Erik P. Pioro

A clinical trial of creatine in ALS

Background: Mitochondrial dysfunction occurs early in the course of ALS, and the mitochondria may be an important site for therapeutic intervention. Creatine stabilizes the mitochondrial transition pore, and is important in mitochondrial ATP production. In a transgenic mouse model of ALS, administration of creatine prolongs survival and preserves motor function and motor neurons. Methods: The authors conducted a randomized double-blind, placebo controlled trial on 104 patients with ALS from 14 sites to evaluate the efficacy of creatine supplementation in ALS. The primary outcome measure was maximum voluntary isometric contraction of eight upper extremity muscles, with secondary outcomes including grip strength, ALS Functional Rating Scale–Revised, and motor unit number estimates. Patients were treated for 6 months, and evaluated monthly. Results: Creatine was tolerated well, but no benefit of creatine could be demonstrated in any outcome measure. CI analysis showed that the study, although powered to detect a 50% or greater change in rate of decline of muscle strength, actually made an effect size of greater than 23% unlikely. It was also demonstrated that motor unit number estimation was performed with acceptable reproducibility and tolerability, and may be a useful outcome measure in future clinical trials. Conclusion: Any beneficial effect of creatine at 5 g per day in ALS must be small. Other agents should be considered in future studies of therapeutic agents to address mitochondrial dysfunction in ALS. In addition, motor unit number estimation may be a useful outcome measure for future clinical trials in ALS.

Subcutaneous IGF-1 is not beneficial in 2-year ALS trial

Background: Previous human clinical trials of insulin-like growth factor type I (IGF-1) in amyotrophic lateral sclerosis (ALS) have been inconsistent. This phase III, randomized, double-blind, placebo-controlled study was undertaken to address whether IGF-1 benefited patients with ALS. Methods: A total of 330 patients from 20 medical centers were randomized to receive 0.05 mg/kg body weight of human recombinant IGF-1 given subcutaneously twice daily or placebo for 2 years. The primary outcome measure was change in their manual muscle testing score. Secondary outcome measures included tracheostomy-free survival and rate of change in the revised ALS functional rating scale. Intention to treat analysis was used. Results: There was no difference between treatment groups in the primary or secondary outcome measures after the 2-year treatment period. Conclusions: Insulin-like growth factor type I does not provide benefit for patients with amyotrophic lateral sclerosis. GLOSSARY: ALS = amyotrophic lateral sclerosis; ALSFRS-r = revised ALS functional rating scale; AUC = area under the curve; DVT = deep venous thromboses; IGF-1 = insulin-like growth factor type I; MMT = manual muscle testing; PE = pulmonary embolisms.

A randomized, placebo-controlled trial of topiramate in amyotrophic lateral sclerosis

Objective: To determine if long-term topiramate therapy is safe and slows disease progression in patients with ALS. Methods: A double-blind, placebo-controlled, multicenter randomized clinical trial was conducted. Participants with ALS (n = 296) were randomized (2:1) to receive topiramate (maximum tolerated dose up to 800 mg/day) or placebo for 12 months. The primary outcome measure was the rate of change in upper extremity motor function as measured by the maximum voluntary isometric contraction (MVIC) strength of eight arm muscle groups. Secondary endpoints included safety and the rate of decline of forced vital capacity (FVC), grip strength, ALS functional rating scale (ALSFRS), and survival. Results: Patients treated with topiramate showed a faster decrease in arm strength (33.3%) during 12 months (0.0997 vs 0.0748 unit decline/month, p = 0.012). Topiramate did not significantly alter the decline in FVC and ALSFRS or affect survival. Topiramate was associated with an increased frequency of anorexia, depression, diarrhea, ecchymosis, nausea, kidney calculus, paresthesia, taste perversion, thinking abnormalities, weight loss, and abnormal blood clotting (pulmonary embolism and deep venous thrombosis). Conclusions: At the dose studied, topiramate did not have a beneficial effect for patients with ALS. High-dose topiramate treatment was associated with a faster rate of decline in muscle strength as measured by MVIC and with an increased risk for several adverse events in patients with ALS. Given the lack of efficacy and large number of adverse effects, further studies of topiramate at a dose of 800 mg or maximum tolerated dose up to 800 mg/day are not warranted.

Phase II trial of CoQ10 for ALS finds insufficient evidence to justify phase III

Amyotrophic lateral sclerosis (ALS) is a devastating, and currently incurable, neuromuscular disease in which oxidative stress and mitochondrial impairment are contributing to neuronal loss. Coenzyme Q10 (CoQ10), an antioxidant and mitochondrial cofactor, has shown promise in ALS transgenic mice, and in clinical trials for neurodegenerative diseases other than ALS. Our aims were to choose between two high doses of CoQ10 for ALS, and to determine if it merits testing in a Phase III clinical trial.

A RANDOMIZED CONTROLLED TRIAL OF RESISTANCE EXERCISE IN INDIVIDUALS WITH ALS

Objective: To determine the effects of resistance exercise on function, fatigue, and quality of life in individuals with ALS. Methods: Subjects with a diagnosis of clinically definite, probable, or laboratory-supported ALS, forced vital capacity (FVC) of 90% predicted or greater, and an ALS Functional Rating Scale (ALSFRS) score of 30 or greater were randomly assigned to a resistance exercise group that received a home exercise program consisting of daily stretching and resistance exercises three times weekly or to a usual care group, who performed only the daily stretching exercises. ALSFRS, the Fatigue Severity Scale (FSS), and Short Form-36 (SF-36) were completed at baseline and monthly for 6 months. FVC and maximum voluntary isometric contraction (MVIC) were monitored monthly throughout the study. Results: Of 33 subjects screened, 27 were randomly assigned (resistance = 13; usual care = 14). Eight resistance exercise subjects and 10 usual care subjects completed the trial. At 6 months, the resistance exercise group had significantly higher ALSFRS and SF-36 physical function subscale scores. No adverse events related to the intervention occurred, MVIC and FVC indicated no negative effects, and less decline in leg strength measured by MVIC was found in the resistance exercise group. Conclusion: Our study, although small, showed that the resistance exercise group had significantly better function, as measured by total ALS Functional Rating Scale and upper and lower extremity subscale scores, and quality of life without adverse effects as compared with subjects receiving usual care.

Dextromethorphan plus ultra low-dose quinidine reduces pseudobulbar affect.

To evaluate dextromethorphan combined with ultra low‐dose quinidine (DMq) for treating pseudobulbar affect (PBA) in patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS).

A two-stage genome-wide association study of sporadic amyotrophic lateral sclerosis

The cause of sporadic amyotrophic lateral sclerosis (ALS) is largely unknown, but genetic factors are thought to play a significant role in determining susceptibility to motor neuron degeneration. To identify genetic variants altering risk of ALS, we undertook a two-stage genome-wide association study (GWAS): we followed our initial GWAS of 545 066 SNPs in 553 individuals with ALS and 2338 controls by testing the 7600 most associated SNPs from the first stage in three independent cohorts consisting of 2160 cases and 3008 controls. None of the SNPs selected for replication exceeded the Bonferroni threshold for significance. The two most significantly associated SNPs, rs2708909 and rs2708851 [odds ratio (OR) = 1.17 and 1.18, and P-values = 6.98 x 10(-7) and 1.16 x 10(-6)], were located on chromosome 7p13.3 within a 175 kb linkage disequilibrium block containing the SUNC1, HUS1 and C7orf57 genes. These associations did not achieve genome-wide significance in the original cohort and failed to replicate in an additional independent cohort of 989 US cases and 327 controls (OR = 1.18 and 1.19, P-values = 0.08 and 0.06, respectively). Thus, we chose to cautiously interpret our data as hypothesis-generating requiring additional confirmation, especially as all previously reported loci for ALS have failed to replicate successfully. Indeed, the three loci (FGGY, ITPR2 and DPP6) identified in previous GWAS of sporadic ALS were not significantly associated with disease in our study. Our findings suggest that ALS is more genetically and clinically heterogeneous than previously recognized. Genotype data from our study have been made available online to facilitate such future endeavors.

1H-MRS evidence of neurodegeneration and excess glutamate glutamine in ALS medulla

Objective: To determine whether short echo-time (TE) proton magnetic resonance spectroscopic imaging (1H-MRSI) can detect in vivo differences in signal intensities of specific metabolites in the medulla of patients with ALS compared with healthy individuals and whether these metabolites could be useful surrogate markers of disease. Background: 1H-MRSI can detect N-acetylaspartate +N-acetylaspartylglutamate (abbreviated NAx), which is localized to neurons, and glutamate (Glu) + glutamine (Gln), abbreviated Glx, which may be important in ALS pathogenesis. The medulla is an ideal region to study ALS because of its high density of nuclei and fiber tracts that frequently undergo degeneration, even when more rostral brain regions show minimal pathology. Methods: Ten patients with ALS and seven healthy control subjects underwent short TE 1H-MRSI on a 1.5 T clinical imaging system. Signal intensities of NAx and Glx were normalized to creatine–phosphocreatine and compared between groups. Results: Compared with normal subjects, the medulla of patients with ALS had 17% lower NAx (p = 0.03) and 55% higher Glx (p = 0.02) signals. Bulbar symptoms, represented by the ALS Functional Rating Scale, correlated with Glx (r = −0.68, p = 0.03) but not NAx (r = 0.22, p = 0.53). Conclusion: There is in vivo 1H-MRSI evidence of neuronal degeneration or loss and excess Glu + Gln in the medulla of patients with ALS. Although this cross-sectional study cannot identify which change occurred first, the higher Glx signal in the medulla of patients with more dysarthria and dysphagia is consistent with the hypothesis of Glu excitotoxicity in ALS pathogenesis. Longitudinal 1H-MRSI studies of the medulla (and other brain regions) in more patients with ALS are required to confirm these findings and to determine whether such metabolite changes will be useful in monitoring disease progression, in clinical diagnosis, and in understanding the pathogenesis of ALS.

Phase II/III randomized trial of TCH346 in patients with ALS

Background: TCH346 exerts antiapoptotic effects by binding to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and blocking the apoptotic pathway in which GAPDH is involved. Apoptosis is considered to be a key pathogenic mechanism in neurodegenerative diseases including ALS. Methods: Patients were randomly assigned in a double-blind fashion to receive either placebo or one of four doses of TCH346 (1.0, 2.5, 7.5, or 15 mg/day) administered orally once daily for at least 24 weeks. The primary outcome measure was the rate of change in the revised ALS functional rating scale (ALSFRS-R). The trial design included a 16-week lead-in phase to determine each patients rate of disease progression. The between treatment comparison was adjusted for the individual pretreatment rates of progression. The study was powered to detect a 25% reduction in the rate of decline of the ALSFRS-R as compared with placebo. Secondary outcome measures included survival, pulmonary function, and manual muscle testing (MMT). Results: Five hundred ninety-one patients were enrolled at 42 sites in Europe and North America. There were no differences in baseline variables. There were no significant differences between placebo and active treatment groups in the mean rate of decline of the ALSFRS-R or in the secondary outcome measures (survival, pulmonary function, and MMT). Conclusion: The trial revealed no evidence of a beneficial effect of TCH346 on disease progression in patients with ALS.

Lack of TDP-43 abnormalities in mutant SOD1 transgenic mice shows disparity with ALS.

Mislocalization of the TAR-DNA binding protein (TDP-43) from the nucleus to the cytoplasm of diseased motor neurons and association with intraneuronal ubiquitinated inclusions has recently been reported in amyotrophic lateral sclerosis (ALS). Here, we have investigated TDP-43 immunoreactivity in three lines of mutant SOD1 transgenic mice, G93A, G37R and G85R and compared with labeling in one sporadic ALS case and two familial ALS cases carrying mutations in SOD1, A4T and I113T. Our findings show that there is no mislocalization of TDP-43 to the cytoplasm in motor neurons of mutant SOD1 transgenic mice, nor association of TDP-43 with ubiquitinated inclusions. In contrast, mislocalization of TDP-43 to the cytoplasm and association with ubiquitinated inclusions was found in the ALS cases, including those carrying mutations in SOD1. Interestingly, there was no association of TDP-43 with ubiquitinated hyaline conglomerate inclusions, pathology closely associated with ALS cases carrying mutations in SOD1. Our findings indicate that the process of motor neuron degeneration in mutant SOD1 transgenic mice is unlikely to involve the abnormalities of TDP-43 described in the human disease.