Evaluation of PXL065 - deuterium-stabilized (R)-pioglitazone in patients with NASH: A phase II randomized placebo-controlled trial (DESTINY-1).

BACKGROUND & AIMS: Pioglitazone (Pio) is efficacious in NASH, but its utility is limited by PPARγ-driven side effects. Pio is a mixture of two enantiomers (R, S). PXL065, deuterium-stabilized R-Pio, lacks PPARγ activity but retains non-genomic activity. We tested the hypothesis that PXL065 would have similar efficacy but a better safety profile than Pio in patients with NASH. METHODS: Patients (≥8% liver fat, NAFLD activity score [NAS] ≥4, F1-F3) received daily doses of PXL065 (7.5, 15, 22.5 mg) or placebo 1:1:1:1 for 36 weeks. The primary endpoint was relative % change in liver fat content (LFC) on MRI-proton density fat fraction; liver histology, non-invasive tests, safety-tolerability, and pharmacokinetics were also assessed. RESULTS: One hundred and seventeen patients were evaluated. All PXL065 groups met the primary endpoint (-21 to -25% LFC, p = 0.008-0.02 vs. placebo); 40% (22.5 mg) achieved a ≥30% LFC reduction. Favorable trends in non-invasive tests including reductions in PIIINP (p = 0.02, 22.5 mg) and NAFLD fibrosis score (p = 0.04, 22.5 mg) were observed. On histology (n = 92), a ≥1 stage fibrosis improvement occurred in 40% (7.5 mg), 50% (15 mg, p = 0.06), and 35% (22.5 mg) vs. 17% for placebo; up to 50% of PXL065-treated patients achieved a ≥2 point NAS improvement without fibrosis worsening vs. 30% with placebo. Metabolic improvements included: HbA1c (-0.41% p = 0.003) and insulin sensitivity (HOMA-IR, p = 0.04; Adipo-IR, p = 0.002). Adiponectin increased (+114%, 22.5 mg, p <0.0001) vs. placebo. There was no dose-dependent effect on body weight or PXL065-related peripheral oedema signal. Overall, PXL065 was safe and well tolerated. Pharmacokinetics confirmed dose-proportional and higher steady state R- vs. S-Pio exposure. IMPACT AND IMPLICATIONS: Pioglitazone (Pio) is an approved diabetes medicine with proven efficacy in non-alcoholic steatohepatitis (NASH); PXL065 is a novel related oral agent which has been shown to retain Pio's efficacy in preclinical NASH models, with reduced potential for PPARγ-driven side effects. Results of this phase II study are important as PXL065 improved several key NASH disease features with a favorable safety profile - these findings can be applied by researchers seeking to understand pathophysiology and to develop new therapies. These results also indicate that PXL065 warrants further clinical testing in a pivotal NASH trial. Other implications include the potential future availability of a distinct oral therapy for NASH that may be relevant for patients, providers and caregivers seeking to prevent the progression and complications of this disease. CONCLUSIONS: PXL065 is a novel molecule which retains an efficacy profile in NASH similar to Pio with reduced potential for PPARγ-driven side effects. A pivotal clinical trial is warranted to confirm the histological benefits reported herein. IMPACT AND IMPLICATIONS: Pioglitazone (Pio) is an approved diabetes medicine with proven efficacy in non-alcoholic steatohepatitis (NASH); PXL065 is a novel related oral agent which has been shown to retain Pio's efficacy in preclinical NASH models, with reduced potential for PPARγ-driven side effects. Results of this phase II study are important as PXL065 improved several key NASH disease features with a favorable safety profile - these findings can be applied by researchers seeking to understand pathophysiology and to develop new therapies. These results also indicate that PXL065 warrants further clinical testing in a pivotal NASH trial. Other implications include the potential future availability of a distinct oral therapy for NASH that may be relevant for patients, providers and caregivers seeking to prevent the progression and complications of this disease.

A Randomized Phase 1 Evaluation of Deupirfenidone, a Novel Deuterium-Containing Drug Candidate for Interstitial Lung Disease and Other Inflammatory and Fibrotic Diseases.

LYT-100 (deupirfenidone) is a selectively deuterated form of pirfenidone under development for the treatment of inflammatory and fibrotic diseases, including interstitial lung disease. Adverse events associated with antifibrotics can be a barrier to adoption and persistence in patients with interstitial lung diseases, most of whom are not on standard-of-care therapy. LYT-100 is designed to have a differentiated pharmacokinetic (PK) profile from pirfenidone and could offer a differentiated safety profile compared to current standard-of-care drugs while retaining the biochemical potency and specificity of pirfenidone. We conducted a phase 1b study to ascertain the safety, tolerability, steady-state PK profile, and food effect of LYT-100. This was a 2-part study. Part 1 assessed multiple ascending doses of LYT-100 from 100, 250, 500, 750, and 1000 mg twice daily given over 5 days without titration. Part 2 assessed the effects of fed vs fasting conditions on the PK profile of a single 500-mg dose of LYT-100. All doses up to 1000 mg were well tolerated, with adverse events being mild and transient. Exposure was slightly lower in the fed condition. LYT-100 was well tolerated and has a dose-proportional PK profile. The ratio of parent to major metabolite concentration was higher than reported with pirfenidone, which is consistent with an effect of deuteration on metabolism. No maximum tolerated dose was identified up to 1000 mg twice-daily dosing. These results support further clinical development of LYT-100, particularly considering the adverse event profile of current standard-of-care drugs.

Deuterium Depletion Inhibits Cell Proliferation, RNA and Nuclear Membrane Turnover to Enhance Survival in Pancreatic Cancer.

The effects of deuterium-depleted water (DDW) containing deuterium (D) at a concentration of 25 parts per million (ppm), 50 ppm, 105 ppm and the control at 150 ppm were monitored in MIA-PaCa-2 pancreatic cancer cells by the real-time cell impedance detection xCELLigence method. The data revealed that lower deuterium concentrations corresponded to lower MiA PaCa-2 growth rate. Nuclear membrane turnover and nucleic acid synthesis rate at different D-concentrations were determined by targeted [1,2-13C2]-D-glucose fate associations. The data showed severely decreased oxidative pentose cycling, RNA ribose 13C labeling from [1,2-13C2]-D-glucose and nuclear membrane lignoceric (C24:0) acid turnover. Here, we treated advanced pancreatic cancer patients with DDW as an extra-mitochondrial deuterium-depleting strategy and evaluated overall patient survival. Eighty-six (36 male and 50 female) pancreatic adenocarcinoma patients were treated with conventional chemotherapy and natural water (control, 30 patients) or 85 ppm DDW (56 patients), which was gradually decreased to preparations with 65 ppm and 45 ppm deuterium content for each 1 to 3 months treatment period. Patient survival curves were calculated by the Kaplan-Meier method and Pearson correlation was taken between medial survival time (MST) and DDW treatment in pancreatic cancer patients. The MST for patients consuming DDW treatment (n = 56) was 19.6 months in comparison with the 6.36 months' MST achieved with chemotherapy alone (n = 30). There was a strong, statistically significant Pearson correlation (r = 0.504, p < 0.001) between survival time and length and frequency of DDW treatment.

Protective Effects of a Hydrogen-Rich Preservation Solution in a Canine Lung Transplantation Model.

BACKGROUND: Molecular hydrogen (H2) has protective effects against ischemia-reperfusion injury in various organs. Because they are easier to transport and safer to use than inhaled H2, H2-rich solutions are suitable for organ preservation. In this study, we examined the protective effects of an H2-rich solution for lung preservation in a canine left lung transplantation (LTx) model. METHODS: Ten beagles underwent orthotopic left LTx after 23 hours of cold ischemia followed by reperfusion for 4 hours. Forty-five minutes after reperfusion, the right main pulmonary artery was clamped to evaluate the function of the implanted graft. The beagles were divided into two groups: control group (n = 5), and H2 group (n = 5). In the control group, the donor lungs were flushed and immersed during cold preservation at 4°C using ET-Kyoto solution, and in the H2 group, these were flushed and immersed using H2-rich ET-Kyoto solution. Physiologic assessments were performed during reperfusion. After reperfusion, the wet-to-dry ratios were determined, and histology examinations were performed. RESULTS: Significantly higher partial pressure of arterial oxygen and significantly lower partial pressure of carbon dioxide were observed in the H2 group than in the control group (P = .045 and P < .001, respectively). The wet-to-dry ratio was significantly lower in the H2 group than in the control group (P = .032). Moreover, in histology examination, less lung injury and fewer apoptotic cells were observed in the H2 group (P < .001 and P < .001, respectively). CONCLUSIONS: Our results demonstrated that the H2-rich preservation solution attenuated ischemia-reperfusion injury in a canine left LTx model.

Possible Mechanisms of Biological Effects Observed in Living Systems during 2H/1H Isotope Fractionation and Deuterium Interactions with Other Biogenic Isotopes.

This article presents the original descriptions of some recent physics mechanisms (based on the thermodynamic, kinetic, and quantum tunnel effects) providing stable 2H/1H isotope fractionation, leading to the accumulation of particular isotopic forms in intra- or intercellular space, including the molecular effects of deuterium interaction with 18O/17O/16O, 15N/14N, 13C/12C, and other stable biogenic isotopes. These effects were observed mainly at the organelle (mitochondria) and cell levels. A new hypothesis for heavy nonradioactive isotope fractionation in living systems via neutron effect realization is discussed. The comparative analysis of some experimental studies results revealed the following observation: "Isotopic shock" is highly probable and is observed mostly when chemical bonds form between atoms with a summary odd number of neutrons (i.e., bonds with a non-compensated neutron, which correspond to the following equation: Nn - Np = 2k + 1, where k ϵ Z, k is the integer, Z is the set of non-negative integers, Nn is number of neutrons, and Np is number of protons of each individual atom, or in pair of isotopes with a chemical bond). Data on the efficacy and metabolic pathways of the therapy also considered 2H-modified drinking and diet for some diseases, such as Alzheimer's disease, Friedreich's ataxia, mitochondrial disorders, diabetes, cerebral hypoxia, Parkinson's disease, and brain cancer.

Design, synthesis and biological activity of deuterium-based FFA1 agonists with improved pharmacokinetic profiles.

The free fatty acid receptor 1 (FFA1) is considered as a promising anti-diabetic target based on its function of glucose-stimulated insulin secretion. The previously reported compound 2 is a highly potent FFA1 agonist, but it might be suffered from poor pharmacokinetic properties because the phenylpropanoic acid is vulnerable to ß-oxidation. To identify orally available analogs, we tried to block the route of ß-oxidation by incorporating deuterium at phenylpropionic acid moiety. As expected, the deuterium-based analogs 3 and 4 exhibited better pharmacokinetic properties than parent compound 2. Although the difference of potency between compound 2 and 3 is quite small, the glucose-lowering effect of deuterium analog 3 was better than that of compound 2. Meanwhile, compound 3 docked well into the same binding pocket of TAK-875, and formed almost identical interactions of TAK-875 in binding site. Different from glibenclamide, a lower risk of hypoglycemia was observed in compound 3 even at the high dose of 60 mg/kg.

Deuterated (d6)-dextromethorphan elicits antidepressant-like effects in mice.

The over-the-counter antitussive dextromethorphan (DM) may have rapid antidepressant actions based on its overlapping pharmacology with ketamine, which has shown fast antidepressant effects but whose widespread use remains limited by problematic side effects. We have previously shown that DM produces antidepressant-like effects in the forced swim test (FST) and tail suspension test (TST) that are mediated in part through α-amino-3-hydroxy-5-methyl-4-isoxazole propionic (AMPA) and sigma-1 receptors, two protein targets associated with a faster onset of antidepressant efficacy. To utilize DM clinically, however, a major challenge that must be addressed is its rapid first-pass metabolism. Two strategies to inhibit metabolism of DM and maintain stable therapeutic blood levels are 1) chemically modifying DM and 2) adding quinidine, an inhibitor of the primary metabolizer of DM, the cytochrome P450 (CYP) 2D6 enzyme. The purpose of this study was to determine if modified DM (deuterated (d6)-DM) elicits antidepressant-like effects and if AMPA and sigma-1 receptors are involved. Furthermore, d6-DM was tested in conjunction with quinidine to determine if further slowing the metabolism of d6-DM affects its antidepressant-like actions. In the FST and TST, d6-DM produced antidepressant-like effects. Upon further investigation in the FST, the most validated animal model for predicting antidepressant efficacy, d6-DM produced antidepressant-like effects both in the absence and presence of quinidine. However, pretreatment with neither an AMPA receptor antagonist (NBQX) nor sigma-1 receptor antagonists (BD1063, BD1047) significantly attenuated the antidepressant-like effects. The data suggest d6-DM has antidepressant-like effects, though it may be recruiting different molecular targets and/or acting through a different mix or ratio of metabolites from regular DM.

[Research progress of the inhibitory effect of deuterium-depleted water on cancers].

OBJECTIVE: Deuterium is an important predisposing factor for cancer. Deuterium-depleted Water, also known as low deuterium water, ultra-light water or no deuterium water, can be obtained by removing deuterium from natural water. Studies have shown that water with a low deuterium concentration (<65% percent of volume) can inhibit cancer growth. Clinical trials demonstrated that drinking DDW (10-20 ppm) caused growth arrest of malignant cells in cancer patients and significantly prolonged the patient survival with also improved quality of life. A wide range of anti-cancer drugs in current use are associated with severe adverse effects, while deuterium-depleted water appears to have virtually no pharmacological side effects and is convenient to administer. The authors review the advances in the researches of anti-cancer effects and the underlying mechanisms of deuterium-depleted water.

Pharmaco-thermodynamics of deuterium-induced oedema in living rat brain via 1H2O MRI: implications for boron neutron capture therapy of malignant brain tumours.

In addition to its common usage as a tracer in metabolic and physiological studies, deuterium possesses anti-tumoural activity and confers protection against gamma-irradiation. A more recent interest in deuterium emanates from the search for alternatives capable of improving neutron penetrance whilst reducing healthy tissue radiation dose deposition in boron neutron capture therapy of malignant brain tumours. Despite this potential clinical application, deuterium induces brain oedema, which is detrimental to neutron capture therapy. In this study, five adult male rats were titrated with deuterated drinking water while brain oedema was monitored via water proton magnetic resonance imaging. This report concludes that deuterium, as well as deuterium-induced brain oedema, possesses a uniform brain bio-distribution. At a steady-state blood fluid deuteration value of 16%, when the deuterium isotope fraction in drinking water was 25%, a mean oedematous volume change of 9 +/- 2% (p-value <0.001) was observed in the rat brain-this may account for neurological and behavioural abnormalities found in mammals drinking highly deuterated water. In addition to characterizing the pharmaco-thermodynamics of deuterium-induced oedema, this report also estimates the impact of oedema on thermal neutron enhancement and effective dose reduction factors using simple linear transport calculations. While body fluid deuteration enhances thermal neutron flux penetrance and reduces dose deposition, oedema has the opposite effect because it increases the volume of interest, e.g., the brain volume. Thermal neutron enhancement and effective dose reduction factors could be reduced by as much as approximately 10% in the presence of a 9% water volume increase (oedema).

A conceptual design of a beam-shaping assembly for boron neutron capture therapy based on deuterium-tritium neutron generators.

A conceptual design of a beam-shaping assembly for boron neutron capture therapy using deuterium-tritium accelerator based neutrons source is developed. Calculations based on a simple geometry model for the radiation transport are initially performed to estimate the assembly materials and their linear dimensions. Afterward, the assembly geometry is produced, optimized and verified. In order to perform these calculations the general-purpose MCNP code is used. Irradiation time and therapeutic gain are utilized as beam assessment parameters. Metallic uranium and manganese are successfully tested for fast-to-epithermal neutron moderation. In the present beam-shaping assembly proposal, the therapeutic gain is improved by 23% and the accelerator current required for a fixed irradiation period is reduced by six times compared to previous proposals based on the same D-T reaction.

Pharmacological uses and perspectives of heavy water and deuterated compounds.

Since the discovery of D20 (heavy water) and its use as a moderator in nuclear reactors, its biological effects have been extensively, although seldom deeply, studied. This article reviews these effects on whole animals, animal cells, and microorganisms. Both "solvent isotope effects," those due to the special properties of D20 as a solvent, and "deuterium isotope effects" (DIE), which result when D replaces H in many biological molecules, are considered. The low toxicity of D20 toward mammals is reflected in its widespread use for measuring water spaces in humans and other animals. Higher concentrations (usually >20% of body weight) can be toxic to animals and animal cells. Effects on the nervous system and the liver and on formation of different blood cells have been noted. At the cellular level, D20 may affect mitosis and membrane function. Protozoa are able to withstand up to 70% D20. Algae and bacteria can adapt to grow in 100% D2O and can serve as sources of a large number of deuterated molecules. D2O increases heat stability of macromolecules but may decrease cellular heat stability, possibly as a result of inhibition of chaperonin formation. High D2O concentrations can reduce salt- and ethanol-induced hypertension in rats and protect mice from gamma irradation. Such concentrations are also used in boron neutron capture therapy to increase neutron penetration to boron compounds bound to malignant cells. D2O is more toxic to malignant than normal animal cells, but at concentrations too high for regular therapeutic use. D2O and deuterated drugs are widely used in studies of metabolism of drugs and toxic substances in humans and other animals. The deuterated forms of drugs often have different actions than the protonated forms. Some deuterated drugs show different transport processes. Most are more resistant to metabolic changes, especially those changes mediated by cytochrome P450 systems. Deuteration may also change the pathway of drug metabolism (metabolic switching). Changed metabolism may lead to increased duration of action and lower toxicity. It may also lead to lower activity, if the drug is normally changed to the active form in vivo. Deuteration can also lower the genotoxicity of the anticancer drug tamoxifen and other compounds. Deuteration increases effectiveness of long-chain fatty acids and fluoro-D-phenylalanine by preventing their breakdown by target microorganisms. A few deuterated antibiotics have been prepared, and their antimicrobial activity was found to be little changed. Their action on resistant bacteria has not been studied, but there is no reason to believe that they would be more effective against such bacteria. Insect resistance to insecticides is very often due to insecticide destruction through the cytochrome P450 system. Deuterated insecticides might well be more effective against resistant insects, but this potentially valuable possibility has not yet been studied.

Heavy water enhances the antineoplastic effect of 5-fluoro-uracil and bleomycin in nude mice bearing human carcinoma.

The antineoplastic effect of heavy water on the growth of xenotransplanted human carcinoma was compared to that of 2 cytostatic drugs. Seven-week-old BALB/c-nu/nu mice were inoculated subcutaneously with a poorly differentiated oropharyngeal squamous-cell carcinoma, or with variants of carcinoma of the large intestine. After tumor inoculation, 3 subgroups of mice were treated by: (i) moderately deuterated drinking water; (ii) i.p. injections of 5-Fluoro-uracil (5-FU) or Bleomycin; (iii) a combination of deuterated drinking water and of the cytostatic drugs. Control mice were not treated. Heavy water delayed growth of all carcinoma variants. The cytostatic drugs slowed down the growth of the 2 poorly differentiated tumor variants. Conversely, 5-FU did not retard the growth of the moderately well differentiated colon carcinoma. Heavy water combined with either cytostatic drug showed synergistic effects in the 2 poorly differentiated tumor variants. The tumors of treated animals weighed 36% to 90% less than those of control animals. The antineoplastic effects were more conspicuous in poorly than in moderately well differentiated tumor variants. Cytokinetic parameters such as labelling indices following application of 5-125I-Iodo-2'deoxyuridine, and of Ki-67, a monoclonal antibody (MAb) directed against an antigen of proliferating cells, or mitotic indices and tumor volume doubling time, combined with the results of histologic evaluation of the tumors, suggested an underlying deuterium-induced prolongation of tumor-cell cycle times and a reduction of the growth fraction.

Heavy water delays growth of human carcinoma in nude mice.

Deuterium-enriched water has an antiproliferative effect on transplantable mouse tumors without toxic side effects. Since the response to treatment of human carcinomas growing in nude mice is deemed to be a good indicator of the potential clinical behavior of these tumors, we studied the influence of this stable isotope of hydrogen on the growth of xenotransplanted human carcinomas of various histologic types, grades, and primary sites. Seven-week-old Balb/c-nu/nu mice were inoculated subcutaneously, either with oropharyngeal squamous cell carcinomas or with carcinomas of the large intestine. After tumor inoculation, the mice were given drinking water containing 30 atom% D2O. Heavy water effectively retarded the growth of the human carcinomas. At the end of the experiment, the weight of the tumors was reduced to values ranging from 22% to 65% of the control values. The reproducible antiproliferative effect was more conspicuous in poorly differentiated carcinomas than in moderately well-differentiated variants. Since animals in both groups, kept under identical conditions, drank the same amount of water and had similar body weights, the difference in tumor growth can be attributed to the moderate deuteration of the hosts.

[Relative biological effectiveness (RBE) of neutrons produced by 50 MeV deuterons and by 34, 45, 65 and 75 MeV protons]. / Efficacité biologique relative (EBR) des neutrons produits à partir de deutons de 50 MeV et de protons de 34, 45, 65 et 75 MeV.

RBE of p(34) + Be, p(45) + Be, p(65), + Be, p(75) + Be and d(50) + Be neutron beams produced at the cyclotron "Cyclone" of Louvain-la-Neuve were measured. The biological criterion was the regeneration of the crypts of the intestinal mucosa (50 regenerated crypts per circumference) after abdominal irradiation in mice. Taking the p(65) + Be neutrons as reference, RBE values were found equal to 1.12, 1.07, 1.00 (Ref.), 0.96 and 1.02 respectively. These results are consistent with those published for cell lethality in vitro. However, the RBE variation is smaller than this previously obtained in the laboratory for growth inhibition in Vicia faba.

Adverse reactions to suxamethonium and other muscle relaxants under general anesthesia.

The mechanisms of anaphylactic reactions to muscle relaxants under general anesthesia are not completely understood. Extending an earlier study, we report 41 cases of anaphylactic shock investigated by intradermal skin tests with muscle relaxants (suxamethonium, pancuronium, gallamine, nortoxiferine), in vitro leukocyte histamine release, and Prausnitz-Küstner tests. Intradermal tests were significantly positive at concentrations ranging from 10 to 10(5) times less than those in controls. Reproducibility tested for suxamethonium at a 1-year interval in five patients was good. Histamine release induced by muscle relaxants in Tris-albumin-Ca++-Mg++ buffer showed positive results in 8/25 instances and was inhibited by antigen excess in seven cases. Addition of 50% deuterium oxide (D2O) caused significant increase of histamine release in positive cases and induced release in all five negative cases studied. Muscle relaxant-induced histamine release was inhibited by in vitro anti-IgE leukocyte desensitization. The mean maximal histamine release dropped from 58.2% +/- 9.7 to 5.8% +/- 2 (p less than 0.01). Similarly, leukocyte desensitization also inhibited histamine release induced by anti-IgE but not by formyl-L-methionyl-L-leucyl-L-phenylalanine or poly-L-arginine. Prausnitz-Küstner tests were positive in five out of 21 cases studied and became negative after heat inactivation. These results confirm the usefulness of intradermal skin tests in diagnosis of patients' reaction to muscle relaxants and suggest an IgE-mediated rather than an idiosyncratic mechanism.

Survival of tumor-bearing mice exposed to heavy water or heavy water plus methotrexate.

Moderate body deuteration combined with a cytostatic drug [methotrexate (MTX)] significantly increases the survival time of young adult DBA/2 mice bearing transplantable P815. L5178Y, or L1210 tumors. Neoplastic cells were grown in vitro from tumor stock and injected i.p. into mice from two groups, one drinking tap water, and other drinking 30% heavy water in tap water. One-half of the animals in each of these two groups was given a single injection of MTX (4 mg/kg body weight) on 3 consecutive days per week. At death, extension of primary and metastatic tumors was examined and was found to be macro- and microscopically comparable in the corresponding groups. The mean survival time of untreated mice drinking tap water was about 2 weeks following injection of the fast-growing P815, L5178Y, or L1210 (V) tumors and approximately 5 weeks after injection of cells from a slower-growing L1210 subline. Body deuteration alone roughly doubled the survival time solely of mice bearing this L1210 subline. Treatment with MTX approximately doubled the mean survival time of hosts bearing one of the fast-growing tumors. Combined treatment with heavy water and MTX increased the mean survival time of the mice in all groups by 15 to 125% as compared to control values. The reasons for this effect are unknown. However, heavy water has been shown to exert antimitotic activity and to depress the incorporation of radioactive precursors into DNA of proliferating mammalian cells. The depression of antibody formation following antigenic stimulation and the reduction in numbers of nonneoplastic lymphoid cells of mice following moderate body deuteration may have contributed to the enhancement of MTX activity in addition to other effects of deuterium.