Clinical Development of Aducanumab, an Anti-Aß Human Monoclonal Antibody Being Investigated for the Treatment of Early Alzheimer's Disease.

The amyloid hypothesis has been the dominant framework for Alzheimer's disease (AD) research, including the development of anti-AD therapies. However, none of the phase III clinical trials conducted to date that targeted amyloid ß (Aß) production, aggregation, or clearance demonstrated a statistically significant treatment effect in patients with AD. This includes the approach of using monoclonal antibodies that recognize various Aß epitopes and display different binding selectivity. While some monoclonal antibodies have failed in phase III trials, several are still in development. Aducanumab (BIIB037) is a human antibody that selectively targets aggregated forms of Aß, including soluble oligomers and insoluble fibrils. In PRIME (NCT01677572), an ongoing phase Ib trial (N=196 patients dosed), aducanumab was shown to reduce Aß plaques and slow decline in clinical measures in patients with prodromal or mild AD, with acceptable safety and tolerability. The main safety finding was amyloid-related imaging abnormalities (ARIA), a side effect associated with removal of Aß, which was dose-dependent and occurred more often in ApoE ε4 carriers than non-carriers. ENGAGE (NCT02477800) and EMERGE (NCT02484547), the ongoing phase III trials of aducanumab in early AD, have been designed based on the outcomes of PRIME and on lessons from past clinical trials in patients with AD. Those study design features include patient selection with confirmed Aß pathology, ensuring sufficient target engagement, and conducting clinical trials in patients at earlier symptomatic stages of AD.

Fingolimod first-dose effects in patients with relapsing multiple sclerosis concomitantly receiving selective serotonin-reuptake inhibitors.

Selective serotonin-reuptake inhibitors (SSRIs), commonly administered for depression and anxiety in patients with multiple sclerosis, are associated with QT interval prolongation. Fingolimod (FTY720; Gilenya(®), Novartis Pharma AG) is a first-in-class sphingosine 1-phosphate receptor modulator approved for relapsing forms of multiple sclerosis. Fingolimod first-dose administration is associated with a transient, generally asymptomatic, slowing of heart rate, which may also prolong QT interval. This posthoc analysis compared cardiac outcomes in over 3300 patients with relapsing multiple sclerosis who were or were not receiving SSRIs during fingolimod treatment initiation, including a subset of patients receiving citalopram or escitalopram. Vital signs were recorded hourly for 6h, and electrocardiograms were obtained pre-dose and 6 h post-dose. Changes in mean hourly heart rate from baseline (pre-dose) to 6 h post-dose were similar among patients not receiving SSRIs (fingolimod 0.5 mg, -7.5 bpm; placebo, 0.0 bpm) and those receiving SSRIs (fingolimod 0.5 mg, -6.6 bpm; placebo, 0.3 bpm). In patients treated with fingolimod 0.5 mg, the mean change in corrected QT interval from baseline to 6 h after treatment initiation was under 10 ms, and few patients had absolute corrected QT intervals of over 450 ms (men) or 470 ms (women), calculated according to Bazett׳s or Fridericia׳s correction methods, irrespective of whether or not they were receiving an SSRI; similar findings were reported in the placebo group. Co-administration of SSRIs and fingolimod was not associated with an increased incidence of any electrocardiogram findings compared with fingolimod therapy alone, and the majority of patients receiving fingolimod (83-86%) were discharged from first-dose monitoring at 6 h irrespective of whether they were also receiving SSRIs. These analyses provide reassurance that concomitant use of SSRIs does not affect cardiac outcomes associated with fingolimod treatment initiation.

Relapses in patients treated with fingolimod after previous exposure to natalizumab.

In post hoc analyses of an open-label, phase 3b study (FIRST), relapse rates during 4 months of fingolimod therapy were compared in patients with and without previous natalizumab exposure. Reductions in the proportion of patients experiencing relapses and annualized relapse rates (ARRs) from years 1 and 1-2 pre-study were evident between months 1 and 2 of fingolimod treatment, and were most pronounced in natalizumab-naïve patients and those who discontinued natalizumab >6 months pre-study. Patients who discontinued natalizumab 3-6 months pre-study had a peak ARR during month 1 of fingolimod treatment, followed by a decrease during months 2-4. These data indicate that fingolimod has the potential to reduce disease reactivation but that timing of treatment initiation may be critical for achieving an optimal effect.

Effect of prior treatment status and reasons for discontinuation on the efficacy and safety of fingolimod vs. interferon ß-1a intramuscular: Subgroup analyses of the Trial Assessing Injectable Interferon vs. Fingolimod Oral in Relapsing-Remitting Multiple Sclerosis (TRANSFORMS).

BACKGROUND: Fingolimod demonstrated superior efficacy compared with interferon ß-1a intramuscular in relapsing multiple sclerosis. The impact of treatment history on fingolimod efficacy is unknown. OBJECTIVES: This post-hoc analysis of phase 3 TRANSFORMS data compared the efficacy and safety of fingolimod and interferon ß-1a intramuscular among patient subgroups defined by prior treatment history. METHODS: Annualized relapse rate and safety of once-daily oral fingolimod 0.5mg, 1.25mg, or once-weekly interferon ß-1a 30µg intramuscular for 12 months were analyzed in 1292 patients with relapsing multiple sclerosis according to prior disease-modifying therapy, reason for prior disease-modifying therapy discontinuation (adverse events or unsatisfactory therapeutic effect), and prior disease-modifying therapy duration. RESULTS: Compared with interferon ß-1a intramuscular, fingolimod 0.5mg significantly reduced annualized relapse rate in patients who were treatment naive, received prior interferon-ß treatment, discontinued prior disease-modifying therapy for unsatisfactory therapeutic effect, or had prior disease-modifying therapy duration of ≥1 year (P≤0.05, all comparisons). Similar trends were observed in patients with prior glatiramer acetate treatment. Significant reductions were also seen with fingolimod 1.25mg for treatment-naive and prior interferon-ß-treated patients. CONCLUSIONS: This analysis demonstrates superiority of fingolimod over interferon ß-1a intramuscular regardless of prior (interferon-ß) treatment and prior treatment efficacy and duration. ClinicalTrials.gov identifier: NCT00340834.

Five-year results from a phase 2 study of oral fingolimod in relapsing multiple sclerosis.

We present here results at 60 months (M), from the extension component of a phase 2, randomized, placebo-controlled, double-blind, six-month study evaluating oral fingolimod (1.25 mg or 5 mg daily) in relapsing multiple sclerosis. Placebo patients from the core study were re-randomized to fingolimod 1.25 mg or 5 mg in the extension. All patients received 1.25 mg fingolimod after the M24 visit. A total of 140/281 (49.8%) patients completed M60. Fingolimod treatment was associated with a low annualized relapse rate (0.2 relapses/ year), low MRI activity, and a modest rate of disability progression in those treated for five years. No new safety issues were reported.

Adjunctive brivaracetam for refractory partial-onset seizures: a randomized, controlled trial.

OBJECTIVE: To explore efficacy and safety/tolerability of adjunctive brivaracetam (BRV), a novel, high-affinity synaptic vesicle protein 2A ligand, which also inhibits neuronal voltage-dependent sodium channels, in patients with refractory partial-onset seizures (POS). METHODS: This was an exploratory, phase IIb, double-blind, randomized, parallel-group, placebo-controlled, dose-ranging study in patients 16-65 years with epilepsy experiencing > or =4 POS during 4-week baseline despite 1-2 concomitant antiepileptic drugs. Patients were randomized (1:1:1:1) to placebo, BRV 5 mg/day (BRV5), BRV 20 mg/day (BRV20), or BRV 50 mg/day (BRV50), administered BID without uptitration during a 7-week treatment period. Primary efficacy endpoint was POS frequency/week during the treatment period relative to placebo. RESULTS: A total of 208 patients constituted the intention-to-treat population; 197 completed the study. Estimated percentage reductions over placebo in POS frequency/week were 9.8% (BRV5; p = 0.240), 14.9% (BRV20; p = 0.062), and 22.1% (BRV50; p = 0.004). Median percent reductions from baseline in POS frequency/week were 21.7% (placebo), 29.9% (BRV5; p = 0.086), 42.6% (BRV20; p = 0.014), and 53.1% (BRV50; p < 0.001); > or =50% responder rates were 16.7% (placebo), 32.0% (BRV5; p = 0.047), 44.2% (BRV20; p = 0.002), and 55.8% (BRV50; p < 0.001); seizure freedom rates (POS) during the 7-week treatment period were 1.9% (placebo), 8.0% (BRV5; p = 0.193), 7.7% (BRV20; p = 0.193), and 7.7% (BRV50; p = 0.201). BRV was well-tolerated. Most adverse events were mild to moderate and occurred with similar incidence in placebo and BRV groups, and discontinuations due to treatment-emergent adverse events were infrequent (placebo 3.7%; BRV 2.6%). CONCLUSIONS: This interventional study provides preliminary Class I evidence that adjunctive BRV was efficacious and well-tolerated in patients aged 16-65 years with POS.

Plasticity of hippocampal corticosteroid receptors during aging in the rat.

Aging is commonly associated with dysregulation of the hypothalamo-pituitary-adrenal axis and cognitive impairment. On the basis of suggestions that these disruptions ensue from changes in the hippocampal complement of corticosteroid (mineralocorticoid and glucocorticoid) receptors (MR and GR), we examined the availability of hippocampal MR and GR by measuring the in vivo uptake of 3H-aldosterone and 3H-dexamethasone (selective MR and GR agonists, respectively); MR and GR mRNA levels were also measured. We observed age-related declines in both the synthesis of MR and GR and the uptake of their respective ligands. Whereas MR mRNA levels and ligand uptake declined in parallel, GR binding declined more steeply than GR mRNA. This latter result, together with our finding that aged rats show impaired corticosteroid receptor mRNA and protein up-regulation after corticosteroid withdrawal, indicates decreased transcription of MR and GR genes and posttranslational modification of GR mRNA during aging. Given that corticosteroids can influence MR and GR synthesis and binding, and based on the finding that aged subjects show reduced basal secretion of corticosterone, we propose that this relative hypocorticalism may be responsible for the changes observed in MR and GR activity, which then leads to disturbances in neuroendocrine regulation and cognitive function in aged subjects.

Exacerbation of apoptosis in the dentate gyrus of the aged rat by dexamethasone and the protective role of corticosterone.

Glucocorticoid-induced cell loss in the dentate gyrus of rats of various ages was studied using the TUNEL procedure to detect apoptotic cells. A highly significant increase in the incidence of apoptosis was observed within the dentate hilus and granule cell layer within 24 h of a single injection of dexamethasone (DEX) in rats aged between 1 and 36 months; DEX-induced apoptosis was more pronounced with increasing age. Corticosterone (CORT) did not cause an increase in the rate of apoptosis above that found in age-matched controls. However, CORT pretreatment (3 h) resulted in a significantly attenuated DEX-induced apoptosis in both areas of the dentate gyrus. Serum CORT levels in saline-treated rats peaked at 6 months of age and reached a nadir at 36 months of age. The results indicate that (i) aged subjects are more susceptible to DEX in terms of dentate gyrus cell loss by apoptosis, (ii) CORT, which binds to Type I corticosteroid receptors with a high affinity, might serve to protect against the damaging effects of DEX which is a ligand of the Type II glucocorticoid receptor, and (iii) declining endogenous levels of CORT may increase the vulnerability of the dentate gyrus of aged rats to insult by DEX.