Konectom™ cognitive processing speed test enables reliable remote, unsupervised cognitive assessment in people with multiple sclerosis: Exploring the use of substitution time as a novel digital outcome measure.

BACKGROUND: The Konectom™ smartphone-based cognitive processing speed (CPS) test is designed to assess processing speed and account for impact of visuomotor function on performance. OBJECTIVE: Evaluate reliability and validity of Konectom CPS Test, performed in clinic and remotely. METHODS: Data were collected from people with multiple sclerosis (PwMS) aged 18-64 years and healthy control participants (HC) matched for age, sex, and education. Remote test-retest reliability (intraclass correlation coefficients, ICC); correlation with established clinical measures (Spearman correlation coefficients); group analyses between cognitively impaired/unimpaired PwMS; and influence of age, sex, education, and upper limb motor function on CPS Test measures were assessed. RESULTS: Eighty PwMS and 66 HC participated. CPS Test measures from remote tests had good test-retest reliability (ICC of 0.67-0.87) and correlated with symbol digit modalities test (highest |ρ| = 0.80, p < 0.0001). Remote measures were stable (change from baseline < 5%) and correlated with MS disability (highest |ρ| = 0.39, p = 0.0004) measured by Expanded Disability Status Scale. CPS Test measures displayed sensitivity to cognitive impairment (highest d = 1.47). Demographics and motor function had the lowest impact on CPS Test substitution time, a measure accounting for visuomotor function. CONCLUSION: Konectom CPS Test measures provide valid, reliable remote measurements of cognitive processing speed in PwMS.

Lymphopenia is Not the Primary Therapeutic Mechanism of Diroximel Fumarate in Relapsing-Remitting Multiple Sclerosis: Subgroup Analyses of the EVOLVE-MS-1 Study.

INTRODUCTION: In EVOLVE-MS-1 (NCT02634307), mean absolute lymphocyte count (ALC) on diroximel fumarate (DRF) declined from baseline by approximately 28% in year 1, then stabilized, similar to ALC decline observed with dimethyl fumarate (DMF). Prior studies reported that clinical efficacy of DMF was not substantially different in patients with and without lymphopenia. METHODS: EVOLVE-MS-1-an open-label, 96-week, phase 3 study-assessed DRF safety and exploratory efficacy in patients with relapsing-remitting multiple sclerosis. This study analyzes efficacy-related outcomes comparing (1) patients with lymphopenia (≥ 1 ALC below lower limit of normal [LLN]) and without (all ALCs ≥ LLN); (2) across quartiles stratified by week 96 ALC decline from baseline: Q1 (≥ 47% decline); Q2 (30% to < 47% decline); Q3 (12% to < 30% decline); Q4 (< 12% decline). RESULTS: Baseline characteristics were similar between patients without (n = 593) and with lymphopenia (n = 452). At week 96, adjusted annualized relapse rate (ARR; 95% confidence interval) was 0.14 (0.11-0.17) without lymphopenia and 0.12 (0.09-0.15) with lymphopenia. Estimated proportions with 12-week confirmed disability progression (CDP12) at week 96 were 10.2% without and 9.3% with lymphopenia. When stratified by quartiles (Q1-Q4), ARR at week 96 was 0.11 (Q1), 0.09 (Q2), 0.13 (Q3), and 0.17 (Q4). Estimated proportions with CDP12 at week 96 were 9.6% (Q1), 10.2% (Q2), 5.7% (Q3), and 10.9% (Q4). At week 96, no evidence of disease activity was achieved by 47.2% (Q1), 47.8% (Q2), 45.4% (Q3), and 37.3% (Q4) of patients. CONCLUSION: In DRF-treated patients in EVOLVE-MS-1, clinical and radiological measurements indicated reduced disease activity regardless of lymphopenia or magnitude of ALC decline from baseline; however, patients who had greater ALC declines appeared to have numerically lower ARR and higher proportions free from relapses and gadolinium-enhancing lesions compared with those with smallest decline. This supports prior evidence that, while lymphopenia may contribute to fumarate efficacy outcomes, it is not the primary mechanism of action. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02634307.

Diroximel Fumarate in Patients with Relapsing-Remitting Multiple Sclerosis: NEDA-3 After Re-Baselining in the Phase 3 EVOLVE-MS-1 Study.

INTRODUCTION: Diroximel fumarate (DRF) and dimethyl fumarate (DMF) are orally administered fumarate disease-modifying therapies (DMTs) for multiple sclerosis (MS). The safety, tolerability, and exploratory efficacy of DRF were evaluated in the phase 3 EVOLVE-MS-1 study. No Evidence of Disease Activity (NEDA-3) is a composite efficacy endpoint used in clinical trials for MS defined as no relapse, no 24-week confirmed disability progression (CDP), no new/newly enlarging T2 lesions, and no new gadolinium-enhancing lesions. As NEDA outcomes in studies may be confounded by initial disease activity, the objective of this analysis was to evaluate NEDA-3 in EVOLVE-MS-1 for newly enrolled patients and patients who were re-baselined after approximately 7 weeks. METHODS: Patients entered EVOLVE-MS-1 as either newly enrolled or having completed the 5-week phase 3 EVOLVE-MS-2 study of DRF and DMF. Magnetic Resonance Imaging (MRI) was performed at baseline before each study (approx. 7 weeks apart) and at weeks 48 and 96 in EVOLVE-MS-1. Therefore, patients entering from EVOLVE-MS-2 were re-baselined after approximately 7 weeks. NEDA-3 outcomes on DRF are reported for prior DRF, prior DMF, and de novo patient groups. RESULTS: Of 1057 patients in EVOLVE-MS-1, 239 (22.6%) had rolled over from receiving DRF in EVOLVE-MS-2 ("prior DRF"), 225 (21.3%) had rolled over from receiving DMF in EVOLVE-MS-2 ("prior DMF"), and 593 (56.1%) were newly enrolled ("de novo"). At week 48, Kaplan-Meier estimates of NEDA-3 were 72.3% (prior DRF), 72.1% (prior DMF), and 62.1% (de novo); at week 96, estimates were 50.2% (prior DRF), 48.2% (prior DMF), and 36.5% (de novo). CONCLUSIONS: In EVOLVE-MS-1, after re-baselining at approximately 7 weeks, approximately half of DRF-treated patients achieved NEDA-3 at week 96, compared with 36.5% of patients who were not re-baselined. Re-baselining may be useful for assessing efficacy of DMTs by mitigating the influence of disease activity prior to the onset of efficacy. CLINICAL TRIAL REGISTRATIONS: NCT03093324 (EVOLVE-MS-2); NCT02634307 (EVOLVE-MS-1).

Diroximel fumarate in patients with relapsing-remitting multiple sclerosis: Final safety and efficacy results from the phase 3 EVOLVE-MS-1 study.

BACKGROUND: Diroximel fumarate (DRF) is approved for adults with relapsing-remitting multiple sclerosis (RRMS) in Europe and for relapsing forms of MS in the United States. DRF and dimethyl fumarate (DMF) yield bioequivalent exposure of the active metabolite monomethyl fumarate. Prior studies indicated fewer gastrointestinal (GI)-related adverse events (AEs) with DRF compared with DMF. OBJECTIVE: To report final outcomes from EVOLVE-MS-1. METHODS: EVOLVE-MS-1 was an open-label, 96-week, phase 3 study assessing DRF safety, tolerability, and efficacy in patients with RRMS. The primary endpoint was safety and tolerability; efficacy endpoints were exploratory. RESULTS: Overall, 75.7% (800/1057) of patients completed the study; median exposure was 1.8 (range: 0.0-2.0) years. AEs occurred in 938 (88.7%) patients, mostly of mild (28.9%) or moderate (50.3%) severity. DRF was discontinued due to AEs in 85 (8.0%) patients, with < 2% discontinuing due to GI or flushing/flushing-related AEs. At Week 96, mean number of gadolinium-enhancing lesions was significantly reduced from baseline (72.7%; p < 0.0001); adjusted annualized relapse rate was 0.13 (95% confidence interval: 0.11-0.15). CONCLUSION: DRF was generally well tolerated over 2 years, with few discontinuations due to AEs; radiological measures indicated decreased disease activity from baseline. These outcomes support DRF as a treatment option in patients with RRMS.

Effect of Dimethyl Fumarate vs Interferon ß-1a in Patients With Pediatric-Onset Multiple Sclerosis: The CONNECT Randomized Clinical Trial.

Importance: With few approved multiple sclerosis therapies in the pediatric population, there is a need for further approved treatment options. Limited data exist for dimethyl fumarate (DMF) treatment in pediatric-onset multiple sclerosis (POMS). Objective: To compare the efficacy, safety, and tolerability of DMF vs intramuscular interferon ß-1a (IFNß-1a) in POMS. Design, Setting, and Participants: The CONNECT study was an active-controlled, open-label, rater-blinded 96-week randomized clinical trial in patients with POMS aged 10 to less than 18 years treated between August 2014 and November 2020. Data were analyzed from January through October 2021. Interventions: Patients were randomized to DMF or IFNß-1a. Main Outcomes and Measures: The primary end point was the proportion of patients free of new or newly enlarging (N or NE) T2 hyperintense lesions at week 96 among trial completers. Secondary end points included number of N or NE T2 lesions, proportion of patients free of relapse, annualized relapse rate (ARR), and safety. The estimated proportion of participants who were relapse free up to week 96 was calculated based on the Kaplan-Meier method. Adjusted ARR was obtained from a negative binomial regression adjusted for baseline relapse rate, baseline Expanded Disability Status Scale (EDSS) score, and age group. Results: Among 150 patients with POMS in the intention-to-treat (ITT) population (median [range] age, 15 [10-17] years; 101 [67.3%] female patients), 78 individuals received DMF and 72 individuals received IFNß-1a. At week 96, the proportion of patients with no N or NE T2 hyperintense lesions among 103 trial completers was 16.1% (95% CI, 8.0%-27.7%) for DMF vs 4.9% (95% CI, 0.6%-16.5%) for IFNß-1a, and in a sensitivity analysis among the ITT population, the proportions were 10 patients receiving DMF (12.8%) vs 2 patients receiving IFNß-1a (2.8%). The estimated proportion of patients who remained relapse free at week 96 was 66.2% for DMF vs 52.3% for IFNß-1a. Adjusted ARR (95% CI) at week 96 was 0.24 (95% CI, 0.15-0.39) for DMF vs 0.53 (95% CI, 0.33-0.84) for IFNß-1a; the rate ratio for DMF vs IFNß-1a was 0.46 (95% CI, 0.26-0.80; P = .006). The number of treatment-emergent adverse events (TEAEs; 74 patients [94.9%] vs 69 patients [95.8%]), serious TEAEs (18 patients [23.1%] vs 21 patients [29.2%]), and treatment discontinuations due to TEAEs (5 patients [6.4%] vs 8 patients [11.1%]) was similar for DMF vs IFNß-1a. Conclusions and Relevance: This study found that more pediatric patients with POMS treated with DMF were free of new or newly enlarging T2 lesions and that the adjusted ARR was lower among these patients compared with those treated with interferon ß-1a. DMF was well tolerated. Trial Registration: ClinicalTrials.gov Identifier: NCT02283853.

Chronic lesion activity and disability progression in secondary progressive multiple sclerosis.

Objective: Slowly expanding lesions (SELs), a subgroup of chronic white matter lesions that gradually expand over time, have been shown to predict disability accumulation in primary progressive multiple sclerosis (MS) disease. However, the relationships between SELs, acute lesion activity (ALA), overall chronic lesion activity (CLA) and disability progression are not well understood. In this study, we examined the ASCEND phase III clinical trial, which compared natalizumab with placebo in secondary progressive MS (SPMS). Methods: Patients with complete imaging datasets between baseline and week 108 (N=600) were analysed for SEL prevalence (the number and volume of SELs), disability progression, ALA (assessed by gadolinium-enhancing lesions and new T2-hyperintense lesions) and CLA (assessed by T1-hypointense lesion volume increase within baseline T2-non-enhancing lesions identified as SELs and non-SELs). Results: CLA in both SELs and non-SELs was greater in patients with SPMS with confirmed disability progression than in those with no progression. In the complete absence of ALA at baseline and on study, SEL prevalence was significantly lower, while CLA within non-SELs remained associated with disability progression. Natalizumab decreased SEL prevalence and CLA in SELs and non-SELs compared with placebo. Conclusions: This study shows that CLA in patients with SPMS is decreased but persists in the absence of ALA and is associated with disability progression, highlighting the need for therapeutics targeting all mechanisms of CLA, including smouldering inflammation and neurodegeneration. Trial registration number: NCT01416181.

Next-generation Bruton's tyrosine kinase inhibitor BIIB091 selectively and potently inhibits B cell and Fc receptor signaling and downstream functions in B cells and myeloid cells.

OBJECTIVES: Bruton's tyrosine kinase (BTK) plays a non-redundant signaling role downstream of the B-cell receptor (BCR) in B cells and the receptors for the Fc region of immunoglobulins (FcR) in myeloid cells. Here, we characterise BIIB091, a novel, potent, selective and reversible small-molecule inhibitor of BTK. METHODS: BIIB091 was evaluated in vitro and in vivo in preclinical models and in phase 1 clinical trial. RESULTS: In vitro, BIIB091 potently inhibited BTK-dependent proximal signaling and distal functional responses in both B cells and myeloid cells with IC50s ranging from 3 to 106 nm, including antigen presentation to T cells, a key mechanism of action thought to be underlying the efficacy of B cell-targeted therapeutics in multiple sclerosis. BIIB091 effectively sequestered tyrosine 551 in the kinase pocket by forming long-lived complexes with BTK with t 1/2 of more than 40 min, thereby preventing its phosphorylation by upstream kinases. As a key differentiating feature of BIIB091, this property explains the very potent whole blood IC50s of 87 and 106 nm observed with stimulated B cells and myeloid cells, respectively. In vivo, BIIB091 blocked B-cell activation, antibody production and germinal center differentiation. In phase 1 healthy volunteer trial, BIIB091 inhibited naïve and unswitched memory B-cell activation, with an in vivo IC50 of 55 nm and without significant impact on lymphoid or myeloid cell survival after 14 days of dosing. CONCLUSION: Pharmacodynamic results obtained in preclinical and early clinical settings support the advancement of BIIB091 in phase 2 clinical trials.

Safety and Pharmacokinetics of the Oral TYK2 Inhibitor PF-06826647: A Phase I, Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation Study.

Selective inhibition of tyrosine kinase 2 (TYK2) may offer therapeutic promise in inflammatory conditions, with its role in downstream pro-inflammatory cytokine signaling. In this first-in-human study, we evaluated the safety, tolerability, and pharmacokinetics (PK) of a novel TYK2 inhibitor, PF-06826647, in healthy participants. This phase I, randomized, double-blind, placebo-controlled, parallel-group study included two treatment periods (single ascending dose (SAD) and multiple ascending dose (MAD)) in healthy participants and a cohort of healthy Japanese participants receiving 400 mg q.d. or placebo in the MAD period (NCT03210961). Participants were randomly assigned to PF-06826647 or placebo (3:1). Participants received a single oral study drug dose of 3, 10, 30, 100, 200, 400, or 1,600 mg (SAD period), then 30, 100, 400, or 1,200 mg q.d. or 200 mg b.i.d. for 10 days (MAD period). Safety (adverse events (AEs), vital signs, and clinical laboratory parameters), tolerability, and PK were assessed. Overall, 69 participants were randomized to treatment, including six Japanese participants. No deaths, serious AEs, severe AEs, or AEs leading to dose reduction or temporary/permanent discontinuation were observed. All AEs were mild in severity. No clinically relevant laboratory abnormalities or changes in vital signs were detected. PF-06826647 was rapidly absorbed with a median time to maximum plasma concentration of 2 hours in a fasted state, with modest accumulation (< 1.5-fold) after multiple dosing and low urinary recovery. PF-06826647 was well-tolerated, with an acceptable safety profile for doses up to 1,200 mg q.d. for 10 days, supporting further testing in patients.

Safety, tolerability, efficacy, pharmacokinetics, and pharmacodynamics of the oral TYK2 inhibitor PF-06826647 in participants with plaque psoriasis: a phase 1, randomised, double-blind, placebo-controlled, parallel-group study.

BACKGROUND: Blockade of tyrosine kinase 2 (TYK2) signalling has previously shown therapeutic potential in the treatment of psoriasis. The primary objective of this study was to assess the safety and tolerability of the TYK2 inhibitor PF-06826647. METHODS: This phase 1, randomised, double-blind, placebo-controlled, parallel-group study assessed once daily oral dosing of PF-06826647 in participants with plaque psoriasis, at a single clinical research site in the USA. Eligible participants (aged 18-65 years) had plaque psoriasis covering at least 15% of total body surface area and a psoriasis area and severity index (PASI) score of at least 12 at baseline. Participants received PF-06826647 (100 mg or 400 mg), or placebo once daily for 28 days. Using a computer-generated randomisation schedule with a block size of 3, participants were sequentially randomly assigned into two cohorts by the investigator; in the first cohort, participants were randomly assigned in a 2:1 ratio to receive either oral PF-06826647 400 mg or placebo once daily, whereas participants in the second cohort were randomly assigned in a 2:1 ratio to receive either oral PF-06826647 100 mg or placebo once daily. Site, investigator, Pfizer personnel, and participants, were masked to treatment. The primary endpoint was the safety of multiple-dose PF-06826647 in participants with plaque psoriasis. Secondary endpoints were the characterisation of the pharmacokinetics of multiple-dose PF-06826647 in plasma and the change in PASI score at day 28. Safety analysis was done in all participants who received at least one dose of study drug. Efficacy analysis was done in all participants who received at least one dose of randomised study drug, and had a baseline and at least one post-baseline measurement. This study is registered as a randomised, controlled trial with ClinicalTrials.gov, NCT03210961 and is completed. FINDINGS: The trial was done between July 14, 2017, and Jan 25, 2019. Overall from 91 participants assessed, 40 participants with moderate-to-severe psoriasis were randomly assigned to treatment (placebo 14 [35%] of 40; PF-06826647 100 mg, 11 [28%] of 40; PF-06826647 400 mg, 15 [38%] of 40). Treatment-emergent adverse events (TEAEs) were reported in 12 (80%) of 15 participants in the PF-06826647 400 mg group, seven (50%) of 14 in the placebo group and five (45%) of 11 in the 100 mg group. All TEAEs were mild in severity, except one moderate TEAE of vomiting reported in the placebo group. There were no deaths, serious TEAEs, severe TEAEs, dose reductions, or temporary discontinuations. Compared with placebo, the change from baseline in PASI score at day 28 showed a significant reduction in least squares mean difference for the PF-06826647 400 mg group (-13·05; 90% CI -18·76 to -7·35; p=0·00077) but not for the PF-06826647 100 mg group (-3·49; -9·48 to 2·50; p=0·33). Both the area under the concentration-time curve over the dosing interval and the maximum concentration increased in a less than dose proportional manner with increasing dose from 100 mg to 400 mg PF-06826647. INTERPRETATION: PF-06826647 showed significant improvement in disease activity within 4 weeks of dosing with an acceptable safety profile. PF-06826647 holds promise over conventional oral treatments for psoriasis that have shown limited efficacy or unfavourable safety profiles. FUNDING: Pfizer.

Molecular and Cellular Responses to the TYK2/JAK1 Inhibitor PF-06700841 Reveal Reduction of Skin Inflammation in Plaque Psoriasis.

The IL-23/T helper type 17 cell axis is a target for psoriasis. The TYK2/Janus kinase 1 inhibitor PF-06700841 will directly suppress TYK2-dependent IL-12 and IL-23 signaling and Janus kinase 1-dependent signaling in cells expressing these signaling molecules, including T cells and keratinocytes. This clinical study sought to define the inflammatory gene and cellular pathways through which PF-06700841 improves the clinical manifestations of psoriasis. Patients (n = 30) with moderate-to-severe psoriasis were randomized to once-daily 30 mg (n = 14) or 100 mg (n = 7) PF-06700841 or placebo (n = 9) for 28 days. Biopsies were taken from nonlesional and lesional skin at baseline and weeks 2 and 4. Changes in the psoriasis transcriptome and genes induced by IL-17 in keratinocytes were evaluated with microarray profiling and reverse transcriptase-PCR. Reductions in IL-17A, IL-17F, and IL-12B mRNA were observed as early as 2 weeks and approximately 70% normalization of lesional gene expression after 4 weeks. Immunohistochemistry showed significant decreases in markers of keratinocyte activation, epidermal thickness, KRT16 and Ki-67 expression, and immune cell infiltrates CD3+/CD8+ (T cells) and CD11c (dendritic cells) after 2 weeks of treatment, corresponding with improvement in histologic score. PF-06700841 improves clinical symptoms of chronic plaque psoriasis by inhibition of proinflammatory cytokines that require TYK2 and Janus kinase 1 for signal transduction.

The Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of a TYK2/JAK1 Inhibitor (PF-06700841) in Healthy Subjects and Patients With Plaque Psoriasis.

The safety, tolerability, pharmacokinetics, and pharmacodynamics of PF-06700841 were assessed in a randomized, double-blind, placebo-controlled, single- and multiple-dose escalation, parallel-group study in healthy subjects and patients with plaque psoriasis. The single ascending dose (1, 3, 10, 30, 100, or 200 mg) and multiple ascending dose (MAD; PF-06700841; up to 175 mg once daily or 50 mg twice daily for 10 days) periods included 54 healthy participants. In addition, 30 patients with psoriasis received PF-06700841 30 or 100 mg or placebo once daily for 28 days. Single PF-06700841 doses were rapidly absorbed, with peak plasma concentrations ≤ 1 hour, proportional exposure up to 100 mg, and mean half-life 3.8-7.5 hours. On day 10 of MAD, plasma concentrations peaked at ≤1.5 hours postdose (10-175 mg once daily). Elimination half-life was 4.9-10.7 hours; steady state was reached by day 8. In psoriasis patients on day 28, peak plasma concentrations occurred at 1-2 hours. Biomarkers IP-10 and high-sensitivity C-reactive protein were reduced and returned to near baseline levels after dosing. Maximal mean percent change from baseline in the Psoriasis Area and Severity Index scores for PF-06700841 30 mg once daily and 100 mg once daily were -67.92% and -96.31%, respectively, in week 4. All adverse events were mild/moderate. PF-06700841 was safe and well tolerated up to 200 mg once daily in healthy subjects and 100 mg once daily in patients with psoriasis, suggesting potential therapeutic utility in plaque psoriasis and other inflammatory diseases.

Effect of oral cladribine on time to conversion to clinically definite multiple sclerosis in patients with a first demyelinating event (ORACLE MS): a phase 3 randomised trial.

BACKGROUND: Patients who develop relapsing-remitting multiple sclerosis (MS) present with a first clinical demyelinating event. In this double-blind, multicentre, randomised, phase 3 study we investigated the effect of oral cladribine on conversion to clinically definite MS in patients with a first clinical demyelinating event, when given at the same doses shown to be effective in relapsing-remitting MS. METHODS: Between Oct 21, 2008, and Oct 11, 2010, we recruited patients aged 18-55 years, inclusive, from 160 hospitals, private clinics, or treatment centres in 34 countries. Eligible patients had a first clinical demyelinating event within 75 days before screening, at least two clinically silent lesions of at least 3 mm on a T2-weighted brain MRI scan, and an Expanded Disability Status Scale score of 5.0 or lower. Patients with a first clinical demyelinating event ≤75 days before screening were randomly assigned (1:1:1) to receive cladribine tablets at cumulative doses of 5.25 mg/kg or 3.5 mg/kg or placebo. Randomisation was done with a central web-based randomisation system and was stratified by geographic region. Masking was maintained using a two-physician model. The primary endpoint of this 96-week study was time to conversion to clinically definite MS according to the Poser criteria. This study is registered with ClinicalTrials.gov, number NCT00725985. FINDINGS: Of 903 participants assessed for eligibility, 616 patients received cladribine 5.25 mg/kg (n=204), cladribine 3.5 mg/kg (n=206), or placebo (n=206). At trial termination on Oct 25, 2011, cladribine was associated with a risk reduction versus placebo for time to conversion to clinically definite MS (hazard ratio [HR] for 5.25 mg/kg=0.38, 95% CI 0.25-0.58, p<0.0001; HR for 3.5 mg/kg=0.33, 0.21-0.51, p<0.0001). Adverse events were reported in 165 (81%) patients in the cladribine 5.25 mg/kg group, 168 (82%) patients in the cladribine 3.5 mg/kg group, and 162 (79%) patients in the placebo group. We noted no increase in risk of adverse events with active treatment versus placebo apart from lymphopenia, which was a severe event in 10 (5%) patients in the 5.25 mg/kg group and four (2%) patients in the 3.5 mg/kg group. INTERPRETATION: Both doses of cladribine significantly delayed MS diagnosis compared with placebo. The safety profile of cladribine was similar to that noted in a trial in patients with relapsing-remitting MS. Further research could clarify the potential effects of oral cladribine treatment in the early stages of MS. FUNDING: Merck Serono SA Geneva, a subsidiary of Merck KGaA, Darmstadt, Germany.

Cladribine tablets for the treatment of relapsing-remitting multiple sclerosis.

INTRODUCTION: Multiple sclerosis (MS) is a chronic immune-mediated disorder of the central nervous system leading to progressive neurodegeneration and disability. Until 2010, all approved disease-modifying drugs for MS required parenteral administration, which is associated with suboptimal adherence. It was anticipated that new approaches to treatment, including oral agents such as cladribine tablets, may improve adherence. In 2011, the development of cladribine tablets was stopped following negative feedback from the EMA and FDA. AREAS COVERED: This article provides an overview of the chemistry, mechanism of action and pharmacological properties of cladribine tablets therapy, and highlights the rationale for its development as an oral treatment for MS. Key efficacy and safety data from the pivotal Phase III CLARITY study are presented, providing context for the opinion received from the regulatory agencies. EXPERT OPINION: Despite the promising efficacy data observed in the cladribine tablets clinical trial program, regulatory agencies identified a potential risk of increased malignancies, and raised concerns about the implications of sustained lymphocyte depletion. Following the feedback received from the regulatory agencies, Merck Serono made the decision to withdraw the agent from the regulatory approval process. The experience gained will benefit other research efforts to address the outstanding unmet treatment needs of patients with relapsing MS.

Reward circuitry in resilience to severe trauma: an fMRI investigation of resilient special forces soldiers.

Enhanced brain reward function could contribute to resilience to trauma. Reward circuitry in active duty, resilient special forces (SF) soldiers was evaluated using functional magnetic resonance imaging during a monetary incentive delay task. Findings in this group of resilient individuals revealed unique patterns of activation during expectation of reward in the subgenual prefrontal cortex and nucleus accumbens area, regions pivotal to reward processes.