Therapeutic HDAC inhibition in hypermutant diffuse intrinsic pontine glioma

Constitutional mismatch repair deficiency (CMMRD) is a cancer predisposition syndrome associated with the development of hypermutant pediatric high-grade glioma, and confers a poor prognosis. While therapeutic histone deacetylase (HDAC) inhibition of diffuse intrinsic pontine glioma (DIPG) has been reported; here, we use a clinically relevant biopsy-derived hypermutant DIPG model (PBT-24FH) and a CRISPR-Cas9 induced genetic model to evaluate the efficacy of HDAC inhibition against hypermutant DIPG. We screened PBT-24FH cells for sensitivity to a panel of HDAC inhibitors (HDACis) in vitro, identifying two HDACis associated with low nanomolar IC50s, quisinostat (27 nM) and romidepsin (2 nM). In vivo, quisinostat proved more efficacious, inducing near-complete tumor regression in a PBT-24FH flank model. RNA sequencing revealed significant quisinostat-driven changes in gene expression, including upregulation of neural and pro-inflammatory genes. To validate the observed potency of quisinostat in vivo against additional hypermutant DIPG models, we tested quisinostat in genetically-induced mismatch repair (MMR)-deficient DIPG flank tumors, demonstrating that loss of MMR function increases sensitivity to quisinostat in vivo. Here, we establish the preclinical efficacy of quisinostat against hypermutant DIPG, supporting further investigation of epigenetic targeting of hypermutant pediatric cancers with the potential for clinical translation. These findings support further investigation of HDAC inhibitors against pontine high-grade gliomas, beyond only those with histone mutations, as well as against other hypermutant central nervous system tumors.

IMMU-09. Interim analysis from BrainChild-03: Seattle Children’s Locoregional B7-H3 CAR T Cell Trial for Children with Recurrent Central Nervous System Tumors and DIPG

BrainChild-03 is a phase 1 clinical trial delivering repeated locoregional 2nd generation B7-H3 CAR T cells with 4-1BB co-stimulation to children with central nervous system (CNS) tumors without lymphodepleting chemotherapy. The primary endpoints are feasibility and safety, with secondary endpoints of disease response and correlatives of CAR T cell activity. There are 3 arms: (A) – weekly delivery into the tumor cavity, (B) – weekly delivery into the lateral ventricle for metastatic disease, (C) – biweekly delivery into the lateral ventricle for diffuse intrinsic pontine glioma (DIPG). In total, 23/24 (96%) enrolled patients have had successful CAR T manufacturing. 16/24 patients are evaluable and have received a total of 141 intracranial CAR T cell doses. Unevaluable patients include 5 never treated and 3 who progressed prior to receiving the minimum doses to become evaluable. The most common adverse events have been headache (16/16, 100%), nausea/vomiting (12/16, 75%), and fever (10/16, 63%). There has been 1 DLT for an intratumoral hemorrhage and no cytokine release syndrome (CRS). 7 evaluable patients with DIPG (Arm C) have received a cumulative 50 infusions. 5/7 DIPG patients enrolled after progression and have a median survival of 246.5 days post-initial CAR T cell infusion, with 4/5 still alive. The 2 DIPG patients enrolled prior to progression had radiographic improvement, including 1 with improvement of a cranial nerve 6 palsy who self-withdrew from protocol therapy after 18 infusions over 12 months and 1 still on protocol therapy after 11 infusions over 6 months. DIPG patients have had increased CSF levels of proinflammatory mediators (e.g. CXCL10, CCL2, IFNg, GM-CSF, IL-12) without systemic cytokine changes. 5/7 DIPG patients had detectable CAR T cells in their CSF post-infusion. Ultimately, the preliminary experience suggests locoregional delivery of B7-H3 CAR T cells may be feasible and tolerable in children with CNS tumors, including DIPG.

DIPG-58. Therapeutic HDAC targeting in hypermutant CNS tumors

Diffuse intrinsic pontine glioma (DIPG) is a universally fatal tumor of the pons, most often characterized by mutations in genes encoding histone 3, that led to the classification diffuse midline glioma, H3 K27M-mutant (DMG). However, 15% of DIPG are histone wildtype (H3WT) and can have a hypermutant phenotype, characterized by mutations in DNA mismatch repair that also occur in pediatric high-grade glioma (pHGG). We previously published the preclinical efficacy of quisinostat in DMG. As hypermutant CNS tumors share transcriptional disruption with DMG, we investigated if HDAC inhibition was also therapeutic against hypermutant DIPG and pHGG. We tested PBT-24, a PMS2 mutant, treatment-naïve, patient-derived hypermutant DIPG model, and found similar quisinostat sensitivity compared to other DMG cultures in vitro (IC50 = ~30 nM), as well as significant efficacy in a xenograft flank model (60 day mean tumor size of 1109mm3 [vehicle] vs. 19mm3 [quisinostat-treated]). This in vivo effect was greater than the anti-tumor effect observed in a xenograft flank non-hypermutant DMG model PBT-09 (60 day mean tumor size of 1006mm3 [vehicle] vs. 244mm3 [quisinostat-treated]). To validate the effect of hypermutation on sensitivity to quisinostat, we generated PMS2 knock-out (KO) and MSH2 KO isogenic cell lines using the H3WT model VUMC-DIPG-10. In a xenograft flank model, we observed increased quisinostat sensitivity in the KO models (20 day mean tumor volume of 547mm3 [parental], 396mm3 [PMS2 KO], and 150mm3 [MSH2 KO]). RNA sequencing of quisinostat-treated PBT-24 revealed an increase in acute inflammatory response genes which we are investigating as a mechanism of action for HDACi against hypermutant tumors. Ultimately, we demonstrate the in vivo efficacy of quisinostat against hypermutant DIPG that supports the investigation of HDAC inhibition as a treatment strategy across hypermutant CNS tumors.

Determination of total phenolic compounds in compost by infrared spectroscopy

Middle and near infrared (MIR and NIR) were applied to determine the total phenolic compounds (TPC) content in compost samples based on models built by using partial least squares (PLS) regression. The multiplicative scatter correction, standard normal variate and first derivative were employed as spectra pretreatment, and the number of latent variable were optimized by leave-one-out cross-validation. The performance of PLS-ATR-MIR and PLS-DR-NIR models was evaluated according to root mean square error of cross validation and prediction (RMSECV and RMSEP), the coefficient of determination for prediction (Rpred(2)) and residual predictive deviation (RPD) being obtained for this latter values of 5.83 and 8.26 for MIR and NIR, respectively.

A phase II and pharmacodynamic study of sunitinib in relapsed/refractory oesophageal and gastro-oesophageal cancers

BACKGROUND

Blockade of the vascular endothelial growth factor (VEGF) pathway shows evidence of activity in gastro-oesophageal (GE) and oesophageal cancer. We investigated the efficacy of sunitinib, a multikinase VEGF inhibitor, in patients with relapsed/refractory GE/oesophageal cancer.

METHODS

This was a single-stage Fleming phase II study. The primary end point was progression-free survival (PFS) at 24 weeks. If five or more patients out of a total of 25 were free of progressive disease at 24 weeks, sunitinib would be recommended for further study. Patients received sunitinib 37.5 mg orally daily and imaged every 6 weeks. Exploratory correlative analysis included serum growth factors, tumour gene expression and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

RESULTS

Twenty-five evaluable patients participated in the study. Progression-free survival at 24 weeks was 8% (n=2 patients; confidence interval (CI): 95% 1.4-22.5%), and the duration of best response for the patients was 23 and 72 weeks. Ten patients (42%) had stable disease (SD) for >10 weeks. Overall response rate is 13%. Median PFS is 7 weeks (95% CI: 5.6-11.4 weeks) and the median overall survival is 17 weeks (95% CI: 8.9-25.3 weeks). Most common grade 3/4 toxicities included fatigue (24%), anaemia (20%) thrombocytopenia (16%), and leucopenia (16%). No patients discontinued therapy due to toxicity. Serum VEGF-A and -C levels, tumour complement factor B (CFB) gene expression, and DCE-MRI correlated with clinical benefit, defined as SD or better as best response.

CONCLUSION

Sunitinib is well tolerated but only a select subgroup of patients benefited. Serum VEGF-A and -C may be early predictors of benefit. On this study, patients with clinical benefit from sunitinib had higher tumour CFB expression, and thus has identified CFB as a potential predictor for efficacy of anti-angiogenic therapy. These findings need validation from future prospective trials.

Preliminary results on the use of leather chrome shavings for air passive sampling

A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler(-1) and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and results were compared with those obtained using empty LDPE tubes, to demonstrate the capacity of chrome shavings to adsorb VOCs.

Phase I study of high-dose interleukin (HD-IL2) and sorafenib in patients with metastatic clear cell renal cell carcinoma (RCC) and melanoma

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Background: HD-IL2 has demonstrated activity for immune therapy of RCC and melanoma. Sorafenib is a multitargeted kinase inhibitor with antiangiogenic activity and may also modulate antitumor immunity. This ongoing phase I study assesses the safety, tolerability, dose-limiting toxicity (DLT), and maximum tolerated dose of the combination of HD-IL2 and sorafenib in patients with unresectable or metastatic clear cell RCC and melanoma.

Methods: Eligible patients with ECOG PS 0-1, adequate organ function, and favorable or intermediate Motzer status (RCC patients) received up to two series of therapy. Each 82-day series consisted of two cycles of bolus HD-IL2 and 8 weeks of sorafenib. HD-IL2 (600,000 IU/kg IV q8h x 8-12 doses) was given on days 1-5 (cycle 1) and 15-20 (cycle 2). Sorafenib was given on days 29-82 and discontinued 48-72 hours prior to the next series. Dosing levels for sorafenib were (1) 200mg daily, (2) 200mg BID, (3) 200mg qAM and 400mg qPM, and (4) 400mg BID. Patients who achieved stable disease (SD), partial response (PR), or complete response (CR) after Series 1 proceeded to Series 2.

Results: Fourteen patients (8 RCC, 6 melanoma) have been treated. Nine patients completed Series 1 (5 patients came off study due to poor tolerance of HD-IL2, prior to receiving sorafenib). Six patients had SD or better (3 PR, 3 SD) after Series 1. Of these, five have completed Series 2 and one patient progressed during sorafenib treatment in the second series. No DLTs were observed at the first 3 dose levels. All observed grade 3 and 4 AEs were transient and attributable to the known toxicities of HD-IL2 or sorafenib, and were not considered DLT. Adverse events occurring more frequently in Series 2 (HD-IL2 after sorafenib) included proteinuria and dry skin. One death occurred in a patient with melanoma who received only the first cycle of HD- IL2 (never received sorafenib) and one week later experienced sudden death at home, an event reported as possibly related to the HD-IL2.

Conclusions: No DLT was seen in this study of HD-IL2 and sorafenib and the toxicity was predictable and manageable. Both RCC and melanoma patients experienced PR and SD, but not CR. Enrollment to cohort 4 is ongoing.

[Table: see text]

Phase I trial of gene-mediated cytotoxic immunotherapy in combination with chemoradiation for locally advanced pancreatic cancer

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Background: More than 80% of patients with pancreatic cancer present with locally advanced or metastatic disease and have a median survival of only 6 months. Immunotherapy approaches may improve outcomes. Gene Mediated Cytotoxic Immunotherapy (GMCI) is an approach that generates a systemic anti-tumor vaccine effect through intra-tumoral delivery of an adenoviral vector expressing the HSV-thymidine kinase gene (AdV-tk) followed by anti-herpetic prodrug and synergy with chemoradiation. The mechanisms of action involve tumor cytotoxicity, activation of antigen presenting cells and stimulation of systemic anti-tumor T-cell immunity. Safety with potential efficacy has been demonstrated in multiple clinical studies. This is the first application of GMCI in pancreatic cancer.

Methods: This study evaluated 4 dose levels of AdV-tk (3x1010 to 1x1012 vector particles) injected into locally advanced tumors via EUS or CT-guidance before and during week 3 of standard 5-FU-chemoradiation. Valacyclovir (Valtrex, GSK) prodrug was given for 14 days after each of 2 AdV-tk injections.

Results: The study completed accrual with 13 patients enrolled and 12 completing therapy with 3 at each of the 4 dose levels. One patient refused further participation during course 1 after recovering from azotemia. Median age was 64 years (range 55-81) and median baseline CA19-9 was 1634 U/ml. No dose limiting toxicities and no injection related complications occurred. Possibly related grade 3-4 toxicities, all of which were transient, included dehydration, azotemia and worsening elevation of bilirubin and AST. Kaplan-Meier estimated median survival is 12.2 months with 6 patients still alive at 8-20 months. Two patients achieved a partial response by RECIST criteria. One occurred in week 6 despite discontinuing 5-FU/radiation during week 1. The other had gradual decrease of a 7 cm tumor over 11 months. Serum CA19-9 levels decreased in 8/8 evaluable patients by 32-91% at 3 months after treatment initiation.

Conclusions: AdV-tk can be safely injected into pancreatic tumors and combined with standard chemoradiation. Early results are highly encouraging and justify further evaluation in a phase II study.

[Table: see text]

Separation of motor oils, oily wastes and hydrocarbons from contaminated water by sorption on chrome shavings

In this paper, the ability of chrome shavings to remove motor oils, oily wastes and hydrocarbons from water has been studied. To determine amount of hydrocarbons sorbed on tanned wastes, a FT-NIR methodology was used and a multivariate calibration based on partial least squares (PLS) was employed for data treatment. The light density, porous tanned waste granules float on the surface of water and remove hydrocarbons and oil films. Wastes fibers from tannery industry have high sorption capacity. These tanned solid wastes are capable of absorbing many times their weight in oil or hydrocarbons (6.5-7.6g of oil and 6.3g of hydrocarbons per gram of chrome shavings). The removal efficiency of the pollutants from water is complete. The sorption of pollutants is a quasi-instantaneous process.

Thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned solid wastes with calcium hydroxide

The thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned wastes with Ca(OH)2 was studied. Ashes obtained after incineration of wastes at various temperatures were analysed by X-ray diffraction and EDX method. The main crystallized phases present in the ash obtained at 600 degrees C are Cr2O3 and NaCl. The diffractograms revealed an increase in the intensities of the chromium oxide peaks and a very notable decrease of the amount of sodium chloride at 1100 degrees C. EDX analysis revealed a total disappearance of the chlorine peak at this temperature. Scanning electron micrographs show that the waste lost its fibrous aspect when the temperature increases. Formation of aggregates was noted after 550 degrees C. Combustion of organic matters and decarbonation phenomenon are the main stages observed on GTA and DTA curves of sludges. These phenomena are, respectively, exothermic and endothermic. The diffractogram of sludges recorded at 550 degrees C, in the presence of a constant oxygen surplus, revealed the presence of CaCrO4 and CaCO3.

Partial least-squares near-infrared determination of hydrocarbons removed from polluted waters by using tanned solid wastes

A new procedure has been developed for the determination of hydrocarbons retained in solid tanned wastes from polluted waters. The method uses near-infrared (NIR) transmission spectra obtained from leachates of the hydrocarbons with CCl4 using a partial least-squares (PLS) calibration model based on the use of mixtures of n-hexane, isooctane, and toluene diluted with CCl4. This methodology was applied to the evaluation of the absorption capacity of chrome shavings in water samples polluted with hydrocarbons, resulting in a maximum absorption capacity of 6.30 g hydrocarbons per g solid waste.

[Arterial blood pressure in Moroccan children and adolescents]

To develop blood pressure reference values for Maroccan children, a survey was carried out in 1987-88 in a group of 10,000 children 4 to 18 years of age. Study subjects were randomly selected among schoolchildren from the Great Casablanca Wilaya. There were 4,818 boys and 5,182 girls. To ensure optimal reliability of data, a precise, standardized methodology was used; blood pressure was measured in the supine position after at least five minutes rest, two cuffs of different sizes were available and selected according to age and body weight, and diastolic blood pressure was defined as Korotkow phase V. Distribution of blood pressure values was studied by age, sex and stature. Results were expressed as means +/- standard deviations and as percentiles. Blood pressure values were found to increase gradually with age, with sex-specific variations. Values were higher in post-pubertal girls. A linear positive correlation between arterial blood pressure and stature was found. This correlation was stronger than the blood pressure-age correlation. These data were compared with previous reports in the literature, although this analysis proved difficult because of variations in methods and results across studies.