Chemoimmunotherapeutic Approach Research Articles

LOAd703, an oncolytic virus-based immunostimulatory gene therapy, combined with chemotherapy for unresectable or metastatic pancreatic cancer (LOKON001): results from arm 1 of a non-randomised, single-centre, phase 1/2 study

Pancreatic ductal adenocarcinoma is characterised by low immunogenicity and an immunosuppressive tumour microenvironment. LOAd703, an oncolytic adenovirus with transgenes encoding TMZ-CD40L and 4-1BBL, lyses cancer cells selectively, activates cytotoxic T cells, and induces tumour regression in preclinical models. The aim of this study was to evaluate the safety and feasibility of combining LOAd703 with chemotherapy for advanced pancreatic ductal adenocarcinoma. LOKON001 was a non-randomised, phase 1/2 study conducted at the Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA, and consisted of two arms conducted sequentially; the results of arm 1 are presented here. In arm 1, patients 18 years or older with previously treated or treatment-naive unresectable or metastatic pancreatic ductal adenocarcinoma were treated with standard 28-day cycles of intravenous nab-paclitaxel 125 mg/m2 plus gemcitabine 1000 mg/m2 (up to 12 cycles) and intratumoural injections of LOAd703 every 2 weeks. Patients were assigned using Bayesian optimal interval design to receive 500 μL of LOAd703 at 5 × 1010 (dose 1), 1 × 1011 (dose 2), or 5 × 1011 (dose 3) viral particles per injection, injected endoscopically or percutaneously into the pancreatic tumour or a metastasis for six injections. The primary endpoints were safety and treatment-emergent immune response in patients who received at least one dose of LOAd703, and antitumour activity was a secondary endpoint. This study was registered with ClinicalTrials.gov, NCT02705196, arm 2 is ongoing and open to new participants. Between Dec 2, 2016, and Oct 17, 2019, 23 patients were assessed for eligibility, leading to 22 patients being enrolled. One patient withdrew consent, resulting in 21 patients (13 [62%] men and eight [38%] women) assigned to a dose group (three to dose 1, four to dose 2, and 14 to dose 3). 21 patients were evaluable for safety. Median follow-up time was 6 months (IQR 4-10), and data cutoff was Jan 5, 2023. The most common treatment-emergent adverse events overall were anaemia (96 [8%] of 1237 events), lymphopenia (86 [7%] events), hyperglycaemia (70 [6%] events), leukopenia (63 [5%] events), hypertension (62 [5%] events), and hypoalbuminaemia (61 [5%] events). The most common adverse events attributed to LOAd703 were fever (14 [67%] of 21 patients), fatigue (eight [38%]), chills (seven [33%]), and elevated liver enzymes (alanine aminotransferase in five [24%], alkaline phosphatase in four [19%], and aspartate aminotransferase in four [19%]), all of which were grade 1-2, except for a transient grade 3 aminotransferase elevation occurring at dose 3. A maximum tolerated dose was not reached, thereby establishing dose 3 as the highest-evaluated safe dose when combined with nab-paclitaxel plus gemcitabine. Proportions of CD8+ effector memory cells and adenovirus-specific T cells increased after LOAd703 injections in 15 (94%) of 16 patients for whom T-cell assays could be performed. Eight (44%, 95% CI 25-66) of 18 patients evaluable for activity had an objective response. Combining LOAd703 with nab-paclitaxel plus gemcitabine in patients with advanced pancreatic ductal adenocarcinoma was feasible and safe. To build upon this novel chemoimmunotherapeutic approach, arm 2 of LOKON001, which combines LOAd703, nab-paclitaxel plus gemcitabine, and atezolizumab, is ongoing. Lokon Pharma, the Swedish Cancer Society, and the Swedish Research Council.

Combined immunotherapeutic effect of Leishmania-derived recombinant aldolase and Ambisome against experimental visceral leishmaniasis.

Available therapeutics for visceral leishmaniasis (VL), a deadly parasitic infection, are usually associated with inadequate efficacy and adverse aftereffects. Further, the primary site of Leishmania parasite are host macrophages resulting in compromised immunity; ensuing marked T-cell immunosuppression. Such settings emphasize the exploration of chemo-immunotherapeutic strategies for improvising the infected person's immune status with better resolution of infection. Present work employs the immunization of Leishmania-infected hamsters with Leishmania-derived recombinant aldolase (rLdAld) and enolase (rLdEno) proteins in consort with the sub-optimal dose of Ambisome (2.5mg/kg). After the completion of immunization, hamsters were sacrificed on day 60 and 90 post infection and different organ samples were collected to perform immunological assay for evaluating the therapeutic efficacy and modulation in protective cellular immune responses. Combining these proteins, particularly rLdAld with Ambisome (2.5mg/kg), has significantly reduced the parasitic load (∼80%) with remarkable enhancement in DTH and lymphoproliferative responses compared to the infected control and only Ambisome treated groups. Moreover, cytokine levels at RNA and protein levels were noticed to be inclined towards Th-1 phenotype through up-regulation of IFN-γ and TNF-α with significant down-regulation in IL-10 and TGF-β expression, an indication towards the generation of protective immunity against experimental VL. Our experimental findings demonstrated that the chemo-immunotherapeutic approach could be an effective way of controlling human VL infection at minimal dosages of antileishmanial with reduced side-effects and propensity of drug resistance emergence.

Cyclophosphamide enhances the antitumor potency of GITR engagement by increasing oligoclonal cytotoxic T cell fitness

Only a subset of cancer patients responds to checkpoint blockade inhibition in the clinic. Strategies to overcome resistance are promising areas of investigation. Targeting glucocorticoid-induced tumor necrosis factor receptor–related protein (GITR) has shown efficacy in preclinical models, but GITR engagement is ineffective in controlling advanced, poorly immunogenic tumors, such as B16 melanoma, and has not yielded benefit in clinical trials. The alkylating agent cyclophosphamide (CTX) depletes regulatory T cells (Tregs), expands tumor-specific effector T cells (Teffs) via homeostatic proliferation, and induces immunogenic cell death. GITR agonism has an inhibitory effect on Tregs and activates Teffs. We therefore hypothesized that CTX and GITR agonism would promote effective antitumor immunity. Here we show that the combination of CTX and GITR agonism controlled tumor growth in clinically relevant mouse models. Mechanistically, we show that the combination therapy caused tumor cell death, clonal expansion of highly active CD8+ T cells, and depletion of Tregs by activation-induced cell death. Control of tumor growth was associated with the presence of an expanded population of highly activated, tumor-infiltrating, oligoclonal CD8+ T cells that led to a diminished TCR repertoire. Our studies show that the combination of CTX and GITR agonism is a rational chemoimmunotherapeutic approach that warrants further clinical investigation.

Can We Harness Immune Responses to Improve Drug Treatment in Leishmaniasis?

Leishmaniasis is a vector-borne parasitic disease that has been neglected in priority for control and eradication of malaria, tuberculosis, and HIV/AIDS. Collectively, over one seventh of the world’s population is at risk of being infected with 0.7–1.2 million new infections reported annually. Clinical manifestations range from self-healing cutaneous lesions to fatal visceral disease. The first anti-leishmanial drugs were introduced in the 1950′s and, despite several shortcomings, remain the mainstay for treatment. Regardless of this and the steady increase in infections over the years, particularly among populations of low economic status, research on leishmaniasis remains under funded. This review looks at the drugs currently in clinical use and how they interact with the host immune response. Employing chemoimmunotherapeutic approaches may be one viable alternative to improve the efficacy of novel/existing drugs and extend their lifespan in clinical use.

CGAS/STING axis mediates a topoisomerase II inhibitor-induced tumor immunogenicity.

Checkpoint blockade antibodies have been approved as immunotherapy for multiple types of cancer, but the response rate and efficacy are still limited. There are few immunogenic cell death (ICD)-inducing drugs available that can kill cancer cells, enhance tumor immunogenicity, increase the in vivo immune infiltration, and thereby boosting a tumor response to immunotherapy. So far, the ICD markers have been identified as the few immuno-stimulating characteristics of dead cells, but whether the presence of such ICD markers on tumor cells translates into enhanced antitumor immunity in vivo is still investigational. To identify anticancer drugs that could induce tumor cell death and boost T cell response, we performed drug screenings based on both an ICD reporter assay and T cell activation assay. We identified that teniposide, a DNA topoisomerase II inhibitor, could induce high mobility group box 1 (HMGB1) release and type I interferon signaling in tumor cells, and teniposide-treated tumor cells could activate antitumor T cell response both in vitro and in vivo. Mechanistically, teniposide induced tumor cell DNA damage and innate immune signaling including NF-κB activation and STING-dependent type I interferon signaling, both of which contribute to the activation of dendritic cells and subsequent T cells. Furthermore, teniposide potentiated the antitumor efficacy of anti-PD1 on multiple types of mouse tumor models. Our findings showed that teniposide could trigger tumor immunogenicity, and enabled a potential chemo-immunotherapeutic approach to potentiate the therapeutic efficacy of anti-PD1 immunotherapy.

Current management of primary central nervous system lymphoma.

Primary central nervous system lymphoma (PCNSL) is a rare but treatable disease. The hallmark therapy is based on the use of high-dose intravenous methotrexate (HDMTX), with clinical trial data suggesting that a more aggressive and targeted chemoimmunotherapeutic approach, to include the use of targeted therapy with rituximab (RTX) and the addition of other chemotherapeutic agents, may improve prognosis and reduce or defer the need for radiation therapy. Understanding of the molecular basis of tumor growth and proliferation may allow for the use of new targeted agents.

Current management of primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare but treatable disease. The hallmark therapy is based on the use of high-dose intravenous methotrexate (HDMTX), with clinical trial data suggesting that a more aggressive and targeted chemoimmunotherapeutic approach, to include the use of targeted therapy with rituximab (RTX) and the addition of other chemotherapeutic agents, may improve prognosis and reduce or defer the need for radiation therapy. Understanding of the molecular basis of tumor growth and proliferation may allow for the use of new targeted agents.

Dichotomous role of protein kinase A type I (PKAI) in the tumor microenvironment: A potential target for ‘two-in-one’ cancer chemoimmunotherapeutics

An emerging trend in cancer chemoimmunotherapeutics is to develop ‘two-in-one’ therapies, which directly inhibit tumor growth and progression, as well as enhance anti-tumor immune surveillance. Protein kinase A (PKA) is a cAMP-dependent protein kinase that mediates signal transduction of G-protein coupled receptors (GPCRs). The regulatory subunit of PKA exists in two isoforms, RI and RII, which distinguish the PKA isozymes, PKA type I (PKAI) and PKA type II (PKAII). The differential expression of both PKA isozymes has long been linked to growth regulation and differentiation. RI/PKAI is particularly implicated in cellular proliferation and neoplastic transformation. Emerging experimental and pre-clinical data also indicate that RI/PKAI plays a key role in tumor-induced immune suppression. More briefly, RI/PKAI possesses a dichotomous role in the tumor microenvironment: not only contributes to tumor growth and progression, but also takes part in tumor-induced suppression of the innate and adaptive arms of anti-tumor immunosurveillance. This review specifically discusses this dichotomous role of RI/PKAI with respect to ‘two-in-one’ chemoimmunotherapeutic manipulation. The reviewed experimental and pre-clinical data provide the proof of concept validation that RI/PKAI may be regarded as an attractive target for a new, single-targeted, ‘two hit’ chemoimmunotherapeutic approach against cancer.

Antigen presenting cells targeting and stimulation potential of lipoteichoic acid functionalized lipo-polymerosome: a chemo-immunotherapeutic approach against intracellular infectious disease.

Antigen presenting cells (APC) are well-recognized therapeutic targets for intracellular infectious diseases, including visceral leishmaniasis. These targets have raised concerns regarding their potential for drug delivery due to overexpression of a variety of receptors for pathogen associated molecular pathways after infection. Since, lipoteichoic acid (LTA), a surface glycolipid of Gram-positive bacteria responsible for recognition of bacteria by APC receptors that also regulate their activation for pro-inflammatory cytokine secretion, provides additive and significant protection against parasite. Here, we report the nanoarchitechture of APC focused LTA functionalized amphotericin B encapsulated lipo-polymerosome (LTA-AmB-L-Psome) delivery system mediated by self-assembly of synthesized glycol chitosan-stearic acid copolymer (GC-SA) and cholesterol lipid, which can activate and target the chemotherapeutic agents to Leishmania parasite resident APC. Greater J774A and RAW264.7 macrophage internalization of FITC tagged LTA-AmB-L-Psome compared to core AmB-L-Psome was observed by FACSCalibur cytometer assessment. This was further confirmed by higher accumulation in macrophage rich liver, lung and spleen during biodistribution study. The LTA-AmB-L-Psome overcame encapsulated drug toxicity and significantly increased parasite growth inhibition beyond commercial AmB treatment in both in vitro (macrophage-amastigote system; IC50, 0.082 ± 0.009 μg/mL) and in vivo (Leishmania donovani infected hamsters; 89.25 ± 6.44% parasite inhibition) models. Moreover, LTA-AmB-L-Psome stimulated the production of protective cytokines like interferon-γ (IFN-γ), interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase and nitric oxide with down-regulation of disease susceptible cytokines, like transforming growth factor-β (TGF-β), IL-10, and IL-4. These data demonstrate the potential use of LTA-functionalized lipo-polymerosome as a biocompatible lucrative nanotherapeutic platform for overcoming toxicity and improving drug efficacy along with induction of robust APC immune responses for effective therapeutics of intracellular diseases.

A New Era is Coming up in the Treatment of Chronic Lymphocytic Leukemia

The survival of patients with chronic lymphocytic leukemia (CLL) has significantly improved in the last 30 years. The introduction of purine analogs in the treatment armamentarium followed by the combination of these compounds with alkylating agents first improved response rates and progression-free survival (PFS) when compared with alkylating agent-based therapy only. However, the great advance arrived with the development of a chemoimmunotherapeutic approach comparing this with chemotherapy alone demonstrating an improvement not only in terms of response rate and PFS but also, for the first time, in the rate of overall survival (OS). The last decade brought significant achievements in the understanding of CLL pathogenesis leading to the development of new agents targeting cell surface, intracellular pathways, and tumor microenvironment. As traditional chemotherapy is associated with acute and long-term toxicity, interest in these non-chemotherapeutic treatments has been constantly growing. The challenge will be to develop a rationale for non-chemotherapeutic approaches using these new agents as monotherapy, or in combination, with the aim of obtaining an individualized strategy based on disease characteristics and even patient basis. Hopefully, an increasing participation of ultra high-risk CLL patients in clinical trials evaluating the efficacy of these new treatments may lead to reasonable success, if not cure, in this unfavorable setting.

The translation inhibitor silvestrol exhibits direct anti-tumor activity while preserving innate and adaptive immunity against EBV-driven lymphoproliferative disease.

Treatment options for patients with Epstein-Barr Virus-driven lymphoproliferative diseases (EBV-LPD) are limited. Chemo-immunotherapeutic approaches often lead to immune suppression, risk of lethal infection and EBV reactivation, thus it is essential to identify agents that can deliver direct anti-tumor activity while preserving innate and adaptive host immune surveillance. Silvestrol possesses direct anti-tumor activity in multiple hematologic malignancies while causing minimal toxicity to normal mononuclear cells. However, the effects of silvestrol on immune function have not been described. We utilized in vitro and in vivo models of EBV-LPD to simultaneously examine the impact of silvestrol on both tumor and normal immune function. We show that silvestrol induces direct anti-tumor activity against EBV-transformed lymphoblastoid cell lines (LCL), with growth inhibition, decreased expression of the EBV oncogene latent membrane protein-1, and inhibition of the downstream AKT, STAT1 and STAT3 signaling pathways. Silvestrol promoted potent indirect anti-tumor effects by preserving expansion of innate and EBV antigen-specific adaptive immune effector subsets capable of effective clearance of LCL tumor targets in autologous co-cultures. In an animal model of spontaneous EBV-LPD, silvestrol demonstrated significant therapeutic activity dependent on the presence of CD8-positive T-cells. These findings establish a novel immune-sparing activity of silvestrol, justifying further exploration in patients with EBV-positive malignancies.

Abstract 680: In vivo immunomodulatory activity of SGI-110, a second generation hypomethylating agent, in hematologic malignancies.

Abstract Second generation DNA hypomethylating agents own pleiotropic properties supporting their clinical application in cancer therapy. Among these, SGI-110 is a dinucleotide synthesized as a deoxyguanosine combined with decitabine to protect the latter from the cytidine deaminase inactivation, thus increasing its in vivo exposure and efficacy. A randomized Phase 1-2 FIH PK/PD-guided, dose-escalation study is being conducted on MDS or AML patients, to determine safety and tolerability of SGI-110 and to establish maximum tolerated dose and biologically effective dose. Subjects were randomized to one of two SQ regimens (daily x 5 or once weekly x 3, both administered in 28-day courses). The PK profile showed efficient conversion of SGI-110 to decitabine, longer apparent half-life and lower Cmax than predicted equivalent decitabine IV doses. Here, we investigated the immunomodulatory activity of in vivo administration of SGI-110 in enrolled AML and MDS patients. The hypomethylating properties of in vivo SGI-110 on CTA-specific promoters and the resulting effects on the levels of CTA expression were analyzed in PBMC from patients. Quantitative methylation-specific PCR analyses showed that the daily regimen reduced the constitutive methylation levels in promoters of investigated CTA (i.e., NY-ESO-1 and MAGE-A1) in a dose-dependent manner. The major hypomethylation was observed in patients treated with the highest dose of SGI-110 (Cohort 7, 125 mg/m2), showing an average percentage of hypomethylation of 14.2 for NY-ESO-1-promoter (range 5.0 to 26.7) and 16.3 for MAGE-A1-promoter (range 3.7 to 35.6). In patients treated with the highest doses (Cohorts 4-6, 60 mg/m2 - 125 mg/m2) of the weekly regimen, it was 4.4 (range 0.4 to 6.2) and 2.5 (range 0.1 to 9.9) for NY-ESO-1- and MAGE-A1-promoter, respectively. The effects of the hypomethylating activity of in vivo SGI-110 on the constitutive CTA expression were evaluated by quantitative real-time RT-PCR. The induction/up-regulation of NY-ESO-1, MAGE-A1, MAGE-A3 expression were transient and observed in 11/18 (NY-ESO-1/β-actin molecules range 10-5 to 1.4*10-3), 5/18 (MAGE-A1/β-actin molecules range 10-5 to 8.2*10-5) and 6/18 (MAGE-A3/β-actin molecules range 10-5 to 2.4*10-3) patients treated with the highest doses of daily regimen (Cohorts 4-7). In weekly regimen the induction/up-regulation were detected in 10/14 (NY-ESO-1/β-actin molecules range 10-5 to 1.8*10-3), 1/14 (1.3*10-5 MAGE-A1/β-actin molecules) and 11/14 (MAGE-A3/β-actin molecules range 10-5 to 5.9*10-3) patients treated with the highest doses (cohorts 4-6). These newly identified immunomodulatory properties of SGI-110, combined with its favorable pharmacologic and pharmacokinetic features, define SGI-110 as a potentially useful agent to implement new and more effective combined chemo-immunotherapeutic approaches in patients with hematologic malignancies. Citation Format: Alessia Covre, Giulia Parisi, Hugues Jmg Nicolay, Ester Fonsatti, Elisabetta Fratta, Luca Sigalotti, Pietro Taverna, Sandra Coral, Michele Maio. In vivo immunomodulatory activity of SGI-110, a second generation hypomethylating agent, in hematologic malignancies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 680. doi:10.1158/1538-7445.AM2013-680

Immunomodulatory activity of SGI-110, a 5-aza-2'-deoxycytidine-containing demethylating dinucleotide.

Pharmacologic DNA hypomethylation holds strong promises in cancer immunotherapy due to its immunomodulatory activity on neoplastic cells. Searching for more efficient DNA hypomethylating agents to be utilized to design novel immunotherapeutic strategies in cancer, we investigated the immunomodulatory properties of the new DNA hypomethylating agent SGI-110, that is resistant to in vivo inactivation by cytidine deaminase. Cutaneous melanoma, mesothelioma, renal cell carcinoma, and sarcoma cells were treated in vitro with SGI-110. RT-PCR, quantitative RT-PCR, quantitative methylation-specific PCR, and flow cytometric analyses were performed to investigate changes induced by SGI-110 in the constitutive immune profile of cancer cells. The recognition by gp100-specific CTL of gp100-positive melanoma cells, treated or not with SGI-110, was tested by LDH release assays. SGI-110 induced/up-regulated the expression of investigated cancer/testis antigens (CTA) (i.e., MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A10, GAGE 1-2, GAGE 1-6, NY-ESO-1, and SSX 1-5) in all cancer cell lines studied, both at mRNA and at protein levels. Quantitative methylation-specific PCR analyses identified a hypomethylation of MAGE-A1 and NY-ESO-1 promoters in SGI-110-treated neoplastic cells, demonstrating a direct role of pharmacologic DNA demethylation in CTA induction. SGI-110 also up-regulated the expression of HLA class I antigens and of ICAM-1, resulting in an improved recognition of cancer cells by gp100-specific CTL. Our findings show that SGI-110 is a highly attractive therapeutic agent to comprehensively increase immunogenicity and immune recognition of neoplastic cells, and provide the scientific rationale for its clinical development to design novel chemo-immunotherapeutic approaches in cancer patients.

Mycobacterium indicus pranii (Mw) Re-Establishes Host Protective Immune Response in Leishmania donovani Infected Macrophages: Critical Role of IL-12

Leishmania donovani, a protozoan parasite, causes a strong immunosuppression in a susceptible host and inflicts the fatal disease visceral leishmaniasis. Relatively high toxicity, low therapeutic index, and failure in reinstating host-protective anti-leishmanial immune responses have made anti-leishmanial drugs patient non-compliant and an immuno-modulatory treatment a necessity. Therefore, we have tested the anti-leishmanial efficacy of a combination of a novel immunomodulator, Mycobacterium indicus pranii (Mw), and an anti-leishmanial drug, Amphotericin B (AmpB). We observe that Mw alone or with a suboptimal dose of AmpB offers significant protection against L. donovani infection by activating the macrophages. Our experiments examining the anti-leishmanial activity of Mw alone or with AmpB also indicate a p38MAPK and ERK-1/2 regulated pro-inflammatory responses. The Mw-AmpB combination induced nitric oxide production, restored Th1 response, and significantly reduced parasite burden in wild type macrophages but not in IL-12-deficient macrophages indicating a pivotal role for IL-12 in the induction of host-protection by Mw and AmpB treatments. In addition, we observed that Mw alone or in combination with suboptimal dose of AmpB render protection against L. donovani infection in susceptible BALB/c mice. However, these treatments failed to render protection in IL-12-deficient mice in vivo which added further support that IL-12 played a central role in this chemo immunotherapeutic approach. Thus, we demonstrate a novel chemo-immunotherapeutic approach- Mw and AmpB crosstalk eliminating the parasite-induced immunosuppression and inducing collateral host-protective effects.

Regression of Established Hepatocellular Carcinoma Is Induced by Chemoimmunotherapy in An Orthotopic Murine Model

The high rate of mortality and frequent incidence of recurrence associated with hepatocellular carcinoma (HCC) reveal the need for new therapeutic approaches. In this study we evaluated the efficacy of a novel chemoimmunotherapeutic strategy to control HCC and investigated the underlying mechanism that increased the antitumor immune response. We developed a novel orthotopic mouse model of HCC through seeding of tumorigenic hepatocytes from SV40 T antigen (Tag) transgenic MTD2 mice into the livers of syngeneic C57BL/6 mice. These MTD2-derived hepatocytes form Tag-expressing HCC tumors specifically within the liver. This approach provides a platform to test therapeutic strategies and antigen-specific immune-directed therapy in an immunocompetent murine model. Using this model we tested the efficacy of a combination of oral sunitinib, a small molecule multitargeted receptor tyrosine kinase (RTK) inhibitor, and adoptive transfer of tumor antigen-specific CD8(+) T cells to eliminate HCC. Sunitinib treatment alone promoted a transient reduction in tumor size. Sunitinib treatment combined with adoptive transfer of tumor antigen-specific CD8(+) T cells led to elimination of established tumors without recurrence. In vitro studies revealed that HCC growth was inhibited through suppression of STAT3 signaling. In addition, sunitinib treatment of tumor-bearing mice was associated with suppression of STAT3 and a block in T-cell tolerance. These findings indicate that sunitinib inhibits HCC tumor growth directly through the STAT3 pathway and prevents tumor antigen-specific CD8(+) T-cell tolerance, thus defining a synergistic chemoimmunotherapeutic approach for HCC.

Fludarabine, cyclophosphamide, doxorubicin (FCD), and rituximab: A remission induction therapy for aggressive pediatric post‐transplant lymphoproliferative disease (PTLD)

Management of aggressive, usually late-occurring, post-transplant lymphoproliferative disorders (PTLDs), a life-threatening complication after solid organ transplants, remains controversial. Four children affected by aggressive CD20+ PTLDs received a chemo-immunotherapy regimen for remission induction based on fludarabine, cyclophosphamide, doxorubicin, and rituximab, associated with a rapid discontinuation of immunosuppression (IS). Subsequent consolidation chemotherapy consisted of Berlin-Frankfurt-Münster-modified blocks. All patients achieved a complete remission, which persisted for 25, 68+, 80+, and 103+ months after diagnosis. Therapy was well tolerated. No patients developed allograft rejection during PTLD treatment. Our experience suggests that this chemo-immunotherapeutic approach may be an effective treatment strategy while allowing for a concomitant discontinuation of IS.

Chemoimmunotherapeutic Approach to Prolonged Survival Time in Combination with Immunization and Glutamic Acid Derivatives with Antitumor Activity in Tumor-Bearing Mice

Cancer is one of the major causes of death. For cancer, the general conventional treatment and standard of care for clinical oncology remains surgery followed by radiation and/or systemic chemotherapy as deemed appropriate based on the clinical findings. Chemoimmunotherapy is an approach to treat cancer where chemotherapy is given along with immunotherapy. Chemoimmunotherapy may be useful to enhance survival time in cancer by improve immunity of the patients. This approach may enhance the therapeutic efficacy. A comparative study was done to assess the therapeutic efficacy of the whole cell vaccine and the tumor extract with or without combination chemotherapy with the synthesized glutamine and glutamic acid derivatives and analogs as well as the standard drug etoposide against Ehrlich Ascites Carcinoma (EAC) cells in Swiss Albino mice. The study showed promising results with the compound 5-N-n-hexyl-2-(4-iso-butylbenzenesulphonyl)glutamine. The compound when combined with the whole cell vaccine as well as the tumor extract increases the survival time and the therapeutic efficacy which is comparable with that of standard drug etoposide.

Epigenetic Immunomodulation of Hematopoietic Malignancies

Significant progress has been made in the clinical management of hematologic malignancies; nevertheless, a proportion of patients still remains unresponsive to available therapeutic options. Furthermore, patients who respond to specific therapeutic regimens may still require additional treatment to eradicate minimal residual disease. In this scenario, novel immunotherapeutic strategies may significantly impact on the clinical course of hematopoietic tumors in different clinical stages of disease. Among immunotherapeutic approaches under development, promising clinical results are being obtained with vaccination of patients with solid malignancies against cancer testis antigens (CTA), which belong to a growing family of methylation-regulated tumor-associated antigens (TAA) shared among human malignancies of different histologies. Based on these notions, the emerging preclinical and clinical evidence suggest that an immunomodulatory role for epigenetic drugs is highly relevant; in fact, by interfering with DNA methylation, these compounds induce or upregulate the constitutive expression of CTA on actively proliferating neoplastic cells. This novel activity of epigenetic drugs combines with their well-known cytotoxic, pro-apoptotic and differentiating activities in hematopoietic tumors that are extensively described in other chapters of this issue. This review will focus on the expression of CTA in hematopoietic malignancies, on their epigenetic regulation, and on the foreseeable immunotherapeutic implications of DNA hypometylating drugs to design new CTA-based chemo-immunotherapeutic approaches in patients with hematopoietic tumors.

VAD-t (Vincristine, Adriamycin, Dexamethasone and Low-Dose Thalidomide) Is an Effective Initial Therapy with High Response Rates for Patients with Treatment Naïve Multiple Myeloma (MM).

Recent understanding of MM biology suggests that MM cells rely on their microenvironment for disease progression and dissemination. MM cell interaction with stromal cells in the bone marrow microenvironment fosters chemotherapy resistance. Targeting the microenvironment with novel biologic agents such as thalidomide (T) has shown encouraging clinical results in patients with previously untreated as well as relapsed/refractory MM. We have previously shown here that VAD plus low dose T (t) is an effective salvage regimen for VAD refractory pts. We report the preliminary results of an ongoing phase II trial studying a combined chemoimmunotherapeutic approach - standard VAD plus t (200 mg) in treatment-naïve MM pts. This regimen was designed to target concurrently the malignant cell and its microenvironment. MM pts, ≥ Stage I with no prior therapy were eligible for study. Monthly infusional VAD (standard dose) was given for 4 cycles every 28 days concurrently with t for 4 months. t (100mg) was started 1 wk prior to VAD and was escalated in 1–2 wks to 200mg. Pts were evaluated for response after each cycle and after cycle 4 using SWOG criteria. Pts characteristics include: enrolled n=16, 8M, 8F; median age 58 yrs range 46–77; Stage III disease n=11, Stage II, n=3 and Stage 1, n=1; and Median B2M, 1.9 mg/L (range 1.2–11.5). Low dose coumadin (1–2 mg) was used for venous thromboembolism (VTE) prophylaxis, t was also held during the 4 days of each infusion of VAD. All pts are evaluable for toxicity and 11 are evaluable for response after completing 4 cyc. 10/11 (91%) responded clinically; CR, n=3, PR, n=7. One pt had progressive disease. Three pts with responding disease were removed from study for Grade III toxicity (1 adriamycin associated cardiomyopathy, 1 pulmonary hypertension and 1 recurrent infections) but are not included in response evaluation. Toxicities: fatigue (Gr. II) was the most common side effect (25%) and DVT was noted in 2 (12%). All pts eligible for stem cell (SC) transplant (n=7), were able to collect adequate amount of SC post VAD-t. Preliminary results of this study suggest that VAD-t is an effective and well-tolerated regimen with improved ORR compared to standard VAD regimen in pts with treatment naïve MM. No increase in incidence of VTE was noted with the combination. Adequate SC collection was achieved in transplant eligible pts. Accrual is ongoing on this study and updated results will be presented at the annual meeting.

Methylation-regulated expression of cancer testis antigens in primary effusion lymphoma: immunotherapeutic implications.

Primary effusion lymphoma (PEL) is a large B-cell neoplasm with an unfavorable prognosis and limited therapeutic options. In this study, cancer testis antigens (CTA) were investigated as potential immunotherapeutic targets in patients with PEL. Baseline expression of a panel of 11 CTA was highly heterogeneous among five PEL cell lines. In particular, the investigated CTA were not expressed in BC-2 and BC-3 cells, while BC-1, HBL-6, and BCBL-1 cells tested positive for 6, 8, and 9 CTA, respectively. The DNA hypomethylating agent 5-aza-2'-deoxycytdine (5-AZA-CdR) invariably induced or up-regulated the expression of all investigated CTA in all cell lines analyzed. The de novo expression of CTA was still detectable at mRNA and protein level at least 2 months after the end of 5-AZA-CdR treatment. These findings, and the concomitant up-regulation of HLA-class I antigens and ICAM-1 by 5-AZA-CdR, support its clinical use to set-up innovative chemo-immunotherapeutic approaches in PEL.