Tuesday, August 10, 2010
Carfilzomib could become new option for patients with relapsed myeloma, IMF says
Monday, August 9, 2010
Impressive Results of Velcade(R) (bortezomib) Based Therapy in Multiple Myeloma...
"This analysis of the PINNACLE study opens the door for additional research into targeted approaches to VELCADE treatment."..
The PINNACLE trial was a Phase II, open-label, single-arm, multicenter study of 155 patients with relapsed/refractory MCL and was the basis of the 2006 approval of VELCADE for the treatment of patients with relapsed/refractory MCL who had received one prior therapy. The overall response rate in the trial was 31 percent, with a median duration of response of 9.3 months; the CR rate was 8 percent, with a median duration of response of 15.4 months.
The Goy analysis used archived tumor samples from 73 patients who participated in the PINNACLE trial. The biopsies were examined for biomarkers associated with poor prognosis in MCL or those regulated by the proteasome. The biomarker levels were then compared to the effect of VELCADE on patients, according to response rates including overall survival and time to progression...
Ref : http://investor.millennium.com/phoenix.zhtml?c=80159&p=irol-newsArticle&ID=1434934&highlight=
Saturday, August 7, 2010
New Class of Drugs for Treating Epileptic Seizures....
A chemical compound called Galanin, that boosts the action of a molecule normally produced in the brain may provide the starting point for a new line of therapies for the treatment of epileptic seizures, according to a new study by scientists at "The Scripps Researcher Institute".
"This compound really provides a new angle for developing drugs to treat seizures," says Scripps Research Assistant Professor Xiaoying Lu..
Galanin is a peptide, a fragment of a protein, produced in the brain to regulate a variety of functions, such as pain, memory, addition, mood, and appetite. In the late 1990s, researchers discovered that galanin is also a potent anticonvulsant.
Recent research suggests that when seizures occur the brain steps up production of galanin, possibly as a way to protect itself against the seizures. As a result, mice engineered to lack galanin are more susceptible to developing seizures.
Because galanin seems to play a role in reducing seizures, several groups of researchers, including those at Scripps Research, have been working to develop drugs that target the galanin system. The first category of such compounds consists of synthetic molecules that mimic galanin's functions (called agonists) and include Galnon, developed by Bartfai's group. Galnon and other galanin agonists have been shown to act as anticonvulsants when given to animals that were rendered prone to developing seizures. But these agonists have several drawbacks as potential therapeutic agents. For one thing, because Galnon acts relativly broadly, it may have unwanted side effects.
Interestingly, now Lu, Roberts, Bartfai, and colleagues at Scripps Research have now designed a compound that targets the galanin system but, unlike the previous agonists, is more selective in its action. The compound, dubbed CYM2503, binds to one of the three receptors for galanin on nerve cells, the galanin receptor type 2 (GalR2). On its own, CYM2503 has no effect on GalR2, but when galanin also binds to the receptor, CYM2503 boosts galanin's function.
The researchers tested the effects of CYM2503 on mice and rats that had received a chemical causing them to have seizures. The animals that received CYM2503 took longer to get the seizures and, when they did, the seizures lasted for a shorter time. Most importantly, when the researchers looked at the animals after 24 hours, the rats that had been treated with CYM2503 had a dramatically higher survival rate than those that had not.
This mechanism of action, modifying a receptor's function, is common to many successful drugs that have been developed for the treatment of a number of conditions, including epilepsy, hyperparathyroidism, and AIDS, but not yet for drug candidates targeting galanin system.
Because CYM2503 only works when galanin, a natural molecule, is also present, the researchers predict it will have fewer side effects than drugs that work on their own. This study provides the first evidence that modulating the GalR2 receptor is an effective strategy for treating seizures, thus opening the door for the development of drugs that target this mechanism.
"It is a double breakthrough" . "The compound is a first new mode-of-action anticonvulsant and it represents a new mechanism of molecular action." Also based on the known functions of the GalR2 receptors, it may also work in treating depression and in protecting the brain from damage," says Lu...
Wednesday, August 4, 2010
Scientists develop obesity drug without neurological side effects....
As per the claim by the researchers, this drug did not cause weight loss or neurological side effects, which rimonabant does, but did have effects on levels of glucose and fats in the blood that should reduce the risk of the serious health consequences of obesity.
The authors therefore hope that this approach of targeting only peripheral CB1R can be translated into the clinic to reduce health risks in obese patients..
Tuesday, August 3, 2010
The Engineering of an Orally Active Conotoxin (Snail Spit) for the Treatment of Neuropathic Pain...
The mollusks use a deadly dose of conotoxins (peptide toxins, e.g., α/ω-conotoxin peptides) that disrupt myriad biological functions. The mollusks inject into passing prey with hypodermic-needle-like teeth that shoot from their mouths like harpoons.
Within the conotoxin brew are several peptides that relieve tough-to-treat neuropathic pain just as well as morphine does but without its addictive properties. Although scientists have tried to turn such compounds into pain relievers, they've been hamstrung with problems administering such drugs. The pain reliever Prialt (see structure, Ziconotide), a synthetic version of ω-conotoxin MVIIA, but it must be injected directly into the spinal cord with a surgically implanted pump.
Now interestingly, scientists in Australia lead by Prof. David Craik (Institute for Molecular Bioscience at the University of Queensland), have managed to engineer a conotoxin that can be taken orally. Researchers found that, by linking the N-terminus of α-conotoxin Vc1.1—a compound derived from Conus victoriae—to its C-terminus, they could make the 16-residue peptide orally active. In the cyclized peptide, which is known as α-conotoxin cVc1.1, the protein's head and tail are tethered by a string of six amino acids—two alanines flanked on each side by two glycines. Prof. Craik says he chose the linker because it was inexpensive, wouldn't add any functionality to the molecule, and would be easy to characterize with nuclear magnetic resonance. In tests with rats, the cyclized peptide proved to be as potent a painkiller as gabapentin, the most popular drug for neuropathic pain, even though the conotoxin-based peptide was administered at a dose that is less than 1% of the dose typically given for gabapentin (other orally prescribed peptide is Ciclosporin a immunosuppressant).
Craik's group has shown that cyclizing larger peptides can make them orally available. His team's analysis of the protein database shows that up to 25% of all proteins have their ends within 10 Å of one another a distance that could easily be spanned with linkers of six to 10 amino acids.
"All you need is for the ends to be roughly close to one another," Prof. Clark says.
Craik says the cyclization also enhances hydrogen bonding across the entire molecule, making it resistant to the endopeptidases that attack a protein's interior amino acids. He says it's sort of like a zipper: "A zipper can be regarded as a series of hydrogen bonds all interlocking together, and when you zip it all up, you've got a beautiful set of coordinated hydrogen bonds. But you've still got two ends, and when you pull apart those two ends of the zipper, then the first hydrogen bond goes, then the next, and then the next. Craik has discovered several other examples of cyclic peptides, which he calls cyclotides (C&EN, April 19, 2004, page 40). He's hoping to use their structural features to guide the engineering of other peptides, as he did with α-conotoxin cVc1.1 At the moment, Craik is trying to raise funds so enough preliminary experiments can be done to file an Investigational New Drug Application. "The most challenging aspect has been just raising the money to get it commercialized," he says. "Pharmaceutical companies are always a little nervous about peptides. We need more success stories so that they'll see peptides not only as fantastic leads but also as potential drugs."...
Ref : http://www3.interscience.wiley.com/journal/123500852/abstract
Monday, August 2, 2010
Phenolic compounds (chlorogenic & neo-chlorogenic acids) in peaches, plums kill breast cancer cells..
Byrne and Dr. Luis Cisneros-Zevallos originally studied the antioxidants and phytonutrients in plums and found them to match or exceed the blueberry which had been considered superior to other fruits in those categories.
"These extracts killed the cancer cells but not the normal cells," Cisneros-Zevallos said...
As per the claim by the researchers, two specific phenolic acid components - chlorogenic and neochlorogenic ( structures, source :ChemBlink) - were responsible for killing the cancer cells while not affecting the normal cells. Researchers add that the two compounds are very common in fruits, the researchers said, but the stone fruits such as plums and peaches have especially high levels. The team said laboratory tests also confirmed that the compounds prevented cancer from growing in animals given the compounds.
"So this is very, very attractive from the point of view of being an alternative to typical chemotherapy which kills normal cells along with cancerous ones," Byrne claims..
Researchers conclude that, phenolic acids present (chlorogenic- left above structure and neo-chlorogenic acids-right below structure) have potential as chemopreventive dietary compounds because of the relatively high growth inhibition exerted on the estrogen-independent MDA-MB-435 breast cancer cell line and low toxicity exerted in the normal MCF-10A cells.
Dr. Byrne plans to examine more fully the lines of the varieties that were tested to see how these compounds might be incorporated into his research of breeding plums and peaches. Dr. Cisneros-Zevallos will continue testing these extracts and compounds in different types of cancer and conduct further studies of the molecular mechanisms involved. Hope they come up with substantial results to support their claim....
Saturday, July 31, 2010
Scientists identify new catalytic process to create pharmaceuticals with less chemical waste
I have read about co-operative catalysis (heterogeneous catalysts), but this is something interesting to me..
"Cooperative catalysis by carbens and Lewis acids in a highly stereoselective route to γ-lactams."
Ref : http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.727.html
Friday, July 30, 2010
Valproic Acid Shown to Halt Vision Loss in Patients With Retinitis Pigmentosa...
UMass Medical School will be the coordinating site for a $2.1 million, three-year clinical trial funded by the Foundation Fighting Blindness/National Neurovision Research Institute quantifying the potential of valproic acid as a treatment for RP. The clinical trials will build upon Kaushal's work in the retrospective study in which patients were treated off-label with doses of valproic acid ranging from 500mg to 750mg per day over the course of two to six months. Treated at a time when patients normally experience rapid vision loss as a result of RP, five of the seven patients in the study experienced improvement in their field of vision.
"Inflammation and cell death are key components of RP," said Kaushal. "It appears the valproic acid protects photoreceptor cells from this. If our observations can be further substantiated by randomized clinical trials then low dose valproic acid could have tremendous potential to help the thousands of people suffering from RP."
Dr. Kaushal and colleagues, having previously demonstrated the use of the small molecule, retinoid, as a pharmacological agent capable of increasing the yield of properly folded RP rhodopsins, began screening other small molecules for similar attributes. Because of its already known qualities as a potent inhibitor of the inflammatory response pathway and cell death, valproic acid was believed to have a unique profile making it a potential candidate as a retinal disease treatment...
Thursday, July 29, 2010
New tablet for type 2 diabetes sufferers.....
Wednesday, July 28, 2010
Cytrx’s tamibarotene achieves molecular complete remission in advanced acute promyelocytic leukemia..
"This event represents a very significant milestone for CytRx and our drug candidate tamibarotene. Tamibarotene has saved a life and nothing can compare with that," said CytRx President and CEO Steven A. Kriegsman. "These important results indicate that tamibarotene warrants further evaluation as a third-line treatment and in combination as a first-line treatment for APL. We are also considering developing tamibarotene for other cancers as well.
Previously published reports indicate that tamibarotene is 10-times more potent and may be better tolerated than all trans retinoic acid (ATRA). Researchers believe that the combination of tamibarotene and arsenic trioxide (ATO) could produce a complete response rate similar to the ATRA and ATO combination with fewer toxicities such as APL differentiation syndrome. The company is currently conducting a dose escalation trial combining tamibarotene with ATO as an important step in their ultimate goal of evaluating tamibarotene as a first-line treatment for APL. The company claims that, In addition to maintaining a complete remission six months following the last dose, tamibarotene was also well tolerated. In the CytRx's STAR-1 registration trial, patient was treated with tamibarotene for 56 days at the Department of Biopathology at the University of Rome 'Tor Vergata'. A molecular complete remission in the bone marrow was documented at the end of the treatment period and again six months following the last treatment with tamibarotene...