Wednesday, June 29, 2016

New extended-release pills could reduce dosage frequency of some drugs

Researchers from MIT and Brigham and Women's Hospital have designed a new type of pill that, once swallowed, can attach to the lining of the gastrointestinal tract and slowly release its contents. The tablet is engineered so that one side adheres to tissue, while the other repels food and liquids that would otherwise pull it away from the attachment site.

Such extended-release pills could be used to reduce the dosage frequency of some drugs, the researchers say. For example, antibiotics that normally have to be taken two or three times a day could be given just once, making it easier for patients to stick to their dosing schedule.

"This could be adapted to many drugs. Any drug that is dosed frequently could be amenable to this kind of system," says Giovanni Traverso, a research affiliate at MIT's Koch Institute for Integrative Cancer Research, a gastroenterologist at Brigham and Women's Hospital, and one of the senior authors of a paper describing the device in the April 6 issue of the journal Advanced Healthcare Materials.

Robert Langer, the David H. Koch Institute Professor and a member of the Koch Institute, is also a senior author of the paper. The paper's lead author is Young-Ah Lucy Lee, a technical assistant at the Koch Institute.

Two faces
Over the past several decades, Langer's lab has developed many types of materials that can be implanted in the body or attached to the skin for long-term drug release. To achieve similar, long-term drug release in the gastrointestinal tract, the researchers focused on a type of material known as mucoadhesives, which can stick to the mucosal linings of organs such as the stomach.

Scientists have previously explored using this kind of material for drug delivery to the GI tract, but it has proven difficult because food and liquid in the stomach become stuck to the tablet, pulling it away from the tissue before it can deliver its entire drug payload.

"The challenge with mucoadhesives is that the GI tract is a very rough and abrasive environment," says Lee, a 2014 Wellesley College graduate who began this project as her senior thesis.

To overcome this challenge, the researchers decided to create a dual-sided device, also called a Janus device after the two-faced Roman god. One side sticks to mucosal surfaces, while the other is omniphobic, meaning that it repels everything it encounters.

New extended-release pills could reduce dosage frequency of some drugs: Researchers from MIT and Brigham and Women's Hospital have designed a new type of pill that, once swallowed, can attach to the lining of the gastrointestinal tract and slowly release its contents. The tablet is engineered so that one side adheres to tissue, while the other repels food and liquids that would otherwise pull it away from the attachment site.

Tuesday, June 28, 2016

Compound from unique blue-green algae could be key to next anti-cancer drug

Could a slippery glob of algae hold the key to the next anti-cancer drug? According to new research into a compound produced by a unique community of blue-green algae, the answer could be yes.

ChemSpider 2D Image | coibamide A | C65H110N10O16

The compound in question is called coibamide A, discovered eight years ago by scuba-diving scientist Kerry McPhail, Ph.D., of Oregon State University. A new study shows coibamide A has potent anti-cancer activity in mice and cell cultures that model brain tumors and triple negative breast cancer, two of the most aggressive and difficult-to-treat types of cancer.

"The chemical diversity found in nature has always been a significant source of inspiration for drug design and development, but although the medicinal properties of plants have been recognized for thousands of years, marine environments remain relatively unexplored," said Jane Ishmael, Ph.D., associate professor of pharmacology at Oregon State University and the lead author of the new study. "We think that with this compound, nature has already found a way to target some of the specific proteins that are relevant to the growth of tumors."
Ishmael will present this research at the American Society for Pharmacology and Experimental Therapeutics Annual Meeting during Experimental Biology 2016.
McPhail, who specializes in blue-green algae and dives all over the world in search of interesting species, collected the algae during a dive in Panama's Coiba National Park. It turned out to be a mash-up of at least three algal species that grow together on rocks in areas with fast-moving water. In addition to Panama, similar algal communities has been found in the Red Sea and off the coast of South Africa. Blue-green algae, or cyanobacteria, have existed for at least two billion years and are one of the oldest life forms on Earth.

After McPhail isolated coibamide A from the original algal specimen, it was run through a National Cancer Institute screening system that looks for potential anti-cancer activity across 60 different types of cancer. Coibamide A showed a pattern of activity unmatched by any other compound, suggesting it might be able to fight cancer through a mechanism of action unlike that of any existing drug.


Compound from unique blue-green algae could be key to next anti-cancer drug: Could a slippery glob of algae hold the key to the next anti-cancer drug? According to new research into a compound produced by a unique community of blue-green algae, the answer could be yes.

Monday, June 27, 2016

Entresto drug shows added benefit in symptomatic chronic heart failure


In continuation of my update on sacubitril and Valsartan   

The fixed-dose combination of sacubitril and valsartan (trade name: Entresto) has been approved since November 2015 for adults with symptomatic chronic heart failure with reduced pump function (ejection fraction). The German Institute for Quality and Efficiency in Health Care (IQWiG) now examined in an early benefit assessment whether this drug combination offers an added benefit for patients in comparison with the appropriate comparator therapy.

According to the findings, the positive effects regarding mortality, necessity of heart failure hospitalizations, and quality of life predominate. These were not put into question by a negative effect in non-severe side effects; hence overall an indication of considerable added benefit can be derived from the data.
Approval study terminated prematurely
In its dossier, the drug manufacturer used data from a randomized controlled trial, which compared sacubitril/valsartan directly with enalapril, each in combination with a beta-blocker. Since a planned interim analysis was able to show after 51 months already that fewer cardiovascular deaths occurred under sacubitril/valsartan, the study was terminated prematurely.
Fewer deaths due to cardiovascular failure
The data from the dossier showed that all-cause mortality was lower under sacubitril/valsartan than under enalapril, which was mainly caused by fewer cardiovascular deaths.
The results regarding the frequency of hospitalizations due to heart failure were also in favour of the new fixed-dose combination; however, these were limited to patients with a lower severity grade (NYHA class I and II). Finally, the data on health-related quality of life also showed an advantage of sacubitril/valsartan.


Valsartan/sacubitril


Entresto drug shows added benefit in symptomatic chronic heart failure: The fixed-dose combination of sacubitril and valsartan (trade name: Entresto) has been approved since November 2015 for adults with symptomatic chronic heart failure with reduced pump function (ejection fraction). The German Institute for Quality and Efficiency in Health Care (IQWiG) now examined in an early benefit assessment whether this drug combination offers an added benefit for patients in comparison with the appropriate comparator therapy.

Friday, June 24, 2016

Researchers identify severe side effects of Clozapine drug

Clozapine (CLZ) is a "gold standard" drug for managing treatment-resistant schizophrenia (TRS), who do not respond adequately to first-line antipsychotics.

Despite its efficacy with TRS, the use of CLZ is significantly restricted by severe side effects, such as Clozapine-induced agranulocytosis (CIA) or Clozapine-induced granulocytopenia (CIG), which are rare (CIA: 1% and CIG: 3%) but potentially life-threatening.

Ryota Hashimoto, an associate professor at Osaka University, Nakao Iwata, a professor at Fujita Health University, and Taisei Mushiroda, a group director at RIKEN conducted a genome-wide pharmacogenomic analysis and detected a significant association of HLA-B*59:01 with CIA/CIG (CIAG).
HLA-B*59:01 is one of the alleles of HLA-B gene, which is involved in recognition of 'self' and 'non-self' and induction of immune response. HLA- B*59:01 may be clinically useful as a marker to prioritize the CIG patients who have low risk to develop CIA, by accumulating scientific grounds through prospective clinical studies based on this group's research results. The analysis of functions of HLA-B*59:01 is also essential for the clarification of mechanism for CIAG.







Researchers identify severe side effects of Clozapine drug: Clozapine (CLZ) is a 'gold standard' drug for managing treatment-resistant schizophrenia (TRS), who do not respond adequately to first-line antipsychotics.

Thursday, June 23, 2016

Epilepsy drug exposure does not increase newborn orofacial cleft risk

In continuation of my update on  lamotrigine

Pregnant women with epilepsy should not rule out continuing lamotrigine therapy due to concerns that exposure could increase the risk of orofacial clefts (OCs) in their babies, say investigators.

Their findings indicate that the excess risk of OC is less than one in every 550 babies exposed to lamotrigine and therefore they do not support the sixfold increased risk suggested by the North American antiepileptic drug registry in 2006, a signal that led to warnings of the risk being added to patient information.

Helen Dolk (Ulster University, UK) and team looked at data from 21 EUROCAT congenital anomaly registries on more than 10 million births spanning 16 years, including from 2006 onwards when lamotrigine exposure was nearly three times more prevalent.

Congenital anomalies were identified in 226,806 babies and within this group 147 with nonchromosomal anomalies had been exposed to lamotrigine within the first trimester of pregnancy.

Exposure to lamotrigine monotherapy was not associated with a significant increase in the incidence of any OC, isolated OCor cleft palate specifically, with odds ratios of 1.31, 1.45 and 1.69.

"Our estimate of the risk of OC relative to other anomalies is nonsignificant with an upper confidence limit of 2.3", reports the team in Neurology.

They add: "Our results concur with other studies published since the original signal, which do not find a large excess of OC or cleft palate."

They suggest that the difference compared with the North American findings may be due to use of a larger baseline population risk of OC of 1.4 per 1000, compared with 1.1 per 1000.
"The size of the original OC signal may also have been a chance finding, or exacerbated by coexposures", the researchers suggest.

Dolk and colleagues also studied the risk of club foot among the sample, having found a significant excess in a previous study. While the current data gave a significant 83% increased risk with lamotrigine exposure, data from an independent study population of 6.3 million births mainly from 2006 on wards found no increased risk.

Lamotrigine.svg














Epilepsy drug exposure does not increase newborn orofacial cleft risk: Pregnant women with epilepsy should not rule out continuing lamotrigine therapy due to concerns that exposure could increase the risk of orofacial clefts in their babies, say investigators.

Wednesday, June 22, 2016

Losmapimod drug fails to meet primary endpoint in clinical trial



Losmapimod.svg



Patients taking losmapimod, an anti-inflammatory drug currently being developed, for 12 weeks following a heart attack did not show improvements in the trial's primary endpoint, the rate of cardiovascular death, subsequent heart attack or urgent coronary revascularization, which includes placement of a stent or coronary artery bypass surgery, according to research presented at the American College of Cardiology's 65th Annual Scientific Session.

The findings are from the initial phase of a losmapimod trial involving 3,500 patients. Because the trial failed to meet its primary endpoint, study authors said the second phase trial involving 22,000 patients will not go forward. However, in a finding that could warrant further study, the trial offers some evidence that the drug may benefit a subset of patients experiencing the most severe form of heart attack, ST-segment elevation myocardial infarction, or STEMI.

"Overall the results were neutral, showing no evidence of efficacy in our primary analysis," said Michelle O'Donoghue, M.D., a cardiologist and investigator in the TIMI Study Group at Brigham and Women's Hospital and the study's lead author. "We did, however, see intriguing signals toward there potentially being some efficacy in ST-elevation myocardial infarction patients. But because that signal was only within a smaller subgroup, we would need to validate those findings in a new study in order to confirm such an effect."

Although inflammation is a natural part of the body's response to injury, in some cases it can cause more harm than good. Inflammation is thought to increase cardiovascular risk after a heart attack by affecting the healing of heart muscle tissue, increasing the formation of plaque in the arteries and raising the likelihood that plaque will dislodge and cause another heart attack.

Tuesday, June 21, 2016

Liraglutide drug makes highly desirable foods less appealing to people

In continuation of my update on Liraglutide

Understanding the motivations that drive humans to eat is an important consideration in the development of weight loss therapies. Now a study led by researchers at Beth Israel Deaconess Medical Center (BIDMC) helps explain how the diabetes and weight loss drug liraglutide acts on brain receptors to make enticing foods seems less desirable. The findings were recently presented at ENDO 2016, the annual meeting of the Endocrine Society, and will appear in the May issue of the journal Diabetologia.

"We know that everything that controls our body weight and metabolism is integrated by the brain," said senior author Christos S. Mantzoros, MD, Director of the Human Nutrition Unit in the Division of Endocrinology, Diabetes and Metabolism at BIDMC and Professor of Medicine at Harvard Medical School. "This includes both internal stimuli such as hormones and stress, and external stimuli, such as the smell and appearance of enticing foods."

The Mantzoros laboratory has been studying the differences in the brain activity of individuals who are overweight and individuals of normal weight when they are exposed to desirable foods. These differences are quantified through computer-based neurocognitive testing, as well as imaging tests using fMRI (functional magnetic resonance imaging) to observe alterations in the activity of specific brain areas.

In this new work, the researchers examined the glucagon-like peptide (GLP) hormone, which is secreted by the gastrointestinal tract to regulate metabolism. They also examined the drug liraglutide, which is an analog, or mimicker, of the GLP hormone.

Liraglutide prolongs the action of GLP-1 receptors (protein molecules that respond to the GLP hormone's signal) and is known to work through the digestive tract and the pancreas. Previous animal studies had shown that GLP-1 may also act on the brain, but this had not been confirmed in humans.



Liraglutide.png





Liraglutide drug makes highly desirable foods less appealing to people: Understanding the motivations that drive humans to eat is an important consideration in the development of weight loss therapies. Now a study led by researchers at Beth Israel Deaconess Medical Center helps explain how the diabetes and weight loss drug liraglutide acts on brain receptors to make enticing foods seems less desirable.

Monday, June 20, 2016

Investigational drug abaloparatide-SC may help increase bone mineral density in postmenopausal women


Chemical structure for Abaloparatide 





The investigational drug abaloparatide-SC (subcutaneous) may help increase bone mineral density in postmenopausal women and reduce their risk of fracture, new industry-sponsored research suggests. The results of the subgroup analysis within the ACTIVE clinical trial will be presented Friday, April 1, at ENDO 2016, the annual meeting of the Endocrine Society in Boston.

"Abaloparatide-SC increased bone mineral density and reduced the risk of vertebral and nonvertebral fractures consistently in postmenopausal women with osteoporosis regardless of their baseline patient characteristics, including age, bone mineral density, and whether or not they had prior fractures," said lead study author Felicia Cosman, MD, endocrinologist and osteoporosis specialist at Helen Hayes Hospital in West Haverstraw, New York, and professor of clinical medicine at Columbia University in New York City.

"If approved by the Food and Drug Administration (FDA), abaloparatide-SC may have the potential to reduce the risk of fractures in postmenopausal women with osteoporosis across a broad range of patient characteristics," said Cosman, who is also a consultant to Radius Health, Inc., in Waltham, Massachusetts.

The researchers investigated patients enrolled in the randomized, double-blind, multinational phase 3 ACTIVE trial to evaluate the efficacy and safety of 80 micrograms of abaloparatide-SC in preventing fractures in otherwise healthy, ambulatory, postmenopausal women with osteoporosis. Overall, 2,463 patient between 49 and 86 years of age were randomized to take one of three medications for 18 months: 80 micrograms of abaloparatide-SC, 20 micrograms of subcutaneous teriparatide (an FDA-approved prescription drug known to increase bone density and strength), or placebo.


Friday, June 17, 2016

Evolocumab could be more effective than ezetimibe in lowering cholesterol in statin-intolerant patients






Ezetimibe.svg 
Ezetimibe                                                                                                           atorvastatin

In the first major trial of its kind, Cleveland Clinic researchers used a blinded rechallenge with atorvastatin or placebo to objectively confirm the presence of muscle-related symptoms in patients with a history of intolerance to multiple statins and found that evolocumab (a PCSK9 inhibitor) was a more effective option to lower cholesterol than ezetimibe in these patients.
The double-blinded, placebo-controlled clinical trial was designed with two stages:
  • In Phase A, patients were assigned to two groups. Each group was treated for 10 weeks with atorvastatin or placebo in a blinded fashion, then crossed over to the alternate therapy for another 10 weeks. Patients were asked to report any muscle pain or weakness.
  • Patients who reported intolerable muscle symptoms on atorvastatin, but not placebo, moved to Phase B. In this 24-week phase, patients with confirmed statin intolerance were administered two alternative non-statin therapies, ezetimibe vs. evolocumab.
  • The research is being presented at the American College of Cardiology's 65th Annual Scientific Session and simultaneously published online in the Journal of the American Medical Association.
    "Statin intolerance has been a very challenging clinical problem," said Steven Nissen, M.D., chairman of Cardiovascular Medicine at Cleveland Clinic. "The study showed that PCSK9 inhibitors can significantly lower cholesterol in patients with documented statin intolerance, providing an effective treatment for these difficult to manage patients."
    The GAUSS-3 trial enrolled 511 patients with very high levels of LDL cholesterol - averaging more than 210 mg/dL ¬¬- and with a history of muscle-related statin intolerance. More than 80% of participants had previously reported intolerance to three or more statins. The study showed that 42.6 percent of these patients reported muscle pain or weakness on atorvastatin, but not placebo, and 26.5 percent on the placebo, but not atorvastatin.

Thursday, June 16, 2016

Inhalable form of Ambrisentan drug could offer faster-acting treatment option for pulmonary edema

In a new study, researchers show an aerosolized, inhalable form of the drug Ambrisentan could offer a faster-acting treatment option for pulmonary edema, a life-threatening condition in which fluid accumulates in the lungs. Pulmonary edema is a significant risk for anyone spending time at high altitudes, and also affects people with chronic conditions including congestive heart failure and sickle cell anemia.


Ambrisentan structure.svg

High altitude pulmonary edema, or HAPE, results when exposure to reduced oxygen levels causes the arteries in the lungs to constrict, which in turn causes blood pressure within the lungs to rise. Unchecked, this process leads to the rapid accumulation of fluid in the lungs, further reducing a person's ability to get oxygen and causing severe physical impairment.
Currently, Ambrisentan is available only in pill form and takes time to provide relief. The new study, conducted in rats, showed that delivering the drug via an inhaler achieved the same effect with just one-fifth of the typical oral dose.

"This mode of delivery gets the drug directly to the site of the problem—the lungs—providing relief much faster than the oral treatment," said Scott Ferguson, Ph.D. a postdoctoral researcher at the University of Colorado, Denver Anschutz Medical Center, who conducted the research. "Additionally, it requires a much lower dose, likely lowering the incidence of side effects and the cost of treatment."

Ferguson will present this research at the American Physiological Society Annual Meeting during Experimental Biology 2016.



Tuesday, June 14, 2016

Adding liraglutide to diet and exercise plan may help people lose weight, reduce diabetes risk

In continuation of my update on liraglutide

For people with prediabetes who are overweight or obese, adding 3.0 mg of liraglutide for three years to a diet and exercise plan may lead to major health improvements, new industry-sponsored research suggests. The results will be presented Monday, April 4, at ENDO 2016, the annual meeting of the Endocrine Society, in Boston.

"Treatment with subcutaneous liraglutide 3.0 mg for three years, combined with a reduced-calorie diet and increased physical activity, can help people to not only lose weight, but also reduce the risk of Type 2 diabetes and improve cardiometabolic risk factors, which may ultimately reduce the risk of cardiovascular disease - the number one cause of death globally," said lead study author Ken Fujioka, MD, director of nutrition and metabolic research, and director for weight management at Scripps Research Institute in La Jolla, California.

"Type 2 diabetes is a major cause of death in the US. Both obesity, a chronic disease with serious health consequences, and prediabetes, typically defined as blood glucose concentrations that are higher than normal but lower than diabetes thresholds, increase the risk of developing Type 2 diabetes," Fujioka said. "For people with overweight or obesity and prediabetes, losing between 5 and 10 percent of their body weight can reduce their risk of Type 2 diabetes and other obesity-related health consequences."

Monday, June 13, 2016

Researchers design more effective version of FDA-approved epilepsy drug with fewer side effects


Researchers at the University of Pittsburgh School of Medicine and Arts & Sciences have designed a more effective version of an FDA-approved epilepsy drug with the potential for fewer side effects, according to a study published on March 22 in Molecular Pharmacology. The experimental agent also could prove to be a treatment for tinnitus and other disorders caused by volatile neural signaling.

Epilepsy, in which erratic firing of nerve signals causes seizures, affects about 1 percent of people worldwide, said senior investigator Thanos Tzounopoulos, Ph.D., Endowed Chair in Auditory Physiology, associate professor of otolaryngology and member of the Auditory Research Group, University of Pittsburgh School of Medicine. Drugs to treat the disorder primarily work by influencing the transport of sodium, potassium and chloride ions across the nerve cell membrane to try to reduce the excitability of the brain cells.

"Unfortunately, these drugs don't work well in nearly a third of patients and there is a great need for better treatments," Dr. Tzounopoulos said. "We have been able to refine an existing medication so that it acts selectively on certain nerve cell membrane transport channels, which should make it more effective."

he available drug is called retigabine, and while it has improved symptoms for some patients, it can also lead to troublesome side effects, including retinal abnormalities, urinary retention and skin discoloration. Dr. Tzounopoulos was part of a study team that evaluated an earlier modification of retigabine, dubbed SF0034, which is being further developed by SciFluor Life Sciences LLC in Cambridge, Mass.

For the current project, Dr. Tzounopoulos and Peter Wipf, Ph.D., Distinguished University Professor of Chemistry at Pitt, rationally redesigned several structural components of retigabine to further increase its potency. Retigabine works by activating all five types of potassium transport channels in the KCNQ category, but only two of the potassium channels, KCNQ2/3, are important for stabilizing the cell membrane of brain cells involved in hyperexcitability-related disorders, such as epilepsy and tinnitus, Dr. Tzounopoulos explained. The new compound, known as RL648_81 ("RL-81"), targets just those channels.
When the researchers compared the three drugs head-to-head in lab tests, they found RL-81 was 15 times more potent than retigabine and three times more potent than SF0034. Because of its specificity, RL-81 also should have fewer side effects.

The experimental compound could also help people with tinnitus by preventing hyper-excitation of nerve cells in auditory pathways, Dr. Tzounopoulos noted.


       

Researchers design more effective version of FDA-approved epilepsy drug with fewer side effects

Friday, June 10, 2016

NTU researchers make breakthrough to tackle growing concern of antibiotic resistance

Scientists at Nanyang Technological University, Singapore (NTU Singapore) have discovered that antibiotics can continue to be effective if bacteria's cell-to-cell communication and ability to latch on to each other are disrupted.

This research breakthrough is a major step forward in tackling the growing concern of antibiotic resistance, opening up new treatment options for doctors to help patients fight against chronic and persistent bacterial infections.

The study, led by Assistant Professor Yang Liang from the Singapore Centre for Environmental Life Sciences (SCELSE) at NTU, found that a community of bacteria, known as biofilm, can put up a strong line of defence to resist antibiotics. The NTU team has successfully demonstrated how biofilms can be disrupted to let antibiotics continue their good work.

The research was published recently in Nature Communications, a prestigious academic journal by the Nature Publishing Group.

"Many types of bacteria that used to be easily killed by antibiotics have started to develop antibiotic resistance or tolerance, either through acquiring the antibiotic resistant genes or by forming biofilms," said Asst Prof Yang, who also teaches at NTU's School of Biological Sciences.

"The US Center for Disease Control estimates that over 60 per cent of all bacterial infections are related to biofilms. Our study has shown that by disrupting the cell-to-cell communication between bacteria and their ability to latch on to each other, we can compromise the biofilms, leaving the bacteria vulnerable and easily killed by antibiotics."

Bacterial resistance to antibiotics is rapidly growing world-wide and this puts at risk the ability to treat common infections in the community and hospitals.

The World Health Organisation states on its factsheet on Antimicrobial resistance that  "without urgent, coordinated action, the world is heading towards a post-antibiotic era, in which common infections and minor injuries, which have been treatable for decades, can once again kill".

Associate Professor Kevin Pethe, an expert in antibiotic development and infectious diseases from NTU's Lee Kong Chian School of Medicine, said that this discovery may yield new treatment options that doctors can employ against chronic and persistent bacterial infections.
"Being able to disable biofilms and its protective benefits for the bacteria is a big step towards tackling the growing concern of antibiotic resistance," said Assoc Prof Pethe.

"While the scientific community is developing new types of antibiotics and antimicrobial treatments, this discovery may help to buy time by improving the effectiveness of older drugs."

Thursday, June 9, 2016

U of S-led researchers develop novel class of compounds for effective cancer treatment

A novel class of compounds developed by a University of Saskatchewan (U of S)-led research team could yield more effective and less toxic chemotherapy drugs to treat cancer.
Team leader Jonathan Dimmock, a medicinal chemistry researcher in the U of S College of Pharmacy and Nutrition, explained their compounds work by interacting with thiols, naturally occurring chemicals that perform several roles in cells.

The approach offers advantages over existing chemotherapy drugs which target nucleic acids found in DNA.

"Many of the compounds or drugs on the market are those that interfere with nucleic acids," Dimmock said. "These types of compounds can be very toxic and they can also cause problems of their own, like actually inducing cancer."

Thiols offer another approach. Among their many roles are defending cells against oxidization and modulating apoptosis—the process in which worn-out cells die. One of the hallmarks of cancer cells is they don't experience apoptosis and keep dividing out of control.

Umashankar Das, a research scientist in the Department of Chemical and Biological Engineering and long-time collaborator of Dimmock, explained that cancer cells produce an excess of thiols, such as one called glutathione. Knocking down levels of these thiols reduces cancer cells' ability to resist drugs.

"In cancer cells, glutathione expression is very high, which creates a defense mechanism," Das said. "Any anti-cancer compound that enters the cell cannot sustain its effect."

To address this, the team developed a two-stage attack, first knocking down thiol levels to make the cancer cells vulnerable, then hitting them again.

"Over the years, we've developed the theory of 'sequential cytotoxicity,' which simply means you give an initial attack on the cancer cell and then you give a second chemical attack," Dimmock said. "The cancer cells may be more vulnerable to the second attack than normal cells."

Designing molecules that selectively target thiols produced by cancer cells that cause drug resistance is the focus of many years' work by Dimmock, Das and their collaborators. In their latest study, they tested compounds against cells from nine different types of human cancer, including common types affecting blood, colon, breast, prostate, ovaries, kidneys, and lungs.

Das explained that since the compounds they've developed make cancer cells more sensitive to attack, they also remove resistance to standard chemotherapy drugs—a serious problem in current therapies.


Wednesday, June 8, 2016

Plitidepsin in combination with dexamethasone shows top-line results in Phase III multiple myeloma trial



Aplidine.svg Skeletal formula of dexamethasone


In continuation of my updates on  dexamethasone and Aplidin (plitidepsin) 

PharmaMar (MSE:PHM)  announced positive top-line results of its Phase III clinical trial -ADMYRE- with Aplidin (plitidepsin) in combination with dexamethasone versus dexamethasone alone in patients with relapsed/refractory multiple myeloma (MM). Aplidin® has shown a statistically significant 35% reduction in the risk of progression or death over the comparator (p=0.0054). The study has met its primary endpoint.

This pivotal, randomized, open-label, international, multicenter Phase III clinical trial, called ADMYRE, enrolled 255 patients in 83 medical centers across 19 countries (including the U.S, Europe and Asia-Pacific) with relapsed or relapsed and refractory multiple myeloma after at least three but no more than six prior therapeutic regimens.

The efficacy of plitidepsin in combination with dexamethasone versus dexamethasone alone has been evaluated by means of PFS calculated using the IMWG (International Myeloma Working Group) criteria and other secondary efficacy endpoints. A full description of the final ADMYRE data will be submitted for presentation at an upcoming medical meeting.

"Taking into account these positive results, we intend to submit a Marketing Authorization Application to the European Medicines Agency during the last quarter of this year", said Luis Mora, Managing Director of the Oncology Business Unit of PharmaMar, who added "I´d like to thank all the patients, physicians and the dedicated team at PharmaMar who helped participate in the success of this trial. Aplidin® may be our second drug of marine origin in the market".

As previously disclosed PharmaMar has entered into licensing agreements to market and distribute the drug candidate Aplidin with Specialised Therapeutics Asia, covering several Asian countries, Australia and New Zealand; with TTY Biopharm in Taiwan; and with a co-promotion agreement in 8 European countries with Chugai Pharma Europe.