Standard Interval Dosing Research Articles

Improvement of fatigue, depression, and processing speed two weeks post Natalizumab infusion in Multiple Sclerosis: No difference between standard and extended interval dosing schedules

BackgroundFatigue, depression and slow processing speed are debilitating symptoms in people with Relapsing-Remitting Multiple Sclerosis (RRMS) that significantly impacts on the quality of life. Natalizumab, a disease-modifying treatment, improves clinical symptoms but questions remain about the comparative efficacy between its standard interval dosing (SID) and extended interval dosing (EID) schedules. ObjectiveTo examine the impact of short term natalizumab dosing schedules—SID versus EID—on the so called “invisible symptoms”, specifically focusing on symptom exacerbation during the 'wearing-off' phase before infusion and the subsequent relief post-infusion. MethodsForty-two RRMS patients were assessed one week before (T0) and two weeks after pre-and post-natalizumab infusion (T1) for fatigue symptoms using the Fatigue Scale for Motor and Cognitive Functions (FSMC), the Modified Fatigue Impact Scale (MFIS), and the Fatigue Symptoms and Impacts Questionnaire–Relapsing Multiple Sclerosis (FSIQ-RMS). Processing speed and depression were measured by the symbol digit modality test (SDMT), and the Beck Depression Inventory-II (BDI-II). Participants were categorized into either the SID or EID dosing schedules of natalizumab, and their outcomes were compared. ResultsForty-two patients (21 SID; 21 EID) completed the study. Fatigue severity scales, SDMT, and BDI-II scores improved from T0 to T1. No significant differences in fatigue symptoms were found between the SID and EID groups, whether during the "wearing-off" period (T0) or post-infusion (T1). ConclusionsBoth SID and EID dosing regimens of natalizumab are similarly effective in reducing fatigue symptoms, depression and improving processing speed in individuals with RRMS, with no observed differences during the "wearing-off" periods or after re-infusion.

Memory B cell–guided extended interval dosing of ocrelizumab in multiple sclerosis

Background: Ocrelizumab (OCR) is an anti-CD20 monoclonal antibody approved for the treatment of relapsing-remitting and primary-progressive multiple sclerosis (MS). We aimed to evaluate the effectiveness of an individualized OCR extended interval dosing (EID), after switching from standard interval dosing (SID). Methods: This was a retrospective, observational, single-centre study including MS patients regularly followed at the Neurocenter of Southern Switzerland. After a cumulative OCR dose ⩾1200 mg, stable patients were switched to EID (OCR infusions following CD19+ 27+ memory B cell repopulation). Results: A total of 128 patients were included in the study, and 113 (88.3%) were switched to EID with a median interval of 9.9 (8.8–11.8) months between infusions. No clinical relapses occurred; 2 (1.8%) patients experienced disability worsening. Three (2.7%) and 2 (1.8%) patients experienced new T2 brain and spinal lesions, respectively. There was a mild decrease in IgG and IgM concentrations during both SID and EID OCR regimens (β = −0.23, p = 0.001 and β = −0.07, p < 0.001, respectively). Conclusion: Switch to personalized dosing of OCR based on CD19+ 27+ memory B cell repopulation led to a great extension of the interval between infusions, with maintained clinical and radiological efficacy. Given the potential advantages in terms of safety and health costs, EID OCR regimens should be further investigated.

Clinical and Immunological Impact of Ocrelizumab Extended Interval Dosing in Multiple Sclerosis: A Single-Center, Real-World Experience.

Ocrelizumab (OCR), an anti-CD20 monoclonal antibody, is approved for treating relapsing remitting (RR) and primary progressive (PP) multiple sclerosis (MS). The standard interval dosing (SID) regimen requires intravenous infusions every six months. Experience of extended dosing due to COVID-19 pandemic-related issues suggests that this strategy may provide comparable efficacy while reducing treatment burden and healthcare costs. This study aimed to evaluate clinical effectiveness, changes in B- and T-cell count, and immunoglobulin dynamics associated with extended interval dosing (EID) of ocrelizumab in a real-world setting. We retrospectively included RRMS or PPMS patients treated with OCR that had already received two OCR cycles and with at least 6 months of follow up after the last infusion. EID was defined as a ≥4 weeks delay compared to SID. Clinical outcomes were occurrence of relapses, MRI activity, 6-months confirmed disability progression (CDP) and their combination (No Evidence of Disease Activity, NEDA-3). We also evaluated changes in CD19+ B cell count, CD4+ and CD8+ T cell count, immunoglobulin titers, and occurrence of hypogammaglobulinemia (hypo-Ig). Frequency tests, multivariate regression models, and survival analysis were applied as appropriate. We analyzed data on 93 subjects (75.3% RRMS) for a total of 389 infusions (272 SID, 117 EID). Clinical and MRI activity, CDP, and NEDA 3 did not significantly differ between EID and SID. EID was associated with lower rates of B-cell depletion. T-cell dynamics and incidence of hypo-Ig were comparable following EID and SID. Hypo-IgG at index infusion was associated with further occurrence of hypo-IgG; male sex and hypo-IgM at index infusion were independently associated with hypo-IgM. In conclusion, OCR EID does not impact MS clinical and radiological outcomes, although it interferes with B-cell dynamics. These findings provide support for a tailored schedule of OCR in MS.

Extended interval dosing with ocrelizumab in multiple sclerosis

Background: This study investigates clinical and biomarker differences between standard interval dosing (SID) and extended interval dosing (EID) of ocrelizumab therapy in multiple sclerosis (MS). Methods: This is a prospective, double-arm, open-label, multi-center study in Denmark. Participants diagnosed with MS on ocrelizumab therapy >12 months were included (n = 184). Clinical, radiological, and blood-based biomarker outcomes were evaluated. MRI disease activity, relapses, worsening of neurostatus, and No Evidence of Disease Activity-3 (NEDA-3) were used as a combined endpoint. Results: Out of 184 participants, 107 participants received EID (58.2%), whereas 77 participants received SID (41.8%). The average extension was 9 weeks with a maximum of 78 weeks. When comparing EID to SID, we found higher levels of B-cells, lower serum concentrations of ocrelizumab, and similar levels of age-adjusted NFL and GFAP in the two groups. No difference in NEDA-3 between EID and SID was demonstrated (hazard ratio: 1.174, p = 0.69). Higher levels of NFL were identified in participants with disease activity. Body mass index correlated with levels of ocrelizumab and B-cells. Conclusion: Extending one treatment interval of ocrelizumab on average 9 weeks and up to 78 weeks did not result in clinical, radiological, or biomarker evidence of worsening compared with SID.

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 ​± ​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.

Ocrelizumab Extended Interval Dosing in Primary Progressive Multiple Sclerosis: An Italian Experience.

The intervals between two courses of anti CD20 therapies in the COVID19 pandemic era provided the opportunity to individually delay therapy, known as extended interval dosing (EID). We collect real-world data on patients with primary progressive MS (PPMS) treated with Ocrelizumab (OCR) during the COVID'19 pandemic. The observation period in which the standard interval dosing (SID) or EID occurred (always a maintenance cycle, 600 mg) was from January 2020 to June 2021. All patients had two infusions during the observation period. Our first aim was to compare confirmed disability progression (CDP) between SID and EID patients. From a total cohort of 410 patients treated with OCR, 96 patients fulfilled the inclusion criteria. All patients received two infusions during the index window, 71 received only SID infusions whilst 25 received at least one EID infusion throughout the entire follow-up. During the entire available follow-up (median 10 months, IQR 7-11), CDP was recorded in 5 patients (3/71, 4.2% SID and 2/25, 8% EID, V-Cramer = 0.141, p-value = 0.167). EID regimen did not influence the risk of CDP during the investigated follow up. In our multicentre real-world cohort, the EID regimen in PPMS patients did not result in increased CDP during the available follow-up.

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

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. This study aimed to study the longitudinal effects of EID compared to standard interval dosing (SID) and natalizumab drug concentrations on brain atrophy. 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. 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. 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.

Control of disease activity with large extended-interval dosing of rituximab/ocrelizumab in highly active pediatric multiple sclerosis.

Recent studies in adults suggested that extended-interval dosing of rituximab/ocrelizumab (RTX/OCR) larger than 12 months was safe and could improve safety. This was an observational cohort study of very active pediatric-onset multiple sclerosis (PoMS) (median (range) age, 16 (12-17) years) treated with RTX/OCR with 6 month standard-interval dosing (n = 9) or early extended-interval dosing (n = 12, median (range) interval 18 months (12-25)). Within a median (range) follow-up of 31 (12-63) months after RTX/OCR onset, one patient (standard-interval) experienced relapse and no patient showed disability worsening or new T2-weighted lesions. This study suggests that the effectiveness of RTX/OCR is maintained with a median extended-interval dosing of 18 months in patients with very active PoMS.

COVID-19 outbreak in Italy: an opportunity to evaluate extended interval dosing of ocrelizumab in MS patients

IntroductionDuring the COVID-19 pandemic, ocrelizumab (OCR) infusions for MS patients were often re-scheduled because of MS center's disruption and concerns regarding immunosuppression. The aim of the present study was to assess changes in OCR schedule during the first wave of pandemic in Italy and to evaluate the effect of delayed infusion on clinical/radiological endpoints.MethodsData were extracted from the Italian MS Register database. Standard interval dosing was defined as an infusion interval ≤ 30 weeks, while extended interval dosing was defined as an infusion interval > 30 weeks at the time of the observation period. Clinico-demographics variables were tested as potential predictors for treatment delay. Time to first relapse and time to first MRI event were evaluated. Cumulative hazard curves were reported along their 95% confidence intervals. A final sample of one-thousand two patients with MS from 65 centers was included in the analysis: 599 pwMS were selected to evaluate the modification of OCR infusion intervals, while 717 pwRMS were selected to analyze the effect of infusion delay on clinical/MRI activity.ResultsMean interval between two OCR infusions was 28.1 weeks before pandemic compared to 30.8 weeks during the observation period, with a mean delay of 2.74 weeks (p < 0.001). No clinico-demographic factors emerged as predictors of infusion postponement, except for location of MS centers in the North of Italy. Clinical relapses (4 in SID, 0 in EID) and 17 MRI activity reports (4 in SID, 13 in EID) were recorded during follow-up period.DiscussionDespite the significant extension of OCR infusion interval during the first wave of pandemic in Italy, a very small incidence of clinical/radiological events was observed, thus suggesting durable efficacy of OCR, as well as the absence of rebound after its short-term suspension.

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

BackgroundExtended 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.MethodsThe...

Extended interval dosing of ocrelizumab in patients with multiple sclerosis is not associated with meaningful differences in disease activity

Risk concerns related to ocrelizumab treatment for multiple sclerosis (MS) during the COVID-19 pandemic caused infusion delays with extended interval dosing (EID). We reviewed medical records of patients on ocrelizumab to determine whether EID maintains its effectiveness compared to standard interval dosing (SID). Among 361 patients, 231 (64%) and 123 (34%) had at least one infusion with infusion intervals of ⩾8 months and ⩾12 months, respectively. There were no differences in demographics or clinical profiles between the SID and EID groups. No significant differences between rates of breakthrough activity among relapsing-remitting patients were observed between SID (three patients) and EID (seven patients).

Lessons learned after 20 years of real-world experience with natalizumab

BackgroundWhile natalizumab (NTZ) is an effective therapy for multiple sclerosis (MS), it is associated with an increased risk of progressive multifocal leukoencephalopathy (PML). After 20 years (2002–2022) of experience with NTZ at our center, we observed no cases of PML. ObjectivesWe evaluated the likelihood of experiencing PML in a subset of our treatment cohort, as well as reviewed treatment practices at our center that may mitigate PML risk. MethodsFor this retrospective study, we reviewed patient characteristics, treatment practices, and clinical and MRI findings in patients receiving NTZ from 2006 to 2020. Observation of no PML cases was compared to the global and US PML incidences, and to the expected incidence based on published risk estimates. Results766 patients were evaluated. The number of NTZ infusions received ranged from 1 to 126, with a mean of 28. Patients received neurological examination prior to each infusion, which sometimes resulted in a pause in therapy to rule out PML if clinical worsening occurred. Extended interval dosing (EID) was the overall dosing schedule for 31% of patients. EID did not result in higher rates of radiological disease worsening than standard interval dosing (SID) patients. Depending on the analysis conducted, the finding of 0 PML cases in our cohort ranged from slightly unexpected to slightly expected. ConclusionsThe utilization of EID as well as regular clinical monitoring of patients may have lowered PML risk while still maintaining NTZ efficacy.

Progressive multifocal leukoencephalopathy with natalizumab extended or standard interval dosing in the United States and the rest of the world

ABSTRACT Background Progressive multifocal leukoencephalopathy (PML), an important identified risk for natalizumab, has been described for standard interval dosing (SID; dosing interval every-4-weeks). Information on PML with natalizumab extended interval dosing (EID; dosing interval >every-4-weeks) in the US and the rest of the world (ROW) is limited. Research design and methods A retrospective analysis of patient demographics, risk factors, clinical characteristics, and clinical outcomes was conducted on confirmed natalizumab EID and SID PML cases evaluated from Biogen pharmacovigilance systems. Results Of 857 confirmed natalizumab PML cases, EID and SID accounted for 7.5% and 92.5%, respectively (US: 12.9% and 87.1%; ROW: 5.4% and 94.6%). PML risk factors included anti-JCV index > 1.5 (US: EID, 56.7% and SID, 12.8%; ROW: EID, 44.1% and SID, 21.0%), mean duration of natalizumab treatment (US: 90.0 and 70.2 months; ROW: 54.1 and 49.8 months), and prior immunosuppressive therapy (US: 20.0% and 21.7%; ROW:11.8% and 18.0%). In the EID and SID groups, 68.8% and 76.0% of patients, respectively, were alive at up to 2 years after diagnosis. Conclusions This analysis provides insights on PML in patients receiving natalizumab that extend current knowledge, particularly regarding PML in patients receiving natalizumab EID, which can be built upon in the future.

Ocrelizumab extended-interval dosing in multiple sclerosis during SARS-CoV-2 pandemic: a real-world experience.

During the COVID-19 pandemic, ocrelizumab administration was frequently postponed because of a lack of safety information and to favour vaccination. The clinical implications of ocrelizumab administration delay in multiple sclerosis (MS) patients were assessed. Relapsing (RMS) and primary progressive (PPMS) MS patients receiving ocrelizumab for at least 6 months at our centre were retrospectively classified, according to the possible occurrence of a delay (≥4 weeks) in treatment administration. Patients were categorized in the extended-interval dosing (EID) group in the presence of at least one delayed infusion; otherwise they were considered as part of the standard interval dosing (SID) cohort. MS history, magnetic resonance imaging examinations and B-cell counts were also retrospectively collected and analysed. A total of 213 RMS and 61 PPMS patients were enrolled; 115 RMS and 29 PPMS patients had been treated according to the SID regimen, whilst 98 RMS and 32 PPMS patients were included in the EID cohort. Average follow-up after delay was 1.28 ± 0.7 years in the EID cohort. In RMS, comparing SID and EID patients, no differences were found considering the occurrence of clinical relapses (9.6% vs. 16.3%, p = 0.338), magnetic resonance imaging activity (9.8% vs. 14.1%, p = 0.374) or disability progression (11.3% vs. 18.4%, p = 0.103). Similar findings were observed in PPMS patients. In the pooled EID group, treatment delay correlated with CD19-positive relative (r = 0.530, p < 0.001) and absolute (r = 0.491, p < 0.001) cell counts, without implications on disease activity. Sporadic ocrelizumab administration delay granted sustained treatment efficacy in our cohort. Prospective data should be obtained to confirm these observations and set up systematic extended-interval regimens.

Evaluation of immune related adverse events following extended interval dosing of immune checkpoint inhibitors.

e14605 Background: Increased use of immune checkpoint inhibitors (ICI) has resulted in a rise in immune related adverse events (irAEs). In 2019, pembrolizumab and nivolumab received approval for extended interval (EI) dosing at 400 mg intravenous (IV) every 6 weeks and 480 mg IV every 4 weeks, respectively, compared to the standard interval (SI) dosing of 200 mg IV every 3 weeks and 240 mg IV every 2 weeks, respectively. Since EI dosing has been implemented, clinicians have hypothesized increased dosing may lead to more irAEs. Mixed results have been published to date with discordant results between studies. The aim of this study was to investigate the incidence and grade of irAEs, including multisystem adverse events (ms irAEs) in SI versus EI dosing in a real-world community-based hospital system in the United States of America. Methods: We performed an Institutional Review Board approved retrospective study of all patients 18 years or older who received SI or EI dosing of pembrolizumab or nivolumab from 2015 through 2021. An irAE was considered connected to the specific dosing group if it was observed after the first date of stated dosing and within 90 days after last dose of such dosing. Statistical analysis included descriptive statistics, Wilcoxon signed-rank test, Fisher’s exact test, and Kaplan-Meier survival analysis and was performed in R version 4.2.2 at a significance level of 0.05. Results: Our study included 458 patients who were 99% white, 59% male, and an average age of 67 years. There were 354 (77%) patients in the SI group and 104 (23%) in the EI group. The overall incidence of irAEs was 32% (146 patients), of which 37% (54 patients) presented at some point with ms irAEs. There was no significant association between dosing group and presence of irAEs (p = 0.087), grade groups 1-2 vs &gt; 3 (p = 0.7), or ms irAEs (p = 0.13). The incidence of irAEs was 34% (120 patients) in the SI group with a distribution of grades 1-2-3-4-5 being 39-62-25-5-1, respectively. The incidence of irAEs was 25% (26 patients) in the EI group with a distribution of grades 1-2-3-4-5 being 18-27-11-1-0, respectively. In the SI group there were 41 (34%) patients with ms irAEs compared to 13 (50%) in the EI group. There was a significant association between dosing groups and overall survival (p &lt; 0.001). Conclusions: Our results lend data to suggest there is indeed no statistically significant risk of increased irAEs with EI dosing. However, there may be a clinically significant trend toward increased ms irAEs in EI dosing that needs further investigation with comparisons of comorbid conditions that increase risk of autoimmune reactions. Of note, the OS in EI dosing group was statistically significant but likely heavily confounded due to patient selection bias, this may also be an avenue for future research to be conducted with a randomized clinical trial.

Impact of extended interval dosing of ocrelizumab on immunoglobulin levels in multiple sclerosis

Long-term B cell depletion with ocrelizumab in multiple sclerosis (MS) is associated with severe side effects such as hypogammaglobulinemia and infections. Our study therefore aimed to assess immunoglobulin levels under treatment with ocrelizumab and implement an extended interval dosing (EID) scheme. Immunoglobulin levels of 51 patients with ≥24months of treatment with ocrelizumab were analyzed. After ≥4 treatment cycles, patients chose to either continue on the standard interval dosing (SID) regimen (n= 14) or, in the case of clinically and radiologically stable disease, switch to B cell-adapted EID (n= 12, next dose at CD19+ Bcells >1% of peripheral blood lymphocytes). Levels of immunoglobulin M (IgM) declined rapidly under ocrelizumab treatment. Risk factors for IgM and IgA hypogammaglobulinemia were lower levels at baseline and more previous disease-modifying therapies. B cell-adapted EID of ocrelizumab increased the mean time until next infusion from 27.3 to 46.1weeks. Ig levels declined significantly in the SID group over 12months but not in the EID group. Previously stable patients remained stable under EID as measured by expanded disability status scale (EDSS), neurofilament light chain, timed 25-foot walk (T25-FW), 9-hole peg test (9-HPT), symbol digit modalities test (SDMT), and multiple sclerosis impact scale (MSIS-29). In our pilot study, B cell-adapted EID of ocrelizumab prevented the decline of Ig levels without affecting disease activity in previously stable patients with MS. Based on these findings, we propose a new algorithm for long-term ocrelizumab treatment. This study was supported by the Deutsche Forschungsgemeinschaft (SFB CRC-TR-128, SFB 1080, and SFB CRC-1292) and the Hertie Foundation.

Extended Interval Dosing of Ocrelizumab in Patients with Multiple Sclerosis Is Not Associated with Meaningful Differences in Disease Activity (P14-3.010)

<h3>Objective:</h3> To determine if extended interval dosing (EID) of ocrelizumab is associated with changes in disease activity in patients with multiple sclerosis (MS). <h3>Background:</h3> During the COVID-19 pandemic, EID of ocrelizumab (standard interval dosing (SID)= every 6 months) was employed variably by neurologists at our center due to concerns about COVID-19 risk or reduced COVID-19 vaccine efficacy. This time period provides the opportunity to evaluate whether EID is associated with greater risk of breakthrough MS activity. <h3>Design/Methods:</h3> Medical records of patients at our institution who were on ocrelizumab treatment as of March 2020 were reviewed. Demographic, clinical, and imaging data and infusion dates were collected. EID was defined as ≥ 8 months in the primary analysis and ≥ 12 months in secondary analyses. <h3>Results:</h3> Overall, 364 patients, 275 (75.5%) with relapsing-remitting MS (RRMS) and 89 (24.5%) with progressive MS (PMS), were included (mean age 42.4±10.9 years; 72% females). They received ocrelizumab for an average of 38.2±14.9 months; and infusion intervals ranged from 4 to 32 months. 190 patients (52.4% of RRMS and 51.6% of PMS) had at least one EID ≥ 8 months, while 89 patients (21% of RRMS and 18% of PMS) had at least one EID ≥ 12 months. There was no difference in sex, age, or MS type between EID and SID groups. Reasons for EID (≥ 8 months) included COVID concerns (58%), infections (8%), pregnancy (8%), or other (26%). Only 1 EID and 1 SID patient had a clinical relapse. Among 258 RRMS patients who had re-baseline MRI after starting ocrelizumab, 3 (2.2%) EID patients (≥ 8 months) had new lesions on imaging vs none in those with SID. No participant with PMS had breakthrough MRI activity. <h3>Conclusions:</h3> Results suggest no marked risk of inflammatory MS activity associated with EID for ocrelizumab when compared to SID. <b>Disclosure:</b> Dr. Bou Rjeily has nothing to disclose. The institution of Dr. Fitzgerald has received research support from NIH. The institution of Dr. Fitzgerald has received research support from National MS Society. Dr. Mowry has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for UpToDate. The institution of Dr. Mowry has received research support from Biogen. The institution of Dr. Mowry has received research support from Teva. The institution of Dr. Mowry has received research support from Genzyme. The institution of Dr. Mowry has received research support from Genentech.

Real-World Effectiveness of Natalizumab Extended Interval Dosing in a French Cohort.

Natalizumab, a therapy for relapsing-remitting multiple sclerosis (RRMS), is associated with a risk of progressive multifocal leukoencephalopathy (PML). Over the last several years, practitioners have used off-label extended interval dosing (EID) of natalizumab to reduce PML risk, despite the absence of a large-scale efficacy evaluation. We conducted a retrospective, multicenter cohort study among adults with RRMS receiving stable standard interval dosing (SID), defined as a ≥ 12-month consecutive period of ≥ 11 natalizumab infusions/year in France. We compared the 12-month risk difference of remaining relapse-free (primary endpoint) between patients who switched to EID (≤ 9 natalizumab infusions) and those who remained on SID, with a noninferiority margin of - 11%. We used propensity score methods such as inverse probability treatment weighting (IPTW) and 1:1 propensity score matching (PSM). Secondary endpoints were annualized relapse rate, disease progression, and safety. Baseline characteristics were similar between patients receiving EID (n = 147) and SID (n = 156). The proportion of relapse-free patients 12months postbaseline was 142/147 in the EID (96.6%) and 144/156 in the SID group (92.3%); risk difference (95% CI) 4.3% (- 1.3 to 9.8%); p < 0.001 for non-inferiority. There were no significant differences between relapse rates (0.043 vs. 0.083 per year, respectively; p = 0.14) or Expanded Disability Status Scale mean scores (2.43 vs. 2.72, respectively; p = 0.18); anti-JC virus index values were similar (p = 0.23); and no instances of PML were reported. The comparisons using IPTW (n = 306) and PSM (n = 204) were consistent. These results support the pertinence of using an EID strategy for RRMS patients treated with natalizumab. gov identifier (NCT04580381).

Ocrelizumab concentration and antidrug antibodies are associated with B-cell count in multiple sclerosis

BackgroundThe majority of patients with multiple sclerosis on ocrelizumab have B-cell depletion after standard interval dosing of 26 weeks. With B-cell-guided dosing patients receive their next dose when B-cell repopulation...

Natalizumab wearing-off symptoms: effect of extend interval dosing during Sars-CoV-2 pandemic.

BackgroundMany patients treated with Natalizumab experience wearing-off symptoms (WoS) towards the end of the administration cycle. During the pandemic we advised and asked patients undergoing treatment with Natalizumab if they wanted to be shifted from a standard interval dosing (StID of 4 weeks) to an extended interval dosing (ExID of 5–6 weeks), regardless of their JCV index. Our main objective was to study prevalence and incidence of WoS when ExID was adopted.MethodsWe enrolled 86 patients, from May 2020 to January 2021, evaluated at baseline and during a 6 months follow-up with a survey focused on WoS, Fatigue Severity Scale (FSS), Expanded Disability Status Scale (EDSS) and MRI.ResultsAmong the 86 patients, 32 (37.2%) reported WoS. Most common one was fatigue (93.7%). Mean EDSS was higher in the group reporting WoS (3.8 WoS vs 3.1 non-WoS, p < 0.05). Sphincterial function was the EDSS item that significantly differed between the WoS group and the non-WoS group (1.4 WoS vs 0.6 non-WoS, p < 0.001). WoS correlate with the FSS scale (p < 0.001).ConclusionAdopting an extended interval dosing does not result in significantly different occurrence of WoS between the ExID and the StID populations, in our cohort of patients. Interestingly, there is a strong correlation between WoS and a higher EDSS and FSS. Safety and efficacy of Natalizumab with ExID are relatively preserved in our study.