The effect of erenumab on brain network function in episodic migraine patients: a randomized, placebo-controlled clinical trial (RESET BRAIN).

BACKGROUND: We aimed to explore whether erenumab, a monoclonal antibody targeting the calcitonin gene-related peptide receptor, could exert a central effect on brain network function in migraine, and investigate the persistence of such an effect following treatment discontinuation. METHODS: This was a randomized, double-blind, placebo-controlled, multicenter trial with a crossover design performed in adult episodic migraine patients with previous treatment failure. Patients were randomized (1:1) to 12 weeks of erenumab 140 mg or placebo, followed by a 12-week crossover. Resting state (RS) functional connectivity (FC) changes of brain networks involved in migraine were investigated using a seed-based correlation approach. RESULTS: Sixty-one patients were randomized to treatment. In each treatment sequence, 27 patients completed the visit at week 12. Forty-four enrolled patients, 22 in each treatment sequence, completed the study procedures with no major protocol violations. We observed a carry-over effect of erenumab during the placebo treatment and therefore data analysis was performed as a parallel comparison of erenumab vs placebo of the first 12 weeks of treatment. From baseline to week 12, compared to placebo, patients receiving erenumab showed RS FC changes within the cerebellar, thalamic and periaqueductal gray matter networks, significantly associated with clinical improvement. Compared to non-responders, patients achieving a 50% reduction in migraine days had distinct patterns of thalamic and visual network RS FC. Brain RS FC changes reversed when erenumab was stopped. A lower baseline RS FC of the pontine network identified patients responding to erenumab. CONCLUSION: Erenumab modulates RS FC of networks involved in migraine pathophysiology. In line with clinical response, erenumab-induced brain RS FC changes tend to reverse when treatment is stopped.

Safety and tolerability of fingolimod in patients with relapsing-remitting multiple sclerosis: results of an open-label clinical trial in Italy.

The safety profile of fingolimod is well established in clinical trials and post-marketing studies. This study aimed to evaluate the safety and tolerability of fingolimod in a cohort of Italian patients with relapsing-remitting multiple sclerosis (RRMS). This is a non-comparative, open-label, multicentre, interventional study conducted in patients with RRMS with no suitable alternative treatment option. Safety and tolerability of fingolimod 0.5 mg were assessed by recording adverse events (AEs) and serious AEs (SAEs). Of the 906 patients enrolled in the study, 91 % of the patients completed the study. AEs and SAEs were reported in 35.4 and 2.9 % of the patients, respectively. Most common AEs reported were headache (4.1 %), influenza (2.1 %), lymphopenia (1.8 %), asthenia (1.8 %) and pyrexia (1.8 %). Increased alanine aminotransferase levels and hypertension were reported as AE in 1.0 and 1.4 % of the patients, respectively. Macular oedema was reported in three patients. These results emphasize the safety of fingolimod in patients representing the real-world clinical practice in the Italian population. Fingolimod was safe and well tolerated in this population, which, compared to those enrolled in pivotal trials in terms of concomitant diseases and used medications, is broader. TRIAL REGISTRATION: EudraCT 2011-000770-60.

Safety of the first dose of fingolimod for multiple sclerosis: results of an open-label clinical trial.

BACKGROUND: In patients with relapsing-remitting MS (RRMS) fingolimod prevents disease relapses and delays disability progression. First dose administration of fingolimod is associated with a transient, dose-dependent decrease in heart rate (HR) in the 6 hours after drug intake.The aim of the study is to to assess safety and tolerability of the first dose of fingolimod in a cohort of Italian patients with RRMS without alternative therapeutic options. METHODS: Open-label, single arm, multicentre study. After the first dose of fingolimod, patients were observed for 6 hours and had their vital signs monitored hourly. Extended on-site monitoring was provided when required. RESULTS: Of the 906 patients enrolled in the study, most (95.2%) did not experience any adverse event (AE) following fingolimod administration. Cardiovascular AEs occurred in 18 patients and included bradycardia (1.3%), first-and second-degree atrioventricular block (0.1% and 0.2%), palpitations (0.1%), sinus arrhythmia (0.1%) and ventricular premature beats (0.1%). All events were self-limiting and did not require any intervention. Extended monitoring was required in 34 patients. CONCLUSIONS: These results, in a population who better resembled real-world clinical practice in terms of concomitant diseases and medications, are consistent with previous clinical trials and confirmed that the first dose administration of fingolimod is generally safe and well tolerated. TRIAL REGISTRATION: EudraCT 2011-000770-60.

A covalent modification of NADP+ revealed by the atomic resolution structure of FprA, a Mycobacterium tuberculosis oxidoreductase.

FprA is a mycobacterial oxidoreductase that catalyzes the transfer of reducing equivalents from NADPH to a protein acceptor. We determined the atomic resolution structure of FprA in the oxidized (1.05 A resolution) and NADPH-reduced (1.25 A resolution) forms. The comparison of these FprA structures with that of bovine adrenodoxin reductase showed no significant overall differences. Hence, these enzymes, which belong to the structural family of the disulfide oxidoreductases, are structurally conserved in very distant organisms such as mycobacteria and mammals. Despite the conservation of the overall fold, the details of the active site of FprA show some peculiar features. In the oxidized enzyme complex, the bound NADP+ exhibits a covalent modification, which has been identified as an oxygen atom linked through a carbonylic bond to the reactive C4 atom of the nicotinamide ring. Mass spectrometry has confirmed this assignment. This NADP+ derivative is likely to form by oxidation of the NADP+ adduct resulting from nucleophilic attack by an active-site water molecule. A Glu-His pair is well positioned to activate the attacking water through a mechanism analogous to that of the catalytic triad in serine proteases. The NADP+ nicotinamide ring exhibits the unusual cis conformation, which may favor derivative formation. The physiological significance of this reaction is presently unknown. However, it could assist with drug-design studies in that the modified NADP+ could serve as a lead compound for the development of specific inhibitors.

Mycobacterium tuberculosis FprA, a novel bacterial NADPH-ferredoxin reductase.

The gene fprA of Mycobacterium tuberculosis, encoding a putative protein with 40% identity to mammalian adrenodoxin reductase, was expressed in Escherichia coli and the protein purified to homogeneity. The 50-kDa protein monomer contained one tightly bound FAD, whose fluorescence was fully quenched. FprA showed a low ferric reductase activity, whereas it was very active as a NAD(P)H diaphorase with dyes. Kinetic parameters were determined and the specificity constant (kcat/Km) for NADPH was two orders of magnitude larger than that of NADH. Enzyme full reduction, under anaerobiosis, could be achieved with a stoichiometric amount of either dithionite or NADH, but not with even large excess of NADPH. In enzyme titration with substoichiometric amounts of NADPH, only charge transfer species (FAD-NADPH and FADH2-NADP+) were formed. At NADPH/FAD ratios higher than one, the neutral FAD semiquinone accumulated, implying that the semiquinone was stabilized by NADPH binding. Stabilization of the one-electron reduced form of the enzyme may be instrumental for the physiological role of this mycobacterial flavoprotein. By several approaches, FprA was shown to be able to interact productively with [2Fe-2S] iron-sulfur proteins, either adrenodoxin or plant ferredoxin. More interestingly, kinetic parameters of the cytochrome c reductase reaction catalyzed by FprA in the presence of a 7Fe ferredoxin purified from M. smegmatis were determined. A Km value of 30 nm and a specificity constant of 110 microM(-1) x s(-1) (10 times greater than that for the 2Fe ferredoxin) were determined for this ferredoxin. The systematic name for FprA is therefore NADPH-ferredoxin oxidoreductase.