Experimental Alzheimer's drug reverses genetic changes thought to spur the disease

After treatment with riluzole, the brains of old rats showed more of a transporter molecule that removes excess glutamate, (green fluorescence, right) as compared to untreated rats (left).

Aging takes its toll on the brain, and the cells of the hippocampus--a brain region with circuitry crucial to learning and memory--are particularly vulnerable to changes that can lead to Alzheimer's disease or cognitive decline. With the hope of counteracting the changes that can lead to these two conditions, researchers at Rockefeller University and their colleagues have begun examining the effects of a drug known to affect this circuitry.

In new research described recently in Molecular Psychiatry, a team led by Ana Pereira, Instructor in Clinical Medicine in Bruce McEwen's laboratory found that the drug, riluzole, is capable of reversing key genetic changes associated with these conditions.

 riluzole

"In aging and Alzheimer's, the chemical signal glutamate can accumulate between neurons, damaging the circuitry," Pereira says. "When we treated rats with riluzole, we saw a suite of changes. Perhaps most significantly, expression of molecules responsible for clearing excess glutamate returned to more youthful levels."

Previous work in McEwen's lab by Pereira has shown that the drug prompted structural changes in rats' neurons that prevent the memory loss often seen in old animals. Pereira is currently testing riluzole for the first time in Alzheimer's patients in a clinical trial at the Rockefeller University Hospital.

Glutamate clean up

Generally, glutamate is released to excite other neurons and doesn't linger in the spaces between them. As we age, though, the system gets a little leaky and glutamate can build up in these intercellular spaces. This happens in part when neurons make less and less of the transporter molecule responsible for removing excess glutamate. When it accumulates, this essential neurotransmitter can cause big problems, damaging or killing neurons and so contributing to Alzheimer's disease, and other disorders.

Pereira and co-first author Jason Gray, a postdoc in the lab sought to better understand the molecular vulnerabilities of an aging glutamate system and riluzole's effect on it.

"The essence is we used a drug known to modulate glutamate, and when we gave it to old rats, we saw it reversed many of the changes that begin in middle age in the hippocampus," Gray says. "We saw a similar pattern when we compared the riluzole-induced changes to data from Alzheimer's patients--in a number of key pathways in the hippocampus, the drug produced an effect opposing that of the disease."

The drug, it turns out, modifies the activity of certain genes in an aged animal to resemble that of a younger rat. For example, the researchers found that the expression of a gene called EAAT2, which has been linked to Alzheimer's and is known to play a role in removing excess glutamate from nerve fibers, declines as the animals age. However, in rats treated with riluzole this gene's activity was brought back to its youthful levels.

New targets for treatments?

In addition to its potential ability to allay memory loss and cognitive decline, riluzole is attractive as a potential treatment for Alzheimer's. The drug is already being used to treat another neurological disease, amyotrophic lateral sclerosis, and is therefore considered relatively safe. In Pereira's ongoing clinical trial, patients with Alzheimer's disease have thus far been treated with either the drug or a placebo, and have been undergoing tests to help determine whether their brain functions have been improved.

"We hope to use a medication to break the cycle of toxicity by which glutamate can damage the neurons that use it as a neurotransmitter, and our studies so far suggest that riluzole may be able to accomplish this," Pereira says. "We found that in addition to recovering the expression of EAAT2, the drug restored genes critical for neural communication and plasticity, both of which decline with aging and even more significantly in Alzheimer's disease."

The findings also help to lay the groundwork for further study of glutamate transporters as potential targets for treating both conditions.

Ref : http://newswire.rockefeller.edu/2016/05/02/an-experimental-alzheimers-drug-reverses-genetic-changes-thought-to-spur-the-disease/

Ref : http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201633a.html

Experimental Alzheimer's drug reverses genetic changes thought to spur the disease  

FDA Approves Exservan (riluzole) Oral Film for the Treatment of Amyotrophic Lateral Sclerosis

In continuation of my update on riluzole

Aquestive Therapeutics, Inc. (NASDAQ: AQST), a specialty pharmaceutical company focused on developing and commercializing differentiated products to solve therapeutic problems,  announced that Exservan (riluzole) Oral Film received early-action approval from the U.S. Food and Drug Administration (FDA) for the treatment of amyotrophic lateral sclerosis (ALS), an orphan disease.

We received full FDA approval for Exservan in advance of our PDUFA action date.  We appreciate the ongoing feedback from the FDA and its early-action approval.  We anticipate that Exservan, via our orally administered PharmFilm® dosage form, will bring meaningful treatment to patients who are diagnosed with ALS and face difficulties swallowing or administering traditional forms of medication,” said Keith J. Kendall, Chief Executive Officer of Aquestive.  “In line with our stated objectives, we licensed this product to Zambon S.p.A. for development and commercialization in the EU.  We are continuing the dialogue with potential licensees for the US commercial rights.”

Exservan (riluzole) Oral Film is now approved for the treatment of ALS, a debilitating and rare disease affecting as many as 30,000 Americans1 and 52,000 Europeans.  Exservan will now fill a critical need in the armamentarium for ALS patients because it can be administered safely and easily, twice daily, without water where many patients have trouble swallowing. Development initiatives conducted by Aquestive have included studies demonstrating Exservan's pharmacokinetic bioequivalence to the reference listed drug, Rilutek®, as well as additional studies to assess patients' ability to swallow Exservan. Exservan received FDA orphan drug designation in January 2018.

https://www.rxlist.com/exservan-drug.htm

Talampanel has potential to slow the muscle weakening that comes with amyotrophic lateral sclerosis (ALS)...

Talampanel (strutcure, source:ChemSpider), (8R)-7-Acetyl-5-  (4-aminophenyl)-8,9-dihydro-8-methyl-7H-1,3-dioxolo[4,5-h][2,3]benzodiazepine  is a drug used to treat epilepsy. Now researchers from Johns Hopkins and Indiana University, have found interesting activity of the same anticonvulsant drug, i.e., the drug has potential to slow the muscle weakening that comes with amyotrophic lateral sclerosis (ALS)  . The researchers after completing a Phase II clinical trial-an early, small-scale test to show if the drug works and continues to be safe. As per the claim by the researchers,  the drug talampanel showed some ability to slow the loss of major daily life activities such as speaking, walking and dressing that typically slip away as the disease progresses. Interestingly the drug  has the anti-anxiety and  muscle relaxing activity too (work in the brain and spinal cord).

The trial in 59 volunteers with ALS - also called Lou Gehrig's disease - showed that talampanel can be safe for patients with the disease and that any recorded side effects are tolerable.  Phase II trials are designed to show on a small scale if a drug is safe and if it works. So the present trial included ways to measure the drug's benefits, which came across as clear, if not statistically significant. The research demonstrates that talampanel appears able to slow the progression of disabling ALS symptoms. Though the effect isn't overwhelming at the dosage of medicine used in this early, very small trial and the researchers claims that  having promising human data is reason enough to keep it in the drug pipeline where they can really find out where it stands for patient.

With the exception of riluzole, the single FDA-approved drug for the disease, there's no other treatment to slow or stop it. Riluzole can extend life only modestly and hasn't been shown to slow ALS symptoms. so the need for better therapy is real. Hope in the days to come people with ALS symptoms will have a better drug...

Ref : http://www.hopkinsmedicine.org/Press_releases/2010/01_04a_10.html

FDA Grants Accelerated Approval for Qalsody (tofersen) for the Treatment of Amyotrophic Lateral Sclerosis Associated with a Mutation in the SOD1 Gene

Biogen Inc. (Nasdaq: BIIB) announced the U.S. Food and Drug Administration (FDA)   approval of  Qalsody (tofersen) 100 mg/15mL injection for the treatment of amyotrophic lateral sclerosis (ALS) in adults who have a mutation in the superoxide dismutase 1 (SOD1) gene. This indication is approved under accelerated approval based on reduction in plasma neurofilament light chain (NfL) observed in patients treated with Qalsody. Continued approval for this indication may be contingent upon verification of clinical benefit in confirmatory trial(s).1 The ongoing Phase 3 ATLAS study of tofersen in people with presymptomatic SOD1-ALS will serve as the confirmatory trial.

Neurofilaments are proteins that are released from neurons when they are damaged, making them a marker of neurodegeneration.6

“For more than a decade, Biogen has been steadfast in our commitment to pursuing treatments for ALS, and I want to thank the scientists as well as the entire ALS community who have all worked tirelessly to bring this first-of-its-kind treatment to people with SOD1-ALS,” said Christopher A. Viehbacher, President and Chief Executive Officer of Biogen. “Today also marks a pivotal moment in ALS research as we gained, for the first time, consensus that neurofilament can be used as a surrogate marker reasonably likely to predict clinical benefit in SOD1-ALS. We believe this important scientific advancement will further accelerate innovative drug development for ALS.”

Qalsody is the first approved treatment to target a genetic cause of ALS. Biogen collaborated with Ionis Pharmaceuticals on the early development of tofersen.

Warnings and precautions associated with Qalsody were serious neurologic events, including myelitis and/or radiculitis; papilledema and elevated intracranial pressure; and aseptic meningitis. If symptoms consistent with myelitis, radiculitis papilledema, elevated intracranial, or aseptic meningitis develop, diagnostic workup and treatment should be initiated according to the standard of care. Management may require interruption or discontinuation of Qalsody. The most common adverse reactions that occurred in ≥10% of Qalsody treated participants and more than the placebo arm were pain, fatigue, arthralgia, cerebrospinal (CSF) white blood cell increased, and myalgia.

“Since SOD1 mutations were first identified as a cause of ALS 30 years ago, the familial ALS community has been searching for genetically targeted treatments. Qalsody offers families who have lost generation after generation in the prime of their life to this devastating disease a therapy targeting the underlying cause of SOD1-ALS. Today marks an important moment in ALS research as Qalsody is the first ALS treatment approved based on a biomarker,” said Jean Swidler, chair of Genetic ALS & FTD: End the Legacy. “We are excited to see what future therapies are developed now that it is understood that lowering levels of neurofilament provides important evidence that a treatment is affecting the neurodegenerative process.”

The efficacy of Qalsody was assessed in a 28-week randomized, double-blind, placebo-controlled clinical study in patients 23 to 78 years of age with weakness attributable to ALS and a SOD1 mutation confirmed by a central laboratory. One hundred eight (108) patients were randomized 2:1 to receive treatment with either Qalsody 100 mg (n=72) or placebo (n=36) for 24 weeks (3 loading doses followed by 5 maintenance doses). Concomitant riluzole and/or edaravone use was permitted for patients and at baseline 62% of patients were taking riluzone, and 8% of patients were taking edaravone.

Over 28 weeks in VALOR, participants in the primary analysis population (n=60) treated with Qalsody experienced less decline from baseline as measured by the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) compared to placebo, though the results were not statistically significant (Qalsody-placebo adjusted mean difference [95% CI]: 1.2 [-3.2, 5.5]). In the overall intent-to-treat population (n=108), Qalsody-treated participants experienced a 55% reduction in plasma NfL compared to a 12% increase in placebo-treated participants (difference in geometric mean ratios for Qalsody to placebo: 60%; nominal p<0.0001). Additionally, levels of CSF SOD1 protein, an indirect measure of target engagement, were reduced by 35% in the Qalsody-treated group compared to 2% in the corresponding placebo group (difference in geometric mean ratios for Qalsody to placebo: 34%; nominal p<0.0001).

https://en.wikipedia.org/wiki/Tofersen

https://go.drugbank.com/drugs/DB14782

FDA Grants Accelerated Approval for Qalsody (tofersen) for the Treatment of Amyotrophic Lateral Sclerosis Associated with a Mutation in the SOD1 Gene