Scientists modify structure of cancer drug to enhance ability to pass through blood-brain barrier

In efforts to develop new treatments for brain cancer, scientists from Johns Hopkins Drug Discovery and the Kimmel Cancer Center's Bloomberg~Kimmel Institute for Cancer Immunotherapy report they have altered the structure of an experimental drug that seems to enhance its ability to slip through the mostly impermeable blood-brain barrier. Results of their proof-of-concept experiments in monkeys, published Aug. 25 in the Journal of Medicinal Chemistry, show a tenfold better delivery of the drug to the brain compared with the rest of animals' bodies.

The scientists began with an experimental anti-cancer drug cultivated from bacteria found in Peruvian soil more than 70 years ago. Called 6 diazo-5-oxo L norleucine, or DON, the drug blocks the cellular use of the protein building block glutamine. On its own, DON has shrunk tumors in clinical trials of people with a variety of advanced cancers, but its damage to the gastrointestinal system, a glutton for glutamine, ultimately proved too toxic for humans, say the scientists.

"We wondered whether we could make a safer and more tolerable form of DON by enhancing its brain penetration and limiting its exposure to the rest of the body and, thus, toxicity," says Barbara Slusher, Ph.D., professor of neurology, medicine, psychiatry, neuroscience and oncology at the Johns Hopkins University School of Medicine and director of Johns Hopkins Drug Discovery.

Slusher teamed up with Johns Hopkins Kimmel Cancer Center immunologist Jonathan Powell, M.D., Ph.D., who has studied how cancer cells use different metabolic pathways to evade destruction by immune cells.

"A tumor uses aggressive metabolism to grow, sucking up all the surrounding nutrients, which leads to a very oxygen-poor, acidic environment that is not conducive to cancer-killing immune cells," says Powell, who is an associate director of the Bloomberg~Kimmel Institute for Cancer Immunotherapy.

Powell suspects that using glutamine-blocking drugs to target tumor metabolism could make the environment around a tumor less harsh, slow down its growth and give the immune system a chance to attack the cancer cells. "The hope is to enhance certain immunotherapy drugs by adding such glutamine antagonists," says Powell.

To alter DON, Slusher and her drug discovery team designed and synthesized various derivatives, focused on making the drug more lipid soluble, or lipophillic, a trait known to aid passage through the blood-brain barrier. Once inside the brain, the new derivatives are designed to rapidly metabolize back to DON.

They gave DON and an altered derivative, dubbed 5c, intravenously to two monkeys and, 30 minutes later, measured the amount of the drugs in the monkeys' cerebrospinal fluid and circulating plasma, which is the liquid portion of blood that remains after blood cells, platelets and other cellular components are removed. The monkey that received DON had about seven times less concentration of the drug in its blood than the monkey that received 5c. In the monkey that received 5c, which converts to DON in the brain, the scientists found 10 times more DON in the cerebrospinal fluid than the monkey treated with unaltered DON.

"We showed that we can modify these drugs to have further specificity to target the brain and limit toxicity to the rest of the body," says Slusher. "This strategy can potentially be used to develop tailored drugs for different cancers."

Scientists modify structure of cancer drug to enhance ability to pass through blood-brain barrier:

U.S. FDA panel narrowly backs Cempra's antibiotic solithromycin

A panel of federal health advisers has narrowly recommended approval for an experimental antibiotic from Cempra Inc., a small North Carolina drugmaker.

The Food and Drug Administration's outside experts voted 7-6 in favor of the drug, saying its effectiveness outweighed risks of liver toxicityseen in company studies. The vote is nonbinding but the FDA often follows the advice of its panelists.

Cempra is one of a handful of drugmakers developing new antibiotics amid growing bacterial resistance to decades-old drugs like penicillin.

On Wednesday Cempra shares plunged more than 60 percent after the FDA posted an online review highlighting irregular liver enzyme measurements reported with the drug, called solithromycin. 

U.S. FDA panel narrowly backs Cempra's antibiotic solithromycin

The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models

A new compound, discovered jointly by international pharmaceutical company Servier, headquartered in France, and Vernalis (R&D), a company based in the UK, has been shown by researchers at the Walter and Eliza Hall Institute and Servier to block a protein that is essential for the sustained growth of up to a quarter of all cancers.

The research presents a new way to efficiently kill these cancerous cells and holds promise for the treatment of blood cancers such as acute myeloid leukemia, lymphoma and multiple myeloma, as well as solid cancers such as melanoma and cancers of the lung and breast. It is published online in the journal Nature.

The Servier compound -- S63845 -- targets a protein of the BCL2 family, called MCL1, which is essential for the sustained survival of these cancer cells.

Institute scientist Associate Professor Guillaume Lessene, who led the Walter and Eliza Hall Institute's research team in Melbourne, Australia, said the work provided the first clear preclinical evidence that inhibiting MCL1 was effective in targeting several cancer types.

"MCL1 is important for many cancers because it is a pro-survival protein that allows the cancerous cells to evade the process of programmed cell death that normally removes cancer cells from the body," Associate Professor Lessene said. "Extensive studies performed in a variety of cancer models have shown that S63845 potently targets cancer cells dependent on MCL1 for their survival."

The institute team of Associate Professor Lessene worked with haematologist Associate Professor Andrew Wei and Dr Donia Moujalled from The Alfred Hospital and Servier scientists, to demonstrate that not only was S63845 effective against several cancer types, but that it could also be delivered at doses that were well tolerated by normal cells.

Dr Olivier Geneste, Director of Oncology Research at Servier, said this preclinical research represented major findings regarding the druggability of MCL1, a valuable and highly challenging target. "S63845 was discovered through collaboration with the fragment and structure based discovery expertise at Vernalis," he said. "As part of the ongoing Servier / Novartis collaboration on this target class, clinical development of a MCL1 inhibitor should be launched in the near future."

Associate Professor Lessene said the research provided further evidence of the usefulness of a new class of anti-cancer drugs called BH3 mimetics. "BH3 mimetics inhibit a group of proteins known as the 'pro-survival BCL-2 proteins'," he said. "MCL1 is a member of this protein family, and inhibiting it activates the process of programmed cell death. Walter and Eliza Hall Institute researchers revealed the role of BCL-2 in cancer more than 28 years ago and the essential role of MCL1 for the survival of malignant cells four years ago."

Ref : 

The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models : Nature : Nature Research

The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models

A new compound, discovered jointly by international pharmaceutical company Servier, headquartered in France, and Vernalis (R&D), a company based in the UK, has been shown by researchers at the Walter and Eliza Hall Institute and Servier to block a protein that is essential for the sustained growth of up to a quarter of all cancers.

The research presents a new way to efficiently kill these cancerous cells and holds promise for the treatment of blood cancers such as acute myeloid leukemia, lymphoma and multiple myeloma, as well as solid cancers such as melanoma and cancers of the lung and breast. It is published online in the journal Nature.

The Servier compound -- S63845 -- targets a protein of the BCL2 family, called MCL1, which is essential for the sustained survival of these cancer cells.

Institute scientist Associate Professor Guillaume Lessene, who led the Walter and Eliza Hall Institute's research team in Melbourne, Australia, said the work provided the first clear preclinical evidence that inhibiting MCL1 was effective in targeting several cancer types.

"MCL1 is important for many cancers because it is a pro-survival protein that allows the cancerous cells to evade the process of programmed cell death that normally removes cancer cells from the body," Associate Professor Lessene said. "Extensive studies performed in a variety of cancer models have shown that S63845 potently targets cancer cells dependent on MCL1 for their survival."

The institute team of Associate Professor Lessene worked with haematologist Associate Professor Andrew Wei and Dr Donia Moujalled from The Alfred Hospital and Servier scientists, to demonstrate that not only was S63845 effective against several cancer types, but that it could also be delivered at doses that were well tolerated by normal cells.

Dr Olivier Geneste, Director of Oncology Research at Servier, said this preclinical research represented major findings regarding the druggability of MCL1, a valuable and highly challenging target. "S63845 was discovered through collaboration with the fragment and structure based discovery expertise at Vernalis," he said. "As part of the ongoing Servier / Novartis collaboration on this target class, clinical development of a MCL1 inhibitor should be launched in the near future."

Associate Professor Lessene said the research provided further evidence of the usefulness of a new class of anti-cancer drugs called BH3 mimetics. "BH3 mimetics inhibit a group of proteins known as the 'pro-survival BCL-2 proteins'," he said. "MCL1 is a member of this protein family, and inhibiting it activates the process of programmed cell death. Walter and Eliza Hall Institute researchers revealed the role of BCL-2 in cancer more than 28 years ago and the essential role of MCL1 for the survival of malignant cells four years ago."

Ref : 

The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models : Nature : Nature Research

Combination of two drugs could be effective strategy to target T-cell lymphocytic leukemia

Researchers have determined that two Phase 1 drugs (CX-4945 and JQ1) can work together to efficiently kill T-cell acute lymphoblastic leukemia cells while having minimal impact on normal blood cells.

 JQ1     CX-4945

Although both drugs were previously tested as single agents in clinical trials to treat cancers, the success of the combined actions on cancer cells was previously unknown until now. The findings appear in the journal Haematologica.

Acute lymphoblastic leukemia, also known as acute lymphocytic leukemia or acute lymphoid leukemia, is a form of cancer of the white blood cells, characterized by the overproduction and accumulation of cancerous, immature white blood cells, known as lymphoblasts. Despite treatment improvement, T-cell leukemia remains fatal in 20 percent of pediatric and 50 percent of adult patients. Both CX-4945 and JQ1 are in clinical trials now as single agents to treat solid and hematological cancers.

"Previous studies provided us a rationale to test the combination of CX-4945 and JQ1 on refractory/relapsed T-cell leukemia," said corresponding author Hui Feng, MD, PhD, assistant professor of pharmacology & experimental therapeutics at Boston University School of Medicine (BUSM). "Our findings suggest that the combination treatment of CX-4945 and JQ1 could be an effective strategy to target refractory/relapsed T-cell leukemia," she added.

According to the researchers the efficacy of using a combination of JQ1 and CX-4945 in treating other cancers should also be investigated.

Ref : http://www.haematologica.org/content/early/2016/10/03/haematol.2016.154013

Cranberry extract disrupts communication between bacteria linked to pervasive infections

In continuation of my update on cranberry

Scientists from McGill University and INRS-Institut Armand-Frappier in Canada recently released a novel investigation showing that cranberry extract successfully interrupted the communication between bacteria associated with problematic and pervasive infections. The authors of the data published in Nature's Scientific Reports, Eric Déziel, professor-investigator at INRS-Institut Armand-Frappier and Nathalie Tufenkji, professor at McGill University, state that not only do the results provide insights into how cranberry compounds may work, they also have implications for the development of alternative approaches to control infections.

Previously published work has shown that the American cranberry (Vaccinium macrocarpon L) contains compounds -- such as proanthocyanidins (PACs) -- that provide meaningful antioxidant, anti-adhesion and anti-microbial properties that help fend off illness. Given this, the scientific team hypothesized that cranberries may also have an anti-virulence potential. They wanted to know if these cranberry compounds could help manage bacterial infections. By feeding fruit flies -- a commonly used model for studying human infections -- cranberry extract, the team discovered that cranberry provided flies protection from a bacterial infection and they lived longer than their cranberry-free counterparts. In essence, the cranberry extract reduced the severity of the bacterial infection.

Study author, Dr. Tufenkji, elaborates on what this might mean for humans, as opposed to flies, "This means that cranberries could be part of the arsenal used to manage infections and potentially minimize the dependence on antibiotics for the global public."

To further explain cranberries' impact on bacteria, Dr. Déziel said, "Cranberry PACs interrupt the ability for bacteria to communicate with each other, spread and become virulent -- a process known as quorum sensing. The cranberry extract successfully interferes with the chain of events associated with the spread and severity of chronic bacterial infections."

Added to the evidence of cranberry's role in preventing recurrent urinary tract infections by blocking bacteria from sticking to cell walls, the current study suggests that PACs may help control the virulence or spread of potentially dangerous bacterial infections around the world.

New drug appears to decrease inflammation in the brain linked to Alzheimer's disease

An experimental drug shows promise in treating Alzheimer's disease by preventing inflammation and removing abnormal protein clumps in the brain that are associated with the disease, suggests a study in mice presented at the ANESTHESIOLOGY® 2016 annual meeting.

A key characteristic of Alzheimer's disease is the development of abnormal protein clumps called amyloid plaques and tangled bundles of fibers in the brain. These changes cause inflammation in the brain and damage to the neurons. This progressive damage leads to memory loss, confusion and dementia. The new drug, known as NTRX-07, appears to decrease this inflammation in the brain, while preserving neurons and regenerative cells in the brain.

"This drug may reduce inflammation in the brain, which is linked to Alzheimer's disease," said lead researcher Mohamed Naguib, M.D., a physician anesthesiologist in the Department of General Anesthesiology at the Cleveland Clinic and professor of anesthesiology at the Cleveland Clinic Lerner College of Medicine. "NTRX-07 uses a different mechanism than many other Alzheimer's drugs currently available, as it targets the cause of the disease, not just the symptoms."

The authors discovered NTRX -07's memory-restoring abilities while studying the drug's potential to treat a complex, chronic pain condition called neuropathic pain. "Patients who have neuropathic pain have chronic neuroinflammation," said Dr. Naguib. "This is a compound that blunts that inflammation."

Researchers tested NTRX -07 on mice bred to have similar brain neurodegenerative issues as seen in Alzheimer's. They found that inflammation produced in response to the disease caused changes in the brain's microglia cells - immune cells that typically remove dangerous amyloid plaques (protein clumps) in the brain. As the amyloid plaques accumulated in the mice, the microglia (immune cells) were unable to remove them, leading to inflammation and damage to nerve cells, which caused decreased cognitive ability.

Microglia cells have receptors on the surface called CB2 receptors, which when activated can produce an anti-inflammatory response. NTRX -07 targets CB2 receptors, which leads to decreased inflammation and prevents damage to the brain tissue. The new drug improved removal of abnormal amyloid plaques and improved memory performance and other cognitive skills.

The drug also increased levels of a protein called SOX2, which has been shown to help new brain cells develop and protect the brain in people with Alzheimer's disease. The study found in mice treated with NTRX-07, the levels of SOX2 were restored to normal levels. In contrast, mice treated with a placebo showed decreased levels of SOX2, active inflammation in the brain, poor removal of amyloid plaques, and poor memory performance.

FDA approves new therapy for initial treatment of soft tissue sarcoma

In continuation of my update on Doxorubicin

The U.S. Food and Drug Administration today granted accelerated approval to Lartruvo (olaratumab) with doxorubicin to treat adults with certain types of soft tissue sarcoma (STS), which are cancers that develop in muscles, fat, tendons or other soft tissues. Lartruvo is approved for use with the FDA-approved chemotherapy drug doxorubicin for the treatment of patients with STS who cannot be cured with radiation or surgery and who have a type of STS for which an anthracycline (chemotherapy) is an appropriate treatment.

"For these patients, Lartruvo, added to doxorubicin, provides a new treatment option," said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA's Center for Drug Evaluation and Research and acting director of the FDA's Oncology Center of Excellence. "This is the first new therapy approved by the FDA for the initial treatment of soft tissue sarcoma since doxorubicin's approval more than 40 years ago."

The National Cancer Institute estimates that 12,310 new cases of STS and nearly 5,000 deaths are likely to occur from the disease in 2016. The most common treatment for STS that cannot be removed by surgery is treatment with doxorubicin alone or with other drugs. STS includes a wide variety of tumors arising in the muscle, fat, blood vessels, nerves, tendons or the lining of the joints.

Lartruvo is a platelet-derived growth factor (PDGF) receptor-alpha blocking antibody. When stimulated, PDGF receptors cause tumor growth. Lartruvo works by blocking these receptors, which may help slow or stop tumor growth.

The safety and efficacy of Lartruvo were studied in a randomized clinical trial involving 133 patients with more than 25 different subtypes of metastatic STS. Patients received either Lartruvo with doxorubicin or doxorubicin alone. This trial measured the length of time patients lived after treatment (overall survival), the length of time tumors did not grow after treatment (progression-free survival) and the percentage of patients who experienced shrinkage of their tumors (overall response rate). Patients in this trial who received Lartruvo with doxorubicin had a statistically significant improvement in overall survival: the median survival was 26.5 months compared to 14.7 months for patients who received doxorubicin alone. Patients who received Lartruvo with doxorubicin had a median progression-free survival of 8.2 months compared to 4.4 months for patients who received doxorubicin alone. Tumor shrinkage was 18.2 percent for patients who received Lartruvo with doxorubicin and 7.5 percent for those who received doxorubicin alone.

Lartruvo has serious risks including infusion-related reactions and embryo-fetal harm. Infusion-related reactions include low blood pressure, fever, chills and rash. The most common side effects of treatment with Lartruvo are nausea, fatigue, low levels of white blood cells (neutropenia), musculoskeletal pain, inflammation of the mucous membranes (mucositis), hair loss (alopecia), vomiting, diarrhea, decreased appetite, abdominal pain, nerve damage (neuropathy) and headache.

The FDA granted the Lartruvo application fast track designation, breakthrough therapy designation and priority review status because preliminary clinical evidence indicated that it may offer a substantial improvement in effectiveness in the treatment of a serious or life-threatening disease or condition. The FDA is approving Lartruvo under the agency's accelerated approval program, which allows approval of a drug to treat a serious or life-threatening disease or condition based on clinical data showing the drug has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit. The sponsor is conducting a larger study, which is currently underway, to further explore the effectiveness of Lartruvo across the multiple subtypes of STS.

Lartruvo also received orphan drug designation, which provides incentives such as tax credits, user fee waivers and eligibility for exclusivity to assist and encourage the development of drugs intended to treat rare diseases.

New clinical study to examine novel dietary approach for TNBC

A new clinical trial for women with clinically aggressive triple-negative breast cancer (TNBC) will test a novel theory: Will a diet low in an essential nutrient make TNBC cells more vulnerable to cell killing by a new cancer drug?

Women with TNBC have limited treatment options apart from chemotherapy because their tumor cells lack three proteins - estrogen, progesterone and human epidermal growth factor receptors -- commonly targeted with standard treatments. But chemotherapy often fails in these patients, so there is an urgent need to develop new therapies.

Dr. Vince Cryns, who is leading the study along with Dr. Ruth O'Regan, says his team has developed an entirely new approach for TNBC that combines diet with a new cancer drug. This drug, called ONC201, is the first of a new class of cancer drugs that selectively kills tumor cells but not normal cells. It is being developed by the Philadelphia company Oncoceutics.

The clinical trial is based on studies by the Cryns lab showing that a diet low in the essential nutrient methionine make tumor cells more susceptible to cell killing by ONC201. In this phase II trial, funded by the V Foundation for Cancer Research and the Wisconsin Partnership Program, 112 women with metastatic TNBC will be randomized to a diet low in methionine or a regular diet followed by ONC201.

"Our strategy is the first of its kind to use diet to prime TNBC cells to respond to a targeted cancer drug,'' says Cryns.

"I think this will be a really attractive trial to patients, because it is safe and the drug is well-tolerated - it's not like chemotherapy,'' O'Regan says. "Our advisory board of breast-cancer survivors is very excited about this trial." The trial will recruit patients across the state through the Wisconsin Oncology Network, which partners community hospitals with the University of Wisconsin Carbone Cancer Center.

That trial is expected to begin sometime in early 2017.

Before that, Cryns and O'Regan are launching a smaller trial to better understand the effects of the diet on TNBC. In this trial, funded by the Avon Breast Cancer Crusade, 25 women who are newly diagnosed with TNBC will take a low-methionine diet for one to three-weeks before their definitive surgery or chemotherapy. The trial will examine the impact of the low methionine diet on the growth and molecular characteristics of the tumors as well as the effects on body composition and metabolic health.

"A low methionine diet has been shown to reduce body fat and improve metabolic health in rodents so we want to determine whether a short-term reduction in methionine has metabolic benefits in women with TNBC,'' Cryns says. These metabolic effects could be an additional health benefit of this dietary intervention.

Folinic acid treatment could help improve language and communication skills of children with ASD

In continuation of my update on Folinic acid

Prescription doses of folinic acid, which is a reduced form of a B vitamin known as folate, could help improve the language and communication skills of children with autism spectrum disorder (ASD). These are the preliminary findings from a placebo-controlled trial in which children were randomized to receive either high-dose folinic acid or a placebo, says lead author Richard Frye of Arkansas Children's Research Institute in the US. The study, which is published in Springer Nature's journal Molecular Psychiatry, also identified a specific blood marker that can be used to predict which patients have the best chance to respond to the treatment.

Up to two percent of American children are said to experience symptoms that place them on the autism spectrum. Many of these children have difficulty communicating and interacting with others, especially within a social setting. Researchers do not yet fully understand all the reasons behind the development of ASD and, importantly, there are currently no approved treatments that address the core symptoms of this disorder.

"The only currently approved medications for autism are both antipsychotic medications that address non-core symptoms and can lead to unwanted side effects," says John Slattery, a co-author of the study.

Scientific research has linked this disorder to abnormalities in the metabolism of folate as well as genes that are involved in folate metabolism. Certain studies have also shown that the offspring of women who took folate supplements before conception and during pregnancy had a lower risk of having a child with ASD.

About ten years ago a condition, known as cerebral folate deficiency (CFD), was described in which the concentration of folate is below normal in the central nervous system but not in the blood. Many children with CFD had ASD symptoms and responded well to treatment with high-dose folinic acid.

Previously Frye's team could show that folate receptor autoantibodies were found with a high prevalence in children with ASD. In the current study, these researchers found that participants with folate receptor autoantibodies had a more favourable response to the folinic acid treatment. This leads the way to a test that might be useful for clinicians to determine if high-dose folinic acid might be a treatment for a particular child with ASD. The deleterious effects of folate receptor antibodies on brain development and function are now confirmed in a laboratory rat model.

"Improvement in verbal communication was significantly greater in participants receiving folinic acid as compared with those receiving the placebo," says Frye. He adds that the findings should be considered preliminary until the treatment has been assessed further in larger long-term studies.

The researchers indicated they were very pleased with the positive findings of this study, but caution that more research is needed in order to replicate the findings in a larger population.