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.

Study on common bacterium presents new pathway to combat gastric cancers

A common bacterium that more than half of people have in their gut can use hydrogen gas present in the gastrointestinal tract to inject a cancer-causing toxin into otherwise healthy cells, according to a recently published study led by University of Georgia researchers.

The bacterium's reliance on hydrogen presents a pathway to potential new treatment and preventive measures in fighting gastric cancers, which kill more than 700,000 people per year, said corresponding author Robert Maier, Georgia Research Alliance Ramsey Eminent Scholar of Microbial Physiology in the Franklin College of Arts and Sciences.

Previous studies solidified the relationship between stomach ulcers and cancer and certain strains of Helicobacter pylori, a stomach-dwelling bacterium that causes 90 percent of all gastric cancers. Earlier research also found a link between a toxin known as CagA, or cytotoxin-associated gene A, and cancer formation, but the new study exposes how the bacterium uses hydrogen as an energy source to inject CagA into cells, resulting in gastric cancer, Maier said.

"There are many known microbes in the human gut that produce hydrogen and others that use hydrogen. The implications of the study are that if we can alter a person's microflora, the bacterial makeup of their gut, we can put bacteria in there that don't produce hydrogen or put in an extra dose of harmless bacteria that use hydrogen," Maier said. "If we can do that, there will be less hydrogen for H. pylori to use, which will essentially starve this bacteria out and result in less cancer."

Changing the microbial makeup of a person's gut sounds complicated, but scientists are already exploring ways to do so through the use of probiotics, antibiotics, nutritional regimes and even fecal transplants.

Although many people carry the H. pylori bacterium, it can take decades for the infection to develop into cancer, providing an opening for aggressive preventive measures in people who have a high risk of developing tumors, said lead author Ge Wang, a senior research scientist in the Department of Microbiology. The presence of H. pylori strains with both CagA and high hydrogen-utilizing activity within patients can potentially serve as biomarkers for predicting future cancer development.

An earlier study led by Maier, "Molecular Hydrogen as an Energy Source for Helicobacter pylori," published by the American Association for the Advancement of Science in 2002, showed that the presence of hydrogen in the gastric chamber was important for bacterial growth, but it wasn't until the current study that researchers learned of the strong cancer connection: The bacterium harnesses the energy from hydrogen gas, via an enzyme known as hydrogenase, to severely disrupt host cell function, leading to cancer.

"If hydrogen is in the gastric mucosa, of course a bacterium will use it," Maier said. "It's an excellent energy source for many bacteria out in nature. But we didn't realize that pathogens like H. pylori could have access to it inside an animal in a way that enables the bacterium to inject this toxin into a host cell and damage it."

Not all strains of the bacteria cause cancer, but those with CagA are known carcinogens. Using human-derived gastric cells, Wang analyzed the hydrogenase activity in the cells that were infected with different strains — both cancer causing and non-carcinogenic — of H. pylori. He found more activity in the cancer-causing strains. After using genetic engineering to knock out the DNA fragment containing the hydrogenase-inducing genes, which prevented those strains from deriving energy from hydrogen, he found that the strain he created could no longer move the cancer-causing toxin into the gastric cells. Collaborators at Vanderbilt University took Wang's in vitro model and adapted it to test the theory in gerbils, which confirmed the UGA researchers' findings.

Cocoa flavanol consumption linked to improvements in cardiometabolic biomarkers

To the tantalizing delight of chocolate lovers everywhere, a number of recent studies employing various methods have suggested that compounds in cocoa called flavanols could benefit cardiovascular health. Now a systematic review and meta-analysis of 19 randomized controlled trials (RCTs) of cocoa consumption reveals some further pieces of supporting evidence.

The meta-analysis in the Journal of Nutrition, an assessment of the combined evidence from all 19 RCTs, focused on whether consumption of flavanol-rich cocoa products was associated with improvements in specific circulating biomarkers of cardiometabolic health as compared to consuming placebos with negligible cocoa flavanol content. In all, 1,139 volunteers were involved in these trials.

"Our meta-analysis of RCTs characterizes how cocoa flavanols affect cardiometabolic biomarkers, providing guidance in designing large, definitive prevention trials against diabetes and cardiovascular disease in future work," said corresponding author Dr. Simin Liu, professor and director of the Center for Global Cardiometabolic Health at Brown University who worked with epidemiology graduate student and lead author Xiaochen Lin. "We found that cocoa flavanol intake may reduce dyslipidemia (elevated triglycerides), insulin resistance and systemic inflammation, which are all major subclinical risk factors for cardiometabolic diseases."

Liu noted some limitations in the trials. All studies were small and of short duration, not all of the biomarkers tracked in these studies changed for the better, and none of the studies were designed to test directly whether cocoa flavanol consumption leads to reduced cases of heart attacks or type 2 diabetes.

But taking into account some of these heterogeneities across studies, the team's meta-analysis summarizing data from 19 trials found potential beneficial effects of flavanol-rich cocoa on cardiometabolic health. There were small-to-modest but statistically significant improvements among those who ate flavanol-rich cocoa product vs. those who did not.

The greatest effects were seen among trial volunteers who ate between 200 and 600 milligrams of flavanols a day (based on their cocoa consumption). They saw significant declines in blood glucose and insulin, as well as another indicator of insulin resistance called HOMA-IR. They also saw an increase in HDL, or "good," cholesterol. Those consuming higher doses saw some of the insulin resistance benefits and a drop in triglycerides, but not a significant increase in HDL. Those with lower doses of flavanols only saw a significant HDL benefit.

In general, Lin said, where there were benefits they were evident for both women and men and didn't depend on what physical form the flavanol-rich cocoa product was consumed in --dark chocolate vs. a beverage, for example.

"The treatment groups of the trials included in our meta-analysis are primarily dark chocolate -- a few were using cocoa powder-based beverages," Lin said. "Therefore, the findings from the current study apparently shouldn't be generalized to different sorts of chocolate candies or white chocolates, of which the content of sugar/food additives could be substantially higher than that of the dark chocolate."

The authors therefore concluded, "Our study highlights the urgent need for large, long-term RCTs that improve our understanding of how the short-term benefits of cocoa flavanol intake on cardiometabolic biomarkers may be translated into clinical outcomes."

Animal studies examine role of raspberry products in weight management and motor function

 

The latest issue of the Journal of Berry Research includes two new animal studies that investigate the effects of raspberry consumption in helping to support healthy weight and motor function (strength, balance and coordination). Future studies are needed to support the results found in these studies.

One-cup of frozen red raspberries has only 80 calories, is an excellent source of vitamin C, and provides nine grams of fiber (more fiber than any other berry). Like most berries, raspberries are a low-glycemic index food. Raspberries contain phytochemicals, such as ellagic acid, quercetin, gallic acid, cyanidins, pelargonidins, catechins, kaempferol and salicylic acid.

Animal and cellular studies examining how phytochemicals may work at the molecular level suggest that certain phytochemicals may help slow age-related declines. Age is the number one risk factor for many chronic diseases. Likewise, obesity is a major risk factor for chronic disease. These latest animal studies examine two important areas of health where raspberry products may play a role in weight management and also support motor function.

OBESITY

An animal study conducted by researchers at Oregon State University found that when added to a high-fat, high-sucrose diet, raspberry products and raspberry phytochemicals were found to significantly decrease weight gain associated with a high-fat, high calorie diet. Raspberry juice and raspberry puree concentrates were provided at 10% of total energy (the equivalent of 200 calories in a 2,000 calorie diet), and a combination of ellagic acid and raspberry ketone were provided at 0.2% weight/weight.

In the study, 76 male mice were divided into the following diets: a low-fat control group (10% calories from fat), a high-fat control group (45% calories from fat) and seven "high-fat treatment" groups that included a high-fat diet plus either raspberry juice concentrate, raspberry puree concentrate, raspberry fruit powder, raspberry seed extract, raspberry ketone and a combination of equal parts of ellagic acid and raspberry ketone.

"The addition of raspberry juice concentrate, raspberry puree concentrate and the combination of ellagic acid plus raspberry ketones to the high fat diet significantly reduced weight gain observed in the high-fat fed mice," said Dr. Neil Shay, Principal Investigator. "In the case of the high-fat and raspberry juice concentrate diet, weight gain was reduced to a level that was statistically equivalent to the weight gain of the low-fat fed mice, despite the fact that all high-fat fed groups consumed the same amount of calories and more energy than the low-fat control group throughout the study."

The researchers concluded that the intake of a reasonable level of some raspberry food products may influence some of the metabolic consequences of consuming a high-fat, high-calorie diet in the development of obesity in male mice.

"We hope that the findings from this study can help guide the design of future clinical trials," said Dr. Shay.

MOTOR FUNCTION

Researchers from the Human Nutrition Research Center on Aging at Tufts University evaluated the effectiveness of a red raspberry-supplemented diet on age-sensitive measures of learning, memory and motor performance in older rats.

In this 10-week study, red raspberry supplementation was found to significantly improve motor skills. Specifically, compared to rats fed a standard well-balanced diet, rats fed a diet supplemented with freeze-dried raspberry extract performed better on tests which measured psychomotor coordination and balance, as well as tests that measure muscle tone, strength, and stamina.

"These results may have important implications for healthy aging," said lead researcher Barbara Shukitt-Hale, PhD. "While further research in humans is necessary, animal model studies are helpful in identifying deficits associated with normal aging."

Combination treatment with CDK4/6 inhibitor improves progression-free survival in HR breast cancer patients

The addition of the CDK4/6 inhibitor ribociclib to letrozole therapy significantly improves progression-free survival in postmenopausal women with hormone receptor-positive advanced breast cancer, researchers reported today at the ESMO 2016 Congress in Copenhagen.

The first interim analysis of data from the randomized, double-blind MONALEESA study showed a 44% improvement in progression-free survival with ribociclib plus letrozole as a first-line treatment combination.

"This was THE definitive study to demonstrate the superiority of the combination of ribociclib and letrozole over letrozole alone," said principle investigator, Professor Gabriel Hortobagyi, from the University of Texas MD Anderson Cancer Center in Houston, Texas, US.

Researchers randomized 668 postmenopausal women with hormone receptor-positive, HER2-negative advanced breast cancer, who had not undergone any prior systemic treatment, to ribociclib (600 mg/day, 3 weeks on/1 week off) and letrozole (2.5 mg/day, continuous), or letrozole plus placebo.

                                

ribociclib                                                                                  letrozole

In the ribociclib arm, there was a 44% improvement in the primary objective of progression-free survival compared to the placebo arm (HR: 0.556, p = 0.00000329). Median progression-free survival was 14.7 months in the placebo arm, but was not reached in the ribociclib arm at data cut-off.

"The results of this trial represent a compelling proof of principle, and suggest a paradigm shift in metastatic, HR+ breast cancer. They also suggest that testing combinations of ribociclib with other inhibitors of various signaling pathways might lead to additional progress in the management of several subtypes of breast cancer," Hortobagyi said.

Patients with measurable disease at baseline showed a significantly higher objective response rate to ribociclib plus letrozole compared to letrozole alone (53% vs. 37%; p=0.00028), and improved clinical benefit rate (80% vs. 72% p=0.02).

Serious adverse events occurred in fewer than 5% of patients in both arms but other adverse events were significantly more common in the ribociclib arm. Neutropenia occurred in 59% of patients in the ribociclib arm compared to 1% of the placebo arm; leukopenia occurred in 21% vs 1%; lymphopenia in 7% vs. 1%, and patients in the ribociclib arm had a higher incidence of elevated alanine aminotransferase and elevated aspartate aminotransferase.

The number of deaths in the study was too low to enable a reliable analysis of the impact of ribociclib therapy on overall survival.

Commenting on the findings, Professor Giuseppe Curigliano, Director of the New Drugs and Early Drug Development for Innovative Therapies Division at the European Institute of Oncology, Milan, Italy, said, "I believe the results of this study are significant because now we have a new CDK4/6 inhibitor for patients with estrogen-receptor positive metastatic breast cancer, in addition to palbociclib (already FDA approved) and abemaciclib (under development)."

"The addition of ribociclib to letrozole does increase the rate of toxicity, but overall, if we evaluate the magnitude of clinical benefit, there is definitely a benefit to be gained from adding ribociclib."

Curigliano also suggested that further studies of ribociclib should examine the use of cancer biomarkers to better identify patients who would respond to the combination.

Researchers report high response rate with single drug in phase I/II trial of paediatric brain cancer

In continuation of my update on Dabrafenib

A high response rate with a single drug in a phase I/II trial of paediatric brain tumour has set the stage for combination therapy with higher response and lower toxicity, researchers reported at the ESMO 2016 Congress in Copenhagen.

"The likelihood of curing a child with a low-grade glioma is very high," said lead author Dr Mark Kieran, Director, Paediatric Medical Neuro-Oncology, Dana-Farber Boston Children's, Boston, US. "In fact many children don't suffer lifelong from the tumour but rather from the cognitive damage and secondary malignancies caused by radiation therapy."

He continued: "The development of drugs that target the specific causative mutation of the tumour and avoid long-term toxicities may revolutionise the treatment of paediatric brain cancer."

Up to 10% of paediatric low-grade gliomas have the BRAF V600 mutation. Today researchers reported the phase I and phase II trial results of dabrafenib, a selective inhibitor of mutant protein. The study included 32 patients aged one to 16 years with BRAF V600-mutant low-grade glioma, of whom 15 participated in the phase I trial and 17 were in the phase II trial.

The phase I trial, which focused on determining the recommended phase II dose, did not find any significant dose-limiting toxicities. The recommended dose was therefore based on the pharmacokinetic activity of the drug and was set at 4.5 mg/kg/day for patients aged 12 years and older and 5.25 mg/kg/day for patients under the age of 12.

The phase II trial assessed toxicities with dabrafenib, and whether it could stop tumours from growing or cause them to shrink. "Paediatric low-grade gliomas are a little bit unique in that patients can survive their entire life with a tumour that stops growing, unlike other cancers which need to be completely removed," said Kieran.

The objective response rate was 72%, with 23 out of 32 patients responding to the drug. In two patients the tumour disappeared and in 11 patients the tumour shrunk by more than half - of these 13 patients eight are still on the therapy. Thirteen patients had stable disease of at least six months' duration, and 11 of them are still on the therapy.

Regarding adverse events, there were no cases of squamous cell carcinoma, which has been observed in previous trials of dabrafenib in adults with BRAF V600E positive tumours, most of whom have melanoma. One patient had an allergic reaction to the drug. Minor side effects were similar to those seen in adults, including transient fever, upset stomach, fatigue and skin rash.

Studies in adults with BRAF V600E mutations have shown that combining a BRAF inhibitor with a MEK inhibitor reduces toxicity and produces more activity for a longer period of time. The encouraging results with dabrafenib in children have provided the impetus for phase I and II trials with a MEK inhibitor to determine the dose and toxicities, and a trial combining the two drugs is now underway.

Kieran said: "We want to make the response rate with dabrafenib even higher by combining it with a MEK inhibitor since that works in adults. Adding two drugs together normally produces twice as much toxicity. But much of the toxicity from the BRAF drug is inhibited by the MEK drug, so the combination is less toxic than either drug alone, which is unusual."

Kieran concluded: "The finding that dabrafenib can shrink tumours or stop them growing is exciting and has led to trials with a MEK inhibitor and now the combination of drugs. This combined therapy may completely change the way we treat low-grade gliomas in children with this mutation. The caveat is that these targeted personalised drugs are relatively new so we need to make sure that they don't have any long-term developmental toxicities in children."

Commenting on the findings, Professor Michael Weller, chairman, Department of Neurology, University Hospital Zurich, Switzerland, said: "The encouraging thing about this study is that this targeted treatment seems to work. At the moment in neuro-oncology we know almost everything about the molecular make-up of gliomas in adults and in children but we have not really been able to translate all this knowledge into an effective therapeutic agent."

"These findings will have implications for clinical practice because many parents are willing to travel all around the world to get access to a promising treatment," he continued. "We have almost no randomised data for brain tumours in children, at least for gliomas, because the tumours are too rare and the trials are difficult for ethical reasons."

Weller concluded: "We need longer follow up to find out how long the responses last and whether we get long-term survival. And then of course in children we want to know if there is any long-term toxicity."