Near-infrared photoimmunotherapy targeting EGFR-Shedding new light on glioblastoma treatment

Glioblastomas (GBMs) are high-grade brain tumors, differentially driven by alterations (amplification, deletion or missense mutations) in the epidermal growth factor receptor (EGFR), that carry a poor prognosis of just 12-15 months following standard therapy. A combination of interventions targeting tumor-specific cell surface regulators along with convergent downstream signaling pathways may enhance treatment efficacy. Against this background, we investigated a novel photoimmunotherapy approach combining the cytotoxicity of photodynamic therapy with the specificity of immunotherapy. An EGFR-specific affibody (ZEGFR:03115 ) was conjugated to the phthalocyanine dye, IR700DX, which when excited with near-infrared light produces a cytotoxic response. ZEGFR:03115 -IR700DX EGFR-specific binding was confirmed by flow cytometry and confocal microscopy. The conjugate showed effective targeting of EGFR positive GBM cells in the brain. The therapeutic potential of the conjugate was assessed both in vitro, in GBM cell lines and spheroids by the CellTiter-Glo® assay, and in vivo using subcutaneous U87-MGvIII xenografts. In addition, mice were imaged pre- and post-PIT using the IVIS/Spectrum/CT to monitor treatment response. Binding of the conjugate correlated to the level of EGFR expression in GBM cell lines. The cell proliferation assay revealed a receptor-dependent response between the tested cell lines. Inhibition of EGFRvIII+ve tumor growth was observed following administration of the immunoconjugate and irradiation. Importantly, this response was not seen in control tumors. In conclusion, the ZEGFR:03115 -IR700DX showed specific uptake in vitro and enabled imaging of EGFR expression in the orthotopic brain tumor model. Moreover, the proof-of-concept in vivo PIT study demonstrated therapeutic efficacy of the conjugate in subcutaneous glioma xenografts.

Impact of antibiotic use during curative treatment of locally advanced head and neck cancers with chemotherapy and radiotherapy

BACKGROUND

Pre-clinical evidence suggests reduced efficacy of anticancer treatment in patients exposed to broad-spectrum antibiotics. It is hypothesised that this phenomenon may be explained by the effects of antibiotics on the composition of the microbiota. To assess this in a clinical setting, we analysed the impact of antibiotics in patients with locally advanced head and neck cancer (LAHNC) treated with curative intent with chemotherapy and radiotherapy (RT).

MATERIAL AND METHODS

Retrospective data for LAHNC patients treated with curative intent (245 induction chemotherapy followed by chemoradiation [CRT], 17 surgery followed by post-operative CRT, six CRT, three RT alone and one RT with concurrent cetuximab) were analysed. We evaluated the impact of antibiotics prescribed during primary anti-cancer treatment on progression-free survival (PFS), overall survival (OS) and disease-specific survival (DSS) rates by multivariate Kaplan-Meier and Cox proportional hazards regression analysis.

RESULTS

Among 272 patients, those receiving antibiotics between within 1 week before and 2 weeks after treatment (N = 124) progressed significantly earlier and had lower OS and DSS rates. In the multivariate analysis, administration of antibiotics was independently associated with reduced PFS (hazards ratio [HR] 1.98, P = 0.001), OS (HR 1.85, P = 0.001) and DSS (HR 1.95, P = 0.004). This effect was maintained with independence of reason for prescription, type and time of antibiotic prescription. The negative impact was greater for patients who received two or more courses of antibiotics. Antibiotic treatment was correlated with increased risk of locoregional relapse.

CONCLUSIONS

Our data suggest a negative impact of antibiotic therapy on treatment outcomes following CRT with curative intent in patients with LAHNC. This potential harm should be considered when prescribing broad-spectrum and prophylactic antibiotics for such patients.

The value of magnetic resonance imaging in target volume delineation of base of tongue tumours--a study using flexible surface coils

INTRODUCTION

Magnetic resonance imaging (MRI) provides superior diagnostic accuracy over computed tomography (CT) in oropharyngeal tumours. Precise delineation of the gross tumour volume (GTV) is mandatory in radiotherapy planning when a GTV boost is required. CT volume definition in this regard is poor. We studied the feasibility of using flexible surface (flex-L) coils to obtain MR images for MR-CT fusion to assess the benefit of MRI over CT alone in planning base of tongue tumours.

METHODS

Eight patients underwent CT and MRI radiotherapy planning scans with an immobilisation device. Distortion-corrected T1-weighted post-contrast MR scans were fused to contrast-enhanced planning CT scans. GTV, clinical target and planning target volumes (CTV, PTV) and organs at risk (OAR) were delineated on CT, then on MRI with blinding to the CT images. The volumetric and spatial differences between MRI and CT volumes for GTV, CTV, PTV and OAR were compared. MR image distortions due to field inhomogeneity and non-linear gradients were corrected and the need for such correction was evaluated.

RESULTS

The mean primary GTV was larger on MRI (22.2 vs. 9.5 cm(3), p=0.05) than CT. The mean primary and nodal GTV (i.e. BOT and macroscopic nodes) was significantly larger on MRI (27.2 vs. 14.4 cm(3), p=0.05). The volume overlap index (VOI) between MRI and CT for the primary was 0.34 suggesting that MRI depicts parts of the primary tumour not detected by CT. There was no significant difference in volume delineation between MR and CT for CTV, PTV, nodal CTV and nodal PTV. MRI volumes for brainstem and spinal cord were significantly smaller due to improved organ definition (p=0.002). Susceptibility and gradient-related distortions were not found to be clinically significant.

CONCLUSION

MRI improves the definition of tongue base tumours and neurological structures. The use of MRI is recommended for GTV dose-escalation techniques to provide precise depiction of GTV and improved sparing of spinal cord and brainstem.

Definitive radiotherapy for extramedullary plasmacytomas of the head and neck

Extramedullary plasmacytoma of the head and neck region (EMPHN) is an uncommon malignant plasma cell neoplasm. In this study we conducted a retrospective analysis of our experience of EMPHN with particular emphasis on the role of definitive radiotherapy. From 1982 to 2001, 10 patients (6 males, 4 females) with EMPHN were treated in our institution. Of nine patients treated at initial diagnosis, all received definitive radiotherapy. One patient treated at relapse underwent surgical resection followed by post-operative radiotherapy. The median age at diagnosis was 55 years (range 35-84 years). The disease was most frequently localized in the paranasal sinuses (50%). All nine patients who received definitive radiotherapy at a dose of 40-50 Gy achieved a complete response. The median follow up period was 29 months (range 7-67 months). Four patients (40%) relapsed, three have died of their disease. Two patients (20%) with paranasal sinus disease subsequently relapsed with multiple myeloma at 10 months and 24 months, respectively. Our results indicate that treatment of EMPHN with radiotherapy achieves excellent rates of local control. The relapse rate in neck nodes of 10% does not justify elective irradiation of the uninvolved neck.

A prognostic index that predicts outcome following palliative whole brain radiotherapy for patients with metastatic malignant melanoma

To determine the outcome of patients with metastatic malignant melanoma (MMM) treated with palliative whole brain radiotherapy (WBRT) and to identify factors that predict treatment outcome to assist future trial design, a retrospective study was performed on patients with MMM who received WBRT at the Royal Marsden Hospital between 1998 and 2003. Data regarding patient factors, tumour factors and survival were collected. A total of 112 patients were identified and full data were available for 102 patients. The median age was 53 years (range 25–81 years), 66.7% were male and 33.3% female. The median dose prescribed was 20 Gy in five fractions as a mid-plane dose. The median survival after WBRT for the whole group was 51 days (range 3–1386). In an attempt to define prognostic groups, we used the validated RTOG recursive partitioning analysis (RPA) classification for brain metastasis (class 1: Karnofsky Performance Score (KPS) ⩾70%, age <65 years with no extracranial metastasis; class 3: KPS <70%; class 2: all others). The median survivals were 151, 71 and 21 days for RPA class 1, 2 and 3, respectively (P<0.001). Multivariate analysis showed that RPA class, leptomeningeal involvement, presence and number of extracranial metastatic sites and progressive disease in the brain on imaging before WBRT are important independent predictive factors. A prognostic index was derived from these factors that allowed identification of patients unlikely to benefit from WBRT. In conclusion, the RTOG RPA classification is valid when applied to patients with MMM. Patients in RPA class 1 and good prognosis class 2 are likely to benefit from palliative WBRT and should be considered for entry into trials that aim to improve duration of response. We identified that patients with RPA class 3, leptomeningeal involvement or RPA class 2 with poor prognostic index are unlikely to benefit from palliative WBRT.

Gene therapy for prostate cancer: current status and future prospects

PURPOSE

Locally advanced, relapsed and metastatic prostate cancer has a dismal prognosis with conventional therapies offering no more than palliation. In recent years advances achieved in understanding the molecular biology of cancer have afforded clinicians and scientists the opportunity to develop a range of novel genetic therapies for this disease.

MATERIALS AND METHODS

We performed a detailed review of published reports of gene therapy for prostate cancer. Particular emphasis was placed on recent developments in the arena of nonviral (plasmid DNA, DNA coated gold particles, liposomes and polymer DNA complexes) and viral (adenovirus, retrovirus, adeno-associated virus, herpes virus and pox virus) vectors. Therapeutic strategies were categorized as corrective, cytoreductive and immunomodulatory gene therapy for the purpose of data analysis and comparison.

RESULTS

Locoregional administration of nonviral and viral vectors can yield impressive local gene expression and therapeutic effects but to our knowledge no efficient systemically delivered vector is available to date. Corrective gene therapy to restore normal patterns of tumor suppressor gene (p53, Rb, p21 and p16) expression or negate the effect of mutated tumor promoting oncogenes (ras, myc, erbB2 and bcl-2) have efficacy in animal models but this approach suffers from the fact that each cancer cell must be targeted. A wide variety of cytoreductive strategies are under development, including suicide, anti-angiogenic, radioisotopic and pro-apoptotic gene therapies. Each approach has strengths and weaknesses, and may best be suited for use in combination. Immunomodulatory gene therapy seeks to generate an effective local immune response that translates to systemic antitumor activity. Currently most studies involve immunostimulatory cytokine genes, such as granulocyte-macrophage colony-stimulating factor, or interleukin-2 or 12.

CONCLUSIONS

Various therapeutic genes have proved activity against prostate cancer in vitro and in vivo. However, the chief challenge facing clinical gene therapy strategies is the lack of efficient gene delivery by local and systemic routes. For the foreseeable future vector development may remain a major focus of ongoing research. Despite this caveat it is anticipated that gene therapy approaches may significantly contribute to the management of prostate cancer in the future.

Harnessing radiotherapy-induced NK-cell activity by combining DNA damage-response inhibition and immune checkpoint blockade

BACKGROUND

Despite therapeutic gains from immune checkpoint inhibitors (ICI) in many tumor types, new strategies are needed to extend treatment benefits, especially in patients failing to mount effective antitumor T-cell responses. Radiation and drug therapies can profoundly affect the tumor immune microenvironment. Here, we aimed to identify immunotherapies to increase the antitumor response conferred by combined ataxia telangiectasia and Rad3-related kinase inhibition and radiotherapy.

METHODS

Using the human papillomavirus (HPV)-negative murine oral squamous cell carcinoma model, MOC2, we assessed the nature of the antitumor response following ataxia telangiectasia and Rad3-related inhibitor (ATRi)/radiotherapy (RT) by performing RNA sequencing and detailed flow cytometry analyses in tumors. The benefit of immunotherapies based on T cell immunoreceptor with Ig and ITIM domains (TIGIT) and Programmed cell death protein 1 (PD-1) immune checkpoint blockade following ATRi/RT treatment was assessed in the MOC2 model and confirmed in another HPV-negative murine oral squamous cell carcinoma model called SCC7. Finally, immune profiling was performed by flow cytometry on blood samples in patients with head and neck squamous cell carcinoma enrolled in the PATRIOT clinical trial of combined ATRi/RT.

RESULTS

ATRi enhances radiotherapy-induced inflammation in the tumor microenvironment, with natural killer (NK) cells playing a central role in maximizing treatment efficacy. We demonstrated that antitumor activity of NK cells can be further boosted with ICI targeting TIGIT and PD-1. Analyses of clinical samples from patients receiving ATRi (ceralasertib) confirm the translational potential of our preclinical studies.

CONCLUSION

This work delineates a previously unrecognized role for NK cells in the antitumor immune response to radiotherapy that can be augmented by small-molecule DNA damage-response inhibitors and immune checkpoint blockade.

The emerging potential of magnetic resonance imaging in personalizing radiotherapy for head and neck cancer: an oncologist's perspective

Head and neck cancer (HNC) is a challenging tumour site for radiotherapy delivery owing to its complex anatomy and proximity to organs at risk (OARs) such as the spinal cord and optic apparatus. Despite significant advances in radiotherapy planning techniques, radiation-induced morbidities remain substantial. Further improvement would require high-quality imaging and tailored radiotherapy based on intratreatment response. For these reasons, the use of MRI in radiotherapy planning for HNC is rapidly gaining popularity. MRI provides superior soft-tissue contrast in comparison with CT, allowing better definition of the tumour and OARs. The lack of additional radiation exposure is another attractive feature for intratreatment monitoring. In addition, advanced MRI techniques such as diffusion-weighted, dynamic contrast-enhanced and intrinsic susceptibility-weighted MRI techniques are capable of characterizing tumour biology further by providing quantitative functional parameters such as tissue cellularity, vascular permeability/perfusion and hypoxia. These functional parameters are known to have radiobiological relevance, which potentially could guide treatment adaptation based on their changes prior to or during radiotherapy. In this article, we first present an overview of the applications of anatomical MRI sequences in head and neck radiotherapy, followed by the potentials and limitations of functional MRI sequences in personalizing therapy.

The HSP90 inhibitor NVP-AUY922 radiosensitizes by abrogation of homologous recombination resulting in mitotic entry with unresolved DNA damage

Background

Heat shock protein 90 (HSP90) is a molecular chaperone responsible for the conformational maintenance of a number of client proteins that play key roles in cell cycle arrest, DNA damage repair and apoptosis following radiation. HSP90 inhibitors exhibit antitumor activity by modulating the stabilisation and activation of HSP90 client proteins. We sought to evaluate NVP-AUY922, the most potent HSP90 inhibitor yet reported, in preclinical radiosensitization studies.

Principal Findings

NVP-AUY922 potently radiosensitized cells in vitro at low nanomolar concentrations with a concurrent depletion of radioresistance-linked client proteins. Radiosensitization by NVP-AUY922 was verified for the first time in vivo in a human head and neck squamous cell carcinoma xenograft model in athymic mice, as measured by delayed tumor growth and increased surrogate end-point survival (p = <0.0001). NVP-AUY922 was shown to ubiquitously inhibit resolution of dsDNA damage repair correlating to delayed Rad51 foci formation in all cell lines tested. Additionally, NVP-AUY922 induced a stalled mitotic phenotype, in a cell line-dependent manner, in HeLa and HN5 cell lines irrespective of radiation exposure. Cell cycle analysis indicated that NVP-AUY922 induced aberrant mitotic entry in all cell lines tested in the presence of radiation-induced DNA damage due to ubiquitous CHK1 depletion, but resultant downstream cell cycle effects were cell line dependent.

Conclusions

These results identify NVP-AUY922 as the most potent HSP90-mediated radiosensitizer yet reported in vitro, and for the first time validate it in a clinically relevant in vivo model. Mechanistic analysis at clinically achievable concentrations demonstrated that radiosensitization is mediated by the combinatorial inhibition of cell growth and survival pathways, ubiquitous delay in Rad51-mediated homologous recombination and CHK1-mediated G₂/M arrest, but that the contribution of cell cycle perturbation to radiosensitization may be cell line specific.

Oncolytic viruses in radiation oncology

Oncolytic viruses are investigational cancer treatments. They are currently being assessed as single agents or in combination with standard therapies such as external beam radiotherapy - a DNA damaging agent that is a standard of care for many tumour types. Preclinical data indicate that combinations of oncolytic viruses and radiation therapy are promising, showing additional or synergistic antitumour effects in in vitro and in vivo studies. This interaction has the potential to be multifaceted: viruses may act as radiosensitizing agents, but radiation may also enhance viral oncolysis by increasing viral uptake, replication, gene expression and cell death (apoptosis, autophagy or necrosis) in irradiated cells. Phase I and II clinical trials investigating combinations of viruses and radiation therapy have been completed, paving the way for ongoing phase III studies. The aim of this review is to focus on the therapeutic potential of these combinations and to highlight their mechanistic bases, with particular emphasis on the role of the DNA damage response.

Oncolytic vaccinia virus as a vector for therapeutic sodium iodide symporter gene therapy in prostate cancer

Oncolytic strains of vaccinia virus are currently in clinical development with clear evidence of safety and promising signs of efficacy. Addition of therapeutic genes to the viral genome may increase the therapeutic efficacy of vaccinia. We evaluated the therapeutic potential of vaccinia virus expressing the sodium iodide symporter (NIS) in prostate cancer models, combining oncolysis, external beam radiotherapy and NIS-mediated radioiodide therapy. The NIS-expressing vaccinia virus (VV-NIS), GLV-1h153, was tested in in vitro analyzes of viral cell killing, combination with radiotherapy, NIS expression, cellular radioiodide uptake and apoptotic cell death in PC3, DU145, LNCaP and WPMY-1 human prostate cell lines. In vivo experiments were carried out in PC3 xenografts in CD1 nude mice to assess NIS expression and tumor radioiodide uptake. In addition, the therapeutic benefit of radioiodide treatment in combination with viral oncolysis and external beam radiotherapy was measured. In vitro viral cell killing of prostate cancers was dose- and time-dependent and was through apoptotic mechanisms. Importantly, combined virus therapy and iodizing radiation did not adversely affect oncolysis. NIS gene expression in infected cells was functional and mediated uptake of radioiodide both in vitro and in vivo. Therapy experiments with both xenograft and immunocompetent Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mouse models showed that the addition of radioiodide to VV-NIS-infected tumors was more effective than each single-agent therapy, restricting tumor growth and increasing survival. In conclusion, VV-NIS is effective in prostate cancer models. This treatment modality would be an attractive complement to existing clinical radiotherapy practice.

Beta human chorionic gonadotropin concentrations in serum of patients with pancreatic adenocarcinoma

BACKGROUND

Human chorionic gonadotropin (hCG) is normally produced and secreted by trophoblastic cells during pregnancy and from gestational trophoblastic neoplasms. It is also detected in ovarian, stomach, and colon adenocarcinomas, as well as in squamous cell carcinoma of the oesophagus. Recently, interest in its role in the pathogenesis of tumours has been enlivened after the presence of beta hCG in the cell membrane of several malignant cells was shown in vitro.

AIMS

To investigate the circulating concentrations of beta hCG in patients with exocrine pancreatic adenocarcinoma and to examine its potential prognostic value.

PATIENTS

Thirty six patients with exocrine pancreatic adenocarcinoma, 12 patients with chronic pancreatitis, and 21 healthy volunteers were studied.

METHODS

beta hCG serum concentrations were detected by the application of a radioimmunoassay technique.

RESULTS

Fifteen of 36 patients with pancreatic adenocarcinoma and only one patient with chronic pancreatitis had detectable plasma concentrations of beta hCG (p < 0.01). The patients with circulating serum titres of beta hCG had a worse outcome compared with the group of beta hCG negative patients: the difference was statistically significant (p = 0.01).

CONCLUSION

More than 40% of pancreatic exocrine tumours produce beta hCG and its production is correlated with an adverse effect on outcome.

Human Papillomavirus-Negative Pharyngeal Cancer

Human papillomavirus-negative head and neck squamous cell carcinoma (HNSCC) carries a poor prognosis, and despite optimal treatment with chemoradiotherapy to the limit of tolerance, many patients will relapse. A number of methods for intensifying treatment of HNSCC have been investigated, leading to the current standards of care. Novel agents targeting tumor cell and stromal signaling, DNA damage response, and immune system are now reaching clinical trials in combination with chemoradiotherapy. In this review, we discuss the evidence for the current treatment of locally advanced human papillomavirus-negative HNSCC, as well as investigational therapies, such as hypoxia modification, molecular targeting of epidermal growth factor receptor family, vascular endothelial growth factor receptor or DNA damage response proteins in combination with radiation therapy.

Intensity Modulated Radiotherapy (IMRT) in locally advanced thyroid cancer: Acute toxicity results of a phase I study

BACKGROUND AND PURPOSE

This phase 1 study was designed to determine the toxicity of accelerated fractionation IMRT in locally advanced thyroid cancer.

METHODS

Patients with high risk locally advanced thyroid cancer who required post-operative EBRT were recruited. A single-phase inverse-planned-simultaneous-boost was delivered by IMRT: 58.8 Gy/28F (daily) to the primary tumour and involved nodes and 50 Gy/28F to the elective nodes. Acute (NCICTCv.2.0) and late toxicity (RTOG and modified LENTSOM) was collected.

RESULTS

Thirteen patients were treated (7 medullary thyroid, 2 Hurthle cell and 4 well differentiated thyroid cancer). G3 and G2 radiation dermatitis rates were 38.5% and 31%; G3 and G2 mucositis rates 8% and 53% and G3 and G2 pain 23% and 54%. Thirty-one percentage required enteral feeding. G3 and G2 xerostomia rates were 0% and 31%. Recovery was seen, with 62% patients having dysphagia G< or =1 2 months after IMRT. Thirty percent of patients developed L'Hermitte's syndrome. No grade 4 toxicity was observed. No dose limiting toxicity was found.

CONCLUSIONS

Accelerated fractionation IMRT in this group of patients is feasible and safe. The acute toxicity appeared acceptable and early indicators of late toxicity moderate and similar to what would be expected with conventional RT. Longer follow up is required to quantify late side effects.

Pre-trial quality assurance processes for an intensity-modulated radiation therapy (IMRT) trial: PARSPORT, a UK multicentre Phase III trial comparing conventional radiotherapy and parotid-sparing IMRT for locally advanced head and neck cancer

The purpose of this study was to compare conventional radiotherapy with parotid gland-sparing intensity-modulated radiation therapy (IMRT) using the PARSPORT trial. The validity of such a trial depends on the radiotherapy planning and delivery meeting a defined standard across all centres. At the outset, many of the centres had little or no experience of delivering IMRT; therefore, quality assurance processes were devised to ensure consistency and standardisation of all processes for comparison within the trial. The pre-trial quality assurance (QA) programme and results are described. Each centre undertook exercises in target volume definition and treatment planning, completed a resource questionnaire and produced a process document. Additionally, the QA team visited each participating centre. Each exercise had to be accepted before patients could be recruited into the trial. 10 centres successfully completed the quality assurance exercises. A range of treatment planning systems, linear accelerators and delivery methods were used for the planning exercises, and all the plans created reached the standard required for participation in this multicentre trial. All 10 participating centres achieved implementation of a comprehensive and robust IMRT programme for treatment of head and neck cancer.

A phase I study of dose-escalated chemoradiation with accelerated intensity modulated radiotherapy in locally advanced head and neck cancer

BACKGROUND AND PURPOSE

Intensity modulated radiotherapy (IMRT) allows the delivery of higher and more homogeneous radiation dose to head and neck tumours. This study aims to determine the safety of dose-escalated chemo-IMRT for larynx preservation in locally advanced head and neck cancer.

METHODS

Patients with T2-4, N1-3, M0 squamous cell carcinoma of the larynx or hypopharynx were treated with a simultaneous-boost IMRT. Two radiation dose levels (DL) were tested: In DL 1, 63 Gy/28F was delivered to primary tumour and involved nodes and 51.8 Gy/28F to elective nodes. In DL 2, the doses were 67.2 Gy/28F and 56 Gy/28F, respectively, representing a 9% dose escalation for the primary. All patients received 2 cycles of neoadjuvant cisplatin and 5-fluorouracil, and concomitant cisplatin. Acute (NCICTCv.2.0) and late toxicity (RTOG and modified LENTSOM) were collected.

RESULTS

Thirty patients were entered, 15 in each dose level. All patients completed the treatment schedule. In DL 1, the incidences of acute G3 toxicities were 27% (pain), 20% (radiation dermatitis), 0% (xerostomia) and 67% required gastrostomy tubes. For DL 2 the corresponding incidences were 40%, 20%, 7%, and 87%. G3 dysphagia and pain persisted longer in DL 2. With regard to mucositis, a prolonged healing time for DL 2 was found, with prevalence of G2 of 58% in week 10. No acute grade 4 toxicity was observed. At 6 months, 1 patient in DL 2 had G3 late toxicity (dysphagia). No dose limiting toxicity was found. Complete response rates were 80% in DL 1, and 87% in DL 2.

CONCLUSION

Moderately accelerated chemo-IMRT is safe and feasible with good compliance and acceptable acute toxicity. Dose escalation was possible without a significant difference in acute toxicity. Longer follow-up is required to determine the incidence of late radiation toxicities, and tumour control rates.

Targeted radiosensitization by the Chk1 inhibitor SAR-020106

PURPOSE

To explore the activity of a potent Chk1 inhibitor (SAR-020106) in combination with radiation.

METHODS AND MATERIALS

Colony and mechanistic in vitro assays and a xenograft in vivo model.

RESULTS

SAR-020106 suppressed-radiation-induced G2/M arrest and reduced clonogenic survival only in p53-deficient tumor cells. SAR-020106 promoted mitotic entry following irradiation in all cell lines, but p53-deficient cells were likely to undergo apoptosis or become aneuploid, while p53 wild-type cells underwent a postmitotic G1 arrest followed by subsequent normal cell cycle re-entry. Following combined treatment with SAR-020106 and radiation, homologous-recombination-mediated DNA damage repair was inhibited in all cell lines. A significant increase in the number of pan-γH2AX-staining apoptotic cells was observed only in p53-deficient cell lines. Efficacy was confirmed in vivo in a clinically relevant human head-and-neck cell carcinoma xenograft model.

CONCLUSION

The Chk1 inhibitor SAR-020106 is a potent radiosensitizer in tumor cell lines defective in p53 signaling.

Potentiating Oncolytic Virus-Induced Immune-Mediated Tumor Cell Killing Using Histone Deacetylase Inhibition

A clinical oncolytic herpes simplex virus (HSV) encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), talimogene laherparepvec, causes regression of injected and non-injected melanoma lesions in patients and is now licensed for clinical use in advanced melanoma. To date, limited data are available regarding the mechanisms of human anti-tumor immune priming, an improved understanding of which could inform the development of future combination strategies with improved efficacy. This study addressed direct oncolysis and innate and adaptive human immune-mediated effects of a closely related HSV encoding GM-CSF (HSVGM-CSF) alone and in combination with histone deacetylase inhibition. We found that HSVGM-CSF supported activation of anti-melanoma immunity via monocyte-mediated type I interferon production, which activates NK cells, and viral maturation of immature dendritic cells (iDCs) into potent antigen-presenting cells for cytotoxic T lymphocyte (CTL) priming. Addition of the histone deacetylase inhibitor valproic acid (VPA) to HSVGM-CSF treatment of tumor cells increased viral replication, viral GM-CSF production, and oncolysis and augmented the development of anti-tumor immunity. Mechanistically, VPA increased expression of activating ligands for NK cell recognition and induced expression of tumor-associated antigens, supporting innate NK cell killing and CTL priming. These data support the clinical combination of talimogene laherparepvec with histone deacetylase inhibition to enhance oncolysis and anti-tumor immunity.

Treatment-related dysgeusia in head and neck cancer patients

Head and neck cancer patients treated with radiotherapy and/or chemotherapy agents may develop altered taste acuity. This, together with radiation induced xerostomia and dysphagia, is a major contributory factor to the anorexia and concomitant morbidity often seen in this group of patients. This paper examines the existing literature in order to assess the prevalence of clinician and patient-reported dysgeusia in HNC patients undergoing oncological treatment. We also describe the temporal manifestations of the same and its reported impact on QOL.

Phase I trial of cyclophosphamide as an immune modulator for optimizing oncolytic reovirus delivery to solid tumors

PURPOSE

Reovirus is a wild-type oncolytic virus that is ubiquitous in the environment; most patients are therefore preimmune. Therapeutic administration leads to an increase in neutralizing antireovirus antibody (NARA) titer. We hypothesized that if NARA limited reovirus antitumor activity, the effect might be attenuated by coadministration of cyclophosphamide.

EXPERIMENTAL DESIGN

In a phase I study, patients with advanced cancer received cyclophosphamide 3 days before intravenous reovirus serotype 3 Dearing (RT3D). The primary objective was to reduce the resulting rise in NARA titer. Cyclophosphamide dose was escalated from 25-1,000 mg/m(2) through nine cohorts; we aimed to define a well-tolerated immunomodulatory dose.

RESULTS

The combination was well tolerated in 36 patients, with grade 3/4 toxicities only seen at or above the maximum tolerated dose of cyclophosphamide, which was 800 mg/m(2) combined with reovirus. Immunosuppressive effect, defined as maintaining NARA titer rise below a predefined threshold, was observed in only one patient. Furthermore, despite expected myelosuppression seen at higher cyclophosphamide doses, no changes in T-cell subsets, including Tregs, occurred with dose escalation. Viable virus was detected in association with peripheral blood mononuclear cells (PBMC) from 14% of patients 10 days after the last RT3D injection, despite high plasma NARA titer, demonstrating a potential mechanism for prolonged evasion of neutralization by reovirus.

CONCLUSIONS

Coadministration of cyclophosphamide with reovirus is safe, but does not attenuate host antiviral responses. Alternative immunomodulation approaches should be explored, but association with PBMCs may allow reovirus to persist and evade even high levels of neutralizing antibodies.

Voice-related Quality of Life in Laryngectomees: Assessment Using the VHI and V-RQOL Symptom Scales

The primary purpose of this study was to investigate the effect of the voice impairment across the physical, emotional, and functional domains in patients using valved speech following total laryngectomy with the help of two symptom specific scales. The study design used was a cross-sectional cohort. The setting was the Head and Neck Oncology Unit of a tertiary referral centre. Subjects were 54 patients who had undergone total laryngectomy. Two voice-specific questionnaires, the Voice-Related Quality of Life (V-RQOL-short form) Measure, and the Voice Handicap Index (VHI-long form) were used. The main outcome measure was patient perception of the voice following total laryngectomy in response to specific questions correlated with sociodemographic/treatment factors. Responses were received from 40 males and 14 females (response rate of 85.7%) with a median age of 63.4 years (range: 37-84). The V-RQOL overall analysis showed that 3 patients (5.6%) scored "excellent," 29 patients (53.7%) "fair to good," 14 patients (25.9%) "poor to fair," and 8 patients (14.8%) "poor." Analysis of the VHI revealed that 20 patients (37.0%) had a minimal handicap, 20 patients (37.0%) a moderate handicap, and 14 patients (25.9%) had a serious voice handicap. The individual domain or subscale scores for the VHI revealed a mean (SD) functional score of 15.8 (7.7), a physical score of 13.6 (7.2), and finally an emotional score of 11.6 (8.9). Functional aspects of the voice were significantly affected by age, radiotherapy, and chemotherapy (Spearman rho, P=0.01; Mann-Whitney, P=0.04 and P=0.01). The physical aspects of the voice were significantly affected by age and chemotherapy (Spearman rho, P=0.004; Mann-Whitney, P=0.04). Only age significantly affected the emotional aspects of the voice (Spearman rho, P=0.002). We found a strong correlation (Spearman rho, P<0.001) between the V-RQOL and VHI questionnaires. Our study revealed that the V-RQOL and VHI scores in our series of patients following voice restoration in laryngectomees were consistent with that reported in the literature. Only age, radiation, and chemotherapy were seen to influence the voice handicap scores. In addition, both symptom scales had good correlation between them and either one could be used with reliability in laryngectomees with a few modifications.

The role of E-cadherin-catenin complex: more than an intercellular glue?

It is now widely recognized that alterations in the adhesion properties of neoplastic cells may play a pivotal role in the development and progression of the malignant phenotype in a range of tumor types. The cadherins and catenins, being the prime mediators of cell-cell adhesion, are intimately involved in the control of morphological differentiation and cellular proliferation; loss of their intercellular function allows malignant cells to escape from their site of origin, degrade the extracellular matrix, acquire a more motile and invasive phenotype, and, finally, invade and metastasize. In addition to participating in tumor invasiveness and metastasis, the E-cadherin-catenin complex is fundamental for the establishment and maintenance of multicellular organisms and regulates or significantly contributes to a variety of functions, including signal transduction, cell growth, differentiation, site-specific gene expression, morphogenesis, immunologic function, cell motility, wound healing, and inflammation. We reviewed the role of the E-cadherin-catenin complex in tumor development and presented the potential clinical applications of these molecules.

Transcriptional control: an essential component of cancer gene therapy strategies?

The therapeutic index of cancer gene therapy approaches will, at least in part, be dictated by the spatial and temporal control of expression of the therapeutic transgenes. Strategies which allow precise control of gene transcription are likely to play a crucial role in the future pre-clinical and clinical development of gene therapy. In this review, we discuss these issues as they relate to tissue and tumor specific promoters. In addition, the exciting opportunities offered by the development of regulated gene expression systems using small molecules, radiation and heat are reviewed. It is realistic to expect that the future offers the prospect of amalgamating elements of a number of these different systems in a co-ordinated gene delivery approach with the potential to increase the efficacy and reduce the toxicity of treatment.

Synergistic cytotoxicity of oncolytic reovirus in combination with cisplatin-paclitaxel doublet chemotherapy

Oncolytic reovirus is currently under active investigation in a range of tumour types. Early phase studies have shown that this agent has modest monotherapy efficacy and its future development is likely to focus on combination regimens with cytotoxic chemotherapy. Indeed, phase I/II clinical trials have confirmed that reovirus can be safely combined with cytotoxic drugs, including a platin-taxane doublet regimen, which is currently being tested in a phase III clinical trial in patients with relapsed/metastatic head and neck cancer. Therefore, we have tested this triple (reovirus, cisplatin, paclitaxel) combination therapy in a panel of four head and neck cancer cell lines. Using the combination index (CI) method, the triple therapy demonstrated synergistic cytotoxicity in vitro in both malignant and non-malignant cell lines. In head and neck cancer cell lines, this was associated with enhanced caspase 3 and 7 cleavage, but no increase in viral replication. In vitro analyses confirmed colocalisation of markers of reovirus infection and caspase 3. Triple therapy was significantly more effective than reovirus or cisplatin-paclitaxel in athymic nude mice. These data suggest that the combination of reovirus plus platin-taxane doublet chemotherapy has significant activity in head and neck cancer and underpin the current phase III study in this indication.

Nivolumab versus investigator's choice in patients with recurrent or metastatic squamous cell carcinoma of the head and neck: Efficacy and safety in CheckMate 141 by age

OBJECTIVES

Many patients with squamous cell carcinoma of the head and neck (SCCHN) are ≥65 years old; comorbidities and other age-related factors may affect their ability to tolerate traditional chemotherapy. Nivolumab is the only immunotherapy to significantly improve overall survival (OS) versus investigator's choice (IC) of single-agent chemotherapy at primary analysis in a phase 3 trial (CheckMate 141) in patients with recurrent/metastatic SCCHN post-platinum therapy. In this post hoc analysis, we report efficacy and safety by age.

PATIENTS AND METHODS

Eligible patients were randomized 2:1 to nivolumab 3 mg/kg every 2 weeks (n = 240) or IC (methotrexate, docetaxel, or cetuximab n = 121). The primary endpoint of the trial was OS. For this analysis, outcomes were analyzed by age < 65 and ≥65 years. The data cut-off date was September 2017 (minimum follow-up 24.2 months).

RESULTS

At baseline, 68 patients (28.3%) receiving nivolumab and 45 patients (37.2%) receiving IC were ≥65 years. Baseline characteristics were generally similar across age groups. OS and tumor response benefits with nivolumab versus IC were maintained regardless of age. The 30-month OS rates of 11.2% (<65 years) and 13.0% (≥65 years) with nivolumab were more than tripled versus corresponding IC rates of 1.4% and 3.3%, respectively. The nivolumab arm had a lower rate of treatment-related adverse events versus IC regardless of age, consistent with the overall patient population.

CONCLUSION

In CheckMate 141, nivolumab resulted in a higher survival versus IC in patients <65 and ≥65 years, with a manageable safety profile in both age groups. ClinicalTrials.gov: NCT02105636.