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.

Intranasal administration of edaravone nanoparticles improves its stability and brain bioavailability

The clinical application of EDV, a potent antioxidant drug approved for amyotrophic lateral sclerosis (ALS), is limited by its short biological half-life and poor water solubility necessitating hospitalization during intravenous infusion. Nanotechnology-based drug delivery constitutes a powerful tool through inferring drug stability and targeted drug delivery improving drug bioavailability at the diseased site. Nose-to-brain drug delivery offers direct access to the brain bypassing the blood brain barrier and reducing systemic biodistribution. In this study, we designed EDV-loaded poly(lactic-co-glycolic acid) (PLGA)-based polymeric nanoparticles (NP-EDV) for intranasal administration. NPs were formulated by the nanoprecipitation method. Morphology, EDV loading, physicochemical properties, shelf-life stability, in vitro release and pharmacokinetic assessment in mice were conducted. EDV was efficiently loaded into ∼90 nm NPs, stable up to 30 days of storage, at ∼3% drug loading. NP-EDV reduced H2O2-induced oxidative stress toxicity in mouse microglial cell line BV-2. Optical imaging and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) showed that intranasal delivery of NP-EDV offered higher and more sustained brain uptake of EDV compared to intravenous administration. This study is the first of its kind to develop an ALS drug in a nanoparticulate formulation for nose-to-brain delivery raising hope to ALS patients where currently treatment options are limited to two clinically approved drugs only.

Clinical effects and safety of edaravone in treatment of acute ischaemic stroke: A meta-analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Edaravone is a new antioxidant and hydroxyl radical scavenger. Although there is evidence that it improves clinical outcomes of patients with acute ischaemic stroke (AIS), it is not yet widely accepted for treatment of AIS in Western countries. We further investigated the efficacy and safety of edaravone through this meta-analysis of randomized controlled clinical trials (RCTs).

METHOD

Pubmed, Embase, Web of Science and Cochrane Library were screened up to December 2020 for original articles from SCI journals that published in English. RCTs that compared edaravone versus placebo or no intervention in adult patients and reported the efficacy or safety of edaravone were regarded as eligible. Mortality was regarded as the primary outcome and the improvement of neurological impairment was regarded as the secondary outcome. Safety evaluation was conducted according to the incidence of adverse events. Review Manager 5.3 was employed to perform the assessment of the risk of bias and data synthesis. The Cochrane risk of bias tool for randomized controlled trials was employed to assess the risk of bias.

RESULTS AND DISCUSSION

Seven randomized controlled trials with 2069 patients were included. For the incidence of mortality, the pooled RR for studies that evaluated edaravone after three-month follow-up was 0.55 (95% Cl, 0.43-0.7, I²  = 0, P < 0.01). The pooled RR for improvement of neurological impairment at the three months follow-up was 1.54 (95% CI, 1.27-1.87, I²  = 0, P < 0.01) in four RCTs. On subgroup analysis of studies that were conducted in Asia, the RR was 1.56 (95% CI, 1.27-1.90, I²  = 0%; P < 0.01); the pooled RR for studies that conducted in Europe was 1.32 (95% CI, 0.64-2.72; P = 0.45); the pooled RR for studies that used edaravone for two weeks was 1.42 (95% CI, 1.10 to 1.83, I²  = 0%; P < 0.01); the pooled RR for studies that used edaravone for one week was 1.64 (95% CI, 1.24-2.16, I²  = 0%; P < 0.01); the pooled RR for studies that conducted in patients with mean age equal to or over 60 years was 1.52 (95% CI, 1.24-1.87, I²  = 0%; P < 0.01); and the pooled RR for studies that conducted in patients with mean age less than 60 was 1.80 (95% CI, 1.05-3.08, I²  = 0%; P = 0.03). For the incidence of any treatment-related adverse events, the pooled RR for studies that evaluated edaravone during treatment was 0.83 (95% CI, 0.51-1.34, I²  = 0, P = 0.43). The difference of the incidence of any treatment-related adverse events between two groups was not statistically significant.

WHAT IS NEW AND CONCLUSION

The limited studies indicate that edaravone can improve neurological impairment with a survival benefit at three-month follow-up, regardless of the mean age and course of treatment. It is worthy of promotion in the clinical treatment of AIS in Asian countries. More well-designed RCTs with larger sample sizes are needed to determine the benefits of edaravone in patients from Western countries.

Renal function in amyotrophic lateral sclerosis patients on long-term treatment with edaravone

Edaravone, a free radical-scavenger, was approved in Japan for the treatment of amyotrophic lateral sclerosis (ALS). However, the effect of the drug on renal function in ALS patients remains unclear. This study aimed to investigate renal function in ALS patients on long-term treatment with edaravone by measuring the serum estimated glomerular filtration rate based on cystatin C (eGFR-CysC).In a retrospective study, the data of ALS patients who were treated with over 10 cycles of intravenous edaravone treatment and were evaluated by eGFR-CysC before and after 10 cycles of treatment between July 2015 and June 2018 were analyzed. Then, the results were compared with those of a control ALS group that had never been treated with edaravone.There were 11 patients with ALS who received over 10 cycles of intravenous edaravone treatment. The mean interval between the first and final eGFR-CysC measurements was 18.7 ± 7.9 months. Three patients (27.3%) had >20 mL/min/1.73 m2 decrease in serum eGFR-CysC. However, no patients discontinued edaravone treatment because of renal dysfunction. The average variation rate of eGFR-CysC was not different between the long-term edaravone group (0.29 ± 1.07) and the control group (-0.34 ± 0.40).This retrospective, single-center analysis showed no clinical exacerbation of renal function in ALS patients who received long-term treatment with edaravone.

Redox treatment ameliorates diabetes mellitus-induced skin flap necrosis via inhibiting apoptosis and promoting neoangiogenesis

Intractable wound healing is the habitual problem of diabetes mellitus. High blood glucose limits wound healing by interrupting inflammatory responses and inhibiting neoangiogenesis. Oxidative stress is commonly thought to be a major pathogenic cause of diabetic complications. Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one, EDV) is a free radical scavenger which suppress oxidative stress. This study investigates whether EDV can reduce oxidative stress in wound healing HaCaT/human dermal fibroblasts cells (HDFs) in vitro and in vivo animal model. Cell viability and wound healing assays, FACS flow cytometry, and Hoechst 33342 staining were performed to confirm apoptosis and cytotoxicity in H2O2 and EDV-treated HaCaT and HDFs. A streptozotocin-induced hyperglycemic animal model was made in adult C57BL6 mice. Full-thickness skin flap was made on dorsomedial back and re-sutured to evaluate the wound healing process. EDV was delivered slowly in the skin flap with degradable fibrin glue. The flap was monitored and analyzed on postoperative days 1, 3, and 5. CD31/DAPI staining was done to detect newly formed blood vessels. The expression levels of NF-κB, bcl-2, NOX3, and STAT3 proteins in C57BL6 mouse tissues were also examined. The wound healing process in hyper- and normoglycemic mice showed a difference in protein expression, especially in oxidative stress management and angiogenesis. Exogenous H2O2 reduced cell viability in a proportion to the concentration via apoptosis. EDV protected HaCaT cells and HDFs from H2O2 induced reactive oxygen species cell damage and apoptosis. In the mouse model, EDV with fibrin resulted in less necrotic areas and increased angiogenesis on postoperative day 5, compared to sham-treated mice. Our results indicate that EDV could protect H2O2-induced cellular injury via inhibiting early apoptosis and inflammation and also increasing angiogenesis. EDV might be valuable in the treatment of diabetic wounds that oxidative stress has been implicated.

Edaravone Dexborneol Versus Edaravone Alone for the Treatment of Acute Ischemic Stroke: A Phase III, Randomized, Double-Blind, Comparative Trial

BACKGROUND AND PURPOSE

Edaravone dexborneol, comprised of 2 active ingredients, edaravone and (+)-borneol, has been developed as a novel neuroprotective agent with synergistic effects of antioxidant and anti-inflammatory in animal models. The present clinical trial aimed at testing the effects of edaravone dexborneol versus edaravone on 90-day functional outcome in patients with acute ischemic stroke (AIS).

METHODS

A multicenter, randomized, double-blind, comparative, phase III clinical trial was conducted at 48 hospitals in China between May 2015 and December 2016. Inclusion criteria included patients diagnosed as AIS, 35 to 80 years of age, National Institutes of Health Stroke Scale Score between 4 and 24, and within 48 hours of AIS onset. AIS patients were randomized in 1:1 ratio into 2 treatment arms: 14-day infusion of edaravone dexborneol or edaravone injection. The primary end point was the proportion of patients with modified Rankin Scale score ≤1 on day 90 after randomization.

RESULTS

One thousand one hundred sixty-five AIS patients were randomly allocated to the edaravone dexborneol group (n=585) or the edaravone group (n=580). The edaravone dexborneol group showed significantly higher proportion of patients experiencing good functional outcomes on day 90 after randomization, compared with the edaravone group (modified Rankin Scale score ≤1, 67.18% versus 58.97%; odds ratio, 1.42 [95% CI, 1.12-1.81]; P=0.004). The prespecified subgroup analyses indicated that a greater benefit was observed in female patients than their male counterparts (2.26, 1.49-3.43 versus 1.14, 0.85-1.52).

CONCLUSIONS

When edaravone dexborneol versus edaravone was administered within 48 hours after AIS, 90-day good functional outcomes favored the edaravone dexborneol group, especially in female patients. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02430350.

Effects of intravenous thrombolysis with alteplase combined with edaravone on cerebral hemodynamics and T lymphocyte level in patients with acute cerebral infarction

Our study aimed to investigate the effect of intravenous thrombolysis with alteplase and edaravone on cerebral hemodynamics and T lymphocyte level in patients harboring acute cerebral infarction.There involved a total of 118 patients with acute cerebral infarction from November 2017 to May 2019 in our hospital were randomly divided into 2 groups: the observation group (59 patients were treated with intravenous thrombolysis with alteplase combined with edaravone) and the control group (59 patients were treated with intravenous thrombolysis of alteplase). The clinical effect, neurological function, cerebral hemodynamic index, T lymphocyte level, oxygen free radical scavenging level and oxidative stress index of the 2 groups were observed and compared.Before the treatment, there were no significant differences in neurological function, cerebral hemodynamic indexes, T-lymphocyte level, oxygen free radical scavenging level and oxidative stress indexes between the 2 groups (P > .05). After the treatment, the neurological function, cerebral hemodynamic indexes, T-lymphocyte level, oxygen free radical scavenging level and oxidative stress indexes of the 2 groups were significantly improved. In addition, the observation group exerted greater beneficial effect in terms of the clinical effect, neurologic function, cerebral hemodynamic index, T lymphocyte level, oxygen free radical scavenging level and oxidative stress index than those of the control group (P < .05).The intravenous thrombolysis with alteplase and edaravone is effective in the treatment of acute cerebral infarction, which also provides better results in terms of improving the clinical efficacy and prognosis of patients and might be an alternative option for clinical practice.

[A case of surfer's myelopathy with serial imaging examination from early stage after onset]

Surfer's myelopathy is non-traumatic spinal cord injury which develops in beginner surfers. The patient was a 17-year-old female who developed severe paraplegia with bilateral sensory dysfunction below the groin and bladder/rectal dysfunctions after her first surfing lesson. A spinal-cord MRI performed six hours after onset revealed an intramedullary hyperintensity area from T8 to the conus medullaris on the T₂ weighted images. Expansion of this hyperintensity area was observed on Day 3 and showed a reduction on Day 8. After providing intravenous methylpredonisolone, intravenous glycerol and intravenous edaravone, motor function and bladder/rectal functions began to improve after approximately three weeks. In this study, the expansion of the lesion in the early stages of the disease course was observed by sequential spinal MRI. Furthermore, a time lag between improvement according to imaging and improvement in symptoms was also observed.

Edaravone at high concentrations attenuates cognitive dysfunctions induced by abdominal surgery under general anesthesia in aged mice

Postoperative cognitive dysfunction (POCD) is a common neurological disease affecting the elderly patients after surgery. Unfortunately, no effective treatment for this disease has been discovered. Edaravone, a clinical-used free radical scavenger, at 3 mg/kg has been reported to prevent neuroinflammation induced by the combination of surgery and lipopolysaccharide in adult rodents. However, we found that edaravone at such low concentration could not inhibit POCD in aged mice. Instead, edaravone at 33.2 mg/kg significantly prevented recognition and spatial cognitive dysfunctions in 14 month aged mice after abdominal surgery under general anesthesia with isoflurane. Furthermore, edaravone significantly prevented the increase of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) induced by abdominal surgery in aged mice. Edaravone could also decrease glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule-1 (Iba-1) positive areas in the hippocampal regions of surgery mice, suggesting that edaravone might inhibit surgery-induced over-activation of microglia and astrocytes. Moreover, edaravone substantially increased the expression of PSD-95 and pSer9-glycogen synthase kinase-3β (pSer9-GSK3β) as demonstrated by Western blotting assay. Furthermore, the activity of acetylcholinesterase (AChE) is decreased in the mice in edaravone group. All these results suggested that edaravone at high concentrations could inhibit surgery-induced cognitive impairments in aged animals, possibly via the attenuation of neuroinflammation, the increase of synaptic proteins, and the elevation of cholinergic transmission, providing a further support that edaravone might be developed as a treatment of POCD.

Young male with syphilitic cerebral arteritis presents with signs of acute progressive stroke: A case report

INTRODUCTION

Neurosyphilis is a chronic infection of the central nervous system that is commonly found in adult with long latency periods. Neurosyphilis-attributed deaths in young patients have grown exponentially in the past decade, yet there have been few studies on the early stages of neurosyphilis.

PATIENT CONCERNS

A young male patient with syphilitic cerebral arteritis was evaluated in our clinic for the clinical signs of progressive ischemic stroke.

DIAGNOSIS

The progression of syphilitic cerebral arteritis was observed through computed tomography imaging, magnetic resonance imaging, magnetic resonance angiogram, and transcranial color Doppler. The pathological changes and clinical outcomes were reviewed. In this specific case, the development of syphilitic cerebral arteritis was dynamic, continuous, and rapid. The pathogenesis was related to Heubner arteritis, in which the formation of a mural thrombus (MT) causes the severe obstruction of blood flow without complete occlusion, leading to an increased risk of infarction. In this patient, formation of the MT resulted in the infarction of the smaller vessels and narrowing of the larger vessels. The partial dislodgment of the MT from the arterial wall of the larger vessels occluded the smaller vessels, leading to infarction.

INTERVENTIONS

Standard pharmacotherapy for the treatment of the cerebral infarction and a single course of penicillin were applied.

OUTCOMES

Muscle strength was recovered. The Glasgow Coma Scale score was 15, whereas the NIH Stroke Scale score was 0. The increase in blood flow of the right MCA was accompanied by severe stenosis with compensation of the anterior communicating artery. In addition, moderate to severe stenosis of the right vertebral artery and the basilar artery was suspected. There was a possibility that the right posterior communicating artery was recruited for compensation.

CONCLUSION

Progressive stroke was the initial symptom of the neurosyphilis. Disease progression is rapid and difficult to control with a single course of penicillin.

Simultaneous Blood-Brain Barrier Crossing and Protection for Stroke Treatment Based on Edaravone-Loaded Ceria Nanoparticles

Cerebral vasculature and neuronal networks will be largely destroyed due to the oxidative damage by overproduced reactive oxygen species (ROS) during a stroke, accompanied by the symptoms of ischemic injury and blood-brain barrier (BBB) disruption. Ceria nanoparticles, acting as an effective and recyclable ROS scavenger, have been shown to be highly effective in neuroprotection. However, the brain access of nanoparticles can only be achieved by targeting the damaged area of BBB, leading to the disrupted BBB being unprotected and to turbulence of the microenvironment in the brain. Nevertheless, the integrity of the BBB will cause very limited accumulation of therapeutic nanoparticles in brain lesions. This dilemma is a great challenge in the development of efficient stroke nanotherapeutics. Herein, we have developed an effective stroke treatment agent based on monodisperse ceria nanoparticles, which are loaded with edaravone and modified with Angiopep-2 and poly(ethylene glycol) on their surface (E-A/P-CeO₂). The as-designed E-A/P-CeO₂ features highly effective BBB crossing via receptor-mediated transcytosis to access brain tissues and synergistic elimination of ROS by both the loaded edaravone and ceria nanoparticles. As a result, the E-A/P-CeO₂ with low toxicity and excellent hemo/histocompatibility can be used to effectively treat strokes due to great intracephalic uptake enhancement and, in the meantime, effectively protect the BBB, holding great potentials in stroke therapy with much mitigated harmful side effects and sequelae.