Evaluation of trans sodium crocetinate on safety and exercise performance in patients with peripheral artery disease and intermittent claudication.

Trans sodium crocetinate (TSC) is a synthetic carotenoid that improves the diffusion of oxygen in animal models of ischemia/hypoxia. This study evaluated multiple doses of TSC in patients with peripheral artery disease (PAD) and hypothesized that a preliminary dose-response relationship could be identified on peak walking time (PWT). Forty-eight patients with symptomatic PAD and an ankle-brachial index < 0.90 were included, while critical limb ischemia, recent revascularization, and exercise limited by symptoms other than claudication were exclusionary. Patients were randomized to placebo or eight dosing levels of TSC ranging from 0.25 mg/kg to 2.0 mg/kg given intravenously once daily for 5 days. Subjects were tested on a graded treadmill protocol to claudication-limited PWT with the change to Day 5 as primary. A cubic regression was fit to detect a pre-specified inverted U-shaped dose-response relationship (65% power). Patient-reported walking distance from the Walking Impairment Questionnaire was a secondary endpoint. Adverse events were not predominant on any drug dose relative to placebo. Changes in PWT demonstrated a cubic trend for dose (p = 0.07, r = 0.39, r (2) = 0.15) with morphologic signals of benefit at doses above 1.00 mg/kg after both the first and fifth dosing days. Similar improvements occurred with the walking distance score at doses above 1.00 mg/kg. In conclusion, TSC was safe and well tolerated at all doses. Notable signals of benefit were observed at higher doses for both PWT and patient-perceived walking distance. These results support a phase II study to define the optimal dose for longer-term therapy with TSC. Clinical Trial Registration - URL:http://www.clinicaltrials.gov. Unique identifier: NCT00725881.

Trans-sodium crocetinate and hemorrhagic shock.

Trans-sodium crocetinate (TSC) has been found to alleviate the symptoms of hemorrhagic shock in that, after the drug is given to hemorrhaged rats, blood pressure rises, elevated lactate levels are reduced, cellular damage in the liver and kidney is less, and survival is increased. The mechanism of action proposed for TSC is that it increases the diffusion of oxygen through blood plasma and into the tissue. The study reported here explores another proposed mechanism, the scavenging of free radicals. It is shown that TSC does scavenge radicals and may be more efficient than other free-radical scavengers. However, this may not be the mechanism of action for TSC during hemorrhagic shock. Not only are the TSC concentrations needed for radical scavenging greater than those which provide beneficial effects in hemorrhagic shock, but it is also shown that another radical scavenger, trolox, has no effect on oxygen consumption during shock. Trans-sodium crocetinate clearly holds promise as a useful treatment of hemorrhagic shock. Pharmacokinetics data are presented for different modes of administration. Initial studies suggest that instillation of TSC into the trachea or intramuscular injection may provide useful alternative treatment routes.

Trans sodium crocetinate with temozolomide and radiation therapy for glioblastoma multiforme.

OBJECTIVE A new drug, trans sodium crocetinate (TSC), has been developed to enhance the delivery of oxygen to hypoxic tissues. Cancerous tumors, such as glioblastoma multiforme (GBM), are very hypoxic, and it has been suggested that radiation therapy (RT) is more beneficial if tumors are better oxygenated. A Phase I/II clinical trial was conducted to determine the effect of adding TSC to RT sessions. METHODS An open, single-arm clinical trial incorporating the standard of care (SOC) for GBM was conducted at 18 clinical sites. There were 6 weeks of RT consisting of 2 Gy/day for 5 days/week, beginning after an initial resection or stereotactic biopsy to confirm GBM. Temozolomide (TMZ), 75 mg/m2, was given before each RT session. The TSC, 0.25 mg/kg, was intravenously administered around 45 minutes before an RT session 3 days/week, usually on Monday, Wednesday, and Friday. A Phase I run-in period included 2 cohorts. The first cohort contained 3 patients who were given a half dose of the intravenous TSC (that is, 0.25 mg/kg, 3 times per week for only the first 3 weeks of RT). After a Safety Monitoring Committee (SMC) had verified that no dose-limiting toxicity (DLT) had occurred, a second cohort of 6 patients was given the same dosage of TSC but for the full 6 weeks of RT. After the SMC verified that no DLTs had occurred, Phase II began, with the administration of the full 18 doses of TSC. Fifty additional patients were enrolled during Phase II. Following the completion of RT, the patients rested for a month. After that, SOC TMZ chemotherapy (150-200 mg/m2) was administered for 5 days of the 1st week of 6 monthly cycles. No TSC was administered during this chemotherapy phase or later in the trial. Any other follow-up therapies were administered at the discretion of the individual investigators. RESULTS Kaplan-Meier analysis showed that 36% of the full-dose TSC patients were alive at 2 years, compared with historical survival values ranging from 27% to 30% for the SOC. Survival for the biopsy-only subset of patients was 40%, as compared with 42.9% for those patients having a complete resection before treatment. In addition, 2 of the 3 Phase I, Cohort 1 patients survived at 2 years. Contrast MRI data suggested that considerable pseudoprogression had occurred. Both Karnofsky Performance Status (KPS) scores and quality of life (QOL) questionnaires indicated that a good quality of life existed for most patients throughout the trial. No serious adverse events occurring in the trial were attributed to TSC. CONCLUSIONS This trial contained a single arm consisting of 59 patients. The results strongly suggested that adding TSC during RT is beneficial for the treatment of GBM. Trans sodium crocetinate offers a novel, easily implemented way to combat hypoxia in tumor tissue. Clinical trial registration no.: NCT01465347 ( clinicaltrials.gov ).

trans-Sodium crocetinate and diffusion enhancement.

trans-Sodium crocetinate (TSC) increases the diffusion coefficient of glucose through water by about 25-30%. This is the same percentage increase that TSC causes in the diffusivity of oxygen through water. TSC is also found to induce order in the surrounding water structure through increased hydrogen bonding of the water molecules, and molecular simulations suggest that the increase in diffusivity occurs only in these ordered regions.

TSC for hemorrhagic shock: effects on cytokines and blood pressure.

Previous studies have shown that administering trans-sodium crocetinate (TSC) as a treatment of hemorrhagic shock leads to increased whole-body oxygen consumption and survival as well as protection of the liver and kidney. It has been suggested that TSC increases oxygen delivery by increasing the diffusivity of oxygen through plasma. However, as with any novel mechanism of action, there are always questions about whether the results could also be ascribed to other, previously described mechanisms of action. This study was designed to look at some aspects of that by examining the effect of different TSC dosing regimens on the blood pressure and the production of cytokines after hemorrhage because both responses have been reported with compounds that act via other mechanisms. In a constant-pressure rat model of hemorrhagic shock, it was seen that a singe bolus injection of TSC results in an immediate but transient increase in the arterial blood pressure. This is similar to the effect reported previously for using 100% oxygen. It was also found that if the TSC injections were repeated periodically over an hour, a sustained increase in the blood pressure would occur. Because inflammatory cytokines have been implicated in mortality and tissue damage, it has been suggested that TSC may affect the production of cytokines. Thus, the effect of TSC on the production of TNF-alpha and IL-10 was also examined. The data show that treatment with TSC results in lower concentrations of TNF-alpha in the liver and spleen as well as lower concentrations of IL-10 in the spleen. Again, similar effects on other cytokines have been seen with 100% oxygen. These results support the hypothesis that the effects of TSC on hemorrhagic shock are mediated via an effect on oxygen.

Trans sodium crocetinate for hemorrhagic shock: effect of time delay in initiating therapy.

A new drug, trans sodium crocetinate (TSC), has been suggested for use in resuscitation after trauma. TSC has been shown to increase survival in a rat model of hemorrhagic shock. It also results in an increase in blood pressure and a decrease in plasma lactate levels when given immediately after hemorrhage. TSC increases whole-body oxygen consumption rates, and it is thought that its physiological effects are due to the increased oxygen availability. In fact, TSC therapy and 100% oxygen therapy show similar results when used in the same rat hemorrhage model. It has been suggested, however, that 100% oxygen therapy is effective only if begun immediately after hemorrhage. Such a window of opportunity has been said to exist for other resuscitation methods; thus, the current study is to determine if this is true for TSC. In one series of experiments, rats were bled 60% of their blood volumes and given an injection of TSC (or saline) 20 min after the hemorrhage ended. The injection was then repeated four times, spaced 10 min apart. Thirty minutes after the final injection, the animals were infused with normal saline. TSC again restored blood pressure and other parameters, but repeated dosing was necessary. In addition, this therapy prevented an increase in liver enzymes (transaminases) as measured 24 h after hemorrhage. In a second study, rats were bled 60% of their blood volumes, followed by a second bleeding (an additional 10%) done 10 min later. No subsequent fluid was infused in this group. The majority of the animals treated with TSC after the second hemorrhage survived, whereas the controls did not. These data suggest that TSC is effective when given after a delay. The dosing regimen must be different, however, presumably because of the blood acidosis that develops after hemorrhage. The results also suggest that TSC may be protective against secondary liver damage resulting from trauma.

Asymmetric synthesis with immobilized yeast in organic solvents: equilibrium conversion and effect of reactant partitioning on whole cell biocatalysis.

A newly isolated strain of the yeast Saccharomyces cerevisiae is investigated for the biocatalytic reduction of ketones and the oxidation of alcohols in organic solvents. The yeast cells are immobilized by entrapment within calcium alginate beads and are found to possess the ability to stereoselectively reduce prochiral ketones and oxidize chiral alcohols to equilibrium conversions. The effect of reactant partitioning on the initial rate of the reactions is also investigated. The observed initial rates are found to vary inversely with reactant partitioning between the organic solvent and the biocatalyst beads. A kinetic model is developed to describe the initial reaction rate of hexanone reduction as a function of substrate concentration within the alginate beads.

Protection against focal ischemic injury to the brain by trans-sodium crocetinate. Laboratory investigation.

OBJECT: Ischemic injury is a potential complication in a variety of surgical procedures and is a particular impediment to the success of surgeries involving highly vulnerable neural tissue. One approach to limiting this form of injury is to enhance metabolic supply to the affected tissue. Trans-sodium crocetinate (TSC) is a carotenoid compound that has been shown to increase tissue oxygenation by facilitating the diffusivity of small molecules, such as oxygen and glucose. The present study examined the ability of TSC to modify oxygenation in ischemic neural tissue and tested the potential neuroprotective effects of TSC in permanent and temporary models of focal cerebral ischemia. METHODS: Adult male rats (330­370 g) were subjected to either permanent or temporary focal ischemia by simultaneous occlusion of both common carotid arteries and the left middle cerebral artery (3-vessel occlusion [3-VO]). Using the permanent ischemia paradigm, TSC was administered intravenously beginning 10 minutes after the onset of ischemia at 1 of 8 dosages, ranging from 0.023 to 4.580 mg/kg. Cerebral infarct volume was measured 24 hours after the onset of ischemia. The effect of TSC on infarct volume was also tested after temporary (2-hour) ischemia using a dosage of 0.092 mg/kg. In other animals undergoing temporary ischemia, tissue oxygenation was monitored in the ischemic penumbra using a Licox probe. RESULTS: Administration of TSC reduced infarct volume in a dose-dependent manner in the permanent ischemia model, achieving statistical significance at dosages ranging from 0.046 to 0.229 mg/kg. The most effective dosage of TSC in the permanent ischemia experiment (0.092 mg/kg) was further tested using a temporary (2-hour) ischemia paradigm. Infarct volume was reduced significantly by TSC in this ischemia-reperfusion model as well. Recordings of oxygen levels in the ischemic penumbra of the temporary ischemia model showed that TSC increased tissue oxygenation during vascular occlusion, but reduced the oxygen overshoot (hyperoxygenation) that occurs upon reperfusion. CONCLUSIONS: The novel carotenoid compound TSC exerts a neuroprotective influence against permanent and temporary ischemic injury when administered soon after the onset of ischemia. The protective mechanism of TSC remains to be confirmed; however, the permissive effect of TSC on the diffusivity of small molecules is a plausible mechanism based on the observed increase in tissue oxygenation in the ischemic penumbra. This represents a form of protection based on "metabolic reflow" that can occur under conditions of partial vascular perfusion. It is particularly noteworthy that TSC could conceivably limit the progression of a wide variety of cellular injury mechanisms by blunting the ischemic challenge to the brain.

Trans-sodium crocetinate for treating hypoxia/ischemia.

BACKGROUND: Trans-sodium crocetinate (TSC) is a novel compound that offers promise as a treatment for conditions caused by hypoxia or ischemia. TSC was originally developed at the University of Virginia for hemorrhagic shock, as part of the battlefield casualty program sponsored by the US Office of Naval Research. Animal toxicology studies have demonstrated that high levels of TSC are well-tolerated, and a Phase I clinical study has shown that TSC is also safe in humans. OBJECTIVE: The drug acts via a mechanism that has not been previously exploited in a pharmaceutical. TSC increases the rate of oxygen diffusion between the erythrocytes and the tissues by altering the 'structure' of water in blood plasma. It does this by causing additional hydrogen bonds to form among the water molecules. CONCLUSION: Further development of TSC for hemorrhagic shock and other hypoxic/ischemic conditions is being done by Diffusion Pharmaceuticals LLC.