Prospective trial of natalizumab personalised extended interval dosing by therapeutic drug monitoring in relapsing-remitting multiple sclerosis (NEXT-MS).

BACKGROUND: Extended interval dosing (EID) of natalizumab is a promising strategy to optimise treatment in multiple sclerosis (MS). Personalised EID by therapeutic drug monitoring can enable further extension of treatment intervals. METHODS: The NEXT-MS trial is an investigator-initiated prospective phase IV non-randomised study. Adults with a diagnosis of relapsing-remitting MS who received ≥6 natalizumab infusions were included in three groups: personalised EID with a target drug trough concentration of 10 µg/mL (EID10), an exploratory group of personalised EID with a target of 5 µg/mL (EID5) and standard interval dosing (SID) of 4 weeks. The primary outcome is radiological disease activity (new/newly enlarged T2 lesions) comparing the EID10 group to a historical cohort of SID (HSID). RESULTS: Results of the first phase of the NEXT-MS trial are reported here (n=376) as the study will continue with an amended protocol. In the EID10 group (n=251), incidence rate of radiological activity was 10.0 per 1000 person-years, which was non-inferior to the HSID cohort (24.7 per 1000 person-years (n=87), incidence rate difference 14.7, 90% CI -4.5 to 34.0). Incidence rate of radiological activity was 10.0 per 1000 person-years in the EID5 group (n=65), and 47.0 per 1000 person-years in the SID group (n=60). Serum neurofilament light levels did not increase over time within the EID groups. There were no cases of progressive multifocal leukoencephalopathy. CONCLUSIONS: MS disease activity is adequately controlled with personalised natalizumab EID. Interval extension to a drug trough concentration of 5 µg/mL is likely a safe target to extend natalizumab treatment intervals >6 weeks. TRIAL REGISTRATION NUMBER: NCT04225312.

Clinical scales in progressive MS: predicting long-term disability.

BACKGROUND: To determine which short-term changes on clinical scales including the Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg test (9HPT) and Guy's Neurological Disability Scale (GNDS) are most predictive of long-term outcome of disability as rated by the EDSS in progressive multiple sclerosis (MS). METHODS: From a longitudinal database, all progressive patients, both primary (PP) and secondary (SP), were selected on the basis of at least two complete examinations being available within a time interval of 1-2 years (short-term change). All patients who fulfilled the selection criteria were invited for a third visit after an interval of at least 3 years (long-term outcome). We used ordinal logistic regression to see which early changes were most predictive of the long-term EDSS. RESULTS: 181 patients fulfilled the selection criteria. Early change on EDSS and T25FW were the best predictors of long-term EDSS; both were significant predictors in a 'single predictor' model. Early EDSS change was a slightly stronger single predictor (R(2) 0.38, Wald χ(2) 42.65, p < 0.001) compared with early T25FW change (R(2) 0.27, Wald χ(2) 12.35, p < 0.001). Adding early T25FW change to early EDSS change in a 'combined predictor' model improved prediction (p = 0.036). CONCLUSION: Both early change on EDSS and T25FW predict long-term EDSS with comparable strength. Early change on T25FW adds significant independent information and improves the prediction model with early EDSS change only. Therefore we support the use of early T25FW examinations in future clinical trials in progressive MS.

Outcome measurement in multiple sclerosis: detection of clinically relevant improvement.

Because the development of new treatments in multiple sclerosis as well as the awareness of the importance of patient-oriented measures have become more important in the last two decades, new outcome measures have been developed with the aim of being more responsive to change and more clinically relevant to patients. The ability to detect improvement is sparsely studied. In the present study we evaluate the responsiveness of the Expanded Disability Status Scale and two quantitative tests (the timed 25-foot walk test and the nine-hole peg test) separately and in combination, to detect improvement after intravenous methylprednisolone. The Expanded Disability Status Scale, the timed 25-foot walk test and the nine-hole peg test were assessed in 112 multiple sclerosis patients before and 6 weeks after intravenous methylprednisolone. In addition patients were asked to rate their change as an anchor to evaluate the performance of the tests. Combining the timed 25-foot walk test and the nine-hole peg test turned out to be the optimal combination of measures to predict patient perceived improvement (positive predictive value of 67% and a negative predictive value of 59%, likelihood ratio of positive test 2.31 (95% confidence interval 1.08-4.95)). In the higher Expanded Disability Status Scale range (4.5 and higher), for all measures a significant change was more often perceived as clinically relevant than in the lower disability range. The Expanded Disability Status Scale seems not to be the preferred outcome of choice to detect patient perceived improvement in multiple sclerosis, especially in the lower Expanded Disability Status Scale range. Combining the timed walk test and the nine-hole peg test can improve the sensitivity to detect clinically relevant changes without conceding with respect to specificity.

The size of the treatment effect: do patients and proxies agree?

BACKGROUND: This study examined whether MS patients and proxy respondents agreed on change in disease impact, which was induced by treatment. This may be of interest in situations when patients suffer from limitations that interfere with reliable self-assessment, such as cognitive impairment. METHODS: MS patients and proxies completed the Multiple Sclerosis Impact Scale (MSIS-29) before and after intravenous steroid treatment. Analyses focused on patient-proxy agreement between MSIS-29 change scores. Transition ratings were used to measure the patient's judgement of change and whether this change was reflected in the MSIS-29 change of patients and proxies. Receiver operating characteristic (ROC) analyses were also performed to examine the diagnostic properties of the MSIS-29 when completed by patients and proxies. RESULTS: 42 patients and proxy respondents completed the MSIS-29 at baseline and follow-up. Patient-proxy differences between change scores on the physical and psychological MSIS-29 subscale were quite small, although large variability was found. The direction of mean change was in concordance with the transition ratings of the patients. Results of the ROC analyses of the MSIS-29 were similar when completed by patients (physical scale: AUC = 0.79, 95% CI: 0.65-0.93 and 0.66, 95% CI: 0.48-0.84 for the psychological scale) and proxies (physical scale: 0.80, 95% CI: 0.72-0.96 and 0.71, 95% CI: 0.56-0.87 for the psychological scale) CONCLUSION: Although the results need to be further explored in larger samples, these results do point towards possible use of proxy respondents to assess patient perceived treatment change at the group level.

Longitudinal proxy measurements in multiple sclerosis: patient-proxy agreement on the impact of MS on daily life over a period of two years.

BACKGROUND: The use of self-report measurements in clinical settings is increasing. However, in patients with limitations that interfere with reliable self-assessment such as cognitive impairment or mood disturbances, as may be the case in multiple sclerosis (MS), data collection might be problematic. In these situations, information obtained from proxy respondents (e.g. partners) may replace self-ratings. The aim of this study was to examine the value of proxy ratings at separate points in time and to assess patient-proxy agreement on possible changes in disease impact of MS. METHODS: Fifty-six MS patients and their partners completed the Multiple Sclerosis Impact Scale (MSIS-29) at baseline and follow-up, two years later. Patient-proxy agreement was assessed at both time points by calculating intraclass correlation coefficients (ICCs), exact and global agreement and the mean directional differences between groups. Agreement of change over time was assessed by calculating ICCs between change scores. In parallel, global ratings of both patients and proxy respondents of the extent to which the patient had improved or deteriorated over the past two years were collected to validate possible changes on the MSIS-29. RESULTS: At both time points, agreement on the physical scale was higher than agreement on the psychological scale (ICCs at baseline were 0.81 for the physical scale and 0.72 for the psychological scale; at follow-up, the ICC values were 0.86 and 0.65 respectively). At follow-up, statistically significant mean differences between patients and proxies were noted for the physical scale (-4.8 +/- 12.7, p = 0.006) and the psychological scale (-8.9 +/- 18.8, p = 0.001). Agreement between change scores on the MSIS-29 was fair (ICC < 0.60). Our analyses suggest that the validity of measuring changes over time might be better for proxy respondents compared to patients. CONCLUSION: Proxy respondents could act as a reliable source of information in cross-sectional studies. Moreover, results suggested that agreement on change over time might be better for proxy respondents compared to patients. Although this remarkable finding should be interpreted cautiously because of several limitations of the study, it does plead for further investigation of this important topic.