A Pharmacokinetic Bioequivalence Study Comparing Sublingual Riluzole (BHV-0223) and Oral Tablet Formulation of Riluzole in Healthy Volunteers

Neuroprotective effects of riluzole in Alzheimer's disease: A comprehensive review

BACKGROUND

Despite several hundred clinical trials of drugs that initially showed promise, there has been limited clinical improvement in Alzheimer's disease (AD). This may be attributed to the existence of at least 25 abnormal cellular pathways that underlie the disease. It is improbable for a single drug to address all or most of these pathways, thus even drugs that show promise when administered alone are unlikely to produce significant results. According to previous studies, eight drugs, namely, dantrolene, erythropoietin, lithium, memantine, minocycline, piracetam, riluzole, and silymarin, have been found to target multiple pathways that are involved in the development of AD. Among these drugs, riluzole is currently indicated for the treatment of medical conditions in both adult patients and children and has gained increased attention from scientists due to its potential in the excitotoxic hypothesis of neurodegenerative diseases.

OBJECTIVE

The aim of this study was to investigate the effects of drugs on AD based on cellular and molecular mechanisms.

METHODS

The literature search for this study utilized the Scopus, ScienceDirect, PubMed, and Google Scholar databases to identify relevant articles.

RESULTS

Riluzole exerts its effects in AD through diverse pathways including the inhibition of voltage-dependent sodium and calcium channels, blocking AMPA and NMDA receptors and inhibiting the release of glutamic acid release and stimulation of EAAT1-EAAT2.

CONCLUSION

In this review article, we aimed to review the neuroprotective properties of riluzole, a glutamate modulator, in AD, which could benefit patients with the disease.

Current State and Future Directions in the Therapy of ALS

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder affecting upper and lower motor neurons, with death resulting mainly from respiratory failure three to five years after symptom onset. As the exact underlying causative pathological pathway is unclear and potentially diverse, finding a suitable therapy to slow down or possibly stop disease progression remains challenging. Varying by country Riluzole, Edaravone, and Sodium phenylbutyrate/Taurursodiol are the only drugs currently approved in ALS treatment for their moderate effect on disease progression. Even though curative treatment options, able to prevent or stop disease progression, are still unknown, recent breakthroughs, especially in the field of targeting genetic disease forms, raise hope for improved care and therapy for ALS patients. In this review, we aim to summarize the current state of ALS therapy, including medication as well as supportive therapy, and discuss the ongoing developments and prospects in the field. Furthermore, we highlight the rationale behind the intense research on biomarkers and genetic testing as a feasible way to improve the classification of ALS patients towards personalized medicine.

Pharmacokinetics, Bioavailability, and Swallowing Safety With Riluzole Oral Film

Dysphagia is highly prevalent in patients with amyotrophic lateral sclerosis (ALS). Riluzole is a US Food and Drug Administration-approved treatment for ALS. Riluzole oral film (ROF; Exservan™) contains riluzole in a polymer-based film matrix. The ROF is administered by placing on the tongue, where it dissolves and the drug is ingested with the saliva. Two clinical trials assessed the safety and tolerability of the ROF. Bioavailability and pharmacokinetics (PK) were evaluated in an open-label, randomized, single-dose, replicate crossover study of 50 mg of ROF and riluzole 50-mg tablets in 32 healthy volunteers. The second study was a videofluoroscopic swallowing examination conducted with nine patients with ALS before and after receiving a single dose of 50 mg of ROF. The primary outcome was change on penetration-aspiration scale (PAS) scores from pre- to post-dose. Overall, the PK parameters for ROF and riluzole tablets were comparable between treatments and administrations when administered under fasting conditions. Administration of ROF with food resulted in a 15% reduction in area under the curve and a 45% reduction in maximum serum concentration. A total of 44 treatment-emergent adverse events (AEs) were reported in the study; all were mild in severity. No serious AEs were observed and no subjects discontinued due to AEs. In the swallowing study, very little numerical or categorical change was observed following the dose of ROF. No evidence of deterioration of swallowing function was observed post-dose. The ROF was bioequivalent to riluzole tablets, was well tolerated, and had no detrimental effect on swallowing.

Pharmacotherapy for Amyotrophic Lateral Sclerosis: A Review of Approved and Upcoming Agents

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disorder involving loss of upper and lower motor neurons, with most cases ending in death within 3-5 years of onset. Several molecular and cellular pathways have been identified to cause ALS; however, treatments to stop or reverse disease progression are yet to be found. Riluzole, a neuroprotective agent offering only a modest survival benefit, has long been the sole disease-modifying therapy for ALS. Edaravone, which demonstrated statistically significant slowing of ALS disease progression, is gaining approval in an increasing number of countries since its first approval in 2015. Sodium phenylbutyrate and taurursodiol (PB-TURSO) was conditionally approved in Canada in 2022, having shown significant slowing of disease progression and prolonged survival. Most clinical trials have focused on testing small molecules affecting common cellular pathways in ALS: targeting glutamatergic, apoptotic, inflammatory, and oxidative stress mechanisms among others. More recently, clinical trials utilizing stem cell transplantation and other biologics have emerged. This rich and ever-growing pipeline of investigational products, along with innovative clinical trial designs, collaborative trial networks, and an engaged ALS community', provide renewed hope to finding a cure for ALS. This article reviews existing ALS therapies and the current clinical drug development pipeline.