Temporal Relationship Between Serum Neurofilament Light Chain and Radiologic Disease Activity in Patients With Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Serum neurofilament light chain (sNfL) levels correlate with multiple sclerosis (MS) disease activity, but the dynamics of this correlation are unknown. We evaluated the relationship between sNfL levels and radiologic MS disease activity through monthly assessments during the 24-week natalizumab treatment interruption period in RESTORE (NCT01071083).

METHODS

In the RESTORE trial, participants with relapsing forms of MS who had received natalizumab for ≥12 months were randomized to either continue or stop natalizumab and followed with MRI and blood draws every 4 weeks to week 28 and again at week 52 The sNfL was measured, and its dynamics were correlated with the development of gadolinium-enhancing (Gd+) lesions. Log-linear trend in sNfL levels were modeled longitudinally using generalized estimating equations with robust variance estimator from baseline to week 28.

RESULTS

Of 175 patients enrolled in RESTORE, 166 had serum samples for analysis. Participants with Gd+ lesions were younger (37.7 vs 43.1, p = 0.001) and had lower Expanded Disability Status Scale scores at baseline (2.7 vs 3.4, p = 0.017) than participants without Gd+ lesions. sNfL levels increased in participants with Gd+ lesions (n = 65) compared with those without (n = 101, mean change from baseline to maximum sNfL value, 12.1 vs 3.2 pg/mL, respectively; p = 0.003). As the number of Gd+ lesions increased, peak median sNfL change also increased by 1.4, 3.0, 4.3, and 19.6 pg/mL in the Gd+ lesion groups of 1 (n = 12), 2-3 (n = 18), 4-9 (n = 21), and ≥10 (n = 14) lesions, respectively. However, 46 of 65 (71%) participants with Gd+ lesions did not increase above the 95th percentile threshold of the group without Gd+ lesions. The initial increase of sNfL typically trailed the first observation of Gd+ lesions, and the peak increase in sNfL was a median [interquartile range] of 8 [0, 12] weeks after the first appearance of the Gd+ lesion.

DISCUSSION

Although sNfL correlated with the presence of Gd+ lesions, most participants with Gd+ lesions did not have elevations in sNfL levels. These observations have implications for the use and interpretation of sNfL as a biomarker for monitoring MS disease activity in controlled trials and clinical practice.

Magnetic resonance fingerprinting in multiple sclerosis

BACKGROUND

In this cross sectional study, we used MRF to investigate tissue properties of normal-appearing white matter, gray matter, and lesions in relapsing remitting MS (n = 21), secondary progressive MS (n = 16) and healthy controls (n = 9). A FISP-based MRF sequence was used for acquisition, imaging time 5 min 15 s. MRF T1 and T2 relaxation times were measured from lesional tissue, normal-appearing frontal white matter, corpus callous, thalamus, and caudate. Differences between healthy controls and MS were examined using ANCOVA adjusted for age and sex. Spearman rank correlations were assessed between T1 and T2 relaxation times and clinical measures.

OBJECTIVES

To examine brain T1 and T2 values using magnetic resonance fingerprinting (MRF) in healthy controls and MS.

METHODS

The subjects included 21 relapsing-remitting (RR) MS, 16 secondary progressive (SP) MS, and 9 age- and sex-matched HC without manifest neurological disease participating in a longitudinal MRI study. A 3T/ FISP-based MRF sequence was acquired. Regions of interest were drawn for lesions and normal appearing white matter. ANCOVA adjusted for age and sex were used to compare the groups with significance set at 0.05.

RESULTS

A step-wise increase in T1 and T2 relaxation times was found between healthy controls, relapsing remitting MS, and secondary progressive MS. Significant differences were found in T1 and T2 between MS and healthy controls in the frontal normal-appearing white matter, corpus callosum, and thalamus (p < 0.04 for all). Significant differences in T1 and T2 between RR and SPMS were found in the frontal normal-appearing white matter and T2 lesions (p < 0.02 for all). T1 relaxation from the frontal normal-appearing white matter correlated with the Expanded Disability Status Scale [ρ = 0.62, p < 0.001], timed 25 foot walk (ρ = 0.45, p = 0.01), 9 hole peg test (ρ = 0.62, p < 0.001), and paced auditory serial addition test (ρ = -0.4, p = 0.01).

CONCLUSION

These results suggest that MRF may be a clinically feasible quantitative approach for characterizing tissue damage in MS.

Serum neurofilament light-chain levels and long-term treatment outcomes in relapsing-remitting multiple sclerosis patients: A post hoc analysis of the randomized CombiRx trial

Background

CombiRx was a randomized, double-blind, placebo-controlled phase 3 trial in treatment-naive relapsing-remitting multiple sclerosis (RRMS) patients randomized to intramuscular interferon beta-1a (IM IFN beta-1a), glatiramer acetate (GA), or both therapies.

Objective

This analysis investigated changes in serum neurofilament light-chain (sNfL) levels in response to treatment and assessed baseline sNfL as a predictor of relapse.

Methods

RRMS patients treated with IM IFN beta-1a 30 µg weekly + placebo (n = 159), GA 20 mg/mL daily + placebo (n = 172), or IM IFN beta-1a + GA (n = 344) were included. A linear mixed model compared sNfL values over time. Cox regression models analyzed baseline sNfL and gadolinium-enhancing (Gd+) lesions as predictors of relapse.

Results

In all treatment arms, the proportion of patients with sNfL ≥16 pg/mL decreased significantly from baseline to 6 months and was maintained at 36 months. A significantly higher percentage of patients with both baseline sNfL ≥16 pg/mL and ≥1 Gd+ lesion experienced relapses within 90 days compared to patients with sNfL <16 pg/mL and/or no Gd+ lesions.

Conclusion

sNfL levels were reduced within 6 months and remained low at 36 months. Results suggest that the combination of lesion activity and sNfL was a stronger predictor of relapse than either factor alone.

Development of a Highly Sensitive Neurofilament Light Chain Assay on an Automated Immunoassay Platform

Background

Neurofilament light chain (NfL) is an axonal cytoskeletal protein that is released into the extracellular space following neuronal or axonal injury associated with neurological conditions such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and other diseases. NfL is detectable in the cerebrospinal fluid (CSF) and blood. Numerous studies on MS have demonstrated that NfL is correlated with disease activity, predicts disease progression, and is reduced by treatment with MS disease-modifying drugs, making NfL an attractive candidate to supplement existing clinical and imaging measures in MS. However, for NfL to achieve its potential as a clinically useful biomarker for clinical decision-making or drug development, a standardized, practical, and widely accessible assay is needed. Our objective was to develop a novel NfL assay on an automated, globally available immunoassay platform and validate its performance.

Methods

A prototype NfL assay was first developed and evaluated on the ADVIA Centaur® XP immunoassay system from Siemens Healthineers. The lower limit of quantitation (LLoQ), within-lab precision, assay range, cross-reactivity with neurofilament medium and heavy chains, and effect of interfering substances were determined. NfL assay values in serum and CSF were compared with radiological and clinical disease activity measures in patients with MS and ALS, respectively. This assay was further optimized to utilize serum, plasma, and CSF sample types on the Atellica® IM system and transferred to Siemens' CLIA laboratory where it was analytically validated as a laboratory-developed test (LDT).

Results

In this study, an LLoQ of 1.85 pg/mL, within-lab precision <6%, and an assay range of up to 646 pg/mL were demonstrated with the serum prototype assay. Cross-reactivity of <0.7% with the neurofilament medium and heavy chains was observed. Serum and CSF NfL assay values were associated with radiological and clinical disease activity measures in patients with MS and ALS, respectively. The optimized version of the NfL assay demonstrated specimen equivalence with additional plasma tube types and was analytically validated as an LDT.

Conclusion

The analytical performance of the NfL assay fulfilled all acceptance criteria; therefore, we suggest that the assay is acceptable for use in both research and clinical practice settings to determine elevated NfL levels in patients.

Measuring treatment response to advance precision medicine for multiple sclerosis

Objective

To assess the independent contributions of clinical measures (relapses, Expanded Disability Status Scale [EDSS] scores, and neuroperformance measures) and nonclinical measures (new brain magnetic resonance imaging [MRI] activity and serum neurofilament light chain [sNfL] levels) for distinguishing natalizumab‐treated from placebo‐treated patients.

Methods

We conducted post hoc analyses using data from the AFFIRM trial of natalizumab for multiple sclerosis. We used multivariable regression analyses with predictors (EDSS progression, no relapse, new or enlarging MRI activity, brain atrophy, sNfL levels, and neuroperformance worsening) to identify measures that independently discriminated between treatment groups.

Results

The multivariable model that best distinguished natalizumab from placebo was no new or enlarging T2 or gadolinium‐enhancing activity on MRI (odds ratio; 95% confidence interval: 7.2; 4.7–10.9), year 2 sNfL levels <97.5th percentile (4.1; 2.6–6.2), and no relapses in years 0–2 (2.1; 1.5–3.0). The next best‐fitting model was a two‐component model that included no MRI activity and sNfL levels <97.5th percentile at year 2. There was little difference between the three‐ and two‐component models.

Interpretation

Nonclinical measures (new MRI activity and sNfL levels) discriminate between treatment and placebo groups similarly to or better than clinical outcomes composites and have implications for patient monitoring.

Quantitative signal properties from standardized MRIs correlate with multiple sclerosis disability

OBJECTIVE

To enable use of clinical magnetic resonance images (MRIs) to quantify abnormalities in normal appearing (NA) white matter (WM) and gray matter (GM) in multiple sclerosis (MS) and to determine associations with MS-related disability. Identification of these abnormalities heretofore has required specialized scans not routinely available in clinical practice.

METHODS

We developed an analytic technique which normalizes image intensities based on an intensity atlas for quantification of WM and GM abnormalities in standardized MRIs obtained with clinical sequences. Gaussian mixture modeling is applied to summarize image intensity distributions from T1-weighted and 3D-FLAIR (T2-weighted) images from 5010 participants enrolled in a multinational database of MS patients which collected imaging, neuroperformance and disability measures.

RESULTS

Intensity distribution metrics distinguished MS patients from control participants based on normalized non-lesional signal differences. This analysis revealed non-lesional differences between relapsing MS versus progressive MS subtypes. Further, the correlation between our non-lesional measures and disability was approximately three times greater than that between total lesion volume and disability, measured using the patient derived disease steps. Multivariate modeling revealed that measures of extra-lesional tissue integrity and atrophy contribute uniquely, and approximately equally, to the prediction of MS-related disability.

INTERPRETATION

These results support the notion that non-lesional abnormalities correlate more strongly with MS-related disability than lesion burden and provide new insight into the basis of abnormalities in NA WM. Non-lesional abnormalities distinguish relapsing from progressive MS but do not distinguish between progressive subtypes suggesting a common progressive pathophysiology. Image intensity parameters and existing biomarkers each independently correlate with MS-related disability.

Impact of natalizumab on quality of life in a real-world cohort of patients with multiple sclerosis: Results from MS PATHS

Background

Optimizing multiple sclerosis treatment warrants understanding of changes in physical, mental, and social health.

Objective

To assess the impact of natalizumab on Quality of Life in Neurological Disorders (Neuro-QoL) scores.

Methods

Annualized change in T-scores and likelihood of ≥5-point improvement over baseline were calculated for each Neuro-QoL domain after natalizumab initiation. Comparisons with ocrelizumab-treated patients were conducted after propensity score weighting and adjustment for relevant co-medications, year, and drug-year interaction.

Results

Among 164 natalizumab patients analyzed, 8 of 12 Neuro-QoL domains improved significantly, with greater improvement in patients with abnormal baseline Neuro-QoL. In the subgroup comparison of natalizumab-treated (n = 145) and ocrelizumab-treated (n = 520) patients, significant improvement occurred in 9 of 12 and 4 of 12 domains, respectively. The difference between groups was statistically significant for positive affect and well-being (p = 0.02), sleep (p = 0.003), and satisfaction with social roles and activities (SRA) (p = 0.03) in the overall population and for emotional and behavioral dyscontrol (p = 0.01), participation in SRA (p = 0.0001), and satisfaction with SRA (p = 0.02) in patients with abnormal baseline Neuro-QoL.

Conclusions

Natalizumab can produce clinically meaningful improvements in mental and social health. Such improvements are unlikely to be primarily driven by expectation bias, as their magnitude exceeded improvements with another high-efficacy therapy, ocrelizumab.

Temporal profile of serum neurofilament light in multiple sclerosis: Implications for patient monitoring

Objective:

To understand how longitudinal serum neurofilament light chain (sNfL) patterns can inform its use as a prognostic biomarker in multiple sclerosis (MS) and evaluate whether sNfL reflects MS disease activity and disease-modifying therapy usage.

Methods:

This was a post hoc analysis of longitudinal data and samples from the ADVANCE trial (NCT00906399) of patients with relapsing–remitting MS (RRMS). sNfL was measured every 3 months for 2 years, then every 6 months for 4 years. Regression models explored how sNfL data predicted 4-year values of brain volume, expanded disability status scale score, and T2 lesions. sNfL levels were assessed in those receiving placebo, peginterferon beta-1a, and those with disease activity.

Results:

Baseline sNfL was a predictor of 4-year brain atrophy and development of new T2 lesions. Clinical (p = 0.02) and magnetic resonance imaging (MRI) (p < 0.01) outcomes improved in those receiving peginterferon beta-1a whose sNfL decreased to <16 pg/mL after 12 months versus those whose sNfL remained ⩾16 pg/mL. Mean sNfL levels decreased in peginterferon beta-1a-treated patients and increased in placebo-treated patients (–9.5% vs. 6.8%; p < 0.01). sNfL was higher and more variable in patients with evidence of active MS.

Conclusion:

These data support sNfL as a prognostic and disease-monitoring biomarker for RRMS.

Association of Serum Neurofilament Light Levels With Long-term Brain Atrophy in Patients With a First Multiple Sclerosis Episode

IMPORTANCE

Data are needed on the potential long-term prognostic association of serum neurofilament light in multiple sclerosis (MS).

OBJECTIVE

To evaluate serum neurofilament light as a biomarker associated with long-term disease outcomes in clinically isolated syndrome.

DESIGN, SETTING, AND PARTICIPANTS

This post hoc cohort study used data from the Controlled High-Risk Avonex Multiple Sclerosis Prevention Study, a 36-month, multicenter, placebo-controlled interferon β-1a randomized clinical trial conducted from April 1996 to March 2000, and its long-term (5- and 10-year) extension study from February 2001 to March 2009. Participants included individuals with a symptomatic initial demyelinating event and brain magnetic resonance imaging (MRI) lesions suggestive of MS. Data were analyzed from April 2017 through 2019.

EXPOSURE

The variable of interest was naturally occurring serum neurofilament light concentration.

MAIN OUTCOMES AND MEASURES

Gadolinium-enhancing (Gd+) lesion number, T2 lesion volume, and brain parenchymal fraction, a measure of brain atrophy were measured at baseline and 5 and 10 years. Multivariate regression models evaluated whether age, sex, and baseline covariates, including serum neurofilament light, brain parenchymal fraction, Expanded Disability Status Scale, Gd+ lesion count, and T2 lesion volume, were associated with brain parenchymal fraction changes over 5 and 10 years.

RESULTS

Among 308 included participants (mean [SD] age, 33.2 [7.6] years; 234 [76.0%] women), baseline serum neurofilament light concentrations were associated with Gd+ lesions (Spearman r = 0.41; P < .001) and T2 lesion volume (Spearman r = 0.42; P < .001). Among covariates for brain parenchymal fraction change, serum neurofilament light concentration had the greatest correlation with change in brain parenchymal fraction at 5 years (Spearman r = -0.38; P < .001) and was the only variable associated with brain parenchymal fraction at 10 years (Spearman r = -0.45; P < .001). Participants in the highest vs lowest baseline serum neurofilament light tertiles showed brain parenchymal fraction reduction at 5 years (-1.83% [95% CI, -1.49% to -2.18%] vs -0.95% [95% CI, -0.78% to -1.12%]; P < .001) and 10 years (-3.54% [95% CI, -2.90% to -4.17%] vs -1.90% [95% CI, -1.43% to -2.37%]; P < .001). At 5 years, 6 of 45 participants (13.3%) in the highest neurofilament tertile and 2 of 52 participants (3.8%) in the lowest neurofilament tertile achieved an Expanded Disability Status Scale score of 3.5 or greater.

CONCLUSIONS AND RELEVANCE

This cohort study found that higher baseline serum neurofilament light levels were associated with increased brain atrophy over 5 and 10 years. These findings suggest that serum neurofilament light could be a biomarker associated with disease severity stratification in early MS and may help to guide intervention.

Harnessing Real-World Data to Inform Decision-Making: Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS)

Background: Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) is the first example of a learning health system in multiple sclerosis (MS). This paper describes the initial implementation of MS PATHS and initial patient characteristics.

Methods: MS PATHS is an ongoing initiative conducted in 10 healthcare institutions in three countries, each contributing standardized information acquired during routine care. Institutional participation required the following: active MS patient census of ≥500, at least one Siemens 3T magnetic resonance imaging scanner, and willingness to standardize patient assessments, share standardized data for research, and offer universal enrolment to capture a representative sample. The eligible participants have diagnosis of MS, including clinically isolated syndrome, and consent for sharing pseudonymized data for research. MS PATHS incorporates a self-administered patient assessment tool, the Multiple Sclerosis Performance Test, to collect a structured history, patient-reported outcomes, and quantitative testing of cognition, vision, dexterity, and walking speed. Brain magnetic resonance imaging is acquired using standardized acquisition sequences on Siemens 3T scanners. Quantitative measures of brain volume and lesion load are obtained. Using a separate consent, the patients contribute DNA, RNA, and serum for future research. The clinicians retain complete autonomy in using MS PATHS data in patient care. A shared governance model ensures transparent data and sample access for research.

Results: As of August 5, 2019, MS PATHS enrolment included participants (n = 16,568) with broad ranges of disease subtypes, duration, and severity. Overall, 14,643 (88.4%) participants contributed data at one or more time points. The average patient contributed 15.6 person-months of follow-up (95% CI: 15.5–15.8); overall, 166,158 person-months of follow-up have been accumulated. Those with relapsing–remitting MS demonstrated more demographic heterogeneity than the participants in six randomized phase 3 MS treatment trials. Across sites, a significant variation was observed in the follow-up frequency and the patterns of disease-modifying therapy use.

Conclusions: Through digital health technology, it is feasible to collect standardized, quantitative, and interpretable data from each patient in busy MS practices, facilitating the merger of research and patient care. This approach holds promise for data-driven clinical decisions and accelerated systematic learning.

Multiple Sclerosis Performance Test: validation of self-administered neuroperformance modules

BACKGROUND AND PURPOSE

The purpose was to determine the test-retest reliability, practice effects, convergent validity and sensitivity to multiple sclerosis (MS) disability of neuroperformance subtests from the patient self-administered Multiple Sclerosis Performance Test (MSPT) designed to assess low contrast vision (Contrast Sensitivity Test, CST), upper extremity motor function (Manual Dexterity Test, MDT) and lower extremity motor function (Walking Speed Test, WST) and to introduce the concept of regression-based norms to aid clinical interpretation of performance scores using the MSPT cognition test (Processing Speed Test, PST) as an example.

METHODS

Substudy 1 assessed test-retest reliability, practice effects and convergent validity of the CST, MDT and WST in 30 MS patients and 30 healthy controls. Substudy 2 examined sensitivity to MS disability in over 600 MS patients as part of their routine clinic assessment. Substudy 3 compared performance on the PST in research volunteers and clinical samples.

RESULTS

The CST, MDT and WST were shown to be reliable, valid and sensitive to MS outcomes. Performance was comparable to technician-administered testing. PST performance was poorer in the clinical sample compared with the research volunteer sample.

CONCLUSIONS

The self-administered MSPT neuroperformance modules produce reliable, objective metrics that can be used in clinical practice and support outcomes research. Published studies which require patient voluntary consent may underestimate the rate of cognitive dysfunction observed in a clinical setting.

Evaluation of multiple sclerosis disability outcome measures using pooled clinical trial data

OBJECTIVE

We report analyses of a pooled database by the Multiple Sclerosis Outcome Assessments Consortium to evaluate 4 proposed components of a multidimensional test battery.

METHODS

Standardized data on 12,776 participants, comprising demographics, multiple sclerosis disease characteristics, Expanded Disability Status Scale (EDSS) score, performance measures, and Short Form-36 Physical Component Summary (SF-36 PCS), were pooled from control and treatment arms of 14 clinical trials. Analyses of Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT), Low Contrast Letter Acuity (LCLA), and Symbol Digit Modalities Test (SDMT) included measurement properties; construct, convergent, and known group validity; and longitudinal performance of the measures individually and when combined into a multidimensional test battery relative to the EDSS and SF-36 to determine sensitivity and clinical meaningfulness.

RESULTS

The performance measures had excellent test-retest reliability and showed expected differences between subgroups based on disease duration and EDSS level. Progression rates in detecting time to 3-month confirmed worsening were lower for T25FW and 9HPT compared to EDSS, while progression rates for LCLA and SDMT were similar to EDSS. When the 4 measures were analyzed as a multidimensional measure rather than as individual measures, progression on any one performance measure was more sensitive than the EDSS. Worsening on the performance measures analyzed individually or as a multidimensional test battery was associated with clinically meaningful SF-36 PCS score worsening, supporting clinical meaningfulness of designated performance test score worsening.

CONCLUSION

These results support the use of the 4 proposed performance measures, individually or combined into a multidimensional test battery as study outcome measures.

Neurofilament light levels are associated with long-term outcomes in multiple sclerosis

Background:

Neurofilament light chain (NfL) is a promising marker of disease activity/treatment response in multiple sclerosis (MS), although its predictive value for long-term clinical outcomes remains unclear.

Objective:

We measured NfL from a phase 3 trial in relapsing-remitting MS and investigated its association with outcomes after 8 and 15 years.

Methods:

NfL concentrations were measured by single molecule array assay in cerebrospinal fluid (CSF) from MS patients (n = 235) in a 2-year randomized clinical trial (RCT) of intramuscular interferon β-1a, and in serum (n = 164) from the extension study.

Results:

Year 2 CSF and Year 3 serum NfL were associated with brain parenchymal fraction (BPF) change over 8 years (p < 0.0001, r = −0.46; p < 0.05. r = −0.36, respectively) and were predictive of reaching Expanded Disability Status Scale (EDSS) ⩾ 6.0 at Year 8 (odds ratio (OR) (upper vs lower tertile) = 3.4; 95% confidence interval (CI) = 1.2–9.9, p < 0.05; OR = 11.0, 95% CI = 2.0–114.6; p < 0.01, respectively). Serum NfL concentration (Year 4) was predictive of reaching EDSS score ⩾6.0 at 15 years (OR (upper vs lower tertile) = 4.9; 95% CI = 1.4–20.4; p < 0.05). NfL concentrations were complementary to 2-year BPF change in predicting long-term outcomes.

Conclusion:

Serum and CSF NfL concentrations were associated with long-term clinical outcomes in MS patients and are promising biomarkers for disease severity stratification supporting treatment decisions.

Multiple Sclerosis Performance Test: Technical Development and Usability

Introduction

In the clinic, the assessment of patients with multiple sclerosis (MS) is typically qualitative and non-standardized.

Objectives

To describe the MS Performance Test (MSPT), an iPad Air^® 2 (Apple, Cupertino, CA, USA)-based neurological assessment platform allowing patients to input relevant information without the aid of a medical technician, creating a longitudinal, clinically meaningful, digital medical record. To report results from human factor (HF) and usability studies, and the initial large-scale implementation in a practice setting.

Methods

The HF study examined use-error patterns in small groups of MS patients and healthy controls (n = 14), the usability study assessed the effectiveness of patient interaction with the tool by patients with a range of MS disability (n = 60) in a clinical setting, and the implementation study deployed the MSPT across a diverse population of patients (n = 1000) in a large MS center for routine clinical care.

Results

MSPT assessments were completed by all users in the HF study; minor changes to design were recommended. In the usability study, 73% of patients with MS completed the MSPT, with an average administration time of 32 min; 85% described their experience with the tool as satisfactory. In the initial implementation for routine care, 84% of patients with MS completed the MSPT, with an average administration time of 28 min.

Conclusion

Patients with MS with varying disability levels completed the MSPT with minimal or no supervision, resulting in comprehensive, efficient, standardized, quantitative, clinically meaningful data collection as part of routine medical care, thus allowing for large-scale, real-world evidence generation.

Funding

Biogen.

Trial Registration

NCT02664324.

Electronic supplementary material

The online version of this article (10.1007/s12325-019-00958-x) contains supplementary material, which is available to authorized users.

Symbol Digit Modalities Test: A valid clinical trial endpoint for measuring cognition in multiple sclerosis

BACKGROUND

The need for more robust outcomes in multiple sclerosis (MS) clinical trials has been a main priority of the field for decades. Dissatisfaction with existing measures has led to several consensus meetings and initiatives over the past few decades in hopes of defining and gaining acceptance of measures that are valid, reliable, sensitive to change and progression, and most importantly, relevant to those living with MS. The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was formed for this purpose.

OBJECTIVE

The objective of this paper is to describe the results of the MSOAC plan to obtain qualification for a cognitive performance measure that meets these requirements.

METHODS

Using data from 14 MS disease-modifying registration trials, we completed a comprehensive examination of the psychometric qualities of the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT) with the goal of compiling evidence to support the utilization of one of these measures in future clinical trials.

RESULTS AND CONCLUSION

Consistent with the published literature, the SDMT proved superior to the PASAT. The SDMT should be considered the measure of choice for MS trials in assessing cognitive processing speed.

Cortical neuronal densities and cerebral white matter demyelination in multiple sclerosis: a retrospective study

BACKGROUND

Demyelination of cerebral white matter is thought to drive neuronal degeneration and permanent neurological disability in individuals with multiple sclerosis. Findings from brain MRI studies, however, support the possibility that demyelination and neuronal degeneration can occur independently. We aimed to establish whether post-mortem brains from patients with multiple sclerosis show pathological evidence of cortical neuronal loss that is independent of cerebral white-matter demyelination.

METHODS

Brains and spinal cords were removed at autopsy from patients, who had died with multiple sclerosis, at the Cleveland Clinic in Cleveland, OH, USA. Visual examination of centimetre-thick slices of cerebral hemispheres was done to identify brains without areas of cerebral white-matter discoloration that were indicative of demyelinated lesions (referred to as myelocortical multiple sclerosis) and brains that had cerebral white-matter discolorations or demyelinated lesions (referred to as typical multiple sclerosis). These individuals with myelocortical multiple sclerosis were matched by age, sex, MRI protocol, multiple sclerosis disease subtype, disease duration, and Expanded Disability Status Scale, with individuals with typical multiple sclerosis. Demyelinated lesion area in tissue sections of cerebral white matter, spinal cord, and cerebral cortex from individuals classed as having myelocortical and typical multiple sclerosis were compared using myelin protein immunocytochemistry. Neuronal densities in cortical layers III, V, and VI from five cortical regions not directly connected to spinal cord (cingulate gyrus and inferior frontal cortex, superior temporal cortex, and superior insular cortex and inferior insular cortex) were also compared between the two groups and with aged-matched post-mortem brains from individuals without evidence of neurological disease.

FINDINGS

Brains and spinal cords were collected from 100 deceased patients between May, 1998, and November, 2012, and this retrospective study was done between Sept 6, 2011, and Feb 2, 2018. 12 individuals were identified as having myelocortical multiple sclerosis and were compared with 12 individuals identified as having typical multiple sclerosis. Demyelinated lesions were detected in spinal cord and cerebral cortex, but not in cerebral white matter, of people with myelocortical multiple sclerosis. Cortical demyelinated lesion area was similar between myelocortical and typical multiple sclerosis (median 4·45% [IQR 2·54-10·81] in myelocortical vs 9·74% [1·35-19·50] in typical multiple sclerosis; p=0·5512). Spinal cord demyelinated area was significantly greater in typical than in myelocortical multiple sclerosis (median 3·81% [IQR 1·72-7·42] in myelocortical vs 13·81% [6·51-29·01] in typical multiple sclerosis; p=0·0083). Despite the lack of cerebral white-matter demyelination in myelocortical multiple sclerosis, mean cortical neuronal densities were significantly decreased compared with control brains (349·8 neurons per mm² [SD 51·9] in myelocortical multiple sclerosis vs 419·0 [43·6] in controls in layer III [p=0·0104]; 355·6 [46·5] vs 454·2 [48·3] in layer V [p=0·0006]; 366·6 [50·9] vs 458·3 [48·4] in layer VI [p=0·0049]). By contrast, mean cortical neuronal densities were decreased in typical multiple sclerosis brains compared with those from controls in layer V (392·5 [59·0] vs 454·2 [48·3]; p=0·0182) but not layers III and VI.

INTERPRETATION

We propose that myelocortical multiple sclerosis is a subtype of multiple sclerosis that is characterised by demyelination of spinal cord and cerebral cortex but not of cerebral white matter. Cortical neuronal loss is not accompanied by cerebral white-matter demyelination and can be an independent pathological event in myelocortical multiple sclerosis. Compared with control brains, cortical neuronal loss was greater in myelocortical multiple sclerosis cortex than in typical multiple sclerosis cortex. The molecular mechanisms of primary neuronal degeneration and axonal pathology in myelocortical multiple sclerosis should be investigated in future studies.

FUNDING

US National Institutes of Health and National Multiple Sclerosis Society.

Brain atrophy and magnetization transfer ratio following methylprednisolone in multiple sclerosis: short-term changes and long-term implications

Background: The short-term effect of corticosteroids on MRI measures of multiple sclerosis (MS) is not well understood and may have a significant impact when using these quantitative measures to evaluate disease activity and changes following other therapeutic interventions. Objective: To determine the impact of a course of intravenous methylprednisolone (IVMP) on quantitative measures of disease activity and tissue injury in MS patients. Methods: We prospectively measured brain parenchymal fraction (BPF), magnetization transfer ratio (MTR, lesional and whole brain), and lesion volumes on nine weekly brain MRI studies in ten MS patients receiving a course of IVMP. A group of nine MS patients not receiving IVMP served as controls. Results: In comparison to untreated controls, BPF declined over the eight weeks following IVMP treatment (P<0.02). BPF decline was most prominent in patients with secondary progressive MS (SPMS, P<0.03), and was not seen in relapsing-remitting (RR) MS patients. Short-term change in BPF correlated with baseline BPF (r=0.62, P=0.05) and short-term change in lesional MTR (r=-0.55, P=0.03), but not with change in enhancing lesion volume. Short-term change in lesional MTR inversely correlated with baseline lesional and whole brain MTR (r=-0.79, P=0.04 for both). There was no significant difference between treated and control patients in measures of MTR or T2, T1 or enhancing lesion volumes. Conclusions: Patients with SPMS showed a greater decline in BPF following IVMP than RRMS patients. A correlation between changes in BPF and MTR suggest that these changes are secondary to altered water content within MS lesions. Differential response to a standardized therapeutic intervention in RRMS and SPMS suggests that responses to therapy may differ due to a fundamental pathologic difference between early and late stage MS.

Eight-year immunogenicity and safety of interferon beta-1a-Avonex®treatment in patients with multiple sclerosis

An open-label extension study of the phase III trial of intramuscular interferon beta-1a (IFNβ-1a-Avonex) was conducted to evaluate the immunogenicity and safety of IFNβ-1a-Avonex over six years in patients with relapsing multiple sclerosis (MS). Patients who participated in the pivotal phase III study were offered enrolment; entry was also open to patients who had not participated. All patients received IFNβ-1a-Avonex 30 mg intramuscularly once weekly for six years, for a treatment duration of up to eight years in patients who received IFNβ-1a-Avonex in the phase III trial. Serum levels of IFNβ antibodies were measured every six months using a screening enzyme-linked immunosorbent assay (ELISA) followed by an antiviral cytopathic effect assay to detect neutralizing antibodies (NAbs) in serum samples positive on ELISA. The incidence of adverse events and laboratory test results assessed safety. Of 382 total patients, 218 had participated in the phase III study (103 placebo, 115 IFNβ-1a-Avonex) and 164 had not participated; 24 of the 164 were IFNβ-naïve. At baseline, 281 patients were negative for IFNβ antibodies (NAb-). NAbs (titre≥ 20) developed at any time over six years in 5% of these patients. Of 140 patients who had been on IFNβ-1b-Betaseron, 49 were positive for NAbs (NAb+) at baseline; 11 of 115 who had been on IFNβ-1a-Avonex were NAb+ at baseline. Thirty-nine of 49 patients who had been on Betaseron and were NAb+ had titres <100; 36 of these 39 seroconverted to NAb-while on IFNβ-1a-Avonex, with a median time of approximately six months. Ten patients who had been on Betaseron had NAb titres ≥ 100; five remained NAb+ during six years on IFNβ-1a-Avonex and five seroconverted to NAb-, but only after at least two years. Five patients who had been on IFNβ-1a-Avonex during the clinical trial were NAb+ with titres <100 at baseline; four seroconverted to NAb-, with a median time of two to three years. Six patients who had been on IFNβ-1a-Avonex had NAb titres ≥100; five of these remained NAb+ at six years. No patient with a NAb titre >1000 seroconverted to NAb-, whether initially treated with IFNβ-1a-Avonex or -Betaseron. Adverse events were similar to those observed in the pivotal phase III trial. Results from this trial indicated that IFNβ-1a-Avonex was associated with a low incidence of NAbs and was well tolerated for up to eight years. Further, the results indicate that persistence of NAbs is dependent on titre and IFNβ product.

Estimating long-term effects of disease-modifying drug therapy in multiple sclerosis patients

Two methods were used to estimate the long-term impact of disease-modifying drug therapy (DMDT) in patients with relapsing multiple sclerosis (MS) who completed a placebo-controlled, randomized clinical trial of interferon beta-1a (IFNβ-1a). The study cohort consisted of patients with ambulatory relapsing MS who had previously participated in a placebo-controlled clinical trial for two years. At its end, patients were managed in an unstructured fashion by their neurologists and re-evaluated at an average of 6.1 years after the end of the trial. Follow-up evaluation was obtained for 93% of the 172 eligible patients. Because study inclusion criteria required that all patients have an Expanded Disability Status Scale (EDSS) score of ≤3.5 at entry, disability progression at follow-up was defined as EDSS≥6.0. Two methods were used to estimate the expected proportions that reached EDSS≥6.0 at follow-up. Estimates were compared with observed proportions. Method 1 used progression rates observed during the two-year phase III clinical trial and the percentage of time that patients were on DMDT during the follow-up period. Method 2 used progression rates from a natural history comparison group of relapsing-remitting MS patients. At the eight-year follow-up, 42.0% of the original placebo patients and 29.1% of the original IFNβ-1a patients reached an EDSS ≥ 6.0, an observed treatment effect of approximately 30%. Using method 1, it was estimated that 36.3% of the original placebo patients and 27.6% of the original IFNβ-1a patients should have reached an EDSS ≥ 6.0. Use of the natural history control group (method 2) predicted less plausible outcomes. Estimated proportions of patients reaching the endpoint were 63.3% for the original placebo group and 55.8% for the original IFNβ-1a group. Treatment effect sizes of 75-90% would be required to match estimates from method 2 with the observed outcome. The paucity of data on the long-term treatment of patients with MS may be aided by applying these or similar methods to vigorously followed cohorts of patients.

Neurodegeneration in Multiple Sclerosis: Relationship to Neurological Disability

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. Most MS patients follow a relapsing-remitting course (RR-MS) for 8 to 15 years that transforms into a secondary progressive disease course (SP-MS). In this review, we discuss current data that describe MS as a neurodegenerative disease in which axonal loss is the major cause of irreversible neurological disability in MS patients. Neurological deficits in MS patients have two pathogeneses: acute inflammatory demyelination and axonal degeneration. Disability caused by inflammatory demyelination clinically dominates the early stages of RR-MS and is reversible. Axonal transection occurs at sites of inflammation and begins at disease onset but is clinically silent in RR-MS because the CNS compensates for neuronal loss. Once a threshold of axon loss is ex ceeded, MS patients enter an irreversible secondary progressive stage. In SP-MS, axonal degeneration is caused by chronic demyelination and may be irreversibly progressive. This view of MS provides a concep tional framework that explains conversion of RR-MS to SP-MS and provides a rationale for early aggressive anti-inflammatory and neuroprotective therapies. NEUROSCIENTIST 5:48-57, 1999

Effect of intramuscular interferon beta-1a on gray matter atrophy in relapsing-remitting multiple sclerosis: A retrospective analysis

BACKGROUND

Changes in gray matter (GM) volume may be a useful measure of tissue loss in multiple sclerosis (MS).

OBJECTIVES

To investigate the rate, patterns, and disability correlates of GM volume change in an MS treatment clinical trial.

METHODS

Patients (n=140) with relapsing-remitting MS were randomized to intramuscular (IM) interferon (IFN) beta-1a or placebo. Treatment effects on GM fraction (GMF) and white matter (WM) fraction (WMF) changes, differences in rates of GMF and WMF change in year one and two on treatment, and differences in atrophy rates by disease progression status were assessed retrospectively.

RESULTS

Significantly less GM atrophy (during year two), but not WM atrophy (at any point), was observed with IM IFN beta-1a compared with placebo. Pseudoatrophy effects were more apparent in WM than in GM; in year one, greater WM volume loss was observed with IM IFN beta-1a than with placebo, whereas GM volume loss was similar between groups. Risk of sustained disability progression was significantly associated with GM, but not WM, atrophy.

CONCLUSIONS

These results suggest that GMF change is more meaningful than WMF as a marker of tissue loss and may be useful to augment whole brain atrophy measurements in MS clinical trials.

Experience with fingolimod in clinical practice

AIM

To report experience with fingolimod in clinical practice.

DESIGN/METHODS

Patients in an academic medical center who were prescribed fingolimod from October 2010 to August 2011 were identified through the electronic medical record and followed for 12 months after fingolimod initiation. Adverse effects (AEs), clinical measures, MRI data, and quality of life measures were assessed.

RESULTS

Three hundred seventeen patients started fingolimod. Eleven patients were treatment naïve (3.5%) and 76 (24.0%) had remote disease modifying therapy (DMT) use prior to fingolimod. One hundred fifty-one (47.6%) switched because of patient preference and 79 (24.9%) switched because of breakthrough disease. About 11.6% transitioned from natalizumab. Follow-up data were available for 306 patients (96.5%) with mean follow-up time 332 days. Fingolimod was discontinued in 76 of 306 patients (24.8%) at mean 248 days after fingolimod start. Discontinuation most often was due to AEs (n = 40) or breakthrough disease (n = 22). Among patients who started fingolimod with available 12 month follow-up data, 267 (87.3%) remained relapse free and 256 (83.7%) had no relapses or gadolinium enhancement. Time to first relapse occurred at mean 282 days after fingolimod initiation. Quality of life measures remained stable at follow-up.

CONCLUSIONS

Fingolimod was discontinued at a higher rate in clinical practice than in clinical trials. Discontinuation was primarily due to AEs or breakthrough disease. Disease activity was adequately controlled in most patients who started fingolimod. This clinical practice cohort is consistent with efficacy data from phase 3 trials and describes the most common tolerability issues in clinical practice.

Factors associated with clinically significant increased walking time in multiple sclerosis: results of a survival analysis of short-term follow-up data from a clinical database

BACKGROUND

Because multiple sclerosis (MS) is variable and unpredictable, if symptom worsening could be predicted, patients may feel better prepared to manage changes in function.

OBJECTIVE

The objective of this paper is to study the prediction of walking impairment in MS.

METHODS

We retrieved data for all MS patients at our center (2008-2009), including baseline and follow-up timed 25-foot walk (T25FW) times. We assessed the incidence of ≥20% worsening in T25FW by developing two survival models: (1) disease course and (2) Multiple Sclerosis Performance Scales (MSPS) score. The outcome was days until ≥20% worsening in T25FW. Covariates were disease subtype, years since diagnosis, Patient Health Questionnaire-9 (PHQ-9) score, and demographics. Data were interval censored; missing data were handled with multiple imputation.

RESULTS

Of 1544 patients, 309 (20%) experienced ≥20% worsening T25FW. For disease course, time to worsening was significantly shorter for secondary progressive vs. relapsing-remitting disease (p < 0.001). For MSPS, patients with lower baseline MSPS scores progressed more slowly (p = 0.001). In both models, sex, baseline T25W, and time since diagnosis were significantly associated with worsening. In the disease course model, PHQ 9 score may be related to worsening (p = 0.07).

CONCLUSION

These findings suggest factors associated with worsening in T25FW and a potential approach to establishing indicators associated with clinically significant change.

The Multiple Sclerosis Performance Test (MSPT): an iPad-based disability assessment tool

Precise measurement of neurological and neuropsychological impairment and disability in multiple sclerosis is challenging. We report a new test, the Multiple Sclerosis Performance Test (MSPT), which represents a new approach to quantifying MS related disability. The MSPT takes advantage of advances in computer technology, information technology, biomechanics, and clinical measurement science. The resulting MSPT represents a computer-based platform for precise, valid measurement of MS severity. Based on, but extending the Multiple Sclerosis Functional Composite (MSFC), the MSPT provides precise, quantitative data on walking speed, balance, manual dexterity, visual function, and cognitive processing speed. The MSPT was tested by 51 MS patients and 49 healthy controls (HC). MSPT scores were highly reproducible, correlated strongly with technician-administered test scores, discriminated MS from HC and severe from mild MS, and correlated with patient reported outcomes. Measures of reliability, sensitivity, and clinical meaning for MSPT scores were favorable compared with technician-based testing. The MSPT is a potentially transformative approach for collecting MS disability outcome data for patient care and research. Because the testing is computer-based, test performance can be analyzed in traditional or novel ways and data can be directly entered into research or clinical databases. The MSPT could be widely disseminated to clinicians in practice settings who are not connected to clinical trial performance sites or who are practicing in rural settings, drastically improving access to clinical trials for clinicians and patients. The MSPT could be adapted to out of clinic settings, like the patient’s home, thereby providing more meaningful real world data. The MSPT represents a new paradigm for neuroperformance testing. This method could have the same transformative effect on clinical care and research in MS as standardized computer-adapted testing has had in the education field, with clear potential to accelerate progress in clinical care and research.

Long-term safety and effectiveness of natalizumab redosing and treatment in the STRATA MS Study

OBJECTIVES

Report long-term safety and effectiveness of natalizumab over 240 weeks in the prospective, observational, open-label Safety of TYSABRI Re-dosing and Treatment (STRATA) Study.

METHODS

Patients (N = 1,094) previously enrolled in natalizumab multiple sclerosis clinical trials received natalizumab 300 mg IV every 4 weeks, up to 240 weeks. Serious adverse events, Expanded Disability Status Scale (EDSS) scores, and annualized relapse rates were analyzed.

RESULTS

At data cutoff (February 9, 2012), natalizumab exposure was 3,460 patient-years; a median of 56 (range 1-70) infusions were received. Serious adverse events, including progressive multifocal leukoencephalopathy, were consistent with natalizumab's known profile. Upon natalizumab re-exposure, rates of anti-natalizumab antibodies and hypersensitivity reactions were 3% and 5% overall, and 40% and 24% among patients with 1 to 2 prior natalizumab doses. Patients originally randomized to placebo/another disease-modifying therapy vs natalizumab in previous studies had significantly higher EDSS scores at STRATA baseline; this difference persisted over 240 weeks. EDSS scores generally remained stable. Patients initially randomized to natalizumab had lower annualized relapse rates over 240 weeks.

CONCLUSIONS

Serious adverse events were consistent with natalizumab's known safety profile; short exposure with a gap before redosing was associated with higher incidences of anti-natalizumab antibodies and hypersensitivity reactions. Stability of EDSS scores and consistently low relapse rates over 5 years of natalizumab treatment are consistent with its known efficacy profile.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that in patients with relapsing-remitting multiple sclerosis, natalizumab stabilizes EDSS scores, decreases relapse rates, and is associated with an increased risk of progressive multifocal leukoencephalopathy.

Defining the clinical course of multiple sclerosis: the 2013 revisions

Accurate clinical course descriptions (phenotypes) of multiple sclerosis (MS) are important for communication, prognostication, design and recruitment of clinical trials, and treatment decision-making. Standardized descriptions published in 1996 based on a survey of international MS experts provided purely clinical phenotypes based on data and consensus at that time, but imaging and biological correlates were lacking. Increased understanding of MS and its pathology, coupled with general concern that the original descriptors may not adequately reflect more recently identified clinical aspects of the disease, prompted a re-examination of MS disease phenotypes by the International Advisory Committee on Clinical Trials of MS. While imaging and biological markers that might provide objective criteria for separating clinical phenotypes are lacking, we propose refined descriptors that include consideration of disease activity (based on clinical relapse rate and imaging findings) and disease progression. Strategies for future research to better define phenotypes are also outlined.

Assessing treatment response to interferon-β: is there a role for MRI?

OBJECTIVE

Interferon-β (IFN-β) has been shown to reduce relapse rates in multiple sclerosis; however, the clinical response appears to vary among individuals. Can early MRI be used to identify those patients who have a poor response to treatment?

METHODS

A systematic review of studies examining differential treatment response and clinical endpoints in groups defined as responders or nonresponders to IFN-β was performed. Meta-analytic techniques were used to combine study results where appropriate.

RESULTS

Patients with MRI evidence of poor response to IFN-β treatment as defined by either ≥2 new hyperintense T2 lesions or new gadolinium-enhancing lesions had significantly increased risk of both future relapses and progression as defined by the Expanded Disability Status Scale. There appeared to be an increased risk of poor outcomes 16 years after treatment initiation in those with an initial poor response to treatment. Previous evidence has shown this not to be the case in placebo arms of clinical trials.

CONCLUSIONS

For those patients starting IFN-β, early MRI, within 6 to 24 months after starting treatment, has the potential to provide important information when counseling patients about the likelihood of future treatment failure. This can inform treatment decisions before clinical relapses or disease progression.

Multiple Sclerosis Outcome Assessments Consortium: Genesis and initial project plan

The need for improved clinical outcome measures in multiple sclerosis trials has been recognized for two decades, but only recently has the Food and Drug Administration (FDA) created a pathway for qualification of new clinician-reported outcome (ClinRO) assessments. Additionally, drug development in multiple sclerosis (MS) has been extraordinarily active, with numerous disease-modifying drugs now on the market. This shifting therapeutic landscape, along with the unmet need for drugs to treat the progressive forms of MS and the changing expectations of clinicians, patients, and payers, have led to the call for more sensitive and meaningful disability progression measures. In response to these drivers, the Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was launched. A public-private partnership, MSOAC aims to accelerate the development of new therapies for MS by generating new tools for measuring outcomes in clinical trials. At the first annual MSOAC/FDA meeting, a regulatory path was outlined for qualifying a new tool for assessing efficacy in registration trials of MS. The European Medicines Agency (EMA) and FDA will provide parallel consultation and review. The consensus approach with engagement by all of the stakeholders, prominently including patients with MS, should also increase acceptance of the measure by clinicians and patients.

Time to integrate clinical and research informatics

Integration of clinical and research informatics can streamline clinical research, patient care, and the building of a learning health care system.

Reliability of classifying multiple sclerosis disease activity using magnetic resonance imaging in a multiple sclerosis clinic

OBJECTIVE

To assess the reliability of new magnetic resonance imaging (MRI) lesion counts by clinicians in a multiple sclerosis specialty clinic.

DESIGN

An observational study.

SETTING

A multiple sclerosis specialty clinic.

PATIENTS

Eighty-five patients with multiple sclerosis participating in a National Institutes of Health–supported longitudinal study were included.

INTERVENTION

Each patient had a brain MRI scan at entry and 6 months later using a standardized protocol.

MAIN OUTCOME MEASURES

The number of new T2 lesions, newly enlarging T2 lesions, and gadolinium-enhancing lesions were measured on the 6-month MRI using a computer-based image analysis program for the original study. For this study, images were reanalyzed by an expert neuroradiologist and 3 clinician raters. The neuroradiologist evaluated the original image pairs; the clinicians evaluated image pairs that were modified to simulate clinical practice. New lesion counts were compared across raters, as was classification of patients as MRI active or inactive.

RESULTS

Agreement on lesion counts was highest for gadolinium-enhancing lesions, intermediate for new T2 lesions, and poor for enlarging T2 lesions. In 18% to 25% of the cases, MRI activity was classified differently by the clinician raters compared with the neuroradiologist or computer program. Variability among the clinical raters for estimates of new T2 lesions was affected most strongly by the image modifications that simulated low image quality and different head position.

CONCLUSIONS

Between-rater variability in new T2 lesion counts may be reduced by improved standardization of image acquisitions, but this approach may not be practical in most clinical environments. Ultimately, more reliable, robust, and accessible image analysis methods are needed for accurate multiple sclerosis disease-modifying drug monitoring and decision making in the routine clinic setting.

Author Response to Comment on “Time to Integrate Clinical and Research Informatics”

Lack of structured clinical data limits research potential of EHRs, and efforts to establish clinical data standards should be a priority.

Predictors of long-term outcome in multiple sclerosis patients treated with interferon β

OBJECTIVE

To identify early predictors of long-term outcomes in patients with relapsing-remitting multiple sclerosis (RRMS) treated with intramuscular (IM) interferon beta-1a (IFNβ-1a).

METHODS

A multicenter, observational, 15-year follow-up study of patients who completed ≥2 years in the pivotal trial of IM IFNβ-1a for RRMS was conducted. One hundred thirty-six patients participated in the 15-year follow-up (69 originally randomized to IM IFNβ-1a and 67 to placebo). After the 2-year clinical trial, treatment was not regulated by study protocol. Disease activity during the 2-year trial was defined as: ≥2 gadolinium-enhancing lesions (cumulative) on year 1 and/or year 2 magnetic resonance imaging (MRI); ≥3 new T2 lesions on year 2 MRI compared to baseline; and ≥2 relapses over 2 years. Odds ratios were calculated for early disease activity predicting severe Expanded Disability Status Scale (EDSS) worsening (worst quartile of change, ≥4.5 EDSS points) during the 15-year interval.

RESULTS

The proportion of patients experiencing early disease activity was lower in patients on IM IFNβ-1a than placebo for all disease activity markers (range, 23.5-29.0% vs 41.0-45.5%). In the IM IFNβ-1a group, persistent disease activity predicted severe EDSS worsening: gadolinium-enhancing lesions (odds ratio [OR], 8.96; p < 0.001); relapses (OR, 4.44; p = 0.010); and new T2 lesions (OR, 2.90; p = 0.080). In placebo patients, early disease activity was not as strongly associated with long-term outcomes (OR range, 1.53-2.62; p = 0.069-0.408).

INTERPRETATION

Disease activity despite treatment with IFNβ is associated with unfavorable long-term outcomes. Particular attention should be paid to gadolinium-enhancing lesions on IFNβ therapy, as their presence strongly correlates with severe disability 15 years later. The results provide rationale for monitoring IFNβ-treated patients with MRI, and for changing therapy in patients with active disease.

Early tolerability and safety of fingolimod in clinical practice

BACKGROUND

Fingolimod is approved by the U.S. Food and Drug Administration to reduce relapses and disability progression in relapsing forms of MS. Several screening studies and a first-dose observation (FDO) period are recommended due to adverse effects observed in clinical trials.

OBJECTIVE

The objective of this study is to describe the early experience with fingolimod, including startup, tolerability and safety in a large academic multiple sclerosis (MS) center.

METHODS

Patients prescribed fingolimod from September 2010 to July 2011 were identified through electronic medical records. Demographics, MS disease history, pre-treatment screening studies, FDO experience during shared medical visits and three month follow-up data were analyzed.

RESULTS

Three hundred ninety-one patients were prescribed fingolimod of whom 317 started the medication and were included in the analysis. Fingolimod was most frequently used in relapsing remitting MS (n=256, 80.8%) and was prescribed as a first-line agent in 11 cases (3.5%). FDO was uneventful in 308 patients (96.8%). Adverse events during FDO were self limited and included symptomatic bradycardia (n=3), chest tightness (n=2) and hypertension (n=1). Fingolimod was discontinued in 30 patients (9.5%) at three months. Adverse effects leading to discontinuation by more than one patient included headache (n=4), macular edema (n=3), nausea (n=3) and hypertension (n=2).

CONCLUSIONS

Fingolimod was well tolerated during FDO and adverse events were self limited. The shared medical visit is an appropriate setting for FDO. Adverse effects were similar to those described in clinical trials but the discontinuation rate was higher.

Multiple sclerosis, natalizumab, and PML: helping patients decide

The treatment benefits of natalizumab in patients with multiple sclerosis (MS) appear to exceed those of other disease-modifying drugs, but progressive multifocal leukoencephalopathy (PML) has been identified as a risk in patients receiving natalizumab. As of August 2011, a total of 150 cases of natalizumab-associated PML had been reported worldwide. The overall risk is estimated at approximately 1.66 in 1,000 patients. Independent risk factors for natalizumab-associated PML are number of infusions beyond 36 and prior use of immunosuppressive drugs. Classifying JC virus antibody status appears to be useful in treatment decision-making for individual MS patients. Patient tolerance for risk plays an important role in the selection of therapy, and the treating physician's perception and tolerance of risk may differ markedly from the patient's. Physicians can help patients make individual informed decisions regarding the use of natalizumab, given the known risk of PML.

Oral treatment for multiple sclerosis

BACKGROUND

The armamentarium for the treatment of relapsing-remitting multiple sclerosis (RRMS) is increasing rapidly. Several oral treatments have shown benefit and will generate much interest because of the convenience of such administration. However, availability of convenient oral drugs will not necessarily translate into clinical effectiveness and safety. Here, we provide an interim report about the mechanisms of action, and efficacy and safety results that have been reported since January, 2010, for five new oral drugs. Additionally, we draw attention to issues that neurologists and patients will encounter when considering the use of new oral drugs.

RECENT DEVELOPMENTS

Positive results have been reported for five new oral drugs for RRMS--fingolimod, cladribine, teriflunomide, laquinimod, and dimethyl fumarate--in phase 3 studies; a few new oral drugs are likely to be approved for RRMS soon. WHERE NEXT?: Emerging oral treatments are ushering in a new era in the treatment of MS, providing not only new treatment options but also new challenges. Since data for some of the new drugs have not been reported in peer-reviewed journals yet and safety profiles are not yet fully developed, opinions about the use of these new oral drugs in practice are preliminary and tentative. Practice will evolve with time as information and experience accumulates. Of importance will be results from comparator trials, information about management of patients with breakthrough disease, results from long-term safety studies, and results of studies to assess the potential for neuroprotective effects of the new drugs.

Natalizumab for the treatment of relapsing multiple sclerosis

Natalizumab is an α4-integrin antagonist approved as monotherapy for patients with relapsing multiple sclerosis (MS), based on demonstrated efficacy in the pivotal AFFIRM study (N = 942). Natalizumab monotherapy reduced risk of disability progression by 42%–54% and annualized relapse rate by 68% during a period of 2 years. Natalizumab was also associated with significant reductions in number of T2-hyperintense, gadolinium-enhancing, and T1-hypointense lesions and in volume of T2-hyperintense lesions (all p < 0.001) on magnetic resonance imaging. Furthermore, natalizumab-treated patients in AFFIRM experienced significant improvements from baseline in the physical and mental components of the Short Form-36 (p ≤ 0.01) and a 35% reduction in risk of clinically significant vision loss (p = 0.008 vs placebo). Natalizumab was well tolerated in phase 3 studies. Common adverse events were generally mild and included headache, fatigue, urinary tract infections, and arthralgia. Serious adverse events were similar between treatment groups. The incidence of serious hypersensitivity reactions associated with natalizumab was <1%. Progressive multifocal leukoencephalopathy was a rare complication of treatment, observed in 2 patients with MS who received natalizumab plus interferon β-1a. The robust clinical benefits of natalizumab, including benefits on patient-reported quality of life, make it an important addition to disease-modifying therapies available to patients with relapsing MS.

Excessive biologic response to IFNβ is associated with poor treatment response in patients with multiple sclerosis

BACKGROUND

Interferon-beta (IFNβ) is used to inhibit disease activity in multiple sclerosis (MS), but its mechanisms of action are incompletely understood, individual treatment response varies, and biological markers predicting response to treatment have yet to be identified.

METHODS

The relationship between the molecular response to IFNβ and treatment response was determined in 85 patients using a longitudinal design in which treatment effect was categorized by brain magnetic resonance imaging as good (n = 70) or poor response (n = 15). Molecular response was quantified using a customized cDNA macroarray assay for 166 IFN-regulated genes (IRGs).

RESULTS

The molecular response to IFNβ differed significantly between patients in the pattern and number of regulated genes. The molecular response was strikingly stable for individuals for as long as 24 months, however, suggesting an individual 'IFN response fingerprint'. Unexpectedly, patients with poor response showed an exaggerated molecular response. IRG induction ratios demonstrated an exaggerated molecular response at both the first and 6-month IFNβ injections.

CONCLUSION

MS patients exhibit individually unique but temporally stable biological responses to IFNβ. Poor treatment response is not explained by the duration of biological effects or the specific genes induced. Rather, individuals with poor treatment response have a generally exaggerated biological response to type 1 IFN injections. We hypothesize that the molecular response to type I IFN identifies a pathogenetically distinct subset of MS patients whose disease is driven in part by innate immunity. The findings suggest a strategy for biologically based, rational use of IFNβ for individual MS patients.