High Resolution Discovery Proteomics Reveals Candidate Disease Progression Markers of Alzheimer's Disease in Human Cerebrospinal Fluid.

Disease modifying treatments for Alzheimer's disease (AD) constitute a major goal in medicine. Current trends suggest that biomarkers reflective of AD neuropathology and modifiable by treatment would provide supportive evidence for disease modification. Nevertheless, a lack of quantitative tools to assess disease modifying treatment effects remains a major hurdle. Cerebrospinal fluid (CSF) biochemical markers such as total tau, p-tau and Ab42 are well established markers of AD; however, global quantitative biochemical changes in CSF in AD disease progression remain largely uncharacterized. Here we applied a high resolution open discovery platform, dMS, to profile a cross-sectional cohort of lumbar CSF from post-mortem diagnosed AD patients versus those from non-AD/non-demented (control) patients. Multiple markers were identified to be statistically significant in the cohort tested. We selected two markers SME-1 (p<0.0001) and SME-2 (p = 0.0004) for evaluation in a second independent longitudinal cohort of human CSF from post-mortem diagnosed AD patients and age-matched and case-matched control patients. In cohort-2, SME-1, identified as neuronal secretory protein VGF, and SME-2, identified as neuronal pentraxin receptor-1 (NPTXR), in AD were 21% (p = 0.039) and 17% (p = 0.026) lower, at baseline, respectively, than in controls. Linear mixed model analysis in the longitudinal cohort estimate a decrease in the levels of VGF and NPTXR at the rate of 10.9% and 6.9% per year in the AD patients, whereas both markers increased in controls. Because these markers are detected by mass spectrometry without the need for antibody reagents, targeted MS based assays provide a clear translation path for evaluating selected AD disease-progression markers with high analytical precision in the clinic.

Cerebrospinal fluid biomarkers distinguish postmortem-confirmed Alzheimer's disease from other dementias and healthy controls in the OPTIMA cohort.

Cerebrospinal fluid (CSF) amyloid-ß (Aß) and tau have been studied as markers of Alzheimer's disease (AD). Combined Aß42 and t-tau distinguishes AD from healthy controls with a sensitivity and specificity (sens/spec) near 89% across studies. This study examined these markers in the homogeneous OPTIMA cohort, using extensive longitudinal follow up and postmortem evaluation to confirm clinicopathological status. Baseline CSF was analyzed from 227 participants with AD (97% autopsy-confirmed), mild cognitive impairment (MCI; 73% confirmed), other dementia syndrome (ODS; 100% confirmed), and controls (CTL; 27% confirmed, follow up approximately 9-13 years). Biomarker concentrations were analyzed using validated ELISAs. AD patients had lower CSF Aß42 and higher t-tau, p-tau, t-tau/Aß42, and t-tau/Aß40 compared to CTLs, with MCI intermediate. CTL and MCI participants who progressed to AD demonstrated more AD-like profiles. Aß40, sAßPPα, and sAßPPß were lower in AD compared to CTL. High-level discriminators of AD from CTL were t-tau/Aß40 (AUROC 0.986, sens/spec of 92%/94%), p-tau/Aß42 (AUROC 0.972, sens/spec of 94%/90%), and Aß42 (AUROC 0.941, sens/spec of 88%). For discriminating AD from ODS, p-tau/Aß42 demonstrated sens/spec of 88%/100% (95%/86% at the AD versus CTL cutoff) and Aß42 demonstrated sens/spec of 84%/100% (88%/100% at the AD versus CTL cutoff). In a well-characterized, homogeneous population, a single cutoff for baseline CSF Aß and tau markers can distinguish AD with a high level of sens/spec compared to other studies. It may be important to characterize sources of demographic and biological variability to support the effective use of CSF diagnostic assays in the broader AD population.

Rizatriptan for treatment of acute migraine in patients taking topiramate for migraine prophylaxis.

OBJECTIVE: To assess efficacy and tolerability of rizatriptan orally disintegrating tablet (ODT) for treatment of acute migraine in patients using topiramate for migraine prophylaxis. BACKGROUND: There are limited data from prospective controlled trials demonstrating the benefit of triptans in patients who experience migraine attacks while taking prophylactic medication. METHODS: This was a worldwide, randomized, placebo-controlled, double-blind, multiple-attack study in adults with a >1-year history of migraine taking a stable dose of topiramate for migraine prophylaxis and experiencing ≥2 moderate/severe attacks per month. Participants treated 3 moderate/severe attacks in crossover fashion (2 with rizatriptan 10-mg ODT, 1 with placebo) following random assignment to 1 of 3 treatment sequences. The primary end point was 2-hour pain relief. RESULTS: Two-hour pain relief was significantly greater with rizatriptan compared with placebo (55.0% vs 17.4%, P < .001). Response rates also favored rizatriptan for sustained pain relief from 2-24 hours (32.6% vs 11.1%, P < .001), 2-hour pain freedom (36.0% vs 6.5%, P < .001), normal functional ability at 2 hours (42.2% vs 12.7%, P < .001), and overall treatment satisfaction at 24 hours (60.8% vs 33.6%, P < .001). Few participants reported adverse experiences (16 [15.8%] with rizatriptan, 3 [3.2%] with placebo); none were serious. CONCLUSION: Rizatriptan 10-mg ODT was superior to placebo at all pain end points for treatment of acute migraine in patients using topiramate for migraine prophylaxis. Rizatriptan was generally well tolerated in this population. These results are comparable with those from clinical trials in patients not using prophylaxis, suggesting that the use of topiramate does not affect the efficacy or tolerability of rizatriptan for acute migraine treatment.

Efficacy and tolerability of rizatriptan for the treatment of acute migraine in sumatriptan non-responders.

OBJECTIVE: The study was carried out to assess the efficacy and tolerability of rizatriptan orally disintegrating tablet (ODT) for treating acute migraine in patients who are non-responders to sumatriptan. BACKGROUND: Many migraineurs report dissatisfaction with sumatriptan efficacy. It is unclear whether sumatriptan 100 mg non-responders will respond to other triptans. METHODS: This was a randomized, placebo-controlled, double-blind study in adults with >1-year history of ICHD-II (International Classification of Headache Disorders, second edition) migraine who reported that they generally do not respond to sumatriptan (≥50% unsatisfactory response). In the baseline phase, participants treated a single moderate/severe migraine attack with open-label generic sumatriptan 100 mg. Those who continued to experience moderate/severe pain at two hours post-dose were eligible to enter the double-blind treatment phase, during which participants treated three migraine attacks in crossover fashion (two with rizatriptan 10-mg ODT, one with placebo) after being randomly assigned to one of three treatment sequences (1 : 1 : 1 ratio). The primary endpoint was two-hour pain relief. RESULTS: A total of 102 (94%) participants treated at least one study migraine. Pain relief at two hours was significantly greater with rizatriptan compared with placebo (51% vs. 20%, p < .001). Response rates also favored rizatriptan on two-hour pain freedom (22% vs. 12%, p = .013) as well as 24-hour sustained pain relief (38% vs. 14%, p < .001) and sustained pain freedom (20% vs. 11%, p = .036). Treatment was generally well tolerated. CONCLUSION: Rizatriptan 10-mg ODT was superior to placebo at providing two-hour pain relief and two-hour pain freedom in the treatment of acute migraine in those who do not respond to sumatriptan 100 mg. Rizatriptan was generally well tolerated in this population.