Highly efficient bacterial agent could improve treatment of Wilson disease

 

In the 'Journal of Clinical Investigation', scientists at the Helmholtz Zentrum München describe a small peptide that very efficiently binds excess copper from liver cells. This molecule comes from a bacterium's bag of tricks and could be suitable for treating Wilson disease. In an experimental model it has already proven superior to conventional medicines.

In Wilson disease, also called Wilson's disease or hepatolenticular degeneration, the body is no longer able to excrete excess copper ingested from food into the intestines via the bile. Instead, the copper is stored in the liver and other organs, where it can cause severe damage. Doctors accordingly employ medicines called chelators that bind the surplus copper. These life-long treatments are especially effective if commenced during the early stages of the disease. The drugs must be taken several times a day, are repeatedly associated with undesired effects, and, particularly in the event of a late diagnosis of the disease, are often ineffective, so that a liver transplant can be necessary as the last resort.

Researchers headed by PD Dr. Hans Zischka, head of the Oxidative Cell Death research group at the Institute of Molecular Toxicology and Pharmacology at the Helmholtz Zentrum München have now conducted a detailed examination of a bacterial agent that could improve the disease treatment. They looked to the bacterium Methylosinus trichosporium, which requires large quantities of copper due to its special methane metabolism. In order to acquire the necessary metal, it excretes the methanobactin molecule, which very efficiently binds copper.

In order to check if methanobactin is also suitable for binding copper from the body, the researchers used an in vivo model for the disease that had the same genetic defect as that found in humans. "We were able to observe that even acute stages of Wilson disease reversed with methanobactin," reports Josef Lichtmannegger, who, together with Christin Leitzinger, is the study's first author. Further analyses showed that the improvement was due to a sharp decline in the copper quantities. Especially the mitochondria, known as the "powerhouse of the cell", greatly profited from the dropping copper levels and were able to resume their full function. Methanobactin hindered the death of liver cells and prevented liver failure.

The researchers then compared methanobactin to chelators that are currently used in hospitals. Unlike the chelators, methanobactin was able to eliminate the copper overload in the liver cells within a few days, even in stages of severe damage, and prevent organ failure. The agent was also very well tolerated in the model.

"We hope that our work will make it possible to improve the treatment of Wilson disease and reduce the number of liver transplants," states Zischka, the study leader. It is conceivable that in the long run it will be possible to replace the current use of less effective chelators several times a day with short treatment cycles using methanobactin. Clinical studies are now necessary to test this.

Researchers find promising drugs that could lead to first antidote for radiation exposure

University of Virginia School of Medicine researchers have identified promising drugs that could lead to the first antidote for radiation exposure that might result from a dirty bomb terror attack or a nuclear accident such as Chernobyl.

Some of the compounds, including the drug rapamycin, have previously been shown toextend life in organisms such as worms and flies, though it's unknown if they would have the same benefit in humans. UVA's research suggests that these compounds, or similar drugs, might counter the deadly effects of ionizing radiation.

 rapamycin

Currently there is no treatment for people exposed to lethal doses of radiation; doctors can only try to ease their suffering until death. "If you're exposed to a very, very high dose, it's rapid deterioration and immediate death," explained John S. Lazo, PhD, of UVA's Department of Pharmacology. "It's the lower doses that people - particularly governments - are concerned about. The type of exposure that might result from a dirty bomb or a nuclear accident. How do we alleviate the effects? What's the antidote? Right now, we just don't have anything."

Innovative Approach

Lazo and his colleague Elizabeth R. Sharlow, PhD, screened a library of more than 3,400 existing drugs, vitamins and other compounds to identify ones that might help cells withstand the effects of radiation exposure. The goal was to keep stem cells - the cells that produce the various cell types in the body - alive long enough to repair the damage caused by radiation.

"We wanted to find already approved drugs that would potentially keep stem cells, or progenitor cells, alive after radiation exposure," Sharlow said. "That's very much of interest to the NIH [National Institutes of Health] right now: How can we keep those se

lf-renewing populations alive so they can actually help heal the effects of radiation exposure?"

After they identified potential leads, Sharlow created 3D computer models to compare the substances' chemical structures. That analysis identified a cluster of promising compounds with similar structures - a tantalizing lead in the quest for an antidote. "If you're a drug hunter, the way we are, this is really cool information," Lazo said. "Because you can say, 'Now I will look in the universe of 40 million compounds. What else looks like that? Are they useful?'"

He noted that it is unlikely any one drug or compound will work on its own. "A lot of us in this field think it will be a cocktail of things you take," he said. "And if you think you need cocktails, you need the individual ingredients. That's why we think this is pretty important - because it's providing new ingredients for that cocktail."

Natural molecule NAC could benefit patients with Parkinson's disease

The natural molecule, n-acetylcysteine (NAC), with strong antioxidant effects, shows potential benefit as part of the management for patients with Parkinson's disease, according to a study published today in the journal PLOS ONE. Combining clinical evaluations of a patient's mental and physical abilities with brain imaging studies that tracked the levels of dopamine, the lack of which is thought to cause Parkinson's, doctors from the Departments of Integrative Medicine, Neurology, and Radiology, at Thomas Jefferson University showed that patients receiving NAC improved on both measures.

 Acetylcysteine

Current treatments for Parkinson's disease are generally limited to temporarily replacing dopamine in the brain as well as some medications designed to slow the progression of the disease process. Recently, researchers have shown that oxidative stress in the brain may play a critical role in the Parkinson's disease process, and that this stress also lowers levels of glutathione, a chemical produced by the brain to counteract oxidative stress. Studies in brain cells showed that NAC helps reduce oxidative damage to neurons by helping restore the levels of the antioxidant glutathione. NAC is an oral supplement that can be obtained at most nutrition stores, and interestingly also comes in an intravenous form which is used to protect the liver in acetaminophen overdose.

"This study reveals a potentially new avenue for managing Parkinson's patients and shows that n-acetylcysteine may have a unique physiological effect that alters the disease process and enables dopamine neurons to recover some function," said senior author on the paper Daniel Monti, M.D., M.B.A., Director of the Myrna Brind Center of Integrative Medicine, and the Brind-Marcus Center of Integrative Medicine at Thomas Jefferson University.

In this study, Parkinson's patients who continued their current standard of care treatment, were placed into two groups. The first group received a combination of oral and intravenous (IV) NAC for three months. These patients received 50mg/kg NAC intravenously once per week and 600mg NAC orally 2x per day on the non IV days. The second group, the control patients, received only their standard of care for Parkinson's treatment. Patients were evaluated initially, before starting the NAC and then after three months of receiving the NAC while the control patients were simply evaluated initially and three months later. The evaluation consisted of standard clinical measures such as the Unified Parkinson's Disease Rating Scale (UPDRS), a survey administered by doctors to help determine the stage of disease, and a brain scan via DaTscan SPECT imaging, which measures the amount of dopamine transporter in the basal ganglia, the area most affected by the Parkinson's disease process. Compared to controls, the patients receiving NAC had improvements of 4-9 percent in dopamine transporter binding and also had improvements in their UPDRS score of about 13 percent.

"We have not previously seen an intervention for Parkinson's disease have this kind of effect on the brain," said first author and neuro-imaging expert Andrew Newberg, M.D., Professor at the Sidney Kimmel Medical College at Jefferson and Director of Research at the Myrna Brind Center of Integrative Medicine. The investigators hope that this research will open up new avenues of treatment for Parkinson's disease patients.

Rice University researchers synthesize new anti-cancer agent

Rice University scientists have synthesized a novel anti-cancer agent, Thailanstatin A, which was originally isolated from a bacterial species collected in Thailand.

 

Thailanstatin A

Thailanstatin A fights cancer by inhibiting the spliceosome, the machinery in the cell that edits messenger RNA after transcription from DNA but before its translation into proteins.

Rice synthetic chemist K.C. Nicolaou and his group reported their success in the Journal of the American Chemical Society.

Nicolaou and his colleagues specialize in the synthesis of potential therapeutic agents that are found in nature but in amounts too small for thorough biological evaluation or clinical use. He is best known for the total synthesis of paclitaxel, a drug commonly used to treat a number of cancers.

The researchers explained that the spliceosome, a complex of proteins and ribonucleoproteins that regulate DNA splicing, is more active and displays higher mutation rates in cancer cells than in healthy cells, which makes it a valid target for investigation.

"This cellular machinery edits mRNA as it emerges from the transcription of DNA through site-specific removal of introns (noncoding regions of DNA) and splicing the remaining exon (coding) sequences prior to translation," Nicolaou said. "Thailanstatin A interferes with this mechanism."

He said the synthesis of Thailanstatin A, first isolated from burkholderia thailandensis bacteria, opens the way to construct and test variations of the molecule. "These studies will be directed toward optimization of the pharmacological properties of this new natural product as part of a drug discovery and development program targeting new therapies for cancer," Nicolaou said.

The program can take two directions, he said: one directed toward high-potency compounds that could be used as payloads for antibody drug conjugates and the other toward selective agents that can kill cancer cells with minimal damage to healthy cells.

The first paradigm is currently a frontier approach for the development of targeted and personalized cancer therapies, while the second represents a more traditional approach that could also lead to powerful anti-cancer drugs, Nicolaou said. "Thailanstatin A exhibits just the right potency to be diverted to either approach through a reiterative molecular design, chemical synthesis and biological evaluation process," he said.

"We're excited about this new molecule and its analogs because of their unique biological properties and the prospects of working collaboratively with industrial and academic partners to advance them toward the clinic," Nicolaou said.

Rice University researchers synthesize new anti-cancer agent

Clinical trial finds pioglitazone drug safe and effective for NASH patients

In continuation of my update on Pioglitazone

Researchers have found that an existing diabetes drug can be used to halt progression of another disease that is a leading cause of liver transplants.

A three-year clinical trial led by University of Florida Health researcher Kenneth Cusi, M.D., found that the drug pioglitazone is safe and effective in certain patients who have nonalcoholic steatohepatitis, or NASH, a chronic liver disease caused by a buildup of fat. The findings are published today (June 20) in the journal Annals of Internal Medicine.

NASH is often known as "silent" liver disease and affects 10 to 20 percent of the population and perhaps as many as one-third of all patients with adult-onset diabetes in the United States, according to recent studies. Left unchecked, NASH can cause chronic inflammation that leads to liver cancer or cirrhosis. NASH is now the second-leading cause of liver transplants and the numbers continue to grow each year, said Cusi, chief of the division of endocrinology, diabetes and metabolism in the UF College of Medicine's department of medicine.

Early diagnosis and treatment of NASH is crucial for those who are at greatest risk for the disease, usually obese patients who also have prediabetes or Type 2 diabetes. But until now, Cusi said, there was little urgency to diagnose NASH because there were no available medications.

The research group's single-center clinical trial involving 101 NASH patients with prediabetes or Type 2 diabetes found that pioglitazone reduced fatty liver disease activity in 58 percent of participants. In just more than half the participants -- 51 percent -- the disease was reduced enough that it was no longer considered a threat to the liver.

"The exciting thing is that there is a generic drug that already prevents the onset of Type 2 diabetes and cardiovascular disease in recent studies. Now, it can reduce disease from excess liver fat accumulation and liver inflammation, and halt fibrosis that leads to cirrhosis. This will have a lot of long-term benefits for many people with a medication that will be very affordable and is already being used to treat Type 2 diabetes," Cusi said.

The study also has implications for people with prediabetes and NASH because fatty liver disease is a risk factor for Type 2 diabetes even in those who aren't obese, researchers said.

Federal regulators approved Actos (pioglitazone) in 2000 and a generic version of the drug in 2012 to improve blood glucose control in adults with Type 2 diabetes. Still, pioglitazone's use against liver disease will require a larger, multicenter clinical trial that could take seven years or more in addition to U.S. Food and Drug Administration approval. A multicenter trial would allow researchers to learn more about the drug's long-term benefits for liver issues and determine why some participants respond better than others to the medication, Cusi said.

Researchers aren't entirely certain about how pioglitazone works against liver disease. Patients with NASH are insulin-resistant, meaning their body does not respond normally to their own insulin. This defect promotes fat accumulation and inflammation in the liver. The researchers believe the medication makes molecular improvements in the liver and other tissues such as fat. That helps the body's response to insulin, making it insulin-sensitive again and restoring normal metabolism.

Despite the recent trial's relatively small size, Cusi noted that it's the largest single-center study and the first long-term study examining the drug as treatment for people who have NASH along with prediabetes or Type 2 diabetes. It is also the longest NASH-related study with any drug and had the greatest treatment effect on NASH compared with other approaches, he said.

Apixaban effective in polypharmacy setting

In continuation of my update on Apixaban

The superiority of apixaban over warfarin in patients with atrial fibrillation is maintained in those taking multiple medications, shows further analysis of the ARISTOTLE trial.

 Apixaban

The researchers found superior efficacy of apixaban against the primary thromboembolic endpoint (stroke or systemic embolism) regardless of the number of drugs patients were taking.

By contrast, the advantage of apixaban over warfarin in terms of major bleeding tended to decline in line with the number of drugs patients were taking. The absolute rate reduction per 100 patient-years with apixaban versus warfarin was 1.28 for patients taking up to five medications, falling to 0.82 and 0.66 for those taking six to eight and more than nine drugs, respectively.

"Importantly, the risk reduction of intracranial bleeding did not diminish with an increasing number of concomitant drugs", write the researchers in The BMJ.

"Therefore, the fact that the relative benefit of apixaban over warfarin appears to diminish across groups is due to other types of major bleeding."

They give the example of major gastrointestinal bleeding, which was significantly reduced with apixaban versus warfarin in patients taking up to five drugs, but not in those taking nine or more drugs.

Polypharmacy was common among the 18,201 ARISTOTLE participants, with 76.5% taking at least five concomitant drugs. Patients' average age rose in line with the number of drugs used, as did their stroke and bleeding risk. Patients taking more drugs also had more cardiovascular comorbidities, and also more neurological, renal, endocrine, musculoskeletal, pulmonary, gastrointestinal and haematological comorbidities.

Rates of the primary thromboembolic and bleeding endpoints rose with the number of drugs taken for patients in the apixaban group as well as those in the warfarin group.

Jeroen Jaspers Focks (Radboud University Nijmegen Medical Centre, the Netherlands) and study co-authors stress that "this increased risk of adverse outcomes should be placed in the context of the association between the number of drug treatments and comorbidities present at baseline, indicating a more frail status of patients with polypharmacy."

The researchers suggest that adjusting for these differences would abolish the relationship between the number of drugs used and safety outcomes, but add that the purpose of the study was to use polypharmacy as a marker of patient frailty.

Moreover, increasing frailty did not significantly influence the efficacy of apixaban against stroke or systemic embolism, with the relative risk versus warfarin being 14% among those taking up to five drugs and 24% in those taking more.

Espero Pharmaceuticals Receives FDA Approval for GoNitro (nitroglycerin) Sublingual Powder

Espero Pharmaceuticals, Inc., a privately held specialty pharmaceutical company, announced that the U.S. Food and Drug Administration (FDA) has approved GoNitro (nitroglycerin) sublingual powder for acute relief of an attack or prophylaxis of angina pectoris due to coronary artery disease. With this approval, GoNitro is the first and only short-acting nitrate in a stabilized crystal granule form available in single dose packets.

“The FDA’s approval of GoNitro enhances the treatment options available to the more than 8 million U.S. patients suffering with stable angina due to coronary artery disease (CAD), the most common type of heart disease,” commented Quang Pham, Founder and CEO of Espero Pharmaceuticals. “GoNitro is a sublingual nitrate and as this class of drug therapy is a Class I recommendation according to the 2012 Stable Ischemic Heart Disease (SIHD) Guidelines, it should be prescribed to all patients with known SIHD.”

“Short-acting nitrates are the current standard of care for acute relief of an angina attack. The novel features of a sublingual powder in a portable single dose packet make GoNitro attractive to angina patients who need fast relief and want to continue to live an active lifestyle,” said Dr. A. Allen Seals, Fellow of the American College of Cardiology (FACC).

Each individual packet of GoNitro contains 400 mcg of nitroglycerin. The clinical data indicate that the sublingual absorption of nitroglycerin is higher following the administration of GoNitro compared to Nitrolingual® Pumpspray (nitroglycerin lingual spray) which was launched in 1997 and is currently marketed by Espero in the U.S. GoNitro was approved by the FDA via the 505(b) regulatory pathway.

Espero will promote and distribute GoNitro nitroglycerin sublingual powder in the U.S. market under an exclusive licensing agreement with G. Pohl-Boskamp GmbH & Co. KG, (Pohl Boskamp), an established global leader in the short-acting nitrate market. The United States Patent and Trademark Office awarded Pohl Boskamp Patent No. 9,101,592 B2 for stabilized granules containing glyceryl trinitrate (GTN or nitroglycerin) in August 2015.

“GoNitro is the first new dosage form in the short-acting nitrate category in nearly 20 years and we intend to educate healthcare providers and patients about our exciting new product immediately,” remarked Jeff Cole, President & CFO of Espero Pharmaceuticals.

GoNitro will be available in the second half of 2016 and promoted by Espero’s specialty sales force at launch.




Cabozantinib extends advanced RCC overall survival

In continuation of my update on Cabozantinib

Patients with advanced or metastatic renal cell carcinoma (RCC) derive a significant overall survival (OS) benefit from second-line treatment with the multi-tyrosine kinase inhibitor (TKI) cabozantinib relative to everolimus.

These findings come from the final analysis of the phase III METEOR trial in which 330 participants were randomly assigned to receive cabozantinib 60 mg/day and 328 allocated to the mammalian target of rapamycin inhibitor everolimus at a dose of 10 mg/day. All patients had received at least one previous vascular endothelial growth factor receptor TKI.

After a median follow-up of 18.7 and 18.8 months in the cabozantinib and everolimus arms, respectively, the corresponding median OS times were 21.4 and 16.5 months, a significant difference equating to a hazard ratio for death of 0.66.

Progression-free survival was also significantly improved in the cabozantinib arm, as was the objective response rate - findings that were consistent with the previously reported results for the first 375 randomly assigned patients, report Toni Choueiri (Dana-Farber Cancer Institute, Boston, Massachusetts, USA) and team.

They conclude in The Lancet Oncology: "Based on these results, cabozantinib should be considered as a new standard-of-care treatment option for previously treated patients with advanced renal cell carcinoma."

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.

Ref : http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045%2816%2930107-3/abstract

Carfilzomib therapy shows promise for pre-kidney transplant patients

In continuation of my update on carfilzomib,

Early findings by researchers at the University of Cincinnati (UC) College of Medicine suggest that the use of a second generation cancer drug, carfilzomib, may provide an improved approach for the reduction of antibodies in potential kidney transplant candidates. The research team includes members from UC Transplant Clinical Research, UC's Division of Hematology Oncology and the Cincinnati Children's Hospital Medical Center's Biomedical Informatics division.

 carfilzomib

This pre-transplant drug therapy approach is aimed at reducing antibodies in kidney transplant candidates with greater success than with traditional methods and with reduced side effects.

Antibodies are Y-shaped proteins that in most instances are good because they help fight infection, but people can also make antibodies that work against other humans, which is often a major barrier to transplantation.

"Carfilzomib has been well tolerated by the first group of six study patients who experienced antibody reductions between 31 to 100 percent," says the study's lead author Simon Tremblay, PharmD, research associate in the UC College of Medicine's transplant research programs.

The study's preliminary findings will be presented at the annual American Transplant Congress on June 13, in Boston, Mass., where Tremblay will be awarded the American Transplant Society's Young Investigator award.

Since 2008, the UC research team has been developing therapies that target plasma cells—the cells that make antibodies. The first generation of drug therapy studied was the cancer drug bortezomib, a proteasome inhibitor that, like carfilzomib, is already approved by the Food and Drug Administration for treatment of multiple myeloma. In that 50 person study, which was published in 2015, a significant decrease in antibodies was observed. Furthermore, transplanted patients had low rejection rates and the chances of developing a new antibody against their kidney was also low. In addition, in some patients, antibodies remained suppressed for several months—something that has not previously been described with other approaches.

In the same scientific session, James Driscoll, MD, PhD, assistant professor in the UC College of Medicine's Division of Hematology Oncology, will present the results of translational research studies in the carfilzomib-treated patients. Driscoll will present new genomic data on plasma cells isolated from patients prior to and after receiving carfilzomib therapy.

"Our gene expression profiling studies in normal human plasma cells are giving us a detailed, comprehensive view of how plasma cells survive and avoid the death inducing effects of carfilzomib," says Driscoll. These studies, he says, were performed in collaboration with Bruce Aronow, PhD, at Cincinnati Children's.

Carfilzomib is one of four new regimens—described as "second-generation plasma cell targeted therapies that are being evaluated by the UC transplant Clinical Research Team, " says the principal investigator on both studies, E. Steve Woodle, MD, UC Health transplant surgeon and director of the division of transplantation at the UC College of Medicine.

New experimental antibiotic can help combat MRSA infections

A new experimental antibiotic developed by a team of scientists at Rutgers University successfully treats the deadly MRSA infection and restores the efficacy of a commonly prescribed antibiotic that has become ineffective against MRSA.

In research published in the July issue of Antimicrobial Agents and Chemotherapy, Rutgers scientists say that the combination of their newly developed antibiotic, TXA709, with cefdinir, an antibiotic that has been on the market for almost two decades, successfully treated the MRSA infection in animals.

"This is important because even though TXA709 is effective on its own in treating MRSA, combining it with cefdinir - used to treat a wide range of bacterial infections like strep throat, pneumonia, bronchitis and middle ear and sinus infections - makes it even more efficacious, while also significantly reducing the potential for the MRSA bacteria to become resistant in the future," said Daniel Pilch, associate professor in the Department of Pharmacology at Robert Wood Johnson Medical School.

Pilch and fellow scientists are racing to develop a new class of antibiotics to treat methicillin-resistant Staphylococcus aureus (MRSA) infections, which are responsible for 19,000 deaths annually and represent $3 billion in annual health care costs.

The threat of MRSA and other antibiotic-resistant infections has become so severe that the World Health Organization predicts that common infections and minor injuries could become life-threatening because of a lack of drug treatments available to destroy these bacterial infections. Last month the first case in the United States of a patient with an infection resistant to all known antibiotics was reported by the U.S. Centers for Disease Control and Prevention.

"Current standard-of-care drugs for the treatment of MRSA infections are limited," said Pilch. "Furthermore, resistance to these drugs is on the rise, and their clinical effectiveness is likely to diminish in the future."

Pilch said that TXA709 kills MRSA bacteria in a unique manner unlike any other antibiotic in current clinical use, inhibiting the function of a protein, FtsZ, essential for the bacteria to divide and survive. By combining TXA709 with cefdinir, a cephalosporin antibiotic that acts much like penicillin, scientists were able to lower the dosage of the new antibiotic required to eradicate the MRSA infection.

This is significant, Rutgers scientists say, because it decreases the potential for any drug-induced toxicity and side effects that might occur from a higher dosage.

"What is also good about this experimental treatment is that both drugs can be taken orally, which means they can be administered on an outpatient basis," said Pilch, who collaborated with Edmond LaVoie, professor and chair of the Department of Medicinal Chemistry at the Ernest Mario School of Pharmacy at Rutgers. "All but two of the current antibiotics being used clinically to treat MRSA need to be administered intravenously," he said.

Researchers say Phase I clinical trials on the new antibiotic, which will assess and evaluate its safety and effectiveness in humans, are expected to begin next spring.

Ref : http://aac.asm.org/content/59/8/4845.full?sid=949e5603-f4b2-4eec-8e5f-f79d0c758e44