armed oncolytic adenoviruses enhanced adoptive cell therapy by favorable alteration of the tumor microenvironment. A clinical trial is in progress to study the utility of Ad5/3-E2F-d24-hTNFa-IRES-hIL2 (TILT-123) in human patients with cancer.
Oncolytic viruses provide a biologically multi-faceted treatment option for patients who cannot be cured with currently available treatment options. We constructed an oncolytic adenovirus, TILT-123, ...to support T-cell therapies and immune checkpoint inhibitors in solid tumors. Adenoviruses are immunogenic by nature, are easy to produce in large quantities, and can carry relatively large transgenes. They are the most commonly used gene therapy vectors and are well tolerated in patients. TILT-123 expresses two potent cytokines, tumor necrosis factor alpha and interleukin-2, to stimulate especially the T-cell compartment in the tumor microenvironment. Before entering clinical studies, the safety and biodistribution of TILT-123 was studied in Syrian hamsters and in mice. The results show that TILT-123 is safe in animals as monotherapy and in combination with an immune checkpoint inhibitor anti-PD-1. The virus treatment induces acute changes in circulating immune cell compartments, but the levels return to normal by the middle of the treatment period. The virus is rapidly cleared from healthy tissues, and it does not cause damage to vital organs. The results support the initiation of a phase 1 dose-escalation trial, where melanoma patients receiving a tumor-infiltrating lymphocyte therapy are treated with TILT-123 (NCT04217473).
Dendritic cells (DCs) are crucial players in promoting immune responses. Logically, adoptive DC therapy is a promising approach in cancer immunotherapy. One of the major obstacles in cancer ...immunotherapy in general is the immunosuppressive tumor microenvironment, which hampers the maturation and activation of DCs. Therefore, human clinical outcomes with DC therapy alone have been disappointing. In this study, we use fully serotype 3 oncolytic adenovirus Ad3-hTERT-CMV-hCD40L, expressing human CD40L, to modulate the tumor microenvironment with subsequently improved function of DCs. We evaluated the synergistic effects of Ad3-hTERT-CMV-hCD40L and DCs in the presence of human peripheral blood mononuclear cells ex vivo and in vivo. Tumors treated with Ad3-hTERT-CMV-hCD40L and DCs featured greater antitumor effect compared with unarmed virus or either treatment alone. 100% of humanized mice survived to the end of the experiment, while mice in all other groups died by day 88. Moreover, adenovirally-delivered CD40L induced activation of DCs, leading to induction of Th1 immune responses. These results support clinical trials with Ad3-hTERT-CMV-hCD40L in patients receiving DC therapy.
Cancer treatment with local administration of armed oncolytic viruses could potentially induce systemic antitumor effects, or the abscopal effect, as they self-amplify in tumors, induce danger ...signaling, and promote tumor-associated antigen presentation. In this study, oncolytic adenovirus coding for human tumor necrosis factor alpha (TNF-α) and interleukin-2 (IL-2) Ad5/3-E2F-d24-hTNF-α-IRES-hIL-2 (also known as a.k.a. TILT-123) provoked antitumor efficacy in tumors that were injected with Ad5/3-E2F-d24-hTNF-α-IRES-hIL-2 and those that were left non-injected in the same animal. Importantly, the virus was able to travel to distant tumors. To dissect the effects of oncolysis and cytokines, we studied replication-incompetent viruses in mice. Systemic antitumor effects were similar in both models, highlighting the importance of the arming device. The cytokines induced positive changes in immune cell infiltrates and induced the expression of several immune-reaction-related genes in tumors. In addition, Ad5/3-E2F-d24-hTNF-α-IRES-hIL-2 was able to increase homing of adoptively transferred tumor-infiltrating lymphocytes into both injected and non-injected tumors, possibly mediated through chemokine expression. In summary, local treatment with Ad5/3-E2F-d24-hTNF-α-IRES-hIL-2 resulted in systemic antitumor efficacy by inducing immune cell infiltration and trafficking into both treated and untreated tumors. Moreover, the oncolytic adenovirus platform had superior systemic effects over replication-deficient vector through spreading into distant tumors.
BackgroundChimeric antigen receptor (CAR) T cell therapy has shown limited success in treating solid tumors. One approach for improving antitumor efficacy in solid tumors is to equip CAR T cells with ...synthetic cytokine receptors to enhance cell-autonomous function. Our lab recently published that an orthologous IL-2/IL-9 receptor could augment antitumor immunity.1 Here we have engineered mouse and human CAR T cells targeting the tumor antigen mesothelin to express an authentic IL-9 receptor (IL-9R), providing them with an IL-9 signal (CAR-IL9R T cells).MethodsFor in vitro studies, T cells were isolated from mouse splenocytes or human donors, activated, transduced, expanded and harvested for in vitro assays. For in vivo studies, we established a syngeneic model in which C57BL/6 mice were implanted with PDA7940b, a pancreatic ductal adenocarcinoma cell line derived from KPC mice. Animals were then treated with intravenous injection of CAR-IL9R T cells and intratumoral injection of an adenovirus encoding murine IL-9 (Ad-mIL9). Control groups included mice treated with CAR T cells, CAR-IL9R T cells, or Ad-mIL9. At the time of peak CAR T cell expansion, tumors were collected and analyzed by flow cytometry and immunohistochemistry. To determine the antitumor efficacy of human IL-9 signaling CAR T cells, we established a xenograft flank tumor model by implanting AsPC-1 tumor cells in NSG mice and treated them with CAR-IL9R T cells combined with an adenovirus encoding human IL-9 (Ad-hIL9).ResultsCAR-IL9R T cells displayed a unique STAT signaling profile, a shift towards a stem cell-like memory T cell phenotype, and improved effector function in vitro compared with control CAR T cells. In our syngeneic model, tumor progression was significantly reduced, overall survival was improved, and higher numbers of CAR T cells were detected in tumors harvested from mice treated with CAR-IL9R + Ad-mIL9 compared with control groups. No significant changes in the tumor microenvironment were observed across the treatment groups, suggesting that the improved antitumor efficacy of IL-9 signaling CAR T cells is largely due to T cell-intrinsic mechanisms. Supporting this hypothesis, treatment with CAR-IL9R T cells + Ad-hIL9 significantly improved antitumor efficacy in immunodeficient NSG mice. Ongoing studies seek to understand the mechanisms underlying the gain-of-function of IL-9 signaling CAR T cells.ConclusionsCAR T cells provided with an IL-9 signal display a unique T cell phenotype combining the beneficial functional characteristics of stem cell-like memory and effector T cells, leading to enhanced in vivo antitumor activity supported by cell-intrinsic mechanisms.ReferenceKalbasi A, Siurala M, Su LL, Tariveranmoshabad M, Picton LK, Ravikumar P, Li P, Lin JX, Escuin-Ordinas H, Da T, Kremer SV, Sun AL, Castelli S, Agarwal S, Scholler J, Song D, Rommel PC, Radaelli E, Young RM, Leonard WJ, Ribas A, June CH, and Garcia KC. Potentiating adoptive cell therapy using synthetic IL-9 receptors. Nature. 2022;607(7918):360–5.
Checkpoint inhibitors have revolutionized cancer therapy and validated immunotherapy as an approach. Unfortunately, responses are seen in a minority of patients. Our objective is to use engineered ...adenoviruses designed to increase lymphocyte trafficking and cytokine production at the tumor, to assess if they increase the response rate to checkpoint inhibition, as these features have been regarded as predictive for the responses. When Ad5/3-E2F-d24-hTNFa-IRES-hIL2 (an oncolytic adenovirus coding for TNFa and IL-2, also known as TILT-123) and checkpoint inhibitors were used together in fresh urological tumor histocultures, a significant shift toward immune activity (not only tumor necrosis alpha and interleukin-2 but also interferon gamma and granzyme B) and increased T-cell trafficking signals (CXCL10) was observed. In vivo, our viruses enabled an anti-PD-L1 (a checkpoint inhibitor) delivering complete responses in all the treated animals (hazard ratios versus anti-PD-L1 alone 0.057 0.007; 0.451 or virotherapy alone 0.067 0.011; 0.415). To conclude, when an engineered oncolytic adenovirus was utilized to modify the tumor microenvironment towards what meta-analyses have pointed as predictive markers for checkpoint inhibitory therapy, the response to them increased synergistically. Of note, key findings were confirmed in fresh patient-derived tumor explants.
Despite some promising results, the majority of patients do not benefit from T cell therapies, as tumors prevent T cells from entering the tumor, shut down their activity, or downregulate key ...antigens. Due to their nature and mechanism of action, oncolytic viruses have features that can help overcome many of the barriers currently facing T cell therapies of solid tumors. This study aims to understand how four different oncolytic viruses (adenovirus, vaccinia virus, herpes simplex virus, and reovirus) perform in that task. For that purpose, an immunocompetent in vivo tumor model featuring adoptive tumor-infiltrating lymphocyte (TIL) therapy was used. Tumor growth control (p < 0.001) and survival analyses suggest that adenovirus was most effective in enabling T cell therapy. The complete response rate was 62% for TILs + adenovirus versus 17.5% for TILs + PBS. Of note, TIL biodistribution did not explain efficacy differences between viruses. Instead, immunostimulatory shifts in the tumor microenvironment mirrored efficacy results. Overall, the use of oncolytic viruses can improve the utility of T cell therapies, and additional virus engineering by arming with transgenes can provide further antitumor effects. This phenomenon was seen when an unarmed oncolytic adenovirus was compared to Ad5/3-E2F-d24-hTNFa-IRES-hIL2 (TILT-123). A clinical trial is ongoing, where patients receiving TIL treatment also receive TILT-123 (ClinicalTrials.gov: NCT04217473).
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Vaccination with dendritic cells (DCs), the most potent professional antigen-presenting cells in the body, is a promising approach in cancer immunotherapy. However, tumors induce immunosuppression in ...their microenvironment that suppresses and impairs the function of DCs. Therefore, human clinical trials with DC therapy have often been disappointing. To improve the therapeutic efficacy and to overcome the major obstacles of DC therapy, we generated a novel adenovirus, Ad3-hTERT-CMV-hCD40L, which is fully serotype 3 and expresses hCD40L for induction of antitumor immune response. The specific aim is to enhance DCs function. Data from a human cancer patient indicated that this capsid allows effective transduction of distant tumors through the intravenous route. Moreover, patient data suggested that virally produced hCD40L can activate DCs in situ. The virus was efficient in vitro and had potent antitumor activity in vivo. In a syngeneic model, tumors treated with Ad5/3-CMV-mCD40L virus plus DCs elicited greater antitumor effect as compared with either treatment alone. Moreover, virally coded CD40L induced activation of DCs, which in turn, lead to the induction of a Th1 immune response and increased tumor-specific T cells. In conclusion, Ad3-hTERT-CMV-hCD40L is promising for translation into human trials. In particular, this virus could enable successful dendritic cell therapy in cancer patients.
Lymphodepleting preconditioning with high-dose chemotherapy is commonly used to increase the clinical efficacy of adoptive T cell therapy (ACT) strategies, however, with severe toxicity for patients. ...Conversely, oncolytic adenoviruses are safe and, when engineered to express interleukin-2 (IL-2) and tumor necrosis factor alpha (TNF-α), they can achieve antitumor immunomodulatory effects similar to lymphodepletion. Therefore, we compare the safety and efficacy of such adenoviruses with a cyclophosphamide- and fludarabine-containing lymphodepleting regimen in the setting of ACT. Human adenovirus (Ad5/3-E2F-D24-hTNF-α-IRES-hIL-2; TILT-123) replication was studied using a Syrian hamster pancreatic tumor model (HapT1) infused with tumor-infiltrating lymphocytes (TILs). Using the oncolytic virus instead of lymphodepletion resulted in superior efficacy and survival. Immune cells responsive to TNF-α IL-2 were studied using an immunocompetent mouse melanoma model (B16.OVA) infused with ovalbumin-specific T (OT-I) cells. Here, the adenovirus approach improved tumor control together with increased intratumoral Th1 cytokine levels and infiltration of CD8+ T cells and CD86+ dendritic cells. Similar to humans, lymphodepleting preconditioning caused severe cytopenias, systemic inflammation, and damage to vital organs. Toxicity was minimal in adenovirus- and OT-I-treated mice. These findings demonstrate that ACT can be effectively facilitated by cytokine-coding adenovirus without requiring lymphodepletion, a rationale being clinically investigated.
Santos and colleagues show enhanced antitumor responses and major safety benefits in using cytokine-coding adenovirus therapy, rather than lymphodepleting preconditioning, to boost the efficacy of different adoptive T cell therapy (ACT) strategies. This study renders chemotherapy-based lymphodepleting regimens not required for ACT protocols utilizing cytokine-coding adenovirus.
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