Efficacy of coxsackievirus A21 against drug-resistant neoplastic B cells.

Primary drug resistance and minimal residual disease are major challenges in the treatment of B cell neoplasms. Therefore, this study aimed to identify a novel treatment capable of eradicating malignant B cells and drug-resistant disease. Oncolytic viruses eradicate malignant cells by direct oncolysis and activation of anti-tumor immunity, have proven anti-cancer efficacy, and are safe and well tolerated in clinical use. Here, we demonstrate that the oncolytic virus coxsackievirus A21 can kill a range of B cell neoplasms, irrespective of an anti-viral interferon response. Moreover, CVA21 retained its capacity to kill drug-resistant B cell neoplasms, where drug resistance was induced by co-culture with tumor microenvironment support. In some cases, CVA21 efficacy was actually enhanced, in accordance with increased expression of the viral entry receptor ICAM-1. Importantly, the data confirmed preferential killing of malignant B cells and CVA21 dependence on oncogenic B cell signaling pathways. Significantly, CVA21 also activated natural killer (NK) cells to kill neoplastic B cells and drug-resistant B cells remained susceptible to NK cell-mediated lysis. Overall, these data reveal a dual mode of action of CVA21 against drug-resistant B cells and support the development of CVA21 for the treatment of B cell neoplasms.

Reovirus-induced cell-mediated immunity for the treatment of multiple myeloma within the resistant bone marrow niche.

BACKGROUND: Multiple myeloma (MM) remains an incurable disease and oncolytic viruses offer a well-tolerated addition to the therapeutic arsenal. Oncolytic reovirus has progressed to phase I clinical trials and its direct lytic potential has been extensively studied. However, to date, the role for reovirus-induced immunotherapy against MM, and the impact of the bone marrow (BM) niche, have not been reported. METHODS: This study used human peripheral blood mononuclear cells from healthy donors and in vitro co-culture of MM cells and BM stromal cells to recapitulate the resistant BM niche. Additionally, the 5TGM1-Kalw/RijHSD immunocompetent in vivo model was used to examine reovirus efficacy and characterize reovirus-induced immune responses in the BM and spleen following intravenous administration. Collectively, these in vitro and in vivo models were used to characterize the development of innate and adaptive antimyeloma immunity following reovirus treatment. RESULTS: Using the 5TGM1-Kalw/RijHSD immunocompetent in vivo model we have demonstrated that reovirus reduces both MM tumor burden and myeloma-induced bone disease. Furthermore, detailed immune characterization revealed that reovirus: (i) increased natural killer (NK) cell and CD8+ T cell numbers; (ii) activated NK cells and CD8+ T cells and (iii) upregulated effector-memory CD8+ T cells. Moreover, increased effector-memory CD8+ T cells correlated with decreased tumor burden. Next, we explored the potential for reovirus-induced immunotherapy using human co-culture models to mimic the myeloma-supportive BM niche. MM cells co-cultured with BM stromal cells displayed resistance to reovirus-induced oncolysis and bystander cytokine-killing but remained susceptible to killing by reovirus-activated NK cells and MM-specific cytotoxic T lymphocytes. CONCLUSION: These data highlight the importance of reovirus-induced immunotherapy for targeting MM cells within the BM niche and suggest that combination with agents which boost antitumor immune responses should be a priority.

Past, Present and Future of Oncolytic Reovirus.

Oncolytic virotherapy (OVT) has received significant attention in recent years, especially since the approval of talimogene Laherparepvec (T-VEC) in 2015 by the Food and Drug administration (FDA). Mechanistic studies of oncolytic viruses (OVs) have revealed that most, if not all, OVs induce direct oncolysis and stimulate innate and adaptive anti-tumour immunity. With the advancement of tumour modelling, allowing characterisation of the effects of tumour microenvironment (TME) components and identification of the cellular mechanisms required for cell death (both direct oncolysis and anti-tumour immune responses), it is clear that a "one size fits all" approach is not applicable to all OVs, or indeed the same OV across different tumour types and disease locations. This article will provide an unbiased review of oncolytic reovirus (clinically formulated as pelareorep), including the molecular and cellular requirements for reovirus oncolysis and anti-tumour immunity, reports of pre-clinical efficacy and its overall clinical trajectory. Moreover, as it is now abundantly clear that the true potential of all OVs, including reovirus, will only be reached upon the development of synergistic combination strategies, reovirus combination therapeutics will be discussed, including the limitations and challenges that remain to harness the full potential of this promising therapeutic agent.

Plasmacytoid dendritic cells orchestrate innate and adaptive anti-tumor immunity induced by oncolytic coxsackievirus A21.

BACKGROUND: The oncolytic virus, coxsackievirus A21 (CVA21), has shown promise as a single agent in several clinical trials and is now being tested in combination with immune checkpoint blockade. Combination therapies offer the best chance of disease control; however, the design of successful combination strategies requires a deeper understanding of the mechanisms underpinning CVA21 efficacy, in particular, the role of CVA21 anti-tumor immunity. Therefore, this study aimed to examine the ability of CVA21 to induce human anti-tumor immunity, and identify the cellular mechanism responsible. METHODS: This study utilized peripheral blood mononuclear cells from i) healthy donors, ii) Acute Myeloid Leukemia (AML) patients, and iii) patients taking part in the STORM clinical trial, who received intravenous CVA21; patients receiving intravenous CVA21 were consented separately in accordance with local institutional ethics review and approval. Collectively, these blood samples were used to characterize the development of innate and adaptive anti-tumor immune responses following CVA21 treatment. RESULTS: An Initial characterization of peripheral blood mononuclear cells, collected from cancer patients following intravenous infusion of CVA21, confirmed that CVA21 activated immune effector cells in patients. Next, using hematological disease models which were sensitive (Multiple Myeloma; MM) or resistant (AML) to CVA21-direct oncolysis, we demonstrated that CVA21 stimulated potent anti-tumor immune responses, including: 1) cytokine-mediated bystander killing; 2) enhanced natural killer cell-mediated cellular cytotoxicity; and 3) priming of tumor-specific cytotoxic T lymphocytes, with specificity towards known tumor-associated antigens. Importantly, immune-mediated killing of both MM and AML, despite AML cells being resistant to CVA21-direct oncolysis, was observed. Upon further examination of the cellular mechanisms responsible for CVA21-induced anti-tumor immunity we have identified the importance of type I IFN for NK cell activation, and demonstrated that both ICAM-1 and plasmacytoid dendritic cells were key mediators of this response. CONCLUSION: This work supports the development of CVA21 as an immunotherapeutic agent for the treatment of both AML and MM. Additionally, the data presented provides an important insight into the mechanisms of CVA21-mediated immunotherapy to aid the development of clinical biomarkers to predict response and rationalize future drug combinations.

Influence of transdermal rotigotine on ovulation suppression by a combined oral contraceptive.

AIMS: To assess the influence of the transdermally applied dopamine agonist rotigotine on ovulation suppression by a combined oral contraceptive (0.03 mg ethinyloestradiol and 0.15 mg levonorgestrel) in a randomized, double-blind crossover study in 40 healthy females. METHODS: Treatment A consisted of the combined oral contraceptive for 28 days plus rotigotine for the first 13 days (2 mg (24 h)(-1) on days 1-3, 3 mg (24 h)(-1) maintenance dose thereafter). During treatment B, subjects received matching placebo patches instead of rotigotine. Pharmacodynamic parameters (progesterone, oestradiol, luteinizing hormone, and follicle stimulating hormone serum concentrations), pharmacokinetic parameters for ethinyloestradiol/levonorgestrel and rotigotine, and safety and tolerability of the treatment were assessed. RESULTS: Progesterone serum concentrations remained below 2 ng ml(-1) in all subjects during the luteal phase. Median serum concentrations of all other pharmacodynamic parameters were similar during both treatments. Pharmacokinetic parameters C(max,ss) and AUC(0,24 h)(ss) at steady state were similar with or without co-administration of rotigotine for both ethinyloestradiol and levonorgestrel with geometric mean ratios close to 1 and 90% confidence intervals within the acceptance range of bioequivalence (0.8, 1.25): C(max,ss) 1.05 (0.93, 1.19), AUC(0,24 h)(ss) 1.05 (0.9, 1.22) for ethinyloestradiol; C(max,ss) 1.01 (0.96, 1.06), AUC(0,24 h)(ss) 0.98 (0.95, 1.01) for levonorgestrel. Mean plasma concentrations of unconjugated rotigotine remained stable throughout the patch-on period (day 13). CONCLUSIONS: Concomitant administration of 3 mg (24 h)(-1) transdermal rotigotine had no impact on the pharmacodynamics and pharmacokinetics of a combined oral contraceptive containing 0.03 mg ethinyloestradiol and 0.15 mg levonorgestrel, suggesting that the dopamine agonist does not influence contraception efficacy.