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

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  

Antisense Pharma presents data from trabedersen Phase I/II cancer study at ASCO 2012

In continuation of my update on antisense drugs

Trabedersen, is an antisense compound that specifically inhibits expression of transforming growth factor beta 2 (TGF-β2) – a protein which is overexpressed in advanced tumors and which triggers key cancer pathomechanisms, i.e. suppression of antitumor immune response and metastasis. 

Antisense Pharma presents data from trabedersen Phase I/II cancer study at ASCO 2012: The biopharmaceutical company Antisense Pharma today presents trabedersen complete data from its clinical Phase I/II study in patients with advanced pancreatic cancer, malignant melanoma or colorectal cancer at the international cancer congress ASCO 2012 in Chicago, USA.

New drug shows promise against Huntington's disease

A drug that would be the first to target the cause of Huntington's disease (HD) is effective and safe when tested in mice and monkeys, according to data released today that will be presented at the American Academy of Neurology's 68th Annual Meeting in Vancouver, Canada, April 15 to 21, 2016. A study to test the drug in humans has begun.

Huntington's disease is a rare, hereditary disease that causes uncontrolled movements, loss of intellectual abilities, emotional problems and eventually death. The disease is passed from parent to child through a mutation in the huntingtin gene. The mutation results in the production of a disease-causing huntingtin protein. Each child has a 50/50 chance of inheriting the gene mutation. Everyone who inherits the mutated gene will eventually develop the disease.

The new drug, called IONIS-HTTRx, is an antisense drug that acts as a "gene silencer" to inhibit the production of huntingtin protein in people with Huntington's disease.

"It is very exciting to have the possibility of a treatment that could alter the course of this devastating disease," said clinical study principal investigator Blair R. Leavitt, MD, of the University of British Columbia in Vancouver. "Right now we only have treatments that work on the symptoms of the disease." Leavitt notes the drug is still years away from being used in human clinical practice.

Earlier studies in mouse models of Huntington's disease showed that treatment with antisense drugs delays disease progression and results in sustained reversal of the disease phenotype. In YAC128 mice, a transgenic model of HD, motor deficits improved within one month of initiating antisense treatment and were restored to normal at two months after treatment termination. Motor skills of antisense-treated BACHD mice, another transgenic model of HD, improved eight weeks after initiation of treatment and persisted for at least nine months after treatment termination. In monkeys, dose-dependent reductions in HTT mRNA and Htt protein throughout the central nervous system were observed after intrathecal administration of an antisense drug. Reduction of cortical huntingtin levels by 50 percent was readily achieved in monkeys and correlated with 15 to 20 percent reduction in the caudate. In further tests in rodents and monkeys, IONIS-HTTRx was found to be well-tolerated without any dose-limiting side effects.

New drug shows promise against Huntington's disease

Antisense drug in combination with paclitaxel for prostate cancer..

I think when I was doing some reference work for my research in 1996, I read about this drug (taxol) [In 1994 the total synthesis has been achieved by Robert Holton of Florida University. He did spend 12 years to achieve the total synthesis because of the assymmtery involved in it [It was after 40 years' after the first exctract from the tree Pacific yew (Taxus brevifolia) has shown anticancer activity and the key ingrediant identified was taxiol]. A diterpenoid, with androgen (a male hormone) blockade chemotherapy has played important role in the treatment of cancer.

Prostate cancer is the second most frequently diagnosed cancer in men after skin cancer. It is estimated there will be 218,890 new cases diagnosed in the U.S. this year(2009). Around 1 in 6 men will develop prostate cancer, a third to a half of whom will recur after local treatment and risk progression to metastatic prostate cancer. Metastatic disease invariably progresses to hormone refractory or castrate resistantprostate cancer (CRPC) if given enough time.

Prostate tumours are initially androgen (male sex hormone) dependent, and can be treated with androgen ablation therapy, however once the disease progresses to its most dangerous and aggressive form, CRPC, treatment options are limited and prognosis is poor. Treatment options depend on disease severity and include radiation and chemotherapy, which are designed to induce programmed cell death (apoptosis) of tumour cells. There is a pressing need for the development of new treatment options.

More interesting and significant results have been achieved by an Australian company (Antisense Therapeutics). i.e., in combination with taxol, antisense drug ATL1101 has yielded good results. ATL1101 is a second generation antisense inhibitor of the insulin-like growth factor-I receptor (IGF-IR) which as reported previously suppressed the growth of human prostate tumors in an animal model of prostate cancer, and slowed down transition to CRPC when used as a single agent.

The research is of great importance because of the fact that in cell culture experiments, the amount of Paclitaxel required to induce tumor cell apoptosis (cell death) was significantly reduced when used in combination with ATL1101. This ability to 'sensitize' tumor cells to the cytotoxic effects of Paclitaxel affirms ATL1101's potential as a chemo-sensitizing agent to be used in combination with existing prostate treatments to improve the outcomes for patients.

I did work for some of the intermediates (ologonucleotides) for ISIS (contract research) and am excited to see that this company has tie up with ISIS. In my opinion as ISIS , is an established company in this field of research, hope soon there will be relief for those patients for whom CRPC, treatment options are limited and prognosis is poor....

Ref: http://www.antisense.com.au/!upload_files%5Cattachment%5Casx%2009%2018%20June%202009_ATL1101.pdf

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

Isis Initiates Phase 1 Study in Patients With Cancer With the First Generation 2.5 Antisense Drug, ISIS-STAT3Rx

 In continuation of my update on antisense drugs...

Isis Pharmaceuticals, Inc.  announced the initiation of a Phase 1 study of ISIS-STAT3Rx, a Generation 2.5 antisense drug designed to treat cancer.  ISIS-STAT3Rx specifically reduces the production of signal transducer and activator of transcription 3 (STAT3). Because STAT3 is over expressed in numerous types of cancers, ISIS-STAT3Rx has the potential to be broadly useful for both solid and liquid tumors.  The ISIS-STAT3Rx development plan is initially focused on key cancers where there is a high unmet medical need and a strong link to STAT3, such as hepatocellular carcinoma (HCC) and ovarian cancer.  Advancements in Isis' technology platform have resulted in the improved potency of Generation 2.5 antisense drugs creating opportunities for drugs like ISIS-STAT3Rx to be effective in the more difficult to treat types of cancer. 

 

"The role of STAT3 as a key factor critical for tumor cell growth and survival of cancer cells has made STAT3 widely viewed as an important target of interest," said David S. Hong, M.D., Assistant Professor, Department of Investigational Cancer Therapeutics at the University of Texas MD Anderson Cancer Center.  "STAT3 is a well understood transcription factor involved in multiple survival mechanisms that intersect with the growth, metastasis and invasiveness of cancer. The ability to selectively inhibit STAT3 could allow us to effectively treat some of the most difficult to treat cancers."

 
Isis Initiates Phase 1 Study in Patients With Cancer With the First Generation 2.5 Antisense Drug, ISIS-STAT3Rx

Ref : http://ir.isispharm.com/phoenix.zhtml?c=222170&p=irol-newsArticle&ID=1691711&highlight=

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)

RNA interference approach for prevention and treatment of STDs ?

In my earlier blog “Diverse use of Nucleic acids”, did mention that there is much interest in the medical uses of nucleic acids. For example, antisense, ribozymes, aptamer and RNA interference (RNAi) technologies are all being developed for potential therapeutic applications. Lots of research is being done in each specified fields and in fact there are already few drugs in “antisense category” and this time something really interesting has been reported by a Post Doc., Dr. Kim Woodrow in the field of RNA interference category. The following lines briefly summerise, what actually RNAis..

RNA interference (RNAi) is a system within living cells that helps to control which genes are active and how active they are. Two types of small RNA molecules – microRNA (miRNA) and small interfering RNA (siRNA) – are central to RNA interference. RNAs are the direct products of genes, and these small RNAs can bind to specific other RNAs and either increase or decrease their activity, for example by preventing a messenger RNA from producing a protein. RNA interference has an important role in defending cells against parasitic genes, viruses and transposons – but also in directing development as well as gene expression in general

The RNAi pathway is found in many eukaryotes including animals and is initiated by the enzyme Dicer, which cleaves long double-stranded RNA (dsRNA) molecules into short fragments of ~20 nucleotides. One of the two strands of each fragment, known as the guide strand, is then incorporated into the RNA-induced silencing complex (RISC). The most well-studied outcome is post-transcriptional gene silencing, which occurs when the guide strand base pairs with a complementary sequence of a messenger RNA molecule and induces cleavage by Argonaute, the catalytic component of the RISC complex. This process is known to spread systemically throughout the organism despite initially limited molar concentrations of siRNA. The importance of the siRNA lies in the fact that “RNAi is selective on gene expression” and hence can be used in the similar fashion like the antisense drugs (already a few drugs by ISIS, Serono and others). I did work on a few oligonucleotides (phosparothiamidates), while working in Innovasynth Technologies Limited Khopoli and know how difficult is to get the precursors of the antisense drugs. In 2006, Andrew Fire and Craig C. Mello shared the Nobel Prize in Physiology or Medicine for their work on RNA interference in the nematode worm C. elegans.

Gene interference therapy is moving rapidly from basic research to application. The PLGA packaging these researchers chose is already approved as safe and non-toxic by the FDA, speeding the path to clinical trials for infectious agents such as HPV and HIV.

Congrats Dr.Kim and co workers for this achievement. The significance of this research is the fact that “a safe and effective administration of potential antiviral drugs - small interfering RNA (siRNA) molecules using densely-loaded nanoparticles made of a biodegradable polymer known as PLGA. The researchers created a stable "time release" vehicle for delivery of siRNAs to sensitive mucosal tissue like that of the female reproductive system.

Ref : http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2444.html

Can Antisense drugs revolutionize the drug discovery ?

Antisense therapy, is an important technology for drug discovery and development. It is broadly used by the pharmaceutical industry as a tool for functional genomics and as highly specific drugs for a wide range of diseases (Anticancer, anti-inflammatory, cardiovascular and neurodegenerative diseases) The most interesting factor of antisense drugs is “specificity” in contrast to the traditional drugs (which binds to the proteins and charge interactions so often ending with undesirable side effects). With the combined efforts of human genome programme and bioinformatics, we may soon have a lesser number of targets, I think this interesting field may revolutionize the drug discovery. But the real concern is, there are a few players as of now. In my opinion, something like High Throughput Screening (HTS), with co-ordination of educational and private institutes may help to have more drug contenders (as for as my knowledge goes, Southern Research Institute, Birmingham did try for antitubercular drugs, for the drug resistant strain). Let us hope, something happen in the near future…..

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.”   

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

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

Antisense Therapeutics completes repeat-dosing toxicology studies for ATL1103

Antisense Therapeutics completes repeat-dosing toxicology studies for ATL1103

One can see the products under development...(by the same co)..

NDA of Cladribine as a drug for Multiple Sclerosis !

When I was working with Innovasynth Technologies, Khopoli, I worked in the field of "antisense drugs" and as the company has tie up with many MNCs (working with these class of compounds) I had many times interacted with Serono, Pharmaceuticals (US) for some of the intermediates (oligonucleotides). When I read this article, I am happy there are many drugs still to be established as antisense drugs and more over this NDA (new drug application) is something to cherish.

We know that 2-chlorodeoxyadenosine, Cladribine (Leustatin) is drug used to treat hairy cell leukemia (leukemic reticuloendotheliosis).

As a purine analog, it is a synthetic anticancer agent that also suppresses the immune system. Chemically, it mimics the nucleoside adenosine and thus inhibits the enzyme adenosine deaminase, which interferes with the cell's ability to process DNA. It is easily destroyed by normal cells except for blood cells, with the result that it produces relatively few side effects and results in very little non-target cell loss.

Though it has been used to treat leukemic reticuloendotheliosis, other activities like B cell leukemias and lymphomas, such as mantle cell lymphoma are still to be established. Now EMD Serono has applied for this NDA with FDA. As per the claim by the company, Cladribine Tablets has the potential to be the first orally administered disease-modifying therapy available for people living with relapsing MS, as all disease-modifying therapies currently approved for the treatment of MS are parenteral therapies. Hope FDA will approve the drug and will help many patients with relapsing forms of multiple scleorosis will have a relief in the days to come..

Ref : http://www.emdserono.com/cmg.emdserono_us/en/images/Cladribine%20Tablets%20FDA%20Submission%20FINAL%20US%20FINAL_tcm115_44365.pdf

A Deep Insight into the World Gene Therapy Market

A new market research report related to the Biotechnologies and Genetics industry about the trends in "antisense drugs".....

Isis receives $5M milestone payment from GSK for initiating ISIS-TTRRx Phase 1 study

In continuation of my update on "antisense drugs"....
Isis receives $5M milestone payment from GSK for initiating ISIS-TTRRx Phase 1 study

OGX-427 Improves PFS in Prostate Cancer | News | Drug Discovery and Development Magazine

In continuation of my update on OGX-427 

OncoGenex Pharmaceuticals Inc. announced data from a Phase 2 study of its investigational compound OGX-427 in chemotherapy-naive metastatic castration resistant prostate cancer (mCRPC) patients. Preliminary results show a higher number of patients taking OGX-427 plus prednisone without disease progression at 12 weeks and with declines in prostate-specific antigen (PSA), compared with those taking prednisone alone.

Sixty-four of 72 planned patients have been randomized to the study and data on 42 patients [22 who received OGX-427 plus prednisone and 20 who received prednisone alone] are now available at or beyond the 12 week assessment time point. Highlights are as follows: 

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...

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.