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

Isis Pharmaceuticals starts Phase 1 clinical study of ISIS-PKKRx to treat patients with HAE

Isis Pharmaceuticals, Inc. (NASDAQ: ISIS) announced  that it initiated a Phase 1 clinical study of ISIS-PKKRx.  ISIS-PKKRx is an antisense drug in development to treat patients with hereditary angioedemia (HAE).  HAE is a rare genetic disease that is characterized by rapid and painful attacks of inflammation in the hands, feet, limbs, face, abdomen, larynx and trachea.  HAE affects approximately 20,000 patients in the United States and Europe and can be fatal if swelling occurs in the larynx.  ISIS-PKKRx is designed to alter the course of HAE and therefore has the potential to be best-in-class for the treatment of HAE.  

Isis Pharmaceuticals starts Phase 1 clinical study of ISIS-PKKRx to treat patients with HAE

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=

Diverse use of Nucleic acids.....

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. The design of nucleic acids, particularly oligonucleotides, for in vivo delivery requires consideration of various factors including binding strength, target specificity, serum stability, resistance to nucleases and cellular uptake. A number of approaches have been proposed in order to produce oligonucleotides that have characteristics suitable for in vivo use, such as modified backbone chemistry, formulation in delivery vehicles and conjugation to various other moieties. Therapeutic oligonucleotides with characteristics suitable for systemic delivery would be particularly beneficial.

There are many oligonucleotides with modified chemical backbones, like peptide nucleic acids (PNAs), locked nucleic acids (LNAs), methylphosphonates, phosphoramidates and thiophosphoramidates. Each of these types of oligonucleotides has reported advantages and disadvantages. For example, peptide nucleic acids (PNAs) display good nuclease resistance and binding strength, but have reduced cellular uptake in test cultures; phosphorothioates display good nuclease resistance and solubility, but are typically synthesized as P-chiral mixtures and display several sequence- non-specific biological effects; methylphosphonates display good nuclease resistance and cellular uptake, but are also typically synthesized as P-chiral mixtures and have reduced duplex stability.

The N3'-P5'phosphoramidate internucleoside linkages are reported to display favorable binding properties, nuclease resistance, and solubility (I did work for quite some time in this field and I had opportunity to interact with Dr. Sergei Gryaznov and group). Though this field is getting wider and wider with many companies trying with some innovative ideas, the real concern in this field is that the polyanionic nature of oligonucleotides reduces the ability of the compound to cross lipid membranes, limiting the efficiency of cellular uptake.But thanks to many other groups they are trying to concentrating on this issue and hope there will be may drugs in the days to come. There are many drugs already in the market by ISIS and Geron corporation has many patents to its credit in the many patents for its novel work (Dr.Sergei, Dr.Cristzina Pongracz and many others have lot of work in this field) N3'-P5'phosphoramidate internucleoside linkages. Though there were a few players in this field of nucleic acids(5-6 years' back), now a days when ever I read any medicinal chemistry news, I do find lot many companies contributing to this field of nucleic acids. Hope there will be many drugs from this field with reduced side effects....

New journal devoted to gene therapy...

As for as my knowledge goes there was no exclusive journal totally devoted to gene therapy until last year. Yeah its really interesting to to see "The Gene Therapy Review" a journal totally devoted to gene therapy. In my opinion it is an important move and was the urgent need of the hour. Now the fields like antisense drugs & gene therapy will get its due importance and hope in the days to come, will bring together all those people to share and gain the knowledge..... Those interested can follow the blog also.....

URL : http://www.genetherapyreview.com/index.php

Blog : http://www.genetherapyreview.com/gene-therapy-blog.html

FDA Advisory Committee Votes in Favor of Waylivra (volanesorsen) for Treatment of Familial Chylomicronemia Syndrome

Akcea Therapeutics, Inc. (NASDAQ:AKCA), an affiliate of Ionis Pharmaceuticals, Inc., and Ionis Pharmaceuticals, Inc. (NASDAQ:IONS)   announced that the U.S. Food and Drug Administration’s (FDA) Division of Metabolism and Endocrinology Products Advisory Committee voted 12-8 to support approval of Waylivra (volanesorsen) for the treatment of people with familial chylomicronemia syndrome (FCS). The committee’s non-binding recommendation will be considered by the FDA in its review of Akcea’s New Drug Application for Waylivra. The PDUFA date for completion of the review of Waylivra is August 30, 2018.

3’—A*—G*—mC*—T*—T*—dmC—dT—dT—dG—dT—dmC—dmC—dA—dG—dmC—T*—T*—T*—A*—T*—5’




* = 2’-O-(2-methoxyethyl)

m = 5-methyl

d = 2’-deoxy

“We thank the committee members for their time and their comments today. The Committee’s majority vote in favor of approval is an important positive step to bring Waylivra to people with FCS who have no adequate treatment options,” said Paula Soteropoulos, chief executive officer of Akcea Therapeutics. “We look forward to working with the FDA to complete the final stages of regulatory review for Waylivra. We are committed to the FCS community and will continue to focus on bringing Waylivra, potentially the first and only treatment, to people living with this serious and potentially fatal disease.”

“Given the severity of FCS and the burden it places on patients, the need for a therapy is critical. The progress in development of a potential first-ever treatment is very encouraging. The planned efforts in monitoring and education are designed to achieve the highest levels of patient adherence, compliance and safety,” said Dr. Seth Baum, president, American Society for Preventive Cardiology. “The medical community is eager to have a medicine to treat our patients with FCS.”

The Advisory Committee reviewed data from two Phase 3 clinical trials, APPROACH and COMPASS, as well as the ongoing APPROACH Open Label study for Waylivra. Results from the phase 3 APPROACH trial, the largest study ever conducted in patients with FCS, show that patients with FCS treated with Waylivra achieved a statistically significant mean reduction in triglycerides of 77% from baseline and decreased risk of pancreatitis. The most common adverse events in the APPROACH study were injection site reactions and platelet declines. The Committee's input will be considered by the FDA in its review of the New Drug Application for Waylivra. The FDA is not bound by the Committee's guidance, but takes its advice into consideration when reviewing investigational medicines. Waylivra is also under regulatory review in the European Union and Canada.

“People with FCS have severely elevated triglycerides, which lead to multiple severe daily and chronic symptoms, such as abdominal pain and increased risk for pancreatitis, which can be fatal. Waylivra is the first drug to demonstrate substantial triglyceride lowering in clinical trials in people with FCS,” said Brett P. Monia, chief operating officer at Ionis. “Waylivra illustrates how our antisense technology can create targeted drugs for people living with severe diseases who currently have no available therapeutic options.”

Ref : http://ir.akceatx.com/news-releases/news-release-details/fda-advisory-committee-votes-favor-waylivra-treatment-familial

Ebola, Marburg Virus Treatments Safe in Phase 1 Studies

In continuation of my update on antisense drugs and RNAi

AVI BioPharma Inc. announced positive safety results from the first five cohorts of Phase 1 single ascending dose trials of AVI-6002 and AVI-6003, AVI's lead drug candidates being evaluated for the treatment of the Ebola virus and Marburg virus.

Data were evaluated by an independent Data and Safety Monitoring Board (DSMB), which issued recommendations for both studies to progress as planned to the next highest dosing level after no safety concerns were identified. The Phase 1 single ascending dose trials are designed to characterize the safety, tolerability, and pharmacokinetics of each therapeutic candidate in healthy adult volunteers.

"We are very encouraged that these two drugs, which use our advanced PMOplus chemistry, have demonstrated a favorable safety profile through five cohorts in our dose-escalation studies,”says Chris Garabedian, president and chief executive officer of AVI BioPharma...

Ref : http://phx.corporate-ir.net/phoenix.zhtml?c=64231&p=RssLanding&cat=news&id=1619940

To date, 25 healthy human subjects (five per group) have been enrolled into five sequential dose groups in each of the two studies. Within each group, four subjects received the indicated dose of the therapeutic and one subject received placebo. For each group, safety, clinical laboratory and renal biomarker results through five days after treatment were reviewed by a DSMB. Subjects enrolled in the sixth group for the drug studies will receive 9.0 mg/kg of the therapeutic or placebo. Final, un-blinded safety and pharmacokinetic results for all subjects will be available upon completion of the trial.

Both candidates employ AVI's patented PMOplus technology that selectively introduces positive charges to its phosphorodiamidate morpholino oligomer (PMO) backbone to improve interaction between the drug and its target.

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

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

Geron plans to advance clinical program for spinal cord injury

In my earlier blog (Euphoria over Stem Cell Therapy.....) did mentioned that, there are many companies which falsely claimed that they have got technology (stem cell treatment) to treat spinal cord injury. But an established company like Geron, has plan to advance clinical development of its human embryonic stem cell (hESC)-based product, GRNOPC1, for the treatment of spinal cord injury. The plan is expected to enable Geron to re-initiate the Phase I clinical trial of GRNOPC1 in patients with complete thoracic spinal cord injury and to support future expansion of the trial to patients with cervical injuries.

I read earlier about the preclinical studies of GRNOPC1 and the company claimed that it is developing GRNOPC1 for spinal cord injury, but is also exploring application for other neurological diseases, including multiple sclerosis, stroke and Alzheimer disease really interesting to see the results.

As I had an opportunity to talk and work (contract research) with Geron [known for its first-in-class biopharmaceuticals (especially "antisense drugs" from oligonucleotides) for the treatment of cancer and chronic degenerative diseases] company, I know its credentials and am really excited to see some interesting out come from their advance clinical program. All the best....

Ref : http://www.geron.com/media/pressview.aspx?id=1195