Local radiotherapy and E7 RNA-LPX vaccination show enhanced therapeutic efficacy in preclinical models of HPV16+ cancer

Human papilloma virus (HPV) infection is a causative agent for several cancers types (genital, anal and head and neck region). The HPV E6 and E7 proteins are oncogenic drivers and thus are ideal candidates for therapeutic vaccination. We recently reported that a novel ribonucleic acid lipoplex (RNA-LPX)-based HPV16 vaccine, E7 RNA-LPX, mediates regression of mouse HPV16+ tumors and establishes protective T cell memory. An HPV16 E6/E7 RNA-LPX vaccine is currently being investigated in two phase I and II clinical trials in various HPV-driven cancer types; however, it remains a high unmet medical need for treatments for patients with radiosensitive HPV16+ tumors. Therefore, we set out to investigate the therapeutic efficacy of E7 RNA-LPX vaccine combined with standard-of-care local radiotherapy (LRT). We demonstrate that E7 RNA-LPX synergizes with LRT in HPV16+ mouse tumors, with potent therapeutic effects exceeding those of either monotherapy. Mode of action studies revealed that the E7 RNA-LPX vaccine induced high numbers of intratumoral-E7-specific CD8+T cells, rendering cold tumors immunologically hot, whereas LRT primarily acted as a cytotoxic therapy, reducing tumor mass and intratumor hypoxia by predisposing tumor cells to antigen-specific T cell-mediated killing. Overall, LRT enhanced the effector function of E7 RNA-LPX-primed T cell responses. The therapeutic synergy was dependent on total radiation dose, rather than radiation dose-fractionation. Together, these results show that LRT synergizes with E7 RNA-LPX and enhances its anti-tumor activity against HPV16+ cancer models. This work paves into a new translational therapy for HPV16+ cancer patients.

Determination of Monitor Doses in Neutron Therapy Using the U-120 Cyclotron

Purpose Analyze the various methods for determining the monitor doses in neutron therapy using the U-120 cyclotron and to choose the monitoring method that provides the highest accuracy in dose delivery to the tumor. Material and methods The distributions of the absorbed dose of the therapeutic beam from the U-120 cyclotron were measured in a tissue-equivalent medium using the differential method, in which two ionization chambers with different sensitivity to neutron radiation were used. A comparison of radiation effects on tissues using various techniques of determining the monitor doses was made. The linear-quadratic model was used to assess responses to ionizing radiation. Results Dosimetry studies revealed that the therapeutic beam of the U-120 cyclotron contains concomitant gamma radiation, the contribution of which to the total neutron-photon dose increases with increasing depth of the irradiated medium. The presence of gamma radiation in the neutron beam dictate the need to find the correct method for monitoring neutron therapy. A comparison of radiation effects on the tumor tissue using different techniques of determining the monitor doses was made. It was found that at equal neutron-photon doses, the neutron dose in the tumor changed depending on its depth. It can lead to an incorrect conclusion about the effectiveness of neutron therapy depending on a single dose as well as in relation to various dose fractionation schedules. Conclusion The analysis of the results obtained showed that the problem can be most accurately solved using a technique in which the monitor coefficient and monitor doses are determined from the distribution of the neutron dose, taking into account the contribution of the gamma radiation dose to the total neutron-photon dose.

Pharmacokinetics and Pharmacodynamics of Vancomycin derivative LYSC98 in a Murine Thigh Infection Model against Staphylococcus aureus

LYSC98 is a vancomycin derivative used for gram-positive bacterial infections therapy. We reported the pharmacokinetic/pharmacodynamic (PK/PD) targets of LYSC98 against Staphylococcus aureus using a murine thigh infection model. Three Staphylococcus aureus strains were utilized. Single-dose plasma pharmacokinetics of LYSC98 were determined in infected mice after the tail vein injection of 2, 4, and 8mg/kg. The results showed maximum plasma concentration (Cmax) 11466.67 -48866.67 ng/mL, area under the concentration-time curve from 0 to 24 h(AUC0-24) 14788.42 -91885.93 ng/mL·h, and elimination half-life(T1/2) 1.70-2.64 h, respectively. The Cmax (R2 0.9994) and AUC0-24 (R2 0.981) were positively correlated with the dose of LYSC98 in the range of 2-8 mg/kg. Dose fractionation studies using total doses of 2 to 8 mg/kg administered with q6h, q8h, q12h, and q24h were performed to evaluate the correlation of different PK/PD indices with efficacy. Sigmoid model analysis showed Cmax/MIC (R2 0.8941) was the best PK/PD index to predict the efficacy of LYSC98. In the dose ranging studies, two Methicillin-resistant Staphylococcus aureus (MRSA) clinical strains were used to infect the mice and 2-fold-increasing doses (1 to 16 mg/kg) of LYSC98 were administered. The magnitude of LYSC98 Cmax/MIC associated with net stasis, 1, 2, 3 and 4 - log10 kill were 5.78, 8.17, 11.14, 15.85 and 30.58, respectively. The results of this study showed LYSC98 a promising antibiotic with in vivo potency against MRSA, and will help in the dose design of phase one study for LYSC98.

Radiation Proctitis: The Potential Role of Hyaluronic Acid in the Prevention and Restoration of Any Damage to the Rectal Mucosa among Prostate Cancer Patients Submitted to Curative External Beam Radiotherapy

Aim: To evaluate if hyaluronic acid reduces proctitis episodes with respect to corticosteroids in prostate cancer patients submitted to radical or adjuvant radiotherapy. Methods: A consecutive series of eligible patients received hyaluronic acid enemas as supportive care (experimental group, from January 2013 to June 2015). A historical group (control group), treated from October 2011 to December 2012, received beclomethasone dipropionate suppositories. We registered each patient’s data regarding acute and chronic proctitis. All patients were treated with static-intensity-modulated radiotherapy coupled to a daily set-up verification with orthogonal anterior–posterior/lateral X-ray pairs. Results: A total of 269 patients, 175 in the experimental group and 94 in the control group, was evaluated; 2 Gy/day (up to a total median dose of 80 Gy) and 2.7 Gy/day (up to a total median dose of 67.5 Gy) fractionation schemes were used for 216 and 53 patients, respectively. All patients had a good tolerance to radiotherapy, reporting no G3 or greater proctitis. No significant difference was reported concerning the total rate of proctitis between the two groups but only with respect to its grade: a higher G2 rate within the control group. There was no correlation between daily dose fractionation and toxicity grade. Conclusions: Hyaluronic acid enemas might be effective in reducing the severity of radiation proctitis.

A Method for Assessing the Risks of Complications in Chemoradiation Treatment of Squamous Cell Carcinoma of the Head and Neck

Background: More than 500,000 new cases of squamous cell carcinoma of the head and neck (SCCHN) are registered annually in the world. 7,036 new cases of the disease were registered in Ukraine during 2018, about 35% of patients did not live even a year from the date of diagnosis as a modern standard for the treatment of patients with inoperable locally advanced SCCHN, chemoradiation treatment in the classical dose fractionation mode with chemo modification with cisplatin is used by specialists. Objective: The objective of this study is to analyze the effectiveness of chemoradiation treatment with cisplatin and 5-fluorouracil in the treatment of patients with SCCHN using modern mathematical models. Methods: During the investigation we assessed the effectiveness of treatment in 108 patients with locally advanced SCCHN (stages III, IVa, IVb). The results of calculating the probabilities of complications were obtained using the method of multivariate classification based on the radial basis ANN. Results: Analyzing the groups with different methods of chemo modification, we can conclude that the method of chrono-modulated radiochemotherapy with 5-fluorouracil and the chemoradiation therapy with cisplatin were almost equal in efficiency, namely 77% and 73.5%, respectively (p=0.35). Conclusion: Using the chemoradiation therapy with 5-fluorouracil in the treatment of patients with low somatic status and elderly patients is more expedient in contrast to the methods using cisplatin. The advantage of selection of mentioned treatment method is also confirmed by the results of calculating the average complication risks using the method of multivariate classification based on a radial-basis neural network.

Treatment and outcome of intracranial ependymoma after first relapse in AIEOP 2 nd protocol

Background More than 40% of patients with intracranial ependymoma need a salvage treatment within 5 years after diagnosis, and no standard treatment is available as yet. We report the outcome after first relapse of 64 patients treated within the 2 nd AIEOP protocol. Methods We considered relapse sites and treatments ,i.e. various combinations of complete/incomplete surgery, if followed by standard or hypo-fractionated radiation(RT) ± chemotherapy(CT). Molecular analyses were available for 38/64 samples obtained at first diagnosis. Of the 64 cases, 55 were suitable for subsequent analyses. Results The median follow-up was 147 months after diagnosis, 84 after first relapse, 5-year EFS/OS were 26.2%/30.8% (median EFS/OS 13/32 months) after relapse. For patients with a local relapse(LR), the 5-year cumulative incidence of second LRs was 51.6%, with a 5-year event-specific probability of being LR-free of 40.0%. Tumor site/grade, need for shunting, age above/below 3 years, molecular subgroup at diagnosis, had no influence on outcomes. Due to variation in the RT dose/fractionation used and the subgroup sizes it was not possible to assess the impact of the different RT modalities. Multivariable analyses identified completion of surgery, absence of symptoms at relapse, and female sex as prognostically favorable. Tumors with a 1q gain carried a higher cumulative incidence of dissemination after first relapse. Conclusions Survival after recurrence was significantly influenced by symptoms and completeness of surgery. Only a homogeneous protocol with well posed, randomized questions could clarify the numerous issues, orient salvage treatment and ameliorate prognosis for this group of patients.

Transparency in Quality of Radiotherapy for Breast Cancer in the Netherlands: a National Registration of Radiotherapy-parameters

Background: Radiotherapy (RT) is part of the curative treatment of approximately 70% of breast cancer (BC) patients. Wide practice variation has been reported in RT dose, fractionation and its treatment planning for BC. To decrease this practice variation, it is essential to first gain insight into the current variation in RT treatment between institutes. This paper describes the development of the NABON Breast Cancer Audit-Radiotherapy (NBCA-R), a structural nationwide registry of BC RT data of all BC patients treated with at least surgery and RT.Methods: A working group consisting of representatives of the BC Platform of the Dutch Radiotherapy Society selected a set of RT parameters deemed to be surrogate outcome parameters. Two pilot studies were carried out in six RT institutes: First, data were manually entered into a secured web-based system, and second, data were entered using an automatic Digital Imaging and Communications in Medicine (DICOM) RT upload module.Results: The NBCA-R dataset was created by selecting RT parameters describing given dose, target volumes, coverage and homogeneity, and dose to organs at risk (OAR). Entering the data was made mandatory for all dutch RT departments. In the first pilot study (N=1093), quite some variation was already detected. Application of partial breast irradiation varied from 0%-17% between the 6 institutes and boost to the tumour bed from 26.5%-70.2%. For patients treated to the left breast or chest wall only, the average mean heart dose (MHD) varied from 0.80 Gy – 1.82 Gy; for patients treated to the breast/chest wall only, the average mean lung dose (MLD) varied from 2.06 Gy – 3.3 Gy. In the second pilot study 6 departments implemented the DICOM-RT upload module in daily practice. Anonymised data will be available for researchers via a FAIR (Findable, Accessible, Interoperable, Reusable) framework.Conclusions: We have developed a set of RT parameters and implemented registration for all dutch BC patients. With the use of an automated upload module registration burden will be minimized. Based on the data in the NBCA-R analyses of the practice variation will be done, with the ultimate aim to improve quality of BC RT. Trial registration: Retrospectively registered