Centro Sclerosi Multipla - Presidio ospedaliero di Gallarate - ASST Valle Olona

Author Of 2 Presentations

Epidemiology Poster Presentation

P0506 - Towards a validated Secondary Progressive Multiple Sclerosis definition: A study from the Italian MS Register (ID 1432)

Abstract

Background

No clear metrics for sensitive and reliable identification of the transition from relapsing-remitting multiple sclerosis (RRMS) to secondary progressive (SP)MS are available.

Objectives

To compare diagnostic performances of two different data-driven Secondary Progressive Multiple Sclerosis definitions.

Methods

patient with RRMS with a follow-up ≥5 years, with a current age ≥18 years, and with ≥3 EDSS scores recorded were selected from the Italian MS Registry. Annual incidence of SPMS conversion was reported as number of patients converting to SP every 100 patients/year. Three different SPMS definitions have been used. Data-driven definitions based on the Lorscheider’s algorithm (LA) and on the EXPAND trial inclusion criteria were validated, using the neurologist’s definition as gold standard, in terms of calibration, discrimination and goodness of fit by calculating: sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV), the Akaike information criterion (AIC), the Area Under the Curve (AUC). The overall calibration of the data-driven definitions was evaluated by the Calibration Slope test.

Results

a cohort of 10,240 RRMS patients was extracted from the Italian MS Registry. According to the neurologist judgment, 880 (8.59%) patients were classified as SPMS in the dataset. By applying the LA and the EXPAND definition, 1,806 (17.64%) and 1,134 (11.07%) patients, respectively, were classified as SPMS. The annual rate of SP conversion during the follow-up was 0.74 every 100 patients/year based on the neurologist’s definition, 1.57 every 100 patients/year using the LA and 0.94 every 100 patients/year applying the EXPAND definition. Both the data-driven definitions were well calibrated, with a p-value of the Calibration Slope test higher than 0.05 (LA=0.55; EXPAND definition=0.57). The AIC (LA=4301; EXPAND definition=5510) and the R-Square (LA=0.15 vs EXPAND definition=0.05), were in favor of the LA. The LA showed a greater discrimination power (AUC: 0.83 vs 0.65) and a higher sensitivity (77.1% vs 38.0%) in comparison to the EXPAND definition. Both definitions showed similar specificity (88.0% vs 91.5%). The PPV and the NPV were both higher using the LA than those obtained by the EXPAND definition (37.5% vs 29.5%; 97.6% vs 94.0%, respectively).

Conclusions

An accurate definition of SP transition is needed for a timely and efficacious treatment of SPMS patients. Real-world data from the Italian MS Registry suggests that data-driven definitions had a greater ability to capture SP transition than neurologist’s definition and that the global accuracy of LA seems to be higher than a definition based on the EXPAND trial inclusion criteria.

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Observational Studies Poster Presentation

P0883 - MRI activity and extended interval of Natalizumab dosing: a multicenter Italian study (ID 1269)

Abstract

Background

Extending the natalizumab interval after the 24th administration could reduce the risk of progressive multifocal leukoencephalopathy (PML) without efficacy reduction.

Objectives

To evaluate the non-inferiority of the efficacy of an extended interval dosing (EID) regimen compared with the standard interval dosing (SID) of natalizumab regarding the multiple sclerosis (MS) MRI activity.

Methods

It is an observational, multicenter (14 Italian centers), retrospective cohort study, starting from the 24th natalizumab infusion to the loss of follow-up or 2 years after baseline. Patients were grouped in 2 categories according to the mean number of weeks between doses: < 5 weeks, SID; ≥ 5 weeks, EID. Three hundred and eight patients were enrolled. Median dose interval (MDI) following 24th infusion was 5 weeks, with a bimodal distribution (modes at 4 and 6 weeks).

Results

Two hundred and sixteen patients were in the SID group (MDI = 4.4 weeks) and 144 in the EID group (MDI 6 weeks). The risk to develop active lesions on MRI is similar in SID and EID groups during the 6 and 12 months after the 24th natalizumab infusion, respectively 2.98% (95% CI: 0.56-5.40) vs 3.32% (95% CI: 0.00-6.65%) [p=0.88] and 6.65% (95% CI: 3.02-10.29) vs 5.67% (95% CI: 1.76-9.58%) [p=0.73]. The EID regimen does not increase the occurrence of MRI activity after 6 and 12 months.

Conclusions

There is no evidence of a reduced efficacy of natalizumab in an EID setting regarding the MRI activity. This observation confirms previous clinical results and together with the increasing evidence of a reduced risk of PML associated to an EID regimen, supports the need of a bigger randomized study to assess the need to change the standard of the natalizumab dosing schedule, in order to better manage JCV-positive patients after 24 doses of natalizumab.

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