Sense oligonucleotide antidote reverses actions of antisense antithrombotic drug, prevents bleeding

Researchers from Isis Pharmaceuticals (Carlsbad, CA) and Prysis Biotechnologies (Pudong, Shanghai, China) have demonstrated proof-of-concept for using a sense oligonucleotide to undo the effects of an antisense drug, an antithrombotic agent in this novel study. The sense oligonucleotide antidote reversed the actions of the antisense antithrombotic drug in the mouse model and prevented the bleeding that commonly occurs with anti-coagulation therapy, as described in an article in Nucleic Acid Therapeutics, a peer-reviewed journal from Mary Ann Liebert, Inc. publishers. The article is available free on the Nucleic Acid Therapeutics website until November 13, 2015.

Jeff Crosby, Chenguang Zhao, Hong Zhang, A. Robert MacLeod, Shuling Guo, and Brett Monia treated mice with an antisense oligonucleotide drug designed to suppress the ability of liver and blood cells to produce prothrombin, a protein required for blood to coagulate. Subsequent treatment with a prothrombin sense oligonucleotide antidote led to a dose-dependent reversal of the antisense drug activity and the return of prothrombin to normal levels. The authors describe the study design and the implications of their findings in the article "Reversing Antisense Oligonucleotide Activity with a Sense Oligonucleotide Antidote: Proof of Concept Targeting Prothrombin."

"An elegant demonstration of the feasibility of reversing the effects of an antisense oligonucleotide in vivo by administering an antidote oligonucleotide," says Executive Editor Graham C. Parker, PhD, The Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, MI. "It will be fascinating to now see how the chemistry can be optimized to achieve translation to clinical efficacy."

Sense oligonucleotide antidote reverses actions of antisense antithrombotic drug,
prevents bleeding

Sense oligonucleotide antidote reverses actions of antisense antithrombotic drug, prevents bleeding

FDA Approves Vyondys 53 (golodirsen) Injection for the Treatment of Duchenne Muscular Dystrophy (DMD) in Patients Amenable to Skipping Exon 53

In continuation of my update on oligonucleotide.

Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today announced that the U.S. Food and Drug Administration (FDA) has approved Vyondys 53™ (golodirsen). Vyondys 53 is an antisense oligonucleotide from Sarepta’s phosphorodiamidate morpholino oligomer (PMO) platform, indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients with a confirmed mutation amenable to exon 53 skipping. This indication is based on a statistically significant increase in dystrophin production in skeletal muscle observed in patients treated with Vyondys 53, which is reasonably likely to predict clinical benefit for those patients who are exon 53 amenable. Consistent with the accelerated approval pathway, the continued approval of Vyondys 53 may be contingent on confirmation of a clinical benefit in this post-marketing confirmatory trial.

Sarepta’s placebo-controlled, post-marketing confirmatory trial to support the Vyondys 53 accelerated approval – titled ESSENCE – is currently enrolling and expected to conclude by 2024.

Hypersensitivity reactions, including rash, pyrexia (fever), pruritis, urticaria (hives), dermatitis, and skin exfoliation have occurred in patients who were treated with Vyondys 53. Renal toxicity was observed in animal studies. Although not observed in the clinical studies with Vyondys 53, renal toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. The most common adverse reactions that occurred in at least 20% of Vyondys 53-treated patients and more frequently than in placebo-treated patients were headache (41%), pyrexia (41%), fall (29%), abdominal pain (27%), nasopharyngitis (27%), cough (27%), vomiting (27%), and nausea (20%).

Following a New Drug Application (NDA) submission to and review by the Division of Neurology Products (the Review Division) for Vyondys 53, which the Review Division recommended for approval, the Office of Drug Evaluation 1 issued a complete response letter (CRL) in August of 2019. Thereafter, Sarepta made a formal dispute resolution request as outlined in relevant FDA Guidance. With the support of the Review Division, the matters raised in the CRL were rapidly evaluated and resolved by Dr. Peter Stein, Director of the Office of New Drugs (OND). OND granted the Company’s appeal and Sarepta re-submitted its NDA to the Review Division, which worked expeditiously to review and approve Vyondys 53.

“Today is monumental for Sarepta and, more importantly, for the DMD community,” said Doug Ingram, president and chief executive officer, Sarepta. “Vyondys 53, our second approved exon-skipping RNA therapy for DMD, may treat up to 8% of the DMD community, representing those patients who have a confirmed exon 53 amenable mutation. Along with EXONDYS 51® (eteplirsen), we now offer treatment options for approximately 20% of those with DMD in the U.S.”

Ingram continued, “In the span of four months, we commenced and completed the formal dispute resolution process culminating in the grant of our appeal, resubmitted our NDA and obtained an approval – a great benefit to DMD patients awaiting treatment. This unprecedented timing could not have been achieved without the commitment of the Review Division under the leadership of Dr. Billy Dunn, and the Office of New Drugs, which expeditiously heard and granted our appeal. Along with the DMD community, we owe our gratitude to both the Review Division and the OND for their objective, evidence-based approach to this review, for their fairness, and for the sense of urgency with which they addressed and resolved the CRL and granted this approval.”

“With the approval of Vyondys 53, up to another 8% of Duchenne families will have a therapy to treat this devastating disease,” said Pat Furlong, founding president and chief executive officer, Parent Project Muscular Dystrophy (PPMD). “For 25 years, PPMD has been working with researchers, clinicians, industry, and the Duchenne community to find treatments for all people living with Duchenne. And while we need to ensure that these approved therapies are accessible for patients, today we celebrate this approval and thank Sarepta for their continued leadership in the fight to end Duchenne.”

Vyondys 53 is priced at parity to EXONDYS 51, the price of which has not increased since its launch in 2016. Patients and physicians can access more information at www.SareptAssist.com or by calling 1-888-727-3782.

About Vyondys 53

Vyondys 53 is an antisense oligonucleotide indicated for the treatment of Duchenne muscular dystrophy in patients who have a confirmed mutation of the DMD gene that is amenable to exon 53 skipping. Vyondys 53 uses Sarepta’s proprietary phosphorodiamidate morpholino oligomer (PMO) chemistry and exon-skipping technology to bind to exon 53 of dystrophin pre-mRNA, resulting in exclusion, or “skipping,” of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 53 skipping. Exon skipping is intended to allow for production of an internally truncated dystrophin protein.

https://www.rxlist.com/vyondys-53-drug.htm

Compound reverses symptoms of Alzheimer's disease in mice

"It reversed learning and memory deficits and brain inflammation in mice that are genetically engineered to model Alzheimer's disease," Farr said. "Our current findings suggest that the compound, which is called antisense oligonucleotide (OL-1), is a potential treatment for Alzheimer's disease."

Farr cautioned that the experiment was conducted in a mouse model. Like any drug, before an antisense compound could be tested in human clinical trials, toxicity tests need to be completed.

Antisense is a strand of molecules that bind to messenger RNA, launching a cascade of cellular events that turns off a certain gene.

In this case, OL-1 blocks the translation of RNA, which triggers a process that keeps excess amyloid beta protein from being produced. The specific antisense significantly decreased the over expression of a substance called amyloid beta protein precursor, which normalized the amount of amyloid beta protein in the body. Excess amyloid beta protein is believed to be partially responsible for the formation of plaque in
the brain of patients who have Alzheimer's disease.

Scientists tested OL-1 in a type of mouse that overexpresses a mutant form of the human amyloid beta precursor gene. Previously they had tested the substance in a mouse model that has a natural mutation causing it to overproduce mouse amyloid beta. Like people who have Alzheimer's disease, both types of mice have age-related impairments in learning and memory, elevated levels of amyloid beta protein that stay in the brain and increased inflammation and oxidative damage to the hippocampus  the part of the brain responsible for learning and memory.

"To be effective in humans, OL-1 would need to be effective at suppressing production of human amyloid beta protein," Farr said.

Scientists compared the mice that were genetically engineered to overproduce human amyloid beta protein with a wild strain, which served as the control. All of the wild strain received random antisense, while about half of the genetically engineered mice received random antisense and half received OL-1. 

The mice were given a series of tests designed to measure memory, learning and appropriate behavior, such as going through a maze, exploring an unfamiliar location and recognizing an object. 

Scientists found that learning and memory improved in the genetically engineered mice that received OL-1 compared to the genetically engineered mice that received random antisense. Learning and memory were the same among genetically engineered mice that received OL-1 and wild mice that received random antisense.

They also tested the effect of administering the drug through the central nervous system, so it crossed the blood brain barrier to enter the brain directly, and of giving it through a vein in the tail, so it circulated through the bloodstream in the body. They found where the drug was injected had little effect on learning and memory.

Ref http://iospress.metapress.com/content/px72758w0158103u/?issue=4&genre=article&spage=1005&issn=1387-2877&volume=40

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Compound
reverses symptoms of Alzheimer's disease in mice  

New approach to kill specific bacteria could be alternative to antibiotics

A new approach to killing C. difficile that silences key bacterial genes while sparing other bacteria may provide a new way to treat the most common hospital-acquired bacterial infection in the United States, according to researchers.

While conventional antibiotics treat bacterial infections, they can also cause a condition in the colon called C. difficile infection, due to the drug killing both good and bad bacteria in the gut.

In a lab, researchers created three new antibiotics that kill C. difficile by preventing the expression of bacterial genes that are important for its survival. This approach -- called antisense therapy -- allows the drug to kill only C. difficile, unlike many antibiotics that kill multiple forms of bacteria.

"We were able to show that these drugs can zero in on and kill C. difficile bacteria while leaving other bacteria alone," said Arun Sharma, associate professor of pharmacology, Penn State College of Medicine. "We're still working to refine these drugs and make them even better, with the eventual goal of testing them clinically."

David Stewart, an associate professor of surgery at the University of Arizona who along with Sharma is a co-principal investigator on this study, said the drug works in a completely different manner than the antibiotics currently used.

"These drugs are organism specific, meaning that they target only one kind of bacteria, kind of like smart antibiotics," Stewart said. "They're precise. And that's especially important with C. difficile infections because this bacteria is uniquely, selectively advantaged to exploit ecological disturbances in the human gut."

While C. difficile is normally present in the gut, other "good" bacteria are also present, and all these bacteria contribute to a person's microbiome. When a person's microbiome is healthy and balanced, it keeps bad bacteria like C. difficile under control.

But if a patient takes an antibiotic for another condition, the antibiotic kills many different types of bacteria, including the good ones keeping C. difficile under control. This allows C. difficile to thrive, causing an infection that can result in severe gastrointestinal symptoms. Since antibiotics can contribute to C. difficile infections, the researchers said a new, alternative treatment for these infections is desirable.

"Ideally, a treatment for C. difficile would have no effect on other bacteria," Stewart said.

The researchers, who recently published their findings in the Journal of Antibiotics, said that while most antibiotics lack organismal specificity -- the ability to target just one type of organism -- antisense treatments show great potential for being able to target only specific bacteria.

"Our antisense antibiotics contain genetic material which is complementary to bacterial genetic material, so we designed our genetic material to target specific genes in C. difficile," Stewart said. "And when our genetic material binds to the bacterial genetic material, it prevents the expression of bacterial genes. And that can cause C. difficile to die."

The drug tested in the study consisted of two components: the antisense compound that targeted the genetic material in C. difficile -- referred to as an antisense oligonucleotide (ASO) -- and a carrier compound that transported the ASO into the bacteria, referred to by the research team as a CAB. The researchers tested three versions of the drug, each with a different version of CAB.

The researchers tested each compound to see how much of the drug was required to kill C. difficile bacteria, whether it was toxic or not to human colon cells, and whether it also harmed other bacteria normally found in the gut -- like E. coli.

"Ultimately, we wanted these compounds to deliver the drug into the C. difficile bacteria without hurting other bacteria or the patient," Sharma said. "After testing these three, we found that one carrier in particular -- CYDE-21 -- was the best at delivering an effective dose of the drug into the bacteria."

 

In the future, the researchers said they will conduct further studies to continue to refine the carriers to increase their capacity and minimize their effect on other bacteria and human cells.

"In this study, as a first effort, the carrier is pretty good, and we'd like to do even better," Stewart said. "It has minimal antibacterial activity, minimal toxicity and it's an effective carrier of our cargo. So what we're working on now is modifying our carriers for future testing in preparation for animal studies."

Ref : https://www.nature.com/articles/s41429-018-0056-9

Phase III clinical study of trabedersen....

In my earlier blogs, did mention about the "antisense drugs belonging to (Geron corporation) phosphorothioate antisense oligonucleotides" . I did also mention that there are many companies working with this field (antisense). Yes now Antisense Pharma GmbH has announced that, it has received the approval by Health Canada for its pivotal Phase III clinical trial SAPPHIRE in patients with recurrent or refractory anaplastic astrocytoma. The SAPPHIRE study is a randomized, active-controlled, clinical trial designed to confirm the efficacy and safety of the investigational drug trabedersen (AP 12009 a phosphorothioate antisense oligonucleotide), observed in previous clinical studies. Trabedersen is being investigated as monotherapy compared to current standard therapy with temozolomide (alternatively BCNU (carmustine)). The results of a previous randomized, active-controlled Phase IIb study show that the novel, targeted therapy holds significant promise. Hope in the days to come, more drugs from this class of compounds...

Ref :http://www.anticancer.de/index.php?id=38.

I found this video, interesting (mode of action of trabedersen)

FDA Approves Amondys 45 (casimersen) Injection for the Treatment of Duchenne Muscular Dystrophy (DMD) in Patients Amenable to Skipping Exon 45

In continuation of my update on antisense oligonucleotides 

Sarepta Therapeutics, Inc. the leader in precision genetic medicine for rare diseases, today announced that the U.S. Food and Drug Administration (FDA) has approved Amondys 45 (casimersen). Amondys 45 is an antisense oligonucleotide from Sarepta’s phosphorodiamidate morpholino oligomer (PMO) platform, indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients with a confirmed mutation amenable to exon 45 skipping. This indication is based on a statistically significant increase in dystrophin production in skeletal muscle observed in patients treated with Amondys 45, which is reasonably likely to predict clinical benefit for those patients who are exon 45 amenable. Consistent with the accelerated approval pathway, the continued approval of Amondys 45 may be contingent on confirmation of a clinical benefit in confirmatory trials.

The ESSENCE trial – a placebo-controlled confirmatory trial to support the Amondys 45 approval – is ongoing and expected to conclude in 2024.

Although kidney toxicity was not observed in the clinical studies with Amondys 45, kidney toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. Kidney function should be monitored in patients taking Amondys 45. In the clinical trial, the most common adverse reactions observed in at least 20% of patients treated with Amondys 45 and at least 5% more frequently than in placebo were (Amondys 45, placebo): upper respiratory tract infections (65%, 55%), cough (33%, 26%), fever (33%, 23%), headache (32%, 19%), joint pain (21%, 10%), and pain in mouth and throat (21%, 7%).

“This is an important day for Sarepta and, far more importantly, for the patients that we serve. After years of scientific commitment, investment and development, the approval of Amondys 45, Sarepta’s third approved RNA therapy, offers treatment to the 8% of the DMD community who have a confirmed exon 45 amenable mutation,” said Doug Ingram, president and chief executive officer, Sarepta. “Along with our other approved RNA therapies, we can now offer treatment options for nearly 30% of Duchenne patients in the U.S. And our commitment to bring therapies to the greatest percentage of the DMD community as soon as possible continues.”

“Decades of research and commitment have fueled and now accelerate our progress towards new treatments for Duchenne,” said Marissa Penrod, founder of Team Joseph and parent of an 18-year old with Duchenne. “The extraordinary diligence and persistence of the Duchenne community – patients and families, clinicians and researchers – have led us to today’s approval, where we now have exon-skipping treatments for almost a third of those with Duchenne.”   

FDA Approves Wainua (eplontersen) for the Treatment of Adults with Polyneuropathy of Hereditary Transthyretin-Mediated Amyloidosis

Ionis Pharmaceuticals, Inc. (Nasdaq: IONS) announced  the U.S. Food and Drug Administration (FDA)   approval of  Ionis and AstraZeneca's Wainua™ (eplontersen) for the treatment of the polyneuropathy of hereditary transthyretin-mediated amyloidosis in adults, commonly referred to as hATTR-PN or ATTRv-PN. Wainua is the only approved medicine for the treatment of ATTRv-PN that can be self-administered via an auto-injector.

"Many people living with hereditary transthyretin-mediated amyloid polyneuropathy are unable to fully enjoy their lives because of the relentless, progressive and debilitating  effects of the disease," said Michael J. Polydefkis, M.D., professor of neurology at Johns Hopkins University School of Medicine and an investigator in the NEURO-TTRansform study. "Approval of Wainua represents a meaningful advancement in treatment, one that gives those who are living with transthyretin-mediated amyloid polyneuropathy help managing the disease."

ATTRv-PN is a debilitating disease that leads to peripheral nerve damage with motor disability within five years of diagnosis and, without treatment, is generally fatal within a decade. Wainua is a ligand-conjugated antisense oligonucleotide (LICA) medicine designed to reduce the production of TTR protein at its source.

"The FDA approval of Wainua marks an important milestone for people living with hereditary transthyretin-mediated amyloid polyneuropathy, who will now have an effective, well-tolerated treatment that can be self-administered via auto-injector to combat this devastating disease," said Brett P. Monia, Ph.D., chief executive officer at Ionis. "It is also a pivotal moment for Ionis as Wainua will be the first in a steady cadence of potential commercial launches for the company. We are proud to have discovered and, together with AstraZeneca, developed Wainua, and are grateful to the patients, caregivers and investigators who participated in our clinical studies, as well as for the dedication of our scientists and researchers."

"People with hereditary transthyretin-mediated amyloid polyneuropathy, and other forms of amyloidosis, are often misdiagnosed since symptoms can mirror other conditions," said Isabelle Lousada, President and CEO, Amyloidosis Research Consortium "The path to getting an accurate diagnosis can often be a long, arduous journey and it is critical that a timely and accurate diagnosis is made not only for the individual experiencing symptoms but for their families and loved ones. It is exciting to see new innovations coming through and increased efforts to raise awareness in an area that has often been overlooked or neglected."

Ref : https://en.wikipedia.org/wiki/Eplontersen

Ref : https://go.drugbank.com/drugs/DB16199

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FDA Approves Wainua (eplontersen) for the Treatment of Adults with Polyneuropathy of Hereditary Transthyretin-Mediated Amyloidosis

A new experimental drug "antagomir" (antisense oligonucleotide) as an anti- miR-21 agent..

MicroRNAs are small scraps of RNA comprising around 20 nucleotides and it is only recently that scientists have discovered their power which is they can regulate the expression (switching on and off) of a large number of human genes (they are like "master controllers"). And also these are the culprits (when microRNAs don't appear in the right place at the right time within cells) for diseases such as cancer, viral infections, inflammatory diseases and metabolic disorders. The potential to use them as targets for drugs is obvious and possibly explains why this is one of the fastest growing areas of development for new drugs and treatments.

Scientists already knew that microRNA was involved in switching genes on and off in the heart, but the underlying mechanisms and how they relate to the development of particular types of heart disease and their potential as drug targets were still relatively unknown.

Thum and colleagues discovered that miR-21 was expressed in the heart's fibroblast cells (cells that make the scaffolding of collagen or connective tissue that hold the shape of the organ) and were in greater numbers in lab mice bred to have heart failure and also in human tissue from patients who had heart failure.

In this study they showed that increasing expression of miR-21 changed the way that signals behaved in a previously unknown stress response pathway that involved the gene sprouty-1 and the MAP-kinase signaling pathway. In turn, increasing the activity of the MAP-kinase pathway led to a number of signs of heart failure, such as enhanced fibroblast survival, increased secretion of factors like fibroblast growth factor, tissue scarring (fibrosis), and cardiac dysfunction including cellular hypertrophy.

The researchers proved they could administer anti-miR-21 effectively to the heart by monitoring it with fluorescence staining. Then, in a mouse transaortic constriction model of human heart failure, they showed that anti-miR-21 silenced increased expression of miR-21 and corrected downstream changes in sprouty-1 and MAP-kinase signaling.

The interesting thing is their conclusion : Anti-miR-21, showed the most statistically significant improvement in the heart failure mouse model when given before induction of heart failure and for as long as three weeks afterward and it might be possible to target entire disease pathways with one drug. Contrats Dr. Thomas Thum.

Positive results from mipomersen- a new hope for FH sufferers...

About Familial hypercholesterolemia :

Familial hypercholesterolemia (also spelled familial hypercholesterolaemia) is a genetic disorder characterized by high cholesterol levels, specifically very high low-density lipoprotein (LDL, "bad cholesterol") levels, in the blood and early cardiovascular disease. Many patients have mutations in the LDLR gene that encodes the LDL receptor protein, which normally removes LDL from the circulation, or apolipoprotein B (ApoB), which is the part of LDL that binds with the receptor; mutations in other genes are rare. Patients who have one abnormal copy (are heterozygous) of the LDLR gene may have premature cardiovascular disease at the age of 30 to 40. Having two abnormal copies (being homozygous) may cause severe cardiovascular disease in childhood. Heterozygous FH is a common genetic disorder, occurring in 1:500 people in most countries; homozygous FH is much rarer, occurring in 1 in a million births.

Heterozygous (FH) is normally treated with statins, bile acid sequestrants or other hypolipidemic agents that lower cholesterol levels. New cases are generally offered genetic counseling. Homozygous FH often does not respond to medical therapy and may require other treatments, including LDL apheresis (removal of LDL in a method similar to dialysis) and occasionally liver transplantation.

Recently, Genzyme Corp. and Isis Pharmaceuticals Inc have come up with some intresting results from the drug mipomersen [mipomersen - is an antisense oligonucleotide, with phosphorothioate linkage at 5'- postion and 2'-O-methoxymethyl moety] ( phase 3). As per the claim by the companies, the study met its primary endpoint in an intent-to-treat analysis, with a 25 percent reduction in LDL-cholesterol after 26 weeks of treatment, vs. 3 percent for placebo (p<0.001)>.

The trial met all of its secondary and tertiary endpoints, suggesting that mipomersen may offer potential benefits to patients beyond LDL-C reduction. Patients treated with mipomersen experienced a 27 percent reduction in apolipoprotein B vs. 3 percent for placebo; a 21 percent reduction in total cholesterol vs. 2 percent for placebo; and a 25 percent reduction in non-HDL cholesterol vs. 3 percent for placebo (all p<0.001).>Mipomersen patients’ HDL-C levels increased 15 percent (p=0.035 vs. placebo), which combined with the LDL-C reductions observed, resulted in improved LDL/HDL ratios, a ratio considered an important measure of cardiovascular risk. Mipomersen patients’ LDL/HDL ratios decreased by 34% (p<0.001>Mipomersen a representative of Isis’ leadership in the field of RNA targeted therapeutics will bring a sigh of relief to the sufferers of FH, in the days to come.

I had an opportunity to work with ISIS (as contract R & D, Innovasynth Technologies Limited, Khopoli) and really excited to see the results..

Ref : http://ir.isispharm.com/phoenix.zhtml?c=222170&p=irol-newsArticle&ID=1356364&highlight=

Telomerase & Telomerase inhibition.......

When I read about the Nobel prize in Medicine, was really excited because the scientists who discovered the enzyme telomerase got the Nobel prize for the year 2009 and the reason for this is simple and obvious....

When I was working with my previous company (Innovasynth Technologies Limited, Khopoli), I had opportunity to learn lots of things (from Dr. Sergei Gryaznov of Geron Corporation) about the drugs with Telomerase inhibition activity. As for as my knowledge goes, there are many companies working on these class of compounds and hope in the days to come there will be many drugs from this class of compounds and antisense drugs.

About Telomerase :

Telomerase, is an enzyme that adds specific DNA sequence repeats to the 3' end of DNA strands in the telomerase regions, which are found at the ends of eukaryotic chromosomes. The telomeres contain condensed DNA material, giving stability to the chromosomes. The enzyme is a reverse transcriptase that carries its own RNA molecule. Though the existence of a compensatory shortening of telomere (telomerase) mechanism, was first predicted by Soviet biologist Alexey Olovnikov (1973), who also suggested the Telomere hypothesis of ageing and the Telomere relations to cancer. Carol Greider and Elizabeth Blackburn in 1985, discovered telomerase together with Jack Szostak. Greider and Blackburn have been awarded the Nobel Prize in Physiology or Medicine. Congrats for this remarkable achievement.


Telomerase inhibitors :

To safeguard against cancer, adult cells keep track of how many times that they have multiplied, and once they have reached a pre-set limit — often around 80 divisions — they die. Telomerase interferes with this record keeping. So if one can find a drug or gene therapy that interferes with telomerase, it could fight the unchecked growth of cancer cells. As per the claim by lead researcher (Mark Muller), 90% all cancer cells are telomerase rich. Geron corporation, is developing modified DNA molecule (for which Innovasynth, has tie up with Geron to provide the intermediate amidites). The oligonucleotides, which target the template region, or active site, of telomerase. Geron's work has focused oligonucleotides (GRN163 and GRN163L,) and as per the claim by the company, both of them have demonstrated highly potent telomerase inhibitory activity at very low concentrations in biochemical assays, various cellular systems and animal studies. Interestingly these compounds are direct enzyme inhibitors, not antisense compounds and smaller than typical antisense compounds or other oligonucleotide drug candidates. Both compounds use a special thiophosphoramidate chemical backbone and the company is hopeful of convincing clinical trial results. All the best...

Ref : 1. http://nobelprize.org/nobel_prizes/medicine/laureates/2009/press.html
2. http://www.geron.com/products/productinformation/cancerdrug.aspx

New drug shows promising results for treating spinal muscular atrophy

A drug developed by an Iowa State University biomedical researcher as a potential treatment for spinal muscular atrophy showed promising results in a recently published study.

Ravindra Singh, a professor of biomedical sciences in the ISU College of Veterinary Medicine, has been studying spinal muscular atrophy, a leading genetic cause of infant mortality, for years. His lab helped to identify a drug known as A15/283, an antisense oligonucleotide, as a potential treatment for spinal muscular atrophy..

In a study recently published in the peer-reviewed scientific journal Molecular Therapy, Singh and his co-authors showed the drug helped to combat the effects of the disease in mice with mild levels of the disorder.

Spinal muscular atrophy results from the loss or mutation of a gene called Survival Motor Neuron 1, often referred to as SMN1. If SMN1 is deleted or doesn't function properly, not enough SMN protein is produced, giving rise to the disease.

The study found that mice that were given the treatment on the first and third days after birth increased SMN levels and alleviated some of the genetic effects of the disease. The study looked in particular at sex-specific symptoms, such as underdeveloped testes, and found the drug helped to normalize testicular growth in male mice. Singh said previous studies failed to control for how males and females may respond differently to the treatment, and this study provides insight into such questions.


"These results in the mouse model are very promising for the possible treatment of mild spinal muscular atrophy cases in children," Singh said. "We're hoping this line of research could someday lead to clinical trials, but more work remains before that can happen."

Ref : http://www.cell.com/molecular-therapy-family/molecular-therapy/fulltext/S1525-0016(17)30157-0

https://www.ncbi.nlm.nih.gov/pubmed/28412171

New drug shows promising results for treating spinal muscular atrophy

SPC3649 ( LNA- locked nucleic acid) - a new hope for hepatitis C.....

When  I was working with Innovasynth Technologies, Khopoli, I had an opportunity to do literature survey about  Lock Nucleic Acids (LNAs) and Peptide Nucleic Acids (PNAs) (we were supposed to work on the preparation of  some of the LNAs & PNAs for US based companies). In my opinion though these class of compounds (including oligonucleotides) are  still emerging,  I think in the days to come there will be more and more drugs from oligonucleotides, Locked Nucleic Acids (LNAs) and Peptide Nucleic Acids, (PNAs) class of compounds.

LNAs : A locked nucleic acid (LNA) (see the right side general structure), is a modified RNA nucleotide. Ribose moiety of an LNA nucleotide is modified with an extra bridge

connecting the 2' oxygen and 4' carbon. The bridge "locks" the ribose  in the 3'-endo (North) conformation, which is often found in the A-form of DNA or RNA. LNA nucleotides can be mixed with DNA or RNA bases in the oligonucleotide whenever desired. This locking  significantly increases the thermal stability (mp) of oligonucleotide.

LNA nucleotides are used to increase the sensitivity and specificity of expression in DNA microarrays, FISH probes, real-time PCR probes and other molecular biology techniques based on oligonucleotides. For the in situ detection of miRNA the use of LNA is currently the only efficient method. A triplet of LNA nucleotides surrounding a single-base mismatch site maximizes LNA probe specificity unless the probe contains the  G-T mismatch. We have already seen some antisense drugs (oligonucleotides from Geron & Isis) and some are into clinical trials.

Now its interesting to see that Santaris Pharma   is currently advancing LNA based compounds within infectious diseases, metabolic disorders, oncology, inflammatory and rare genetic disorders.

Santaris Pharama, has developed a LNA,  SPC3649 - which captures a small RNA molecule in the liver, called microRNA122, that is required for HCV replication.

As per the claim by the company, SPC3649 works by altering the environment in the host liver cell to inhibit viral replication rather than inhibiting the virus itself. This subtle difference (in comparison  with other therapies) may have significant implications, as it may reduce the risk of the virus becoming resistant to therapy – a major concern with current therapies.

As per the claim by Dr. Robert Lanford,  (who has collaboration with Santaris Pharma), that in a preclinical study  SPC3649 successfully inhibited miR-122, a liver-expressed microRNA important for Hepatitis C viral replication. By inhibiting miR-122, SPC3649 dramatically reduced Hepatitis C virus in the liver and in the bloodstream in chimpanzees chronically infected with the Hepatitis C virus. Four HCV chronically infected chimpanzees were treated weekly with 5 or 1 mg/kg of SPC3649 for 12 weeks followed by a treatment free period of 17 weeks. The two animals that received the 5 mg/kg dose had a significant decline in viral levels in the blood and liver of approximately 2.5 orders of magnitude or approximately 350 fold. Hope the new therapy could potentially replace interferon (interferon and ribavirin is  approved by FDA for hepatitis C and this treatment is very toxic, requires 48 weeks with 50% success) in future cocktails, since it provides a high barrier to resistance. This antiviral could be used alone to treat disease progression and there are indications that it can convert interferon non-responders to responders, so that non-responders to the current therapy could be treated with the combination of this drug with interferon.   More....

Those interested  can see the video demo with the link

Idera's gene-silencing oligonucleotide studies published in Journal of Medicinal Chemistry

In continuation of my update on antisense drugs and nucleotides

Idera's gene-silencing oligonucleotide studies published in Journal of Medicinal Chemistry

Ref : JMC 

Regulus present advancements in microRNA platform at Oligonucleotide Therapeutics Society meeting

Recently, I did write an article regarding the future of antisense drugs for BlogNotions (wherein I did mention about the Regulus plans for mRNA platform)...


Regulus present advancements in microRNA platform at Oligonucleotide Therapeutics Society meeting

Japanese patent for Archexin (a novel anti-cancer drug)....

Rexahn Pharmaceuticals, Inc., a clinical stage pharmaceutical company commercializing potential best in class oncology and CNS therapeutics, announced that the Japanese Patent Office has issued a patent for its novel anti-cancer compound, Archexin. As per the claim by the company,  Archexin is a first in class, potent inhibitor of Akt protein kinase in the treatment of cancer. 

The AKT pathway is an important therapeutic target for cancer drug discovery as it functions as a main point for transducing extracellular and intracellular oncogenic signals. Moreover, alternations of the AKT pathway have been found in a wide range of cancers. Akt regulates signal processes of cell proliferation and survival, angiogenesis, and drug resistance in cancer. Archexin is being developed to treat solid tumors and has FDA Orphan drug designation for RCC, pancreatic, stomach, glioblastoma, and ovarian cancers. Archexin is in Phase II clinical development for pancreatic cancer as lead indication.

Archexin(R) was fromerly named as RX-0201, is  an oligonucleotide compound that  inhibits the expression of human Akt-1. I am really happy for this approval because, in my opinion this will boost the new field of drugs (ologonucleotides/antisense). I have covered some developments in this field, those interested can read earlier articles...