The safety profile of dalfampridine extended release in multiple sclerosis clinical trials

Cellular and Molecular Evidence of Multiple Sclerosis Diagnosis and Treatment Challenges

Multiple sclerosis (MS) is a chronic autoimmune disease that impacts the central nervous system and can result in disability. Although the prevalence of MS has increased in India, diagnosis and treatment continue to be difficult due to several factors. The present study examines the difficulties in detecting and treating multiple sclerosis in India. A lack of MS knowledge among healthcare professionals and the general public, which delays diagnosis and treatment, is one of the significant issues. Inadequate numbers of neurologists and professionals with knowledge of MS management also exacerbate the situation. In addition, MS medications are expensive and not covered by insurance, making them inaccessible to most patients. Due to the absence of established treatment protocols and standards for MS care, India's treatment techniques vary. In addition, India's population diversity poses unique challenges regarding genetic variations, cellular and molecular abnormalities, and the potential for differing treatment responses. MS is more difficult to accurately diagnose and monitor due to a lack of specialized medical supplies and diagnostic instruments. Improved awareness and education among healthcare professionals and the general public, as well as the development of standardized treatment regimens and increased investment in MS research and infrastructure, are required to address these issues. By addressing these issues, it is anticipated that MS diagnosis and treatment in India will improve, leading to better outcomes for those affected by this chronic condition.

Seizures and epilepsy in multiple sclerosis, aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Seizure is one of the manifestations of central nervous system (CNS) inflammatory demyelinating diseases, which mainly include multiple sclerosis (MS), aquaporin 4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). "Acute symptomatic seizures secondary to MS / AQP4-NMOSD / MOGAD" occur in the acute phase of the diseases, and are more frequent in MOGAD. In contrast, recurrent non-provoked seizures, mainly attributed to "autoimmune-associated epilepsy", occur in the non-acute phase of the diseases. Seizures in MS / AQP4-NMOSD / MOGAD mostly have a focal-onset. MS patients with concomitant systemic infections, an earlier onset and a higher disease activity are more likely to have seizures, whereas factors such as higher MS severity, the presence of status epilepticus and cortical damage indicate a greater risk of developing epilepsy. In MOGAD, cerebral cortical encephalitis, acute disseminated encephalomyelitis (ADEM)-like phenotypes (predominately ADEM and multiphasic disseminated encephalomyelitis) indicate a higher seizure risk. Multiple relapses with ADEM-like phenotypes predict epilepsy in pediatrics with MOGAD. Pathophysiologically, acute symptomatic seizures in MS are associated with neuronal hyperexcitability secondary to inflammation and demyelination. Chronic epilepsy in MS is largely due to gliosis, neuronal dysfunction and synaptic abnormalities. The mainstay of treatment for seizures secondary to MS / AQP4-NMOSD / MOGAD include immunotherapy along with antiseizure medications. This critical review discusses the most-updated evidence on epidemiology, clinical correlates, and inflammatory mechanisms underlying seizures and epilepsy in MS / AQP4-NMOSD / MOGAD. Treatment cautions including drug-drug interactions and the impact of treatments on the other are outlined. We also highlight pitfalls and challenges in managing such patients and future research perspectives to address unsolved questions.

Study on Dalfampridine in the treatment of Multiple Sclerosis Mobility Disability: A meta-analysis

Objective

Systematic Review was used to evaluate the efficacy and safety of Dalfampridine (DAP) in the treatment of Mobility Disability (MS) in patients with Multiple Sclerosis.

Methods

Clinical randomized controlled studies about DAP and placebo in the treatment of Mobility Disability in patients with Multiple Sclerosis until March 2019 were explored by searching Embase, PubMed, Cochrane, Web of Knowledge, and ClinicalTrials.gov. Literature screening, data extraction, quality assessment, and statistical analysis were performed by using Stata 14.0.

Results

10 papers were included in the meta-analysis, and the number of patients was 2100. In conclusion, the application of DAP in clinical can significantly improve the Mobility Disability of patients [OR = 2.73, 95%CI (1.66, 4.50), P<0.001, I² = 74.1%] and boost the mobility speed of patients in Timing 24 Minute Walk Test (T24FW) [SMD = 3,08, 95%CI(1,58, 4.58), P<0.001, I² = 98.7%]. There are no significant differences of the incidence of adverse events [RR = 1.06, 95%CI (0.99, 1.14), P = 0.928, I² = 0.0%] and urinary tract infection [RR = 1.21, 95%CI(0.91, 1.60), P = 0.145, I² = 37.2%] between the DAP test group (Doses≤10 mg) and the placebo control group, and the incidence of adverse events [RR = 1.14, 95%CI(1.02, 1.28), P = 0.793, I² = 0.0%] and urinary tract infection[RR = 3.05, 95%CI(1.04, 8.99), P = 0.680, I² = 0.0%] for the DAP test group (Doses>10 mg) is a litter higher than the placebo control group.

Conclusion

DAP can effectively improve Mobility Disability in patients with Multiple Sclerosis, which is safe and reliable in specific DAP usage doses.

4-aminopyridine – the new old drug for the treatment of neurodegenerative diseases

In this review are described the preclinical and clinical pharmacological data as well as new therapeutic indications for the use of 4-aminopyridine. 4-aminopyridine is a potassium (K+) channel blocker that has a long history and various application areas. It is a chemical agent developed in 1963 as a bird poison. The first approval for clinical application of 4-aminopyridine was in 70’s in Bulgaria, since anesthetists in that country have confirmed its effect as reversal agent for nondepolarizing myorelaxants. The Bulgarian pharmaceutical company Sopharma commersialized 4-aminopyridine under the trade name Pymadin. Since then 4-aminopyridine was extensively studied and in 2010 is approved in the USA for the treatment of walking disabilities in patients with multiple sclerosis. In recent years, data from clinical trials indicated that K-channel blockade may prove to be an appropriate strategy to overcome disturbances in nerve impulses conduction associated with demyelination of the central nervous system.

Relevance of silica surface morphology in Ampyra adsorption. Insights from quantum chemical calculations

Theoretical calculations are performed using the Vienna Ab-initio simulation package (VASP) to understand the mechanisms that control the adsorption of Ampyra drug on the different crystallographic planes of β-cristobalite: the hydroxylated (111) and (100) surfaces. The Ampyra-silica interaction is most favored on the (100) surface where the entire ring of the molecule interacts with the surface while on the (111) face, lesser exchange and fewer non-polar atoms are involved. Calculations show that the interactions mainly occur at the interface between the Ampyra and the closest silanol groups, according to the formation of the H-bonding interactions. The results indicate that the H-bonds have an important influence on the adsorption of the Ampyra. In consequence, adsorption on the (111) surface is observed to a lesser extent than on the (100) surface according the smaller hydroxyl density.

DFT calculations are performed to understand the mechanisms that control the adsorption of Ampyra drug on the different crystallographic planes of β-cristobalite: the hydroxylated (111) and (100) surfaces.

De novo convulsive status epilepticus in patients with multiple sclerosis treated with dalfampridine

BACKGROUND

Dalfampridine extended release (DAL) is a broad-spectrum voltage-gated potassium channel blocker that is indicated in multiple sclerosis to improve the nerve conduction of demyelinated axons. Seizures are a known side effect of DAL, which is contraindicated in patients with a history of epilepsy.

OBJECTIVE

Three cases of multiple sclerosis (MS) with de novo convulsive status epilepticus (CSE) probably related to dalfampridine administration are described.

METHODS

No patients had a history of seizures or renal impairment. Biological tests were normal. A brain magnetic resonance imaging (MRI) showed diffuse cortical and subcortical atrophy without active inflammatory lesions.

RESULTS

All three patients presented with CSE that was attributed to DAL and so was discontinued.

CONCLUSION

These case reports illustrate that, aside from seizures, de novo CSE is a potential complication of MS patients treated with DAL.

Effect of 4-Aminopyridine on Genioglossus Muscle Activity during Sleep in Healthy Adults

RATIONALE

The reduction in upper airway muscle activity from wakefulness to sleep plays a key role in the development of obstructive sleep apnea. Potassium (K⁺) channels have been recently identified as the downstream mechanisms through which hypoglossal motoneuron membrane excitability is reduced both in non-rapid eye movement (NREM) sleep and REM sleep. In animal models, the administration of 4-aminopyridine (4-AP), a voltage-gated K⁺ channel blocker, increased genioglossus activity during wakefulness and across all sleep stages.

OBJECTIVES

We tested the hypothesis that administration of a single dose of 4-AP 10 mg extended release would increase genioglossus activity (electromyography of the genioglossus muscle [EMG_GG]) during wakefulness and sleep, and thereby decrease pharyngeal collapsibility.

METHODS

We performed a randomized controlled crossover proof-of-concept trial in 10 healthy participants. Participants received active treatment or placebo in randomized order 3 hours before bedtime in the physiology laboratory.

RESULTS

EMG_GG during wakefulness and NREM sleep and upper airway collapsibility measured during NREM sleep were unchanged between placebo and 4-AP nights. Tonic but not phasic EMG_GG during REM sleep was higher on the 4-AP night when measured as a percentage of maximal voluntary activation (median [interquartile range] 0.3 [0.5] on placebo vs. 0.8 [1.9] %_max on 4 AP; P = 0.04), but not when measured in μV or as a percentage of wakefulness value.

CONCLUSIONS

A single dose of 4-AP 10 mg extended release showed only a small increase in tonic EMG_GG during REM sleep in this group of healthy subjects. We speculate that a higher dose of 4-AP may further increase EMG_GG. However, given the potentially severe, dose-related adverse effects of this drug, including seizures, the administration of 4-AP does not appear to be an effective strategy to increase genioglossus activity during sleep in humans. Clinical Trial registered with clinicaltrials.gov (NCT02656160).

Cutaneous Adverse Effects of Neurologic Medications

Life-threatening and benign drug reactions occur frequently in the skin, affecting 8 % of the general population and 2-3 % of all hospitalized patients, emphasizing the need for physicians to effectively recognize and manage patients with drug-induced eruptions. Neurologic medications represent a vast array of drug classes with cutaneous side effects. Approximately 7 % of the United States (US) adult population is affected by adult-onset neurological disorders, reflecting a large number of patients on neurologic drug therapies. This review elucidates the cutaneous reactions associated with medications approved by the US Food and Drug Administration (FDA) to treat the following neurologic pathologies: Alzheimer disease, amyotrophic lateral sclerosis, epilepsy, Huntington disease, migraine, multiple sclerosis, Parkinson disease, and pseudobulbar affect. A search of the literature was performed using the specific FDA-approved drug or drug classes in combination with the terms 'dermatologic,' 'cutaneous,' 'skin,' or 'rash.' Both PubMed and the Cochrane Database of Systematic Reviews were utilized, with side effects ranging from those cited in randomized controlled trials to case reports. It behooves neurologists, dermatologists, and primary care physicians to be aware of the recorded cutaneous adverse reactions and their severity for proper management and potential need to withdraw the offending medication.

A guide to treating gait impairment with prolonged-release fampridine (Fampyra®) in patients with multiple sclerosis

INTRODUCTION

Gait impairment, a frequent sign in multiple sclerosis (MS), places a major burden on patients since it results in progressive loss of personal and social autonomy, along with work productivity. This guide aims to provide recommendations on how to evaluate gait impairment and use prolonged-release fampridine (PR-fampridine) as treatment for MS patients with gait impairment in Spain.

DEVELOPMENT

PR-fampridine dosed at 10mg every 12hours is currently the only drug approved to treat gait impairment in adults with MS. Additionally, PR-fampridine has been shown in clinical practice to significantly improve quality of life (QoL) in patients who respond to treatment. Treatment response can be assessed with the Timed 25-Foot Walk (T25FW) or the 12-item MS Walking Scale (MSWS-12); tests should be completed before and after starting treatment. The minimum time recommended for evaluating treatment response is 2 weeks after treatment onset. Patients are considered responders and permitted to continue the treatment when they demonstrate a decrease in their T25FW time or an increase in MSWS-12 scores. A re-evaluation is recommended at least every 6 months. The SF-36 (Short Form-36) and the MSIS-29 (MS Impact Scale-29) tests are recommended for clinicians interested in performing a detailed QoL assessment. This drug is generally well-tolerated and has a good safety profile. It should be taken on an empty stomach and renal function must be monitored regularly.

CONCLUSIONS

These recommendations will help ensure safer and more efficient prescription practices and easier management of PR-fampridine as treatment for gait impairment in Spanish adults with MS.

Safety profile of dalfampridine extended release in multiple sclerosis: 5-year postmarketing experience in the United States

BACKGROUND

Dalfampridine extended release tablets (dalfampridine-ER; prolonged-, modified, or sustained-release fampridine outside the US), 10 mg twice daily, was approved by the US Food and Drug Administration (FDA) in January 2010 to improve walking in people with multiple sclerosis, as determined by an increase in walking speed.

OBJECTIVE

To provide a descriptive analysis of reported adverse events (AEs) for commercially available dalfampridine-ER from March 2010 through March 31, 2015.

METHODS

Five-year postmarketing data for dalfampridine-ER were available from the exposure of approximately 107,000 patients in the US (103,700 patient-years). Commonly reported AEs (≥2% of all reported AEs) and serious AEs were determined. The incidence of reported seizures was determined and the events were further investigated.

RESULTS

Among the 107,000 patients exposed to dalfampridine-ER (70% female; mean age 52.1), the most common AEs were dizziness (3.7%), insomnia (3.2%), balance disorder (3%), fall (2.4%), headache (2.4%), nausea (2.1%), and urinary tract infection (2%). Other common AEs were drug ineffectiveness (5.8%), gait disturbance (4.6%), and inappropriate dosing (3.1%). Serious AEs included rare anaphylactic reactions (five cases) and drug hypersensitivity reactions (eight cases). A total of 657 seizure cases were reported (6.3/1,000 patient-years); of these, 324 were medically confirmed (3.1/1,000 patient-years). Incidence of reported seizures was stable over time. Duration of treatment prior to a seizure ranged from a single dose to >4 years; 12% of the seizures occurred within a week of starting treatment.

CONCLUSION

The 5-year US postmarketing safety data of dalfampridine-ER is consistent with the safety profile observed in clinical trials. Incidence of reported seizures remained stable over time. Since commercial availability in March 2010, a warning regarding the risk of anaphylaxis and severe allergic reactions was added to the US prescribing information.

Potassium channel Kv1.3 is highly expressed by microglia in human Alzheimer's disease

Recent genetic studies suggest a central role for innate immunity in Alzheimer's disease (AD) pathogenesis, wherein microglia orchestrate neuroinflammation. Kv1.3, a voltage-gated potassium channel of therapeutic relevance in autoimmunity, is upregulated by activated microglia and mediates amyloid-mediated microglial priming and reactive oxygen species production in vitro. We hypothesized that Kv1.3 channel expression is increased in human AD brain tissue. In a blinded postmortem immunohistochemical semi-quantitative analysis performed on ten AD patients and ten non-disease controls, we observed a significantly higher Kv1.3 staining intensity (p = 0.03) and Kv1.3-positive cell density (p = 0.03) in the frontal cortex of AD brains, compared to controls. This paralleled an increased number of Iba1-positive microglia in AD brains. Kv1.3-positive cells had microglial morphology and were associated with amyloid-β plaques. In immunofluorescence studies, Kv1.3 channels co-localized primarily with Iba1 but not with astrocyte marker GFAP, confirming that elevated Kv1.3 expression is limited to microglia. Higher Kv1.3 expression in AD brains was also confirmed by western blot analysis. Our findings support that Kv1.3 channels are biologically relevant and microglia-specific targets in human AD.

Use of whole exome sequencing for the identification of Ito-based arrhythmia mechanism and therapy

BACKGROUND

Identified genetic variants are insufficient to explain all cases of inherited arrhythmia. We tested whether the integration of whole exome sequencing with well-established clinical, translational, and basic science platforms could provide rapid and novel insight into human arrhythmia pathophysiology and disease treatment.

METHODS AND RESULTS

We report a proband with recurrent ventricular fibrillation, resistant to standard therapeutic interventions. Using whole-exome sequencing, we identified a variant in a previously unidentified exon of the dipeptidyl aminopeptidase-like protein-6 (DPP6) gene. This variant is the first identified coding mutation in DPP6 and augments cardiac repolarizing current (Ito) causing pathological changes in Ito and action potential morphology. We designed a therapeutic regimen incorporating dalfampridine to target Ito. Dalfampridine, approved for multiple sclerosis, normalized the ECG and reduced arrhythmia burden in the proband by >90-fold. This was combined with cilostazol to accelerate the heart rate to minimize the reverse-rate dependence of augmented Ito.

CONCLUSIONS

We describe a novel arrhythmia mechanism and therapeutic approach to ameliorate the disease. Specifically, we identify the first coding variant of DPP6 in human ventricular fibrillation. These findings illustrate the power of genetic approaches for the elucidation and treatment of disease when carefully integrated with clinical and basic/translational research teams.

Pharmacokinetics of dalfampridine extended release 7.5-mg tablets in healthy subjects and individuals with mild and moderate renal impairment: an open-label study

Dalfampridine extended release tablets (D-ER; prolonged-release fampridine in Europe) are available to improve walking in patients with multiple sclerosis (MS). D-ER is mainly renally eliminated; the approved 10-mg twice daily dose is contraindicated in the United States in patients with moderate or severe renal impairment. This study evaluated single-dose and steady-state pharmacokinetics of a 7.5-mg dose of D-ER in healthy subjects (n = 13) and subjects with mild (n = 17) and moderate (n = 12) renal impairment. D-ER plasma concentrations were consistently higher in subjects with renal impairment relative to healthy individuals with a significant (P < .0001) inverse linear relationship between creatinine clearance and drug exposure. Steady-state AUC0-12 among healthy subjects, 167.0 ± 55.3 ng h/mL, increased 74% and 151% with mild and moderate renal impairment, respectively. The overall incidence of adverse events was 61.5%, 47.1%, and 33.3% in healthy subjects, and subjects with mild and moderate renal impairment, respectively, and for treatment-related adverse events the rates were 0%, 17.6%, and 8.3%, respectively. The most common adverse events were headache, dizziness, and arthralgia. The pharmacokinetics of D-ER 7.5-mg twice daily in subjects with mild renal impairment was comparable to 10-mg twice daily in patients with MS who had normal renal function. Exposure was significantly higher in moderate renal impairment.

Pharmacokinetic profile of dalfampridine extended release: clinical relevance in patients with multiple sclerosis

BACKGROUND

In January 2010, dalfampridine extended release tablets (dalfampridine-ER [Ampyra *]; prolonged-, modified- or sustained-release fampridine [Fampyra †] in some countries), 10 mg to be administered twice daily approximately 12 hours apart, were approved by the US Food and Drug Administration. This was the first drug indicated to improve walking in patients with MS.

SCOPE

Publications describing the pharmacokinetics of dalfampridine-ER or the immediate release formulation were identified from a search of PubMed through June 2012 using the search terms 'dalfampridine OR fampridine OR 4-aminopyridine' AND 'pharmacokinetics' and were supplemented with unpublished studies made available by Acorda Therapeutics Inc.

FINDINGS

Pharmacokinetic studies show dose proportionality, with dalfampridine-ER having a more favorable profile than immediate-release dalfampridine. With twice-daily dosing of dalfampridine-ER, time to peak plasma concentration (3.2-3.9 hours) and apparent terminal plasma half-life (5.6-6.4 hours) are approximately twice those of immediate-release formulations, with comparable overall exposure and peak plasma concentrations (21.6 ng/mL) that were maintained at levels approximately 50% lower than immediate release. Steady state is achieved within 39 hours; pharmacokinetics are predictable based on single dosing. Trough plasma concentrations of 13-15 ng/mL are required to maintain efficacy. Renal excretion is predominantly as unchanged compound, and renal clearance in healthy individuals exceeds the glomerular filtration rate. Since dalfampridine-ER exposure increases with renal impairment, it is contraindicated in patients with moderate or severe impairment in the US, and in patients with any renal impairment in the European Union.

CONCLUSIONS

Dalfampridine-ER has low protein binding, is not a substrate for p-glycoprotein and does not affect CYP450 enzymes, suggesting a low potential for drug-drug interactions. Because of the narrow therapeutic range and risk of adverse events, including seizure, with increasing plasma concentrations, the recommended dose and regimen of dalfampridine-ER should not be exceeded and not be used with other dalfampridine formulations. A limitation of this review is that it includes some data that have not yet been published.

Multiple sclerosis and the blood-central nervous system barrier

The central nervous system (CNS) is isolated from the blood system by a physical barrier that contains efflux transporters and catabolic enzymes. This blood-CNS barrier (BCNSB) plays a pivotal role in the pathophysiology of multiple sclerosis (MS). It binds and anchors activated leukocytes to permit their movement across the BCNSB and into the CNS. Once there, these immune cells target particular self-epitopes and initiate a cascade of neuroinflammation, which leads to the breakdown of the BCNSB and the formation of perivascular plaques, one of the hallmarks of MS. Immunomodulatory drugs for MS are either biologics or small molecules, with only the latter having the capacity to cross the BCNSB and thus have a propensity to cause CNS side effects. However, BCNSB penetration is a desirable feature of MS drugs that have molecular targets within the CNS. These are nabiximols and dalfampridine, which target cannabinoid receptors and potassium channels, respectively. Vascular cell adhesion molecule-1, present on endothelial cells of the BCNSB, also serves as a drug discovery target since it interacts with α4-β1-integrin on leucocytes. The MS drug natalizumab, a humanized monoclonal antibody against α4-β1-integrin, blocks this interaction and thus reduces the movement of immune cells into the CNS. This paper further elaborates on the role of the BCNSB in the pathophysiology and pharmacotherapy of MS.

Enhancing neural transmission in multiple sclerosis (4-aminopyridine therapy)

Enhancing neural transmission by improving axonal conduction and synaptic neurotransmitter release is a novel strategy to improve symptoms in multiple sclerosis. Dalfampridine (4-aminopyridine extended-release) is a first-in-class medication that targets the damaged nervous system through blockage of voltage-gated potassium channels. Through a series of clinical trials, dalfampridine (dosed at 10 mg twice daily) has been found to improve walking speed by approximately 25 % on average in one third of individuals with multiple sclerosis regardless of disease stage. Furthermore, it significantly improves patients' perception of their ambulatory disability and may improve lower extremity strength. Given the mechanism of action, the most serious adverse effect is its pro-convulsant property, which occurs more frequently at high serum concentrations. The most common adverse events include increased falls, urinary tract infections, dizziness, insomnia, and headaches. Despite these potential side-effects, the vast majority of individuals who derive benefit continue on the treatment. The exact mechanism of action is uncertain, as is the reason for response variability. The medication serves as proof-of-concept that targeting axonal transmission can improve disability in multiple sclerosis.

Dalfampridine extended release tablets: 1 year of postmarketing safety experience in the US

BACKGROUND

Dalfampridine extended release tablets (dalfampridine-ER; prolonged-, modified, or sustained-release fampridine in some countries) were approved in the US to improve walking in patients with multiple sclerosis, as demonstrated by improvement in walking speed. Postmarketing safety experience is available from exposure of approximately 46,000 patients in the US from product approval through March 2011.

OBJECTIVE

To provide a descriptive analysis of all spontaneously reported postmarketing adverse events (AEs) for dalfampridine-ER since product launch.

METHODS

AE data were extracted from the safety database from product launch through March 31, 2011; AEs were classified using the Medical Dictionary for Regulatory Activities. Seizure cases were reviewed for patient demographics, time to event from treatment onset, and presence of additional risk factors.

RESULTS

THE MOST FREQUENTLY REPORTED POSTMARKETING AES WERE SIMILAR TO THOSE REPORTED DURING CLINICAL DEVELOPMENT: dizziness, insomnia, balance disorder, headache, nausea, urinary tract infection, asthenia, and back pain (all included in US product labeling). New clinically significant findings are related to lack of efficacy and inappropriate dosing. Of the approximately 46,000 patients exposed, 85 seizures were reported (∼5.4/1000 patient-years), of which 82 were reported or confirmed by a health care practitioner (∼5.2/1000 patient-years). Beyond the intrinsic multiple sclerosis-related seizure risk, more than half of the 85 cases (62%) had an additional potential risk factor for seizure including a previous history of convulsions, renal impairment, incorrect dosing, or use of concurrent medications with a labeled seizure risk. Duration of treatment prior to the seizure ranged from one dose to 365 days; 26/85 (31%) patients suffered a seizure within a week of starting treatment.

CONCLUSION

Spontaneous safety data from the US postmarketing experience were consistent with the safety profile seen during clinical development. Although first-year seizure incidence was not substantially different from that observed in dalfampridine-ER clinical trials, patients should be monitored for concomitant use of drugs that lower seizure threshold.

Pharmacotherapeuetic Options for the Treatment of Multiple Sclerosis

Multiple sclerosis is the most common progressive and disabling neurological condition in young adults. Neuro-inflammation is an early and persistent change and forms the basis of most pharmacotherapy for this disease. Immunomodulatory drugs are mainly biologies (β-interferons, a four amino acid peptide, and a monoclonal antibody to a cell adhesion molecule on the blood-CNS barrier) that either attenuate the inflammatory response or block the movement of immune cells into the CNS. They reduce the rate of relapse, but have little or no effect on the progression of disability. The market landscape for MS drugs is in the midst of major change because the patent life of many of these medicines will soon expire, which will lead to the emergence of biosimilars. In addition, new small molecule immunomodulatory and palliative drugs have entered the market, with more in the pipeline; a number of monoclonal antibodies and other immunomodulatory drugs are also in clinical development.