Oral Edaravone - Introducing a Flexible Treatment Option for Amyotrophic Lateral Sclerosis

Activity of pyridyl-pyrazolone derivatives against Trypanosoma cruzi

New affordable drugs are needed for the treatment of infection with the protozoan parasite Trypanosoma cruzi responsible for the Chagas disease (CD). Only two old drugs are currently available, nifurtimox and benznidazole (Bz) but they exhibit unwanted side effects and display a weak activity in the late chronic phase of the disease. In this context, we evaluated the activity of a series of aryl-pyrazolone derivatives against T cruzi, using both bloodstream trypomastigote and intracellular amastigote forms of the parasite. The test compounds originate from a series of anticancer agents targeting the immune checkpoint ligand PD-L1 and bear an analogy with known anti-trypanosomal pyrazolones. A first group of 6 phenyl-pyrazolones was tested, revealing the activity of a single pyridyl-pyrazolone derivative. Then a second group of 8 compounds with a common pyridyl-pyrazolone core was evaluated. The in vitro testing process led to the identification of two non-cytotoxic and highly potent molecules against the intracellular form of T. cruzi, with an activity comparable to Bz. Moreover, one compound revealed an activity largely superior to that of Bz against bloodstream trypomastigotes, while being non-cytotoxic (selectivity index >1000). Unfortunately, the compound showed little activity in vivo, most likely due to its very limited plasma stability. However, the study opens novel perspectives for the design of new anti-trypanosomal products and the mechanism of action of the compounds is discussed.

Chronological and Biological Aging in Amyotrophic Lateral Sclerosis and the Potential of Senolytic Therapies

Amyotrophic Lateral Sclerosis (ALS) is a group of sporadic and genetic neurodegenerative disorders that result in losses of upper and lower motor neurons. Treatment of ALS is limited, and survival is 2-5 years after disease onset. While ALS can occur in younger individuals, the risk significantly increases with advancing age. Notably, both sporadic and genetic forms of ALS share pathophysiological features overlapping hallmarks of aging including genome instability/DNA damage, mitochondrial dysfunction, inflammation, proteostasis, and cellular senescence. This review explores chronological and biological aging in the context of ALS onset and progression. Age-related muscle weakness and motor unit loss mirror aspects of ALS pathology and coincide with peak ALS incidence, suggesting a potential link between aging and disease development. Hallmarks of biological aging, including DNA damage, mitochondrial dysfunction, and cellular senescence, are implicated in both aging and ALS, offering insights into shared mechanisms underlying disease pathogenesis. Furthermore, senescence-associated secretory phenotype and senolytic treatments emerge as promising avenues for ALS intervention, with the potential to mitigate neuroinflammation and modify disease progression.

Protein aggregation and therapeutic strategies in SOD1- and TDP-43- linked ALS

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with severe socio-economic impact. A hallmark of ALS pathology is the presence of aberrant cytoplasmic inclusions composed of misfolded and aggregated proteins, including both wild-type and mutant forms. This review highlights the critical role of misfolded protein species in ALS pathogenesis, particularly focusing on Cu/Zn superoxide dismutase (SOD1) and TAR DNA-binding protein 43 (TDP-43), and emphasizes the urgent need for innovative therapeutic strategies targeting these misfolded proteins directly. Despite significant advancements in understanding ALS mechanisms, the disease remains incurable, with current treatments offering limited clinical benefits. Through a comprehensive analysis, the review focuses on the direct modulation of the misfolded proteins and presents recent discoveries in small molecules and peptides that inhibit SOD1 and TDP-43 aggregation, underscoring their potential as effective treatments to modify disease progression and improve clinical outcomes.

Edaravone Oral Suspension: A Neuroprotective Agent to Treat Amyotrophic Lateral Sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is characterized by loss of motor neurons due to degeneration of nerve cells within the brain and spinal cord. Early symptoms include limb weakness, twitching or muscle cramping, and slurred speech. As the disease progresses, difficulty breathing, swallowing, and paralysis can lead to death. Currently, there are no medications that cure ALS, and guidelines recommend treatments focused on symptom management. Intravenous (IV) edaravone was approved by the US Food and Drug Administration (FDA) in 2017 as a treatment to slow the progression of ALS. In May 2022, the FDA approved an oral suspension (ORS) formulation of edaravone.

MECHANISM OF ACTION

The mechanism of action of edaravone is not well defined. However, its neuroprotective effects are thought to result from antioxidant properties occurring through elimination of free radicals.

PHARMACOKINETICS

Edaravone ORS (105 mg) has a bioavailability of 57% when compared with edaravone IV (60 mg). The ORS should be taken on an empty stomach in the morning, with water and no food or beverages, for 1 hour. Edaravone is bound to albumin (92%), has a mean volume of distribution of 63.1 L, a half-life of 4.5-9 hours, and a total clearance of 35.9 L/h after intravenous administration. Edaravone is metabolized into nonactive sulfate and glucuronide conjugates.

CLINICAL TRIALS

The FDA approval was based on studies of the pharmacokinetics, safety, tolerability, and bioavailability of edaravone ORS. A phase III, global, multicenter, open-label safety study was conducted on edaravone ORS in 185 patients with ALS over 48 weeks. The most reported treatment-emergent adverse events were falls, muscular weakness, and constipation. Serious treatment-emergent adverse events included disease worsening, dysphagia, dyspnea, and respiratory failure.

THERAPEUTIC ADVANCE

Oral edaravone is an ALS treatment that can be self-administered or administered by a caregiver, precluding the need for administration by a health care professional in an institutional setting.

Biomarkers for Managing Neurodegenerative Diseases

Neurological disorders are the leading cause of cognitive and physical disability worldwide, affecting 15% of the global population. Due to the demographics of aging, the prevalence of neurological disorders, including neurodegenerative diseases, will double over the next two decades. Unfortunately, while available therapies provide symptomatic relief for cognitive and motor impairment, there is an urgent unmet need to develop disease-modifying therapies that slow the rate of pathological progression. In that context, biomarkers could identify at-risk and prodromal patients, monitor disease progression, track responses to therapy, and parse the causality of molecular events to identify novel targets for further clinical investigation. Thus, identifying biomarkers that discriminate between diseases and reflect specific stages of pathology would catalyze the discovery and development of therapeutic targets. This review will describe the prevalence, known mechanisms, ongoing or recently concluded therapeutic clinical trials, and biomarkers of three of the most prevalent neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD).

Understanding depression with amyotrophic lateral sclerosis: a short assessment of facts and perceptions

Depression with an average prevalence of 25-40% is a serious condition in amyotrophic lateral sclerosis (ALS) that can impact quality of life and survival of patients and caregiver burden, yet the underlying neurobiology is poorly understood. Preexisting depression has been associated with a higher risk of developing ALS, while people with ALS have a significantly higher risk of developing depression that can cause multiple complications. Depression may be a prodromal or subclinical symptom prior to motor involvement, although its relations with disease progression and impairment of quality of life are under discussion. Unfortunately, there are no studies existing that explore the pathogenic mechanisms of depression associated with the basic neurodegenerative process, and no specific neuroimaging data or postmortem findings for the combination of ALS and depression are currently available. Experience from other neurodegenerative processes suggests that depressive symptoms in ALS may be the consequence of cortical thinning in prefrontal regions and other cortex areas, disruption of mood-related brain networks, dysfunction of neurotransmitter systems, changing cortisol levels and other, hitherto unknown mechanisms. Treatment of both ALS and depression is a multidisciplinary task, depression generally being treated with a combination of antidepressant medication, physiotherapy, psychological and other interventions, while electroconvulsive therapy and deep brain stimulation might not be indicated in the majority of patients in view of their poor prognosis. Since compared to depression in other neurodegenerative diseases, our knowledge of its molecular basis in ALS is missing, multidisciplinary clinicopathological studies to elucidate the pathomechanism of depression in motor system disorders including ALS are urgently warranted.

A protocol for directly accessing geminal C-4 diarylated pyrazol-5(4H)-ones via tandem C-H aryne insertion and their inceptive neurobiological evaluation

Geminal C-4 diarylation of substituted pyrazol-5(4H)-ones with in situ generated arynes as the aryl source has been achieved in a one-flask operation. All the newly accessed C4-gem-diarylated pyrazolone entities were found to be non-cytotoxic with varying AChE enzyme inhibitory activities and BBB permeability attributes that augur well for further advancement towards CNS therapeutics for untreatable disorders.

[Promising approaches to the pathogenetic therapy of amyotrophic lateral sclerosis]

Amyotrophic lateral sclerosis is a severe incurable disease of the nervous system. Currently only methods of palliative care for the patients with this disease are available. Few medications for the pathogenetic therapy are registered in some countries, i.e. riluzole, edaravon, sodium phenylbutyrate/taurursodiol as well as tofersen (conditionally). Their efficacy is relatively low. The main directions in the development of pathogenetic therapy of ALS include gene therapy, use of stem cells, immunomodulators, agents affecting gut microbiota. A search is also underway for low-molecular compounds with neuroprotective and antioxidant properties. Perspective direction is prevention of ALS. This will be possible when biomarkers for identification of patients in pre-manifest/prodromal stage are detected.