Prognosis in Paracetamol Self-Poisoning: The Use of Plasma Paracetamol Concentration in a Region without a Poisoning Treatment Centre

Published criteria for prognosis following self-poisoning with paracetamol have been applied to 30 cases in a region without centralised facilities for investigation of the poisoned patient. The results show that, despite difficulties in collection and transport of specimens, useful prognostic indices can be provided by a central laboratory. The biochemical assessment of liver damage is discussed and one of two fatal cases is presented in detail.

A randomized controlled trial of methotrexate for patients with generalized myasthenia gravis

OBJECTIVE

To determine the steroid-sparing effect of methotrexate (MTX) in patients with symptomatic generalized myasthenia gravis (MG).

METHODS

We performed a 12-month multicenter, randomized, double-blind, placebo-controlled trial of MTX 20 mg orally every week vs placebo in 50 acetylcholine receptor antibody-positive patients with MG between April 2009 and August 2014. The primary outcome measure was the prednisone area under the dose-time curve (AUDTC) from months 4 to 12. Secondary outcome measures included 12-month changes of the Quantitative Myasthenia Gravis Score, the Myasthenia Gravis Composite Score, Manual Muscle Testing, the Myasthenia Gravis Quality of Life, and the Myasthenia Gravis Activities of Daily Living.

RESULTS

Fifty-eight patients were screened and 50 enrolled. MTX did not reduce the month 4-12 prednisone AUDTC when compared to placebo (difference MTX - placebo: -488.0 mg, 95% confidence interval -2,443.4 to 1,467.3, p = 0.26); however, the average daily prednisone dose decreased in both groups. MTX did not improve secondary measures of MG compared to placebo over 12 months. Eight participants withdrew during the course of the study (1 MTX, 7 placebo). There were no serious MTX-related adverse events. The most common adverse event was nonspecific pain (19%).

CONCLUSIONS

We found no steroid-sparing benefit of MTX in MG over 12 months of treatment, despite being well-tolerated. This study demonstrates the challenges of conducting clinical trials in MG, including difficulties with recruitment, participants improving on prednisone alone, and the need for a better understanding of outcome measure variability for future clinical trials.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for patients with generalized MG MTX does not significantly reduce the prednisone AUDTC over 12 months of therapy.

A multi-center screening trial of rasagiline in patients with amyotrophic lateral sclerosis: Possible mitochondrial biomarker target engagement

Rasagiline, a monoamine oxidase B inhibitor, slowed disease progression in the SOD1 mouse, and in a case series of patients with amyotrophic lateral sclerosis (ALS). Here we determine whether rasagiline is safe and effective in ALS compared to historical placebo controls, and whether it alters mitochondrial biomarkers. We performed a prospective open-label, multicenter screening trial of 36 ALS patients treated with 2 mg oral rasagiline daily for 12 months. Outcomes included the slope of deterioration of the revised ALS Functional Rating Scale (ALSFRS-R), adverse event monitoring, time to treatment failure, and exploratory biomarkers. Participants experienced no serious drug-related adverse events, and the most common adverse event was nausea (11.1%). Rasagiline did not improve the rate of decline in the ALSFRS-R; however, differences in symptom duration compared to historical placebo controls differentially affected ALSFRS-R slope estimates. Rasagiline changed biomarkers over 12 months, such that the mitochondrial membrane potential increased (JC-1 red/green fluorescent ratio 1.92, p = 0.0001) and apoptosis markers decreased (Bcl-2/Bax ratio 0.24, p < 0.0001). In conclusion, engagement of exploratory biomarkers and questions about comparability of baseline characteristics lead us to recommend a further placebo-controlled trial.

Exome sequencing in amyotrophic lateral sclerosis identifies risk genes and pathways

Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment. We report the results of a moderate-scale sequencing study aimed at increasing the number of genes known to contribute to predisposition for ALS. We performed whole-exome sequencing of 2869 ALS patients and 6405 controls. Several known ALS genes were found to be associated, and TBK1 (the gene encoding TANK-binding kinase 1) was identified as an ALS gene. TBK1 is known to bind to and phosphorylate a number of proteins involved in innate immunity and autophagy, including optineurin (OPTN) and p62 (SQSTM1/sequestosome), both of which have also been implicated in ALS. These observations reveal a key role of the autophagic pathway in ALS and suggest specific targets for therapeutic intervention.

Safety and efficacy of ceftriaxone for amyotrophic lateral sclerosis: a multi-stage, randomised, double-blind, placebo-controlled trial

BACKGROUND

Glutamate excitotoxicity might contribute to the pathophysiology of amyotrophic lateral sclerosis. In animal models, decreased excitatory aminoacid transporter 2 (EAAT2) overexpression delays disease onset and prolongs survival, and ceftriaxone increases EAAT2 activity. We aimed to assess the safety and efficacy of ceftriaxone for amyotrophic lateral sclerosis in a combined phase 1, 2, and 3 clinical trial.

METHODS

This three-stage randomised, double-blind, placebo-controlled study was done at 59 clinical sites in the USA and Canada between Sept 4, 2006, and July 30, 2012. Eligible adult patients had amyotrophic lateral sclerosis, a vital capacity of more than 60% of that predicted for age and height, and symptom duration of less than 3 years. In stages 1 (pharmacokinetics) and 2 (safety), participants were randomly allocated (2:1) to ceftriaxone (2 g or 4 g per day) or placebo. In stage 3 (efficacy), participants assigned to ceftriaxone in stage 2 received 4 g ceftriaxone, participants assigned to placebo in stage 2 received placebo, and new participants were randomly assigned (2:1) to 4 g ceftriaxone or placebo. Participants, family members, and site staff were masked to treatment assignment. Randomisation was done by a computerised randomisation sequence with permuted blocks of 3. Participants received 2 g ceftriaxone or placebo twice daily through a central venous catheter administered at home by a trained caregiver. To minimise biliary side-effects, participants assigned to ceftriaxone also received 300 mg ursodeoxycholic acid twice daily and those assigned to placebo received matched placebo capsules. The coprimary efficacy outcomes were survival and functional decline, measured as the slope of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) scores. Analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00349622.

FINDINGS

Stage 3 included 66 participants from stages 1 and 2 and 448 new participants. In total, 340 participants were randomly allocated to ceftriaxone and 173 to placebo. During stages 1 and 2, mean ALSFRS-R declined more slowly in participants who received 4 g ceftriaxone than in those on placebo (difference 0·51 units per month, 95% CI 0·02 to 1·00; p=0·0416), but in stage 3 functional decline between the treatment groups did not differ (0·09, -0·06 to 0·24; p=0·2370). No significant differences in survival between the groups were recorded in stage 3 (HR 0·90, 95% CI 0·71 to 1·15; p=0·4146). Gastrointestinal adverse events and hepatobiliary adverse events were more common in the ceftriaxone group than in the placebo group (gastrointestinal, 245 of 340 [72%] ceftriaxone vs 97 of 173 [56%] placebo, p=0·0004; hepatobiliary, 211 [62%] vs 19 [11%], p<0·0001). Significantly more participants who received ceftriaxone had serious hepatobiliary serious adverse events (41 participants [12%]) than did those who received placebo (0 participants).

INTERPRETATION

Despite promising stage 2 data, stage 3 of this trial of ceftriaxone in amyotrophic lateral sclerosis did not show clinical efficacy. The adaptive design allowed for seamless transition from one phase to another, and central venous catheter use in the home setting was shown to be feasible.

FUNDING

National Institute of Neurological Disorders and Stroke.

Seeking a measure of clinically meaningful change in ALS

We sought to identify a method to assess 'clinically meaningful change' perceived by patients, caregivers and clinical raters in relation to changes in ALSFRS-R scores at three-month intervals. In this five-site study, 81 patient-caregiver dyads were interviewed at baseline, three, and six months to assess changes in ALSFRS-R in relation to perceived occurrence of change, its magnitude and impact. Ratings by patients, caregivers and clinical raters were analyzed over three-month intervals within and between respondent groups. We found that patients, clinical raters, and caregivers agreed about 80% of the time about whether change occurred, and in what direction, on each of three visits. The perceived magnitude of change for the four domains measured by the ALSFRS-R was correlated with ratings of impact within respondent groups and across time. We also found moderate associations between changes in ALSFRS-R domain scores and judgments of symptom impact as rated by patient, caregiver and clinical rater. Independent measures (Quality of Life, Goal Assessment Scaling) showed no consistent correlations with ALSFRS-R change scores. In conclusion, the use of scales to assess the perceived magnitude and impact of change corresponding with the domains of the ALSFRS-R may be a step towards understanding of the clinical meaning of changes in that measure.

TREM2 variant p.R47H as a risk factor for sporadic amyotrophic lateral sclerosis

IMPORTANCE

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which microglia play a significant and active role. Recently, a rare missense variant (p.R47H) in the microglial activating gene TREM2 was found to increase the risk of several neurodegenerative diseases, including Alzheimer disease. Whether the p.R47H variant is a risk factor for ALS is not known.

OBJECTIVES

To determine whether p.R47H (rs75932628) in TREM2 is a risk factor for ALS and assess whether TREM2 expression is dysregulated in disease.

DESIGN, SETTING, AND PARTICIPANTS

Samples of DNA from 923 individuals with sporadic ALS and 1854 healthy control individuals self-reported as non-Hispanic white were collected from ALS clinics in the United States and genotyped for the p.R47H variant in TREM2. Clinical data were obtained on ALS participants for genotype/phenotype correlations. Expression of TREM2 was measured by quantitative polymerase chain reaction and compared in spinal cord samples from 18 autopsied patients with ALS and 12 neurologically healthy controls, as well as from wild-type and transgenic SOD1G93A mice.

MAIN OUTCOMES AND MEASURES

Minor allele frequency of rs75932628 and relative expression of TREM2.

RESULTS

The TREM2 variant p.R47H was more common in patients with ALS than in the controls and is therefore a significant risk factor for ALS (odds ratio, 2.40; 95% CI, 1.29-4.15; P = 4.1×10-3). Furthermore, TREM2 expression was increased in spinal cord samples from ALS patients and SOD1G93A mice (P = 2.8×10-4 and P = 2.8×10-9, respectively), confirming dysregulated TREM2 in disease. Expression of TREM2 in the human spinal cord was negatively correlated with survival (P = .04) but not with other phenotypic aspects of disease.

CONCLUSIONS AND RELEVANCE

This study demonstrates that the TREM2 p.R47H variant is a potent risk factor for sporadic ALS. To our knowledge, these findings identify the first genetic influence on neuroinflammation in ALS and highlight the TREM2 signaling pathway as a therapeutic target in ALS and other neurodegenerative diseases.

Systemic pharmacokinetics and cerebrospinal fluid uptake of intravenous ceftriaxone in patients with amyotrophic lateral sclerosis

The cephalosporin antibiotic ceftriaxone was evaluated as a potential therapeutic agent for the treatment of amyotrophic lateral sclerosis (ALS). The pharmacokinetics (PK) of ceftriaxone in plasma and cerebrospinal fluid (CSF) were investigated in 66 participants in a previously reported clinical trial. Their mean age was 51 years, and 65% were male. Participants were randomly assigned to 1 of 3 treatment groups receiving intravenous infusions (mean duration: 25 minutes) every 12 hours of either: placebo and placebo; 2 g ceftriaxone and placebo; or 2 g ceftriaxone twice. Mean steady-state plasma PK variables were: volume of distribution, 14 L (0.17 L/kg); elimination half-life, 8-9 h; total clearance, 17-21 mL/min (0.22-0.25 mL/min/kg). Values were not different between dosage groups. CSF PK analysis, determined through sparse CSF sampling, indicated apparent entry and elimination half-life values of 1.0 and 34 hours, respectively. With both dosage regimens, CSF concentrations were maintained above the target threshold of 1.0 µM (0.55 µg/mL) as determined from in vitro models. The plasma and CSF PK profiles of ceftriaxone were used as a basis for planning the Phase 3 clinical trial of ceftriaxone in ALS.

Design and initial results of a multi-phase randomized trial of ceftriaxone in amyotrophic lateral sclerosis

OBJECTIVES

Ceftriaxone increases expression of the astrocytic glutamate transporter, EAAT2, which might protect from glutamate-mediated excitotoxicity. A trial using a novel three stage nonstop design, incorporating Phases I-III, tested ceftriaxone in ALS. Stage 1 determined the cerebrospinal fluid pharmacokinetics of ceftriaxone in subjects with ALS. Stage 2 evaluated safety and tolerability for 20-weeks. Analysis of the pharmacokinetics, tolerability, and safety was used to determine the ceftriaxone dosage for Stage 3 efficacy testing.

METHODS

In Stage 1, 66 subjects at ten clinical sites were enrolled and randomized equally into three study groups receiving intravenous placebo, ceftriaxone 2 grams daily or ceftriaxone 4 grams daily divided BID. Participants provided serum and cerebrospinal fluid for pharmacokinetic analysis on study day 7. Participants continued their assigned treatment in Stage 2. The Data and Safety Monitoring Board (DSMB) reviewed the data after the last participants completed 20 weeks on study drug.

RESULTS

Stage 1 analysis revealed linear pharmacokinetics, and CSF trough levels for both dosage levels exceeding the pre-specified target trough level of 1 µM (0.55 µg/mL). Tolerability (Stages 1 and 2) results showed that ceftriaxone at dosages up to 4 grams/day was well tolerated at 20 weeks. Biliary adverse events were more common with ceftriaxone but not dose-dependent and improved with ursodeoxycholic (ursodiol) therapy.

CONCLUSIONS

The goals of Stages 1 and 2 of the ceftriaxone trial were successfully achieved. Based on the pre-specified decision rules, the DSMB recommended the use of ceftriaxone 4 g/d (divided BID) for Stage 3, which recently closed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00349622.

An antisense oligonucleotide against SOD1 delivered intrathecally for patients with SOD1 familial amyotrophic lateral sclerosis: a phase 1, randomised, first-in-man study

BACKGROUND

Mutations in SOD1 cause 13% of familial amyotrophic lateral sclerosis. In the SOD1 Gly93Ala rat model of amyotrophic lateral sclerosis, the antisense oligonucleotide ISIS 333611 delivered to CSF decreased SOD1 mRNA and protein concentrations in spinal cord tissue and prolonged survival. We aimed to assess the safety, tolerability, and pharmacokinetics of ISIS 333611 after intrathecal administration in patients with SOD1-related familial amyotrophic lateral sclerosis.

METHODS

In this randomised, placebo-controlled, phase 1 trial, we delivered ISIS 333611 by intrathecal infusion using an external pump over 11·5 h at increasing doses (0·15 mg, 0·50 mg, 1·50 mg, 3·00 mg) to four cohorts of eight patients with SOD1-positive amyotrophic lateral sclerosis (six patients assigned to ISIS 333611, two to placebo in each cohort). We did the randomisation with a web-based system, assigning patients in blocks of four. Patients and investigators were masked to treatment assignment. Participants were allowed to re-enrol in subsequent cohorts. Our primary objective was to assess the safety and tolerability of ISIS 333611. Assessments were done during infusion and over 28 days after infusion. This study was registered with Clinicaltrials.gov, number NCT01041222.

FINDINGS

Seven of eight (88%) patients in the placebo group versus 20 of 24 (83%) in the ISIS 333611 group had adverse events. The most common events were post-lumbar puncture syndrome (3/8 [38%] vs 8/24 [33%]), back pain (4/8 [50%] vs 4/24 [17%]), and nausea (0/8 [0%] vs 3/24 [13%]). We recorded no dose-limiting toxic effects or any safety or tolerability concerns related to ISIS 333611. No serious adverse events occurred in patients given ISIS 333611. Re-enrolment and re-treatment were also well tolerated.

INTERPRETATION

This trial is the first clinical study of intrathecal delivery of an antisense oligonucleotide. ISIS 333611 was well tolerated when administered as an intrathecal infusion. Antisense oligonucleotides delivered to the CNS might be a feasible treatment for neurological disorders.

FUNDING

The ALS Association, Muscular Dystrophy Association, Isis Pharmaceuticals.

Systematic review of the efficacy of cilostazol, naftidrofuryl oxalate and pentoxifylline for the treatment of intermittent claudication

BACKGROUND

A systematic review and network meta-analysis was undertaken to consider the evidence for the efficacy and tolerability of placebo, cilostazol, naftidrofuryl oxalate and pentoxifylline in patients with intermittent claudication due to peripheral arterial disease (PAD).

METHODS

MEDLINE, Embase, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Conference Proceedings, BIOSIS, National Research Register and MetaRegister databases were searched. Eligible studies were randomized controlled trials (RCTs) and published systematic reviews of patients with intermittent claudication due to PAD and whose symptoms persisted despite a period of conservative management. Study selection was conducted by one reviewer with involvement from a clinician. Data were extracted by one reviewer with no blinding to authors or journal, and checked by a second reviewer. Outcome measures were maximum walking distance (MWD) and pain-free walking distance (PFWD).

RESULTS

The review identified 1876 citations; 26 RCTs met the inclusion criteria for the systematic review. Eleven trials provided data relevant for the meta-analysis. Naftidrofuryl oxalate was ranked first for both MWD and PFWD (probability of 0·947 and 0·987, respectively, of being the best treatment) followed by cilostazol and pentoxifylline. For naftidrofuryl oxalate, cilostazol and pentoxifylline, MWD increased by 60 (95 per cent credible interval 20 to 114) per cent, 25 (11 to 40) per cent and 11 (-1 to 24) per cent respectively relative to placebo, and PFWD increased by 49, 13 and 9 per cent.

CONCLUSION

Naftidrofuryl oxalate and cilostazol are both effective treatments for claudication; naftidrofuryl oxalate is likely to be the most effective, with minimal serious adverse events.

A systematic review and economic evaluation of cilostazol, naftidrofuryl oxalate, pentoxifylline and inositol nicotinate for the treatment of intermittent claudication in people with peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) is a condition in which there is blockage or narrowing of the arteries that carry blood to the legs and arms. It is estimated to affect around 4.5% of people aged between 55 and 74 years within the UK. The most common symptom of PAD is intermittent claudication (IC), characterised by pain in the legs on walking that is relieved with rest.

OBJECTIVE

To assess the effectiveness and cost-effectiveness of cilostazol, naftidrofuryl oxalate, pentoxifylline and inositol nicotinate, compared with no vasoactive drugs, for IC due to PAD in adults whose symptoms continue despite a period of conventional management.

DATA SOURCE

Electronic bibliographic databases were searched during April to June 2010 (MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Conference Proceedings Citation Index, BIOSIS Previews).

REVIEW METHODS

Effectiveness outcomes sought were maximal walking distance (MWD), pain-free walking distance (PFWD), ankle-brachial pressure index, cardiovascular events, mortality, adverse events (AEs) and health-related quality of life (HRQoL). A narrative synthesis was provided for all outcomes and a network meta-analysis was undertaken for the walking distance outcomes. A Markov model was developed to assess the relative cost-effectiveness of the interventions from a NHS perspective over a lifetime. The model has three states: vasoactive drug treatment, no vasoactive drug treatment and death. Each 1-week cycle, patients may continue with the drug, discontinue the drug or die. Regression analysis was undertaken to model the relationship between MWD and utility so that a cost per quality-adjusted life-year (QALY) outcome measure could be presented. Univariate and probabilistic sensitivity analyses were undertaken. All costs and outcomes were discounted at 3.5%.

RESULTS

Twenty-six randomised controlled trials were identified that met the inclusion criteria for the clinical effectiveness review. There was evidence that walking distance outcomes were significantly improved by both cilostazol and naftidrofuryl oxalate; the 95% credible intervals for the difference from placebo in the logarithm mean change MWD from baseline were 0.108 to 0.337 and 0.181 to 0.762, respectively. It was not possible to include inositol nicotinate within the meta-analysis of MWD and PFWD owing to the lack of 24-month data; however, the shorter-term data did not suggest a significant effect. AEs were minor for all drugs and included headaches and gastrointestinal difficulties. The incidence of serious adverse events (SAEs), including cardiovascular events and mortality, was not increased by the vasoactive drugs compared with placebo; however, most studies had a relatively short follow-up time to address this outcome. HRQoL data were limited. Two studies of limited quality were identified within the review of cost-effectiveness. The de novo model developed suggests that naftidrofuryl oxalate dominates cilostazol and pentoxifylline and has a cost per QALY gained of around £6070 compared with no vasoactive drug. This result is reasonably robust to changes within the key model assumptions. Inositol nicotinate was not included within the main analysis owing to lack of data. However, it is unlikely to be considered to be cost-effective due to its high acquisition cost (£900 vs £100-500 per year for the other drugs).

CONCLUSIONS

Naftidrofuryl oxalate and cilostazol both appear to be effective treatments for this patient population, with minimal SAEs. However, naftidrofuryl oxalate is the only treatment that is likely to be considered cost-effective. The long-term effectiveness is uncertain and hence a trial comparing cilostazol, naftidrofuryl oxalate and placebo beyond 24 weeks would be beneficial. Outcomes associated with naftidrofuryl oxalate could also be compared with those associated with supervised exercise programmes and angioplasty.