Avasopasem manganese (GC4419) protects against cisplatin-induced chronic kidney disease: An exploratory analysis of renal metrics from a randomized phase 2b clinical trial in head and neck cancer patients

Head and neck squamous cell carcinoma (HNSCC) patients treated with high-dose cisplatin concurrently with radiotherapy (hdCis-RT) commonly suffer kidney injury leading to acute and chronic kidney disease (AKD and CKD, respectively). We conducted a retrospective analysis of renal function and kidney injury-related plasma biomarkers in a subset of HNSCC subjects receiving hdCis-RT in a double-blinded, placebo-controlled clinical trial (NCT02508389) evaluating the superoxide dismutase mimetic, avasopasem manganese (AVA), an investigational new drug. We found that 90 mg AVA treatment prevented a significant reduction in estimated glomerular filtration rate (eGFR) three months as well as six and twelve months after treatment compared to 30 mg AVA and placebo. Moreover, AVA treatment may have allowed renal repair in the first 22 days following cisplatin treatment as evidenced by an increase in epithelial growth factor (EGF), known to aid in renal recovery. An upward trend was also observed in plasma iron homeostasis proteins including total iron (Fe-blood) and iron saturation (Fe-saturation) in the 90 mg AVA group versus placebo. These data support the hypothesis that treatment with 90 mg AVA mitigates cisplatin-induced CKD by inhibiting hdCis-induced renal changes and promoting renal recovery.

Development of a hardened THz energy meter for use on the kilojoule-scale, short-pulse OMEGA EP laser

A highly adaptable and robust terahertz (THz) energy meter is designed and implemented to detect energetic THz pulses from high-intensity (>10¹⁸ W/cm²) laser-plasma interactions on the OMEGA EP. THz radiation from the laser driven target is detected by a shielded pyrometer. A second identical pyrometer is used for background subtraction. The detector can be configured to detect THz pulses in the 1 mm to 30 μm (0.3- to 10-THz) range and pulse energies from joules to microjoules via changes in filtration, aperture size, and position. Additional polarization selective filtration can also be used to determine the THz pulse polarization. The design incorporates significant radiation and electromagnetic pulse shielding to survive and operate within the OMEGA EP radiation environment. We describe the design, operational principle, calibration, and testing of the THz energy meter. The pyrometers were calibrated using a benchtop laser and show linear sensitivity to up to 1000 nJ of absorbed energy. The initial results from four OMEGA EP THz experiments detected up to ∼15μJ at the detector, which can correspond to hundreds of mJ depending on THz emission and reflection models.

A knock-on deuteron imager for measurements of fuel and hotspot asymmetry in direct-drive inertial confinement fusion implosions (invited)

A knock-on deuteron imager (KoDI) has been implemented to measure the fuel and hotspot asymmetry of cryogenic inertial confinement fusion implosions on OMEGA. Energetic neutrons produced by D-T fusion elastically scatter ("knock on") deuterons from the fuel layer with a probability that depends on ρR. Deuterons above 10 MeV are produced by near-forward scattering, and imaging them is equivalent to time-integrated neutron imaging of the hotspot. Deuterons below 6 MeV are produced by a combination of side scattering and ranging in the fuel, and encode information about the spatial distribution of the dense fuel. The KoDI instrument consists of a multi-penumbral aperture positioned 10-20 cm from the implosion using a ten-inch manipulator and a detector pack at 350 cm from the implosion to record penumbral images with magnification of up to 35×. Range filters and the intrinsic properties of CR-39 are used to distinguish different charged-particle images by energy along the same line of sight. Image plates fielded behind the CR-39 record a 10 keV x-ray image using the same aperture. A maximum-likelihood reconstruction algorithm has been implemented to infer the source from the projected penumbral images. The effects of scattering and aperture charging on the instrument point-spread function are assessed. Synthetic data are used to validate the reconstruction algorithm and assess an appropriate termination criterion. Significant aperture charging has been observed in the initial experimental dataset, and increases with aperture distance from the implosion, consistent with a simple model of charging by laser-driven EMP.

ROMAN: Reduction in oral mucositis with avasopasem manganese (GC4419)–Phase III trial in patients receiving chemoradiotherapy for locally advanced, nonmetastatic head and neck cancer

TPS6596

Background: Approximately 70% of patients receiving intensity-modulated radiotherapy (IMRT) plus cisplatin for locally advanced head and neck cancer (HNC) develop SOM, defined as WHO Grade 3 or 4, which limits patients' ability to eat solids (Gr 3) or liquids (Gr 4, requiring enteral nutrition). An RT-induced burst of superoxide initiates oral mucositis (OM) development. GC4419, a superoxide dismutase mimetic, interrupts this process by converting superoxide to H2O2. It showed promising reduction of SOM in a published open-label Phase 1b/2a trial (IJROBP 1 Feb 2018). In a subsequent randomized, double-blind placebo-controlled trial in 223 patients receiving IMRT/cisplatin for HNC (ASCO 2018), 90 mg of GC4419 administered M-F prior to IMRT demonstrated statistically significant reduction in SOM duration (p=0.024, median 1.5 days @ 90 mg vs. 19 days placebo) and meaningful reductions @ 90 mg in SOM incidence (43% vs. 65%) and severity (incidence of Grade 4, 16% vs. 30%). The safety results were acceptable and consistent with the known toxicities of IMRT/cisplatin. Methods: 335 patients at multiple centers in the U.S. and Canada with locally-advanced, nonmetastatic head and neck cancer (oral cavity/oropharyngeal) receiving 70 Gy IMRT (>50 Gy to > 2 oral sites) plus cisplatin (40 mg/m2 qwk x 6-7, or 100 mg/m2 q3wk x 3) are being randomized (double-blinded) 3:2 to 90 mg of GC4419 or placebo, M-F before each RT fraction. Enrollment is stratified by cisplatin schedule and treatment setting (definitive vs. post-op). OM by the WHO scale will be assessed twice weekly during RT & weekly for 2 weeks post RT. The primary efficacy endpoint is incidence of SOM through the end of IMRT. Secondary efficacy endpoints include severity (incidence of Grade 4 OM through the end of IMRT), & days of SOM (days from first to last SOM for all patients, with patients never developing SOM having 0 days of SOM by definition). Days of SOM for the subset developing SOM will be analyzed descriptively. Patients will be followed for one year post IMRT for tumor progression/recurrence and for two years for survival. Clinical trial information: NCT03689712 .

Effects of GC4419 (avasopasem manganese) on chronic kidney disease in head and neck cancer patients treated with radiation and cisplatin

12071

Background: Nephrotoxicity is a major complication of platinum-based chemotherapy and ranges in incidence from 31-68%. The effects of platinum-based chemotherapeutics on long-term renal outcomes (chronic kidney disease, CKD) profoundly affect morbidity and mortality. Concurrent chemoradiotherapy (CRT) including cisplatin is standard for locally advanced squamous cell head and neck cancer (HNC) but is accompanied by the risk of CKD. In a randomized, multi-center, placebo-controlled Phase 2b trial ( NCT02508389 ) of GC4419 (avasopasem manganese) in HNC patients receiving CRT, avasopasem reduced the duration, incidence, and severity of severe oral mucositis (Anderson et al, JCO 2019). Avasopasem did not appear to alter the safety profile of CRT in that trial, including incidence of adverse events of kidney injury or azotemia. Methods: Pre- and post-treatment markers of kidney function including blood urea nitrogen (BUN), serum creatinine (sCr), and estimated glomerular filtration rate (eGFR) were retrospectively evaluated for a subset of 52 of the trial patients who received 3 cycles x 100 mg/m2 cisplatin plus placebo or 30 or 90 mg of avasopasem intravenously prior to RT, and 7 comparator patients who received the same CRT outside the study. Kidney function was evaluated between 3- and 24-months post-completion of cisplatin-radiation therapy by two-way analysis of variance (ANOVA) as defined by the Kidney Disease Improving Global Outcomes (KDIGO) CKD staging. Results: Baseline patient characteristics were skewed towards a male population but were balanced across all treatment arms with regards to baseline kidney function (comparator + placebo, n = 19; 30 mg GC4419, n = 18; 90 mg GC4419, n = 15). Treatment with 90 mg GC4419 demonstrated normal BUN values (10-20 mg/dL) at 3, 6, and 18 months and normal sCr values (0.6-1.2 mg/dL) between 3 and 24 months as compared to the placebo arm + comparator group, which exhibited statistically elevated BUN and sCr (p < 0.05). Treatment with 90 mg GC4419 also demonstrated significantly higher eGFR between 3 and 24 months post-chemoradiation (p < 0.05) compared to the placebo arm + comparator group. 90 mg GC4419 treatment significantly reduced the incidence of CKD compared to the placebo arm and comparator group, as determined by fold change in sCr values and eGFR measurements < 60 mL/min (stage G3a/b, G4, or G5 CKD). Conclusions: Avasopasem has the potential to reduce the incidence and severity of CKD in patients receiving cisplatin therapy. Clinical trial information: NCT02508389 .

Using audit in a district-wide management system

As a consequence of the NHS reforms, the budgeting and competitive tendering of clinical services between districts requires accurate accumulation of data. John Mosley and Roger Fairbanks describe how data obtained by clinicians from their own audit has been used to construct a casemix solution that provides the necessary financial information for a district.

Arginine vasopressin stimulates human mesangial cell production of endothelin

Endothelin (ET) is a vasoactive peptide produced by both endothelial epithelial cells with documented mitogenic action on mesangial cells. The present studies were designed to test the hypothesis that ET is also produced by human mesangial cells (HMC) and that other mitogens such as arginine vasopressin (AVP) and insulin stimulate cellular proliferation, in part, through modulation of endogenous production of this peptide. Studies were conducted on cultured normal HMC between the third and seventh passages. All mitogenesis experiments were carried out in 96-well plates and assessed by tritiated thymidine incorporation into DNA under various concentrations of AVP in the presence and absence of insulin, antiendothelin antisera (ETAS), a MAb against ET-1 (AbET), and a vasopressin-1 receptor antagonist. ET concentrations were measured daily from conditioned medium by a sensitive and specific RIA. ET was present in all concentrations of FCS as well as conditioned medium compared with medium alone. AVP (10(-6) M) in the presence of insulin increased ET production by quiescent HMC by 261% as well as cellular proliferation by 440% after 48 h incubation. In addition, cells cultured with ETAS or AbET demonstrated a blunted mitogenic response to AVP, a response not observed in cells cultured with ETAS where ET was added. Insulin significantly potentiated the mitogenic effects of AVP as well as media levels of ET, an effect significantly blunted by AbET. We conclude that ET is produced by HMC and its production is affected, in part, by both AVP and insulin. ET may thus serve to modulate the mitogenic effects of AVP on human mesangial cells.

Carbon-14 in Methane Sources and in Atmospheric Methane: The Contribution from Fossil Carbon

Measurements of carbon-14 in small samples of methane from major biogenic sources, from biomass burning, and in "clean air" samples from both the Northern and Southern hemispheres reveal that methane from ruminants contains contemporary carbon, whereas that from wetlands, pat bogs, rice fields, and tundra is somewhat, depleted in carbon-14. Atmospheric (14)GH(4) seems to have increased from 1986 to 1987, and levels at the end of 1987 were 123.3 +/- 0.8 percent modern carbon (pMC) in the Northern Hemisphere and 120.0 +/- 0.7 pMC in the Southern Hemisphere. Model calculations of source partitioning based on the carbon-14 data, CH(4) concentrations, and delta(13)C in CH(4) indicate that 21 +/- 3% of atmospheric CH(4) was derived from fossil carbon at the end of 1987. The data also indicate that pressurized water reactors are an increasingly important source of (14)CH(4).