Long-lasting severe anemia following treatment with natalizumab for relapsing-remitting multiple sclerosis: a case report.

BACKGROUND: Natalizumab is a monoclonal antibody used to treat patients with relapsing-remitting multiple sclerosis. Anemia is a recognized side effect, but it is usually mild and of a short duration when natalizumab is stopped. Here, we describe a case of a young woman with severe and especially long lasting anemia associated with treatment with natalizumab, persisting up to a year after treatment was stopped. CASE PRESENTATION: A 24 year-old Caucasian woman with relapsing-remitting multiple sclerosis developed severe transfusion dependent anemia after 27 infusions with natalizumab, which was her first and only treatment for her multiple sclerosis. Extensive hematologic diagnostics did not reveal any malignant cause or any other plausible non-malignant cause for her anemia. The bone marrow was found to be hypercellular, with a maturation arrest of the erythropoiesis and with grade 1-2 fibrosis. No specific treatment for the anemia was given. The hemoglobin level showed signs of spontaneous increase after nearly one year after natalizumab was discontinued. CONCLUSION: Severe anemia can be caused by treatment with natalizumab. This case adds information to the few other similar reported cases, demonstrating the potential duration of the anemia, as well as detailed description of hematologic findings. The mechanism is most likely due to inhibition of α4 subunit of the α4ß1-integrin, which is present on both lymphocytes and erythroid precursor cells.

PB006: A Natalizumab Biosimilar.

PB006 (Tyruko®) is the first biosimilar of the reference monoclonal anti-α4-integrin antibody natalizumab. It is approved for use in the same indications for which reference natalizumab is approved, as a single disease-modifying therapy in adults with highly active relapsing-remitting multiple sclerosis (RRMS). PB006 has similar physicochemical and pharmacodynamic properties to those of reference natalizumab, and the pharmacokinetic similarity of the agents has been demonstrated in a study in healthy subjects. PB006 demonstrated clinical efficacy similar to that of reference natalizumab in patients with RRMS, and was generally well tolerated in this population. The tolerability, safety and immunogenicity profiles of PB006 were similar to those of reference natalizumab, and switching from reference natalizumab to PB006 appeared to have no impact on tolerability or immunogenicity. The role of reference natalizumab in the management of RRMS is well established and PB006 provides an effective biosimilar alternative for patients requiring natalizumab therapy.

Switching from natalizumab to an anti-CD20 monoclonal antibody in relapsing remitting multiple sclerosis: A systematic review.

BACKGROUND: Use of natalizumab (NTZ) is precluded in many Multiple Sclerosis (MS) patients by the risk of progressive multifocal leukoencephalopathy (PML). Regardless, some patients may commence natalizumab for short term disease control in spite of being seropositive, and others may seroconvert whilst on treatment. In these circumstances, discontinuation of NTZ should not occur until a clear exit strategy is established to prevent post-NTZ disease reactivation, which often exceeds the severity of disease activity prior to NTZ treatment. The objective of this systematic review was to summarise the available evidence for CD20-monoclonal antibodies (CD20mAb) as a suitable NTZ exit strategy, and to identify whether a superior switch protocol can be established. METHODS: In accordance with PRISMA guidelines, a total of 2393 references were extracted from a search of three online databases (PubMed, Scopus, MEDLINE). Following the application of inclusion/exclusion criteria, a total of 5 studies representing 331 patients were included. RESULTS: The overall incidence of clinical relapse during washout periods ranging from 4.4-10.7 weeks was 0 %. The incidence of clinical relapse during two-year follow-up ranged from 1.8 % to 10 % for switches to all types of CD20 monoclonal antibody. The weighted mean for clinical relapse at 12 months was 8.8 %. Three studies reported an annualised relapse rate (ARR) ranging from 0.02-0.12 with a weighted mean ARR of 0.07. The overall incidence of PML during washout was 0 % and the overall incidence of PML within 6 months follow-up was 0.6 %. CONCLUSIONS: This systematic review provides the first attempt at identifying a superior switch protocol in patients at risk of PML transitioning from NTZ to a CD20mAb. Our results indicate that CD20mAb's are a suitable transitional option for patients who discontinue NTZ, with our cohort demonstrating very low rates of carryover PML and low rates of clinical relapse. The most appropriate washout period is unclear due to confounding factors but is likely between 4 and 12 weeks.

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.

Immunosenescence and vaccine efficacy revealed by immunometabolic analysis of SARS-CoV-2-specific cells in multiple sclerosis patients.

Disease-modifying therapies (DMT) administered to patients with multiple sclerosis (MS) can influence immune responses to SARS-CoV-2 and vaccine efficacy. However, data on the detailed phenotypic, functional and metabolic characteristics of antigen (Ag)-specific cells following the third dose of mRNA vaccine remain scarce. Here, using flow cytometry and 45-parameter mass cytometry, we broadly investigate the phenotype, function and the single-cell metabolic profile of SARS-CoV-2-specific T and B cells up to 8 months after the third dose of mRNA vaccine in a cohort of 94 patients with MS treated with different DMT, including cladribine, dimethyl fumarate, fingolimod, interferon, natalizumab, teriflunomide, rituximab or ocrelizumab. Almost all patients display functional immune response to SARS-CoV-2. Different metabolic profiles characterize antigen-specific-T and -B cell response in fingolimod- and natalizumab-treated patients, whose immune response differs from all the other MS treatments.

Comparative Effectiveness of Natalizumab, Fingolimod, and Injectable Therapies in Pediatric-Onset Multiple Sclerosis: A Registry-Based Study.

BACKGROUND AND OBJECTIVES: Patients with pediatric-onset multiple sclerosis (POMS) typically experience higher levels of inflammation with more frequent relapses, and though patients with POMS usually recover from relapses better than adults, patients with POMS reach irreversible disability at a younger age than adult-onset patients. There have been few randomized, placebo-controlled clinical trials of multiple sclerosis (MS) disease-modifying therapies (DMTs) in patients with POMS, and most available data are based on observational studies of off-label use of DMTs approved for adults. We assessed the effectiveness of natalizumab compared with fingolimod using injectable platform therapies as a reference in pediatric patients in the global MSBase registry. METHODS: This retrospective study included patients with POMS who initiated treatment with an injectable DMT, natalizumab, or fingolimod between January 1, 2006, and May 3, 2021. Patients were matched using inverse probability treatment weighting. The primary outcome was time to first relapse from index therapy initiation. Secondary study outcomes included annualized relapse rate; proportions of relapse-free patients at 1, 2, and 5 years; time to treatment discontinuation; and times to 24-week confirmed disability worsening and confirmed disability improvement. RESULTS: A total of 1,218 patients with POMS were included in this analysis. Patients treated with fingolimod had a significantly lower risk of relapse than patients treated with injectable DMTs (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.29-0.83; p = 0.008). After adjustment for prior DMT experience in the unmatched sample, patients treated with natalizumab had a significantly lower risk of relapse than patients treated either with injectable DMTs (HR, 0.15; 95% CI 0.07-0.31; p < 0.001) or fingolimod (HR, 0.37; 95% CI 0.14-1.00; p = 0.049). The adjusted secondary study outcomes were generally consistent with the primary outcome or with previous observations. The findings in the inverse probability treatment weighting-adjusted patient populations were confirmed in multiple sensitivity analyses. DISCUSSION: Our analyses of relapse risk suggest that natalizumab is more effective than fingolimod in the control of relapses in this population with high rates of new inflammatory activity, consistent with previous studies of natalizumab and fingolimod in adult-onset patients and POMS. In addition, both fingolimod and natalizumab were more effective than first-line injectable therapies. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that patients with POMS treated with natalizumab had a lower risk of relapse than those with fingolimod.

Natalizumab promotes anti-inflammatory and repair effects in multiple sclerosis.

BACKGROUND: Multiple sclerosis is an inflammatory and degenerative disease of the central nervous system leading to demyelination and axonal loss. Relapsing-remitting multiple sclerosis (RRMS) is commonly treated by anti-inflammatory drugs, where one of the most effective drugs to date is the monoclonal antibody natalizumab. METHODS: The cerebrospinal fluid (CSF) proteome was analyzed in 56 patients with RRMS before and after natalizumab treatment, using label-free mass spectrometry and a subset of the changed proteins were verified by parallel reaction monitoring in a new cohort of 20 patients, confirming the majority of observed changes. RESULTS: A total of 287 differentially abundant proteins were detected including (i) the decrease of proteins with roles in immunity, such as immunoglobulin heavy constant mu, chitinase-3-like protein 1 and chitotriosidase, (ii) an increase of proteins involved in metabolism, such as lactate dehydrogenase A and B and malate-dehydrogenase cytoplasmic, and (iii) an increase of proteins associated with the central nervous system, including lactadherin and amyloid precursor protein. Comparison with the CSF-PR database provided evidence that natalizumab counters protein changes commonly observed in RRMS. Furthermore, vitamin-D binding protein and apolipoprotein 1 and 2 were unchanged during treatment with natalizumab, implying that these may be involved in disease activity unaffected by natalizumab. CONCLUSIONS: Our study revealed that some of the previously suggested biomarkers for MS were affected by the natalizumab treatment while others were not. Proteins not previously suggested as biomarkers were also found affected by the treatment. In sum, the results provide new information on how the natalizumab treatment impacts the CSF proteome of MS patients, and points towards processes affected by the treatment. These findings ought to be explored further to disclose potential novel disease mechanisms and predict treatment responses.

Natalizumab reduces loss of gray matter and thalamic volume in patients with relapsing-remitting multiple sclerosis: A post hoc analysis from the randomized, placebo-controlled AFFIRM trial.

BACKGROUND: Loss of brain gray matter fractional volume predicts multiple sclerosis (MS) progression and is associated with worsening physical and cognitive symptoms. Within deep gray matter, thalamic damage is evident in early stages of MS and correlates with physical and cognitive impairment. Natalizumab is a highly effective treatment that reduces disease progression and the number of inflammatory lesions in patients with relapsing-remitting MS (RRMS). OBJECTIVE: To evaluate the effect of natalizumab on gray matter and thalamic atrophy. METHODS: A combination of deep learning-based image segmentation and data augmentation was applied to MRI data from the AFFIRM trial. RESULTS: This post hoc analysis identified a reduction of 64.3% (p = 0.0044) and 64.3% (p = 0.0030) in mean percentage gray matter volume loss from baseline at treatment years 1 and 2, respectively, in patients treated with natalizumab versus placebo. The reduction in thalamic fraction volume loss from baseline with natalizumab versus placebo was 57.0% at year 2 (p < 0.0001) and 41.2% at year 1 (p = 0.0147). Similar findings resulted from analyses of absolute gray matter and thalamic fraction volume loss. CONCLUSION: These analyses represent the first placebo-controlled evidence supporting a role for natalizumab treatment in mitigating gray matter and thalamic fraction atrophy among patients with RRMS. CLINICALTRIALS.GOV IDENTIFIER: NCT00027300URL: https://clinicaltrials.gov/ct2/show/NCT00027300.

High-Efficacy Therapy Discontinuation vs Continuation in Patients 50 Years and Older With Nonactive MS.

Importance: A recent randomized clinical trial concluded that discontinuing medium-efficacy therapy might be a reasonable option for older patients with nonactive multiple sclerosis (MS), but there is a lack of data on discontinuing high-efficacy therapy (HET). In younger patients, the discontinuation of natalizumab and fingolimod is associated with a risk of rebound of disease activity. Objective: To determine whether discontinuing HET in patients 50 years and older with nonactive MS is associated with an increased risk of relapse compared with continuing HET. Design, Setting, and Participants: This observational cohort study used data from 38 referral centers from the French MS registry (Observatoire Français de la Sclérose en Plaques [OFSEP] database). Among 84704 patients in the database, data were extracted for 1857 patients 50 years and older with relapsing-remitting MS treated by HET and with no relapse or magnetic resonance imaging activity for at least 2 years. After verification of the medical records, 1620 patients were classified as having discontinued HET or having remained taking treatment and were matched 1:1 using a dynamic propensity score (including age, sex, disease phenotype, disability, treatment of interest, and time since last inflammatory activity). Patients were included from February 2008 to November 2021, with a mean (SD) follow-up of 5.1 (2.9) years. Data were extracted in June 2022. Exposures: Natalizumab, fingolimod, rituximab, and ocrelizumab. Main Outcomes and Measures: Time to first relapse. Results: Of 1620 included patients, 1175 (72.5%) were female, and the mean (SD) age was 54.7 (4.8) years. Among the 1452 in the HET continuation group and 168 in the HET discontinuation group, 154 patients in each group were matched using propensity scores (mean [SD] age, 57.7 [5.5] years; mean [SD] delay since the last inflammatory activity, 5.6 [3.8] years; mean [SD] follow-up duration after propensity score matching, 2.5 [2.1] years). Time to first relapse was significantly reduced in the HET discontinuation group compared with the HET continuation group (hazard ratio, 4.1; 95% CI, 2.0-8.5; P < .001) but differed between HETs, with a hazard ratio of 7.2 (95% CI, 2.1-24.5; P = .001) for natalizumab, 4.5 (95% CI, 1.3-15.5; P = .02) for fingolimod, and 1.1 (95% CI, 0.3-4.8; P = .85) for anti-CD20 therapy. Conclusion and Relevance: As in younger patients, in patients 50 years and older with nonactive MS, the risk of relapse increased significantly after stopping HETs that impact immune cell trafficking (natalizumab and fingolimod). There was no significant increase in risk after stopping HETs that deplete B-cells (anti-CD20 therapy). This result may inform decisions about stopping HETs in clinical practice.

Treatment modifiers across different regimens of natalizumab treatment in MS: An Italian real-world experience.

Despite its widespread use in clinical practice, the effectiveness of natalizumab extended interval dosing (EID) adopted from treatment start across different treatment intervals and individual modifiers (body mass index - BMI) is still under-investigated. Here, seven-hundred and forty-five multiple sclerosis (MS) patients, exposed to natalizumab for 3.30 â€‹± â€‹1.34 years, were retrospectively enrolled in an observational multicenter study. After stratifying patients in EID or standard interval dosing (SID), we assessed differences in time to relapse, MRI activity and Expanded Disability Status Scale (EDSS) progression. The primary analysis was conducted on patients exposed to EID interval from 5 weeks and 1 day to 7 weeks, while a secondary analysis included also EID periods up to 8 weeks. An additional analysis explored the impact of BMI. No differences in time to first relapse, time to radiological activity, time to EDSS progression or time to EDA (evidence of disease activity) were detected between SID and EID group (EID interval from 5 weeks to 1 day to 7 weeks). When including EID periods from 7 weeks and 1 day to 8 weeks, the EID group showed a trend towards higher risk of experience clinical relapses than the SID group. A higher EDA risk was also identified in EID patients with BMI above median. In conclusion, a higher risk of relapses seems to occur for EID above 7 weeks. Independently from the EID scheme adopted, higher BMI increases the risk of EDA in these patients.

Risk of secondary progression in patients with highly active multiple sclerosis treated with natalizumab: a real-life study.

BACKGROUND: one of the most important therapeutic goals in relapse-onset multiple sclerosis is to preclude conversion to secondary progression. Our objective was to determine the risk of progression associated with natalizumab treatment in an registry-based cohort of patients and to identify determinant factors. METHODS: Patients with relapse-onset multiple sclerosis from the Registre Lorrain des Scléroses en Plaques (ReLSEP) were included if they had received one infusion of natalizumab between 2002 and 2021. The risk of secondary progression was determined using a standardized definition and a multi-state estimator to account for the possibility of stopping natalizumab before progression, and analyzed with multivariate Cox models. RESULTS: 574 patients were followed up for a median of 6.7 years. Of the 304 who stopped NTZ before progression onset, the probabilities (95% confidence interval) to convert to progression after 1, 2, 5 and 10 years were 3.2% (2.0-4.8%), 5.3% (3.6-7.3%), 17.5% (14.3-21.3%) and 28.3% (23.7-33.7%), respectively. Discontinuation of NTZ during follow-up was significantly associated with an increased risk of conversion in case of no resumption of a highly active treatment thereafter (adjusted hazard ratio = 2.7; 95% confidence interval 1.5-4.9; p = 0.001). The use of such a treatment was associated with a lower risk of progression (adjusted hazard ratio = 0.42; 95% confidence interval 0.23-0.79; p = 0.007). CONCLUSION: the risk of conversion to secondary progression associated with natalizumab treatment is relatively low but increases in case of natalizumab discontinuation in the absence of switch to highly active immunosuppressant.

Plasma antioxidant potential measured by total radical trapping antioxidant parameter in a cohort of multiple sclerosis patients.

BACKGROUND: Oxidative injury has been implicated as a mediator of demyelination, axonal damage, and neurodegeneration in multiple sclerosis (MS). There is a high demand for oxidative injury biomarkers. The aim of the study was to evaluate MS patients' plasma antioxidant potential using the total radical trapping parameter (TRAP) assay and examine its usefulness as an MS disease biomarker. METHODS: A total number of 112 MS patients underwent an analysis of TRAP. In addition, plasma uric acid (UA) levels were analyzed. The neurological and radiological data were collected from patient records from Helsinki University Hospital during 2012-2013 when first-line injectables of moderate-efficacy, natalizumab (NTZ), and fingolimod (FTY) of high efficacy disease modifying therapies and in some cases azathioprine (AZT) were used to treat MS. RESULTS: TRAP values were negatively associated with expanded disability status scale (EDSS) score with p-value .052, ß = -28. There was also a negative association in TRAP values between patients with no medication (n = 22, TRAP mean 1255 µmol/L (95% confidence interval [CI] 1136-1374)) and patients who received NTZ, p-value .020 (n = 19, TRAP mean was 991 µmol/L (95% CI 849-1133) or FTY treatment, p-value .030 (n = 5, TRAP mean 982 µmol/L (95% CI 55-1909). Due to a small sample size, these results were not significant after applying a false discovery rate correction at a 0.05 significance level but are worth highlighting. Men in the study had higher TRAP values, p-value = .001 (TRAP mean 1320 ± 293 µmol/L) than women (TRAP mean 1082 ± 288 µmol/L). UA was positively associated with TRAP values, p-value <.001 and UA levels in men (UA mean 334.5 ± 62.6 µmol/L) were higher compared to women (UA mean 240 ± 55.8 µmol/L), t-test p-value <.001. The significant difference in TRAP levels between genders, with men showing higher TRAP values than women, may be attributed to the variation in UA levels. CONCLUSION: Our findings suggest that lower plasma antioxidant potential is linked to more severe disability measured by EDSS scores. Patients treated with NTZ and FTY had reduced antioxidant power, which might be influenced by the active MS disease rather than the treatments themselves. The study reveals a strong positive correlation between UA levels and TRAP, particularly among women. However, men on average had better antioxidant potential than women. Neither the disease type nor the duration influences TRAP levels. While serving as a marker of antioxidant potential, plasma TRAP in MS patients does not reliably reflect overall oxidative stress (OS) and should not be solely used as an indicator of OS.

Immunomodulators and immunosuppressants for relapsing-remitting multiple sclerosis: a network meta-analysis.

BACKGROUND: Different therapeutic strategies are available for the treatment of people with relapsing-remitting multiple sclerosis (RRMS), including immunomodulators, immunosuppressants and biological agents. Although each one of these therapies reduces relapse frequency and slows disability accumulation compared to no treatment, their relative benefit remains unclear. This is an update of a Cochrane review published in 2015. OBJECTIVES: To compare the efficacy and safety, through network meta-analysis, of interferon beta-1b, interferon beta-1a, glatiramer acetate, natalizumab, mitoxantrone, fingolimod, teriflunomide, dimethyl fumarate, alemtuzumab, pegylated interferon beta-1a, daclizumab, laquinimod, azathioprine, immunoglobulins, cladribine, cyclophosphamide, diroximel fumarate, fludarabine, interferon beta 1-a and beta 1-b, leflunomide, methotrexate, minocycline, mycophenolate mofetil, ofatumumab, ozanimod, ponesimod, rituximab, siponimod and steroids for the treatment of people with RRMS. SEARCH METHODS: CENTRAL, MEDLINE, Embase, and two trials registers were searched on 21 September 2021 together with reference checking, citation searching and contact with study authors to identify additional studies. A top-up search was conducted on 8 August 2022. SELECTION CRITERIA: Randomised controlled trials (RCTs) that studied one or more of the available immunomodulators and immunosuppressants as monotherapy in comparison to placebo or to another active agent, in adults with RRMS. DATA COLLECTION AND ANALYSIS: Two authors independently selected studies and extracted data. We considered both direct and indirect evidence and performed data synthesis by pairwise and network meta-analysis. Certainty of the evidence was assessed by the GRADE approach. MAIN RESULTS: We included 50 studies involving 36,541 participants (68.6% female and 31.4% male). Median treatment duration was 24 months, and 25 (50%) studies were placebo-controlled. Considering the risk of bias, the most frequent concern was related to the role of the sponsor in the authorship of the study report or in data management and analysis, for which we judged 68% of the studies were at high risk of other bias. The other frequent concerns were performance bias (34% judged as having high risk) and attrition bias (32% judged as having high risk). Placebo was used as the common comparator for network analysis. Relapses over 12 months: data were provided in 18 studies (9310 participants). Natalizumab results in a large reduction of people with relapses at 12 months (RR 0.52, 95% CI 0.43 to 0.63; high-certainty evidence). Fingolimod (RR 0.48, 95% CI 0.39 to 0.57; moderate-certainty evidence), daclizumab (RR 0.55, 95% CI 0.42 to 0.73; moderate-certainty evidence), and immunoglobulins (RR 0.60, 95% CI 0.47 to 0.79; moderate-certainty evidence) probably result in a large reduction of people with relapses at 12 months. Relapses over 24 months: data were reported in 28 studies (19,869 participants). Cladribine (RR 0.53, 95% CI 0.44 to 0.64; high-certainty evidence), alemtuzumab (RR 0.57, 95% CI 0.47 to 0.68; high-certainty evidence) and natalizumab (RR 0.56, 95% CI 0.48 to 0.65; high-certainty evidence) result in a large decrease of people with relapses at 24 months. Fingolimod (RR 0.54, 95% CI 0.48 to 0.60; moderate-certainty evidence), dimethyl fumarate (RR 0.62, 95% CI 0.55 to 0.70; moderate-certainty evidence), and ponesimod (RR 0.58, 95% CI 0.48 to 0.70; moderate-certainty evidence) probably result in a large decrease of people with relapses at 24 months. Glatiramer acetate (RR 0.84, 95%, CI 0.76 to 0.93; moderate-certainty evidence) and interferon beta-1a (Avonex, Rebif) (RR 0.84, 95% CI 0.78 to 0.91; moderate-certainty evidence) probably moderately decrease people with relapses at 24 months. Relapses over 36 months findings were available from five studies (3087 participants). None of the treatments assessed showed moderate- or high-certainty evidence compared to placebo. Disability worsening over 24 months was assessed in 31 studies (24,303 participants). Natalizumab probably results in a large reduction of disability worsening (RR 0.59, 95% CI 0.46 to 0.75; moderate-certainty evidence) at 24 months. Disability worsening over 36 months was assessed in three studies (2684 participants) but none of the studies used placebo as the comparator. Treatment discontinuation due to adverse events data were available from 43 studies (35,410 participants). Alemtuzumab probably results in a slight reduction of treatment discontinuation due to adverse events (OR 0.39, 95% CI 0.19 to 0.79; moderate-certainty evidence). Daclizumab (OR 2.55, 95% CI 1.40 to 4.63; moderate-certainty evidence), fingolimod (OR 1.84, 95% CI 1.31 to 2.57; moderate-certainty evidence), teriflunomide (OR 1.82, 95% CI 1.19 to 2.79; moderate-certainty evidence), interferon beta-1a (OR 1.48, 95% CI 0.99 to 2.20; moderate-certainty evidence), laquinimod (OR 1.49, 95 % CI 1.00 to 2.15; moderate-certainty evidence), natalizumab (OR 1.57, 95% CI 0.81 to 3.05), and glatiramer acetate (OR 1.48, 95% CI 1.01 to 2.14; moderate-certainty evidence) probably result in a slight increase in the number of people who discontinue treatment due to adverse events. Serious adverse events (SAEs) were reported in 35 studies (33,998 participants). There was probably a trivial reduction in SAEs amongst people with RRMS treated with interferon beta-1b as compared to placebo (OR 0.92, 95% CI 0.55 to 1.54; moderate-certainty evidence). AUTHORS' CONCLUSIONS: We are highly confident that, compared to placebo, two-year treatment with natalizumab, cladribine, or alemtuzumab decreases relapses more than with other DMTs. We are moderately confident that a two-year treatment with natalizumab may slow disability progression. Compared to those on placebo, people with RRMS treated with most of the assessed DMTs showed a higher frequency of treatment discontinuation due to AEs: we are moderately confident that this could happen with fingolimod, teriflunomide, interferon beta-1a, laquinimod, natalizumab and daclizumab, while our certainty with other DMTs is lower. We are also moderately certain that treatment with alemtuzumab is associated with fewer discontinuations due to adverse events than placebo, and moderately certain that interferon beta-1b probably results in a slight reduction in people who experience serious adverse events, but our certainty with regard to other DMTs is lower. Insufficient evidence is available to evaluate the efficacy and safety of DMTs in a longer term than two years, and this is a relevant issue for a chronic condition like MS that develops over decades. More than half of the included studies were sponsored by pharmaceutical companies and this may have influenced their results. Further studies should focus on direct comparison between active agents, with follow-up of at least three years, and assess other patient-relevant outcomes, such as quality of life and cognitive status, with particular focus on the impact of sex/gender on treatment effects.

Imaging Very Late Antigen-4 on MOLT4 Leukemia Tumors with Cysteine Site-Specific 89Zr-Labeled Natalizumab Immuno-Positron Emission Tomography.

Very late antigen-4 (VLA4; CD49d) is a promising immune therapy target in treatment-resistant leukemia and multiple myeloma, and there is growing interest in repurposing the humanized monoclonal antibody (Ab), natalizumab, for this purpose. Positron emission tomography with radiolabeled Abs (immuno-PET) could facilitate this effort by providing information on natalizumab's in vivo pharmacokinetic and target delivery properties. In this study, we labeled natalizumab with 89Zr specifically on sulfhydryl moieties via maleimide-deferoxamine conjugation. High VLA4-expressing MOLT4 human T cell acute lymphoblastic leukemia cells showed specific 89Zr-natalizumab binding that was markedly blocked by excess Ab. In nude mice bearing MOLT4 tumors, 89Zr-natalizumab PET showed high-contrast tumor uptake at 7 days postinjection. Biodistribution studies confirmed that uptake was the highest in MOLT4 tumors (2.22 ± 0.41%ID/g) and the liver (2.33 ± 0.76%ID/g), followed by the spleen (1.51 ± 0.42%ID/g), while blood activity was lower at 1.12 ± 0.21%ID/g. VLA4-specific targeting in vivo was confirmed by a 58.1% suppression of tumor uptake (0.93 ± 0.15%ID/g) when excess Ab was injected 1 h earlier. In cultured MOLT4 cells, short-term 3 day exposure to the proteasome inhibitor bortezomib (BTZ) did not affect the α4 integrin level, but BTZ-resistant cells that survived the treatment showed increased α4 integrin expression. When the effects of BTZ treatment were tested in mice, there was no change of the α4 integrin level or 89Zr-natalizumab uptake in MOLT4 leukemia tumors, which underscores the complexity of tumor VLA4 regulation in vivo. In conclusion, 89Zr-natalizumab PET may be useful for noninvasive monitoring of tumor VLA4 and may assist in a more rational application of Ab-based therapies for hematologic malignancies.

Exploring the effects of extended interval dosing of natalizumab and drug concentrations on brain atrophy in multiple sclerosis.

BACKGROUND: Extended interval dosing (EID) of natalizumab treatment is increasingly used in multiple sclerosis. Besides the clear anti-inflammatory effect, natalizumab is considered to have neuroprotective properties as well. OBJECTIVES: This study aimed to study the longitudinal effects of EID compared to standard interval dosing (SID) and natalizumab drug concentrations on brain atrophy. METHODS: Patients receiving EID or SID of natalizumab with a minimum radiological follow-up of 2 years were included. Changes in brain atrophy measures over time were derived from clinical routine 3D-Fluid Attenuated Inversion Recovery (FLAIR)-weighted magnetic resonance imaging (MRI) scans using SynthSeg. RESULTS: We found no differences between EID (n = 32) and SID (n = 50) for whole brain (-0.21% vs -0.16%, p = 0.42), ventricular (1.84% vs 1.13%, p = 0.24), and thalamic (-0.32% vs -0.32%, p = 0.97) annualized volume change over a median follow-up of 3.2 years. No associations between natalizumab drug concentration and brain atrophy rate were found. CONCLUSION: We found no clear evidence that EID compared to SID or lower natalizumab drug concentrations have a negative impact on the development of brain atrophy over time.

Quantifying the administration and monitoring time burden of several disease-modifying therapies for relapsing multiple sclerosis in the United Kingdom: A time and motion study.

BACKGROUND: The treatment landscape for relapsing multiple sclerosis (MS) has changed dramatically in recent decades, including an increasing number of high-efficacy disease-modifying therapies (DMTs) with varied administration and monitoring requirements. Coupled with greater focus on earlier treatment, these factors have resulted in stretching of the capacity of MS specialist services and allied healthcare professionals (HCPs). To assist with the effective planning of MS services in the UK NHS, this study quantified the administration and monitoring time burden associated with high-efficacy DMTs (alemtuzumab, cladribine tablets, fingolimod, natalizumab, and ocrelizumab) for relapsing MS. METHODS: A Time and Motion (T&M) study was conducted across four MS centres in the UK, over 3-4 months per centre (Aug 2019-Feb 2021). Time dedicated by HCPs (including but not limited to neurologists, MS specialist nurses, infusion nurses, and healthcare assistants) to pre-specified drug administration and monitoring activities, elicited during pre-study interviews at each centre, was assessed for each of the selected DMTs. Administration activities included: installing peripheral access; pre-medication administration (if needed); preparing drug for infusion; infusion initiation, monitoring, and disconnection; and patient monitoring post-infusion. Monitoring activities included: booking appointments for blood draws; blood draw; retrieval and review of blood results; maintaining blood records and follow-up with the patient; checking availability of MRI results and follow-up with the patient; booking appointments for neurologist or nurse consultations; and checking patient files prior to clinic visits. A T&M model was built using observational T&M study results, data obtained through pre-study interviews, as well as stipulated monitoring intervals from relevant Summaries of Product Characteristics for the selected DMTs, to estimate active HCP time with each DMT, extrapolated over a period of 4 years per-patient. RESULTS: For oral DMTs, projected total active HCP time (monitoring only) per-patient over 4 years was 14.7 h for cladribine tablets and 19.2 h for fingolimod. For infused DMTs, total time (administration and monitoring) for alemtuzumab was 37.7 h (6.0 and 31.6 h, respectively), 48.1 h for natalizumab (17.4 and 30.8 h, respectively), and 23.5 h for ocrelizumab (6.1 and 17.4 h, respectively). CONCLUSIONS: While active HCP time varied across centres, infused DMTs were projected to require the greatest amount of HCP time associated with administration and monitoring over 4 years versus oral DMTs. These findings may assist MS-specific HCPs in planning and delivering the equitable provision of DMT services for patients with relapsing MS.

Comparative effectiveness and cost-effectiveness of natalizumab and fingolimod in rapidly evolving severe relapsing-remitting multiple sclerosis in the United Kingdom.

AIM: To evaluate the real-world comparative effectiveness and the cost-effectiveness, from a UK National Health Service perspective, of natalizumab versus fingolimod in patients with rapidly evolving severe relapsing-remitting multiple sclerosis (RES-RRMS). METHODS: Real-world data from the MSBase Registry were obtained for patients with RES-RRMS who were previously either naive to disease-modifying therapies or had been treated with interferon-based therapies, glatiramer acetate, dimethyl fumarate, or teriflunomide (collectively known as BRACETD). Matched cohorts were selected by 3-way multinomial propensity score matching, and the annualized relapse rate (ARR) and 6-month-confirmed disability worsening (CDW6M) and improvement (CDI6M) were compared between treatment groups. Comparative effectiveness results were used in a cost-effectiveness model comparing natalizumab and fingolimod, using an established Markov structure over a lifetime horizon with health states based on the Expanded Disability Status Scale. Additional model data sources included the UK MS Survey 2015, published literature, and publicly available sources. RESULTS: In the comparative effectiveness analysis, we found a significantly lower ARR for patients starting natalizumab compared with fingolimod (rate ratio [RR] = 0.65; 95% confidence interval [CI], 0.57-0.73) or BRACETD (RR = 0.46; 95% CI, 0.42-0.53). Similarly, CDI6M was higher for patients starting natalizumab compared with fingolimod (hazard ratio [HR] = 1.25; 95% CI, 1.01-1.55) and BRACETD (HR = 1.46; 95% CI, 1.16-1.85). In patients starting fingolimod, we found a lower ARR (RR = 0.72; 95% CI, 0.65-0.80) compared with starting BRACETD, but no difference in CDI6M (HR = 1.17; 95% CI, 0.91-1.50). Differences in CDW6M were not found between the treatment groups. In the base-case cost-effectiveness analysis, natalizumab dominated fingolimod (0.302 higher quality-adjusted life-years [QALYs] and £17,141 lower predicted lifetime costs). Similar cost-effectiveness results were observed across sensitivity analyses. CONCLUSIONS: This MSBase Registry analysis suggests that natalizumab improves clinical outcomes when compared with fingolimod, which translates to higher QALYs and lower costs in UK patients with RES-RRMS.

There are several medications used to treat people with relapsing remitting multiple sclerosis, such as interferon-based therapies (Betaferon/Betaseron (US), Rebif, Avonex, Extavia), glatiramer acetate (Copaxone), teriflunomide (Aubagio), and dimethyl fumarate (Tecfidera), collectively named BRACETD. Other treatments for multiple sclerosis (MS) have a narrower use, such as natalizumab (Tysabri) or fingolimod (Gilenya), among others.This study objective was to assess how well natalizumab and fingolimod helped treating MS (clinical effectiveness) and subsequently estimate what the cost of these treatments is in comparison to the benefit they bring to people with rapidly evolving severe MS that use them in the United Kingdom (UK) (cost-effectiveness).We used an international disease registry (MSBase), which collects clinical data from people with MS in various centers around the world to compare the effectiveness of natalizumab, fingolimod and BRACETD treatments. We used a technique called propensity score matching to obtain results from comparable patient groups. People treated with natalizumab had better disease control, namely with fewer relapses and higher improvement on their disability level, than patients on fingolimod or BRACETD. Conversely, there were no differences between each group of people on a measure called disability worsening.Based on these clinical results, we built an economic model that simulates the lifetime costs and consequences of treating people with MS with natalizumab in comparison with fingolimod. We found that using natalizumab was less costly and was more effective compared to using fingolimod in UK patients.

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.