Epoch Analysis of On-Treatment Disability Progression Events over Time in the Tysabri Observational Program (TOP)

Real-world treatment outcomes and safety of natalizumab in Finnish multiple sclerosis patients

Objectives

The primary objective was to evaluate long-term treatment persistence and safety of natalizumab in Finnish multiple sclerosis patients. The secondary objectives were to assess patient characteristics, use of natalizumab-related safety protocol, and treatment persistence in patients with different anti-John Cunningham virus antibody statuses (John Cunningham virus status).

Materials & Methods

All adult multiple sclerosis patients in the Finnish multiple sclerosis register who started natalizumab between 1/2006 and 12/2018 were included in this study and followed retrospectively until treatment discontinuation or end of follow-up (12/2019).

Results

In total, 850 patients were included. Median duration of natalizumab treatment was 7.8 years in John Cunningham virus negative (n = 229) and 2.1 years in John Cunningham virus positive patients (n = 115; p < 0.001). The most common cause for treatment discontinuation was John Cunningham virus positivity. After natalizumab discontinuation, patients who had a washout duration of less than 6 weeks had fewer relapses during the first 6 months (p = 0.012) and 12 months (p = 0.005) compared with patients who had a washout duration of over 6 weeks. During the median follow-up of 3.6 years, 76% of patients remained stable or improved on their Expanded Disability Status Scale.

Conclusions

Treatment persistence was very high among John Cunningham virus negative patients. The study supports long-term effectiveness of natalizumab and a washout duration of less than 6 weeks after discontinuation.

Assessing Blood-Based Biomarkers to Define a Therapeutic Window for Natalizumab

Natalizumab is a monoclonal antibody that binds CD49d. Although it is one of the most effective treatments for Relapsing-Remitting Multiple Sclerosis (RRMS), a dosing regimen has not been optimized for safety and efficacy in individual patients. We aimed to identify biomarkers to monitor Natalizumab treatment and to establish a personalized dose utilizing an ongoing longitudinal study in 29 RRMS patients under Natalizumab with standard interval dose (SD) of 300 mg/4wks or extended interval dose (EID) of 300 mg/6wks. Blood samples were analyzed by flow cytometry to determine CD49d saturation and expression in several T and B lymphocytes subpopulations. Each patient was analyzed at two different timepoints separated by 3 Natalizumab administrations. Natalizumab and sVCAM-1 levels in serum were also analyzed using ELISA. To determine the reproducibility of various markers, two different timepoints were compared and no significant differences were observed for CD49d expression nor for saturation; SD patients had higher saturation levels (~80%) than EID patients (~60%). A positive correlation exists between CD49d saturation and Natalizumab serum levels. CD49d expression and saturation are stable parameters that could be used as biomarkers in the immunomonitoring of Natalizumab treatment. Moreover, Natalizumab and sVCAM-1 serum levels could be used to optimize an individual's dosing schedule.

Long-term outcome and predictors of long-term disease activity in natalizumab-treated patients with multiple sclerosis: real life data from the Austrian MS Treatment Registry

Objectives

To evaluate long-term effectiveness of natalizumab (NTZ) and to determine demographic, clinical, and radiological predictors regarding long-term disease activity (≥ 7 years) in a nationwide observational cohort, using data collected prospectively in a real-life setting.

Materials and methods

We analysed data from 230 patients from the Austrian Multiple Sclerosis Treatment Registry (AMSTR), who had started treatment with NTZ at any time since 2006 and stayed on NTZ for at least 7 years without treatment gap of more than three months.

Results

Estimated mean annualised relapse rates (ARR) over a mean treatment period of 9.3 years were 0.07 for NTZ. Sustained EDSS progression for 12 weeks was observed in 36 (19%) patients and for 24 weeks in 31 (16.3%) cases. Sustained EDSS regression for 12 and 24 weeks was seen in 45 (23.7%) and 42 (22.1%) cases. The baseline parameters ≥ 1 Gadolinium-enhancing MRI lesion(s) [incidence rate ratio (IRR) of 0.409 (95% CI 0.283–0.593), p = 0.001], ARR ≤ 1 in the prior 12 month before treatment initiation with NTZ [IRR of 0.353 (95% CI 0.200–0.623), p = 0.001] and EDSS ≤ 1 [incidence rate ratio (IRR) of 0.081 (95% CI 0.011–0.581), p = 0.012] were significantly associated with a reduced relapse risk, whereas a disease duration ≤ 5 years increased significantly the ARR [IRR of 1.851 (95% CI 1.249–2.743), p = 0.002]. The only predictive baseline parameter for experiencing EDSS progression (sustained for 12 and 24 weeks) was age > 35 years [HR of 2.482 (95% CI 1.110–5.549), p = 0.027, and HR of 2.492 (95% CI 1.039–5.978), p = 0.041, respectively].

Conclusions

These real-life data show a stable disease course regarding relapse activity and disease progression under NTZ treatment for more than 7 years. The main predictors for disease activity were higher relapse rate before treatment initiation, higher disability, shorter disease duration and absence of Gadolinium-enhancing MRI lesions at baseline. Older age at NTZ start was the only significant risk factor for disease progression over long-term.

New Algorithms Improving PML Risk Stratification in MS Patients Treated With Natalizumab

Overview: We assessed the role of age and disease activity as new factors contributing to establish the risk of progressive multifocal leucoencephalopathy in multiple sclerosis patients treated with natalizumab in 36 University Hospitals in Europe. We performed the study in 1,307 multiple sclerosis patients (70.8% anti-John Cunninghan virus positive antibodies) treated with natalizumab for a median time of 3.28 years. Epidemiological, clinical, and laboratory variables were collected. Lipid-specific IgM oligoclonal band status was available in 277 patients. Factors associated with progressive multifocal leucoencephalopathy onset were explored by uni- and multivariate logistic regression. Results: Thirty-five patients developed progressive multifocal leucoencephalopathy. The multivariate analysis identified anti-John Cunninghan virus antibody indices and relapse rate as the best predictors for the onset of this serious opportunistic infection in the whole cohort. They allowed to stratify progressive multifocal leucoencephalopathy risk before natalizumab initiation in individual patients [area under the curve (AUC) = 0.85]. The risk ranged from <1/3,300 in patients with anti-John Cunninghan virus antibody indices <0.9 and relapse rate >0.5, to 1/50 in the opposite case. In patients with lipid-specific IgM oligoclonal bands assessment, age at natalizumab onset, anti-John Cunninghan virus antibody indices, and lipid-specific IgM oligoclonal band status predicted progressive multifocal leucoencephalopathy risk (AUC = 0.92). The absence of lipid-specific IgM oligoclonal bands was the best individual predictor (OR = 40.94). The individual risk ranged from <1/10,000 in patients younger than 45 years at natalizumab initiation, who showed anti John Cunningham virus antibody indices <0.9 and lipid-specific IgM oligoclonal bands to 1/33 in the opposite case. Conclusions: In a perspective of personalized medicine, disease activity, anti-lipid specific IgM oligoclonal bands, anti Jonh Cunninghan virus antibody levels, and age can help tailor natalizumab therapy in multiple sclerosis patients, as predictors of progressive multifocal leucoencephalopathy.

Long-term safety and effectiveness of natalizumab treatment in clinical practice: 10 years of real-world data from the Tysabri Observational Program (TOP)

OBJECTIVE

The Tysabri Observational Programme (TOP), which began >10 years ago, is an open-label, multinational, prospective observational study evaluating the long-term safety and effectiveness of natalizumab in relapsing-remitting multiple sclerosis patients.

METHODS

These data provide a 10-year interim analysis of safety and effectiveness in TOP. Annualised relapse rates (ARRs) and disability progression/improvement were analysed using the Poisson model and the Kaplan-Meier method, respectively. Analyses included patients on natalizumab and those who discontinued natalizumab but remained in TOP.

RESULTS

As of November 2017, TOP included 6148 patients. Overall, 829 patients (13.5%) experienced ≥1 serious adverse event (SAE), with infection the most common (4.1%). Fifty-three patients (0.9%) had confirmed progressive multifocal leukoencephalopathy. SAE data were consistent with natalizumab's known safety profile; no new safety signals were identified. A total of 3210 patients (52.2%) discontinued natalizumab; 2117 (34.4%) withdrew from TOP. Median time on natalizumab was 3.3 (range 0-11.6) years; median follow-up time was 5.2 (range 0-10.8) years. The on-natalizumab ARR was 0.15, a 92.5% reduction from the year before initiation. Ten-year cumulative probabilities of disability worsening and improvement were 27.8% and 33.1%, respectively. On-natalizumab ARRs were similar between patients who discontinued or remained on natalizumab, suggesting limited attrition bias.

CONCLUSIONS

Since the TOP 5-year interim analysis (December 2012), cohort size (6148 vs 4821), median exposure (3.3 vs 1.8 years) and median follow-up time (62 vs 26 months) have increased. This 10-year interim analysis further supports the robust real-world effectiveness and well-established safety profile of natalizumab.

TRIAL REGISTRATION NUMBER

NCT00493298.

The role of natalizumab in the treatment of multiple sclerosis: benefits and risks

Natalizumab, a monoclonal antibody that blocks lymphocyte infiltration in the central nervous system, is a valuable tool in the treatment of relapsing forms of multiple sclerosis (MS). In a phase III clinical trial comparing natalizumab with placebo over 2 years, natalizumab reduced annualized relapse rate by 68%, 12-week confirmed disability progression by 42%, and reduced contrast-enhancing lesions by 92%. In post hoc analyses, natalizumab treatment was associated with 37% of patients achieving no evidence of disease activity (versus 7% on placebo) and 30% achieving sustained disability improvement (versus 19% on placebo). Natalizumab did not achieve a statistically significant primary composite disability outcome in a trial of 887 patients with secondary progressive MS, but it did demonstrate a benefit on a prespecified component of the 9-Hole Peg Test. The greatest risk of natalizumab treatment is progressive multifocal leukoencephalopathy (PML), with a 23% mortality rate. Risk stratification on the basis of immunosuppressant exposure, natalizumab treatment duration and anti-John Cunningham virus (JCV) antibody status and index has greatly improved clinical decision making. Other potential serious natalizumab-associated risks reported in clinical trials and postmarketing settings include infusion reactions, hepatotoxicity and rare, serious opportunistic infections. With more than a decade of continuous postmarketing experience, natalizumab remains a very effective option for patients with relapsing forms of MS. To optimize appropriate selection of natalizumab for patients with relapsing MS, however, a thorough understanding of individual patient risk factors for PML or other adverse events is also required.