Long-term effectiveness of natalizumab in secondary progressive multiple sclerosis: A propensity-matched study.

Treatment options for secondary progressive MS (SPMS) are limited, especially considering that the new drugs recently approved are licensed for actively relapsing patients. We aimed to compare the disability progression in a real-world cohort of SPMS patients treated with natalizumab (NTZ) or interferon beta-1b (IFNb-1b). This multicenter retrospective enrolled patients with a diagnosis of SPMS according to 2014 Lublin criteria, who received NTZ or IFNb-1b for at least 48 months between the 1st June 2012 and the 15th May 2018 â€‹at 33 Italian MS centers contributing to the Italian MS Registry NTZ or IFNb-1b. Confirmed Expanded Disability Status Scale worsening (CEW) and progression independent of relapse (PIRA) were evaluated. In order to correct for non-randomization, a propensity score matching of the groups was performed. Out of 5206 MS patients identified at the time of data extraction, 421 SPMS patients treated with NTZ (224 [53.2%] females, mean age 45.3 â€‹± â€‹25.4 years) and 353 with IFNb-1b (133 [37.8%] females, mean age 48.5 â€‹± â€‹19.8 years) were enrolled. After applying the matching procedure, 102 patients were retained in the NTZ group and 98 in the IFNb-2b group. The proportion of patients who reached the 48-month 1-point CEW was significantly higher in IFNb-1b compared to NTZ group (58.2% versus 30.4%, p â€‹= â€‹0.01). The proportion of patients who developed PIRA at 48 months were significantly higher in IFNb-1b compared to NTZ (72.4% versus 40.2%, p â€‹= â€‹0.01). EDSS before treatment initiation and SPMS duration were risk factors for disability progression in terms of PIRA (HR 2.54, 25%CI 1.67-5.7; p â€‹= â€‹0.006 and HR 2.04, 25%CI 1.22-3.35; p â€‹= â€‹0.01, respectively). Patients treated with IFNb-1b were 1.64 times more to likely to develop PIRA (HR 1.64, 25%CI 1.04-4.87; p â€‹= â€‹0.001). Treatment with NTZ in SPMS patients showed more favorable disability outcomes compared to IFNb-1b with beneficial effects over 48 months.

DNA Methylation in the Anti-Mullerian Hormone Gene and the Risk of Disease Activity in Multiple Sclerosis.

OBJECTIVE: Multiple sclerosis (MS) has a complex pathobiology, with genetic and environmental factors being crucial players. Understanding the mechanisms underlying heterogeneity in disease activity is crucial for tailored treatment. We explored the impact of DNA methylation, a key mechanism in the genetics-environment interplay, on disease activity in MS. METHODS: Peripheral immune methylome profiling using Illumina Infinium MethylationEPIC BeadChips was conducted on 249 untreated relapsing-remitting MS patients, sampled at the start of disease-modifying treatment (DMT). A differential methylation analysis compared patients with evidence of disease activity (EDA) to those with no evidence of disease activity (NEDA) over 2 years from DMT start. Utilizing causal inference testing (CIT) and Mendelian randomization (MR), we sought to elucidate the relationships between DNA methylation, gene expression, genetic variation, and disease activity. RESULTS: Four differentially methylated regions (DMRs) were identified between EDA and NEDA. Examining the influence of single nucleotide polymorphisms (SNPs), 923 variants were found to account for the observed differences in the 4 DMRs. Importantly, 3 out of the 923 SNPs, affecting DNA methylation in a DMR linked to the anti-Mullerian hormone (AMH) gene, were associated with disease activity risk in an independent cohort of 1,408 MS patients. CIT and MR demonstrated that DNA methylation in AMH acts as a mediator for the genetic risk of disease activity. INTERPRETATION: This study uncovered a novel molecular pathway implicating the interaction between DNA methylation and genetic variation in the risk of disease activity in MS, emphasizing the role of sex hormones, particularly the AMH, in MS pathobiology. ANN NEUROL 2024.

Impact of COVID-19 on pregnancy and fetal outcomes in women with multiple sclerosis.

BACKGROUND: In the general population, maternal COVID-19 is associated with worse maternal and fetal outcomes. Two previous studies have assessed COVID-19 clinical outcomes in pregnant women with multiple sclerosis (MS), but there are no data about maternal and fetal outcomes. OBJECTIVES: In this multicenter study, we aimed to assess maternal and fetal outcomes in pregnant women with MS and COVID-19 infection. METHODS: We recruited pregnant patients with MS who contracted COVID-19 and were followed up in Italian and Turkish Centers, during 2020-2022. A control group was extracted from a previous Italian cohort. Associations between group (COVID-19 or healthy patients) and clinical outcomes (maternal complications, fetal malformations, and spontaneous abortion) were investigated with a weighted logistic regression where propensity score-based inverse probability of treatment weighting (IPTW) approach was applied for adjusting for difference in baseline confounders. RESULTS: In the multivariable analysis, COVID-19 during pregnancy was associated with a higher risk of maternal complications (odd ratio (OR) = 2.12; 95% confidence interval (CI) = 1.32-3.48; p = 0.002), while it was not associated with higher risk of spontaneous abortion and fetal malformations. CONCLUSION: Our data indicate that COVID-19 during pregnancy increases the risk of maternal complications, while it seems to have no significant impact on fetal outcomes.

Cognitive Impairment Is Related to Glymphatic System Dysfunction in Pediatric Multiple Sclerosis.

OBJECTIVE: The aim of this study was to investigate whether, compared to pediatric healthy controls (HCs), the glymphatic system is impaired in pediatric multiple sclerosis (MS) patients according to their cognitive status, and to assess its association with clinical disability and MRI measures of brain structural damage. METHODS: Sixty-five pediatric MS patients (females = 62%; median age = 15.5 [interquartile range, IQR = 14.5;17.0] years) and 23 age- and sex-matched HCs (females = 44%; median age = 14.1 [IQR = 11.8;16.2] years) underwent neurological, neuropsychological and 3.0 Tesla MRI assessment, including conventional and diffusion tensor imaging (DTI). We calculated the diffusion along the perivascular space (DTI-ALPS) index, a proxy of glymphatic function. Cognitive impairment (Co-I) was defined as impairment in at least 2 cognitive domains. RESULTS: No significant differences in DTI-ALPS index were found between HCs and cognitively preserved (Co-P) pediatric MS patients (estimated mean difference [EMD] = -0.002 [95% confidence interval = -0.069; 0.065], FDR-p = 0.956). Compared to HCs and Co-P patients, Co-I pediatric MS patients (n = 20) showed significantly lower DTI-ALPS index (EMD = -0.136 [95% confidence interval = -0.214; -0.058], FDR-p ≤ 0.004). In HCs, no associations were observed between DTI-ALPS index and normalized brain, cortical and thalamic volumes, and normal-appearing white matter (NAWM) fractional anisotropy (FA) and mean diffusivity (MD) (FDR-p ≥ 0.348). In pediatric MS patients, higher brain WM lesion volume (LV), higher NAWM MD, lower normalized thalamic volume, and lower NAWM FA were associated with lower DTI-ALPS index (FDR-p ≤ 0.016). Random Forest selected lower DTI-ALPS index (relative importance [RI] = 100%), higher brain WM LV (RI = 59.5%) NAWM MD (RI = 57.1%) and intelligence quotient (RI = 51.3%) as informative predictors of cognitive impairment (out-of-bag area under the curve = 0.762). INTERPRETATION: Glymphatic system dysfunction occurs in pediatric MS, is associated with brain focal lesions, irreversible tissue loss accumulation and cognitive impairment. ANN NEUROL 2024;95:1080-1092.

Fast but not furious: Rapid ocrelizumab infusion as a strategy to optimize multiple sclerosis patients' management.

OBJECTIVES: Multiple sclerosis clinicians are continuously challenged to be innovative in delivering therapies and there is ongoing pressure to maximize day-hospital vacancies. We describe our single-center experience with ocrelizumab (OCR) rapid infusion (OCR-RI) in patients with MS (pwMS). METHODS: For pwMS with prior exposure to OCR standard infusion (OCR-SI) for at least one year/two cycles, infusion time was reduced from 3.5 to 2.0 h. A comparative analysis between OCR-RI vs OCR-SI patients was conducted. RESULTS: 283 (76.7%) out of 369 OCR-treated pwMS performed OCR-RI; 86 subjects did not start OCR-RI due to infusion-related reactions (IRR) occurring with OCR-SI (n = 13) or OCR-treatment duration shorter than one year (n = 73). Disease duration was longer in OCR-RI (p < 0.001). Median numbers of overall-OCR and OCR-RI cycles were 7 (IQR = 5-8) and 4 (IQR = 2-5) (p < 0.001). Overall, 38 (10.3%) IRR were reported, 25 (8.8%) in OCR-RI and 13 (15.1%) in OCR-SI group. IRR frequency did not differ between the two groups (p = 0.106). IRR included throat irritation, rash, hypotension, fever and gastrointestinal symptoms. IRR severity was mild (81.6%) or moderate (18.4%), all resolved and did not differ in distribution between the two groups. When IRR occurred, infusions were temporarily stopped, hydration and/or symptomatic medications were given and infusions were subsequently resumed at standard velocity. OCR-RI was not a risk factor for IRR (OR 0.55, 95% CI: 0.27-1.13, p = 0.096). CONCLUSIONS: In our cohort, IRR frequency, severity and management were comparable to literature. No severe IRR were observed. RI protocols represent a strategy to optimize patients' management in the clinic.

COVID-19 has no impact on disease activity, progression and cognitive performance in people with multiple sclerosis: a 2-year study.

BACKGROUND: Sequelae of COVID-19 in people with multiple sclerosis (PwMS) have not been characterised. We explored whether COVID-19 is associated with an increased risk of disease activity, disability worsening, neuropsychological distress and cognitive dysfunction during the 18-24 months following SARS-COV-2 infection. METHODS: We enrolled 174 PwMS with history of COVID-19 (MS-COVID) between March 2020 and March 2021 and compared them to an age, sex, disease duration, Expanded Disability Status Scale (EDSS), and a line of treatment-matched group of 348 PwMS with no history of COVID-19 in the same period (MS-NCOVID). We collected clinical, MRI data and SARS-CoV2 immune response in the 18-24 months following COVID-19 or baseline evaluation. At follow-up, PwMS also underwent a complete neuropsychological assessment with brief repeatable battery of neuropsychological tests and optimised scales for fatigue, anxiety, depression and post-traumatic stress symptoms. RESULTS: 136 MS-COVID and 186 MS-NCOVID accepted the complete longitudinal evaluation. The two groups had similar rate of EDSS worsening (15% vs 11%, p=1.00), number of relapses (6% vs 5%, p=1.00), disease-modifying therapy change (7% vs 4%, p=0.81), patients with new T2-lesions (9% vs 11%, p=1.00) and gadolinium-enhancing lesions (7% vs 4%, p=1.00) on brain MRI. 22% of MS-COVID and 23% MS-NCOVID were cognitively impaired at 18-24 months evaluation, with similar prevalence of cognitive impairment (p=1.00). The z-scores of global and domain-specific cognitive functions and the prevalence of neuropsychiatric manifestations were also similar. No difference was detected in terms of SARS-CoV2 cellular immune response. CONCLUSIONS: In PwMS, COVID-19 has no impact on disease activity, course and cognitive performance 18-24 months after infection.

Choroid plexus and perivascular space enlargement in neuropsychiatric systemic lupus erythematosus.

Choroid plexus (CP) enlargement is proposed as a marker of neuroinflammation in immune-mediated conditions. CP involvement has also been hypothesized in the immunopathology of systemic lupus erythematosus (SLE). We investigated whether CP enlargement occurs in SLE patients and its association with neuropsychiatric involvement. Additionally, we explored abnormalities along the glymphatic system in SLE patients through enlarged perivascular space (PVS) quantification. Clinical assessment and 3 Tesla brain dual-echo and T1-weighted MRI scans were obtained from 32 SLE patients and 32 sex and age-matched healthy controls (HC). CPs were manually segmented on 3D T1-weighted sequence and enlarged PVS (ePVS) were assessed through Potter's score. Compared to HC, SLE patients showed higher normalized CP volume (nCPV) (p = 0.023), with higher CP enlargement in neuropsychiatric SLE (NPSLE) (n = 12) vs. non-NPSLE (p = 0.027) patients. SLE patients with antiphospholipid antibodies (APA) positivity (n = 18) had higher nCPV compared to HC (p = 0.012), while APA negative ones did not. SLE patients also had higher Potter's score than HC (p < 0.001), with a tendency towards a higher number of basal ganglia ePVS in NPSLE vs. non-NPSLE patients. Using a random forest analysis, nCPV emerged as a significant predictor of NPSLE, together with T2-hyperintense white matter (WM) lesion volume (LV) and APA positivity (out-of-bag AUC 0.81). Our findings support the hypothesis of a role exerted by the CP in SLE physiopathology, especially in patients with neuropsychiatric involvement. The higher prevalence of ePVS in SLE patients, compared to HC, suggests the presence of glymphatic system impairment in this population.

Effectiveness of Ocrelizumab in Primary Progressive Multiple Sclerosis: a Multicenter, Retrospective, Real-world Study (OPPORTUNITY).

Ocrelizumab is a recombinant humanized monoclonal antibody selectively targeting CD20-expressing B cells. The effect of ocrelizumab on primary progressive multiple sclerosis (PPMS) has been evaluated during phase 3 trials that enrolled patients under 55 years with a maximum Expanded Disability Status Scale (EDSS) of 6.5. However, little is known on older disabled patients with longer disease duration. We aimed to assess the clinical effectiveness of ocrelizumab in PPMS patients out of the ORATORIO eligibility criteria. This multicenter retrospective study collected data about the effectiveness of ocrelizumab in PPMS patients who received treatment between May 2017 and June 2022 in the Italian MS centers contributing to the Italian MS Registry who adhered to the Compassionate Use Program. The confirmed EDSS worsening (CEW) (defined as either a ≥ 1-point or ≥ 2-point increase in EDSS score from baseline that was confirmed at T12 and T24) was calculated. At the date of data extraction, out of 887 PPMS patients who had received ocrelizumab, 589 (mean age 49.7 ± 10.7 years, 242 (41.1%) females) were enrolled. The mean follow-up period was 41.3 ± 12.3 months. A total of 149 (25.3%) received ocrelizumab according to the ORATORIO criteria (ORATORIO group) and 440 (74.7%) outside the ORATORIO criteria (non-ORATORIO group). No differences in terms of cumulative probabilities of 12 and 24 months of CEW of ≤ 1 point were found between ORATORIO and non-ORATORIO groups. Cox regression analyses showed that age older than 65 years (HR 2.51, 25% CI 1.07-3.65; p = 0.01) was associated with higher risk of CEW at 24 months. Patients not responding to ORATORIO criteria for reimbursability may benefit from ocrelizumab treatment, as disease activity, disease duration, and EDSS seem to not impact the disability outcome. Our results may suggest to extend the possible use of this powerful agent in selected patients under the age of 65 years.

Clinical relevance of thymic and bone marrow outputs in multiple sclerosis patients treated with alemtuzumab.

Thymic and bone marrow outputs were evaluated in 13 sequential samples of 68 multiple sclerosis patients who initiated alemtuzumab and were clinically followed for 48 months. Three months after alemtuzumab infusions, the levels of new T lymphocytes were significantly reduced, but progressively increased reaching the highest values at 36 months, indicating the remarkable capacity of thymic function recovery. Newly produced B cells exceeded baseline levels as early as 3 months after alemtuzumab initiation. Heterogeneous patterns of new T- and B-cell recovery were identified, but without associations with age, sex, previous therapies, development of secondary autoimmunity or infections, and disease re-emergence. Trial registration version 2.0-27/01/2016.

Sars-CoV2 infection in pregnant women with multiple sclerosis.

BACKGROUND: In the general population, maternal SARS-CoV-2 infection during pregnancy is associated with worse maternal outcomes; however, only one study so far has evaluated COVID-19 clinical outcomes in pregnant and postpartum women with multiple sclerosis, showing no higher risk for poor COVID-19 outcomes in these patients. OBJECTIVE: In this multicenter study, we aimed to evaluate COVID-19 clinical outcomes in pregnant patients with multiple sclerosis. METHODS: We recruited 85 pregnant patients with multiple sclerosis who contracted COVID-19 after conception and were prospectively followed-up in Italian and Turkish Centers, in the period 2020-2022. A control group of 1354 women was extracted from the database of the Multiple Sclerosis and COVID-19 (MuSC-19). Univariate and subsequent logistic regression models were fitted to search for risk factors associated with severe COVID-19 course (at least one outcome among hospitalization, intensive care unit [ICU] admission and death). RESULTS: In the multivariable analysis, independent predictors of severe COVID-19 were age, body mass index ⩾ 30, treatment with anti-CD20 and recent use of methylprednisolone. Vaccination before infection was a protective factor. Vaccination before infection was a protective factor. Pregnancy was not a risk nor a protective factor for severe COVID-19 course. CONCLUSION: Our data show no significant increase of severe COVID-19 outcomes in patients with multiple sclerosis who contracted the infection during pregnancy.

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

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

HNF4α, SP1 and c-myc are master regulators of CNS autoimmunity.

Hepatocyte nuclear factor 4 α (HNF4α), a transcription factor (TF) essential for embryonic development, has been recently shown to regulate the expression of inflammatory genes. To characterize HNF4a function in immunity, we measured the effect of HNF4α antagonists on immune cell responses in vitro and in vivo. HNF4α blockade reduced immune activation in vitro and disease severity in the experimental model of multiple sclerosis (MS). Network biology studies of human immune transcriptomes unraveled HNF4α together with SP1 and c-myc as master TF regulating differential expression at all MS stages. TF expression was boosted by immune cell activation, regulated by environmental MS risk factors and higher in MS immune cells compared to controls. Administration of compounds targeting TF expression or function demonstrated non-synergic, interdependent transcriptional control of CNS autoimmunity in vitro and in vivo. Collectively, we identified a coregulatory transcriptional network sustaining neuroinflammation and representing an attractive therapeutic target for MS and other inflammatory disorders.

Effectiveness and safety profile of cladribine in an Italian real-life cohort of relapsing-remitting multiple sclerosis patients: a monocentric longitudinal observational study.

INTRODUCTION: Cladribine is approved for the treatment of active relapsing MS (RRMS), but its positioning in MS therapeutic scenario still needs to be fully elucidated. METHODS: This is a monocentric, observational, real-world study on RRMS patients treated with cladribine. Relapses, magnetic resonance imaging (MRI) activity, disability worsening, and loss of no-evidence-of-disease-activity-3 (NEDA-3) status were assessed as outcomes. White blood cell, lymphocyte counts and side effects were also evaluated. Patients were analyzed overall and in subgroups according to the last treatment before cladribine. The relationship between baseline characteristics and outcomes was tested to identify predictors of response. RESULTS: Among the 114 patients included, 74.9% were NEDA-3 at 24 months. We observed a reduction of relapses and MRI activity, along with a stabilization of disability. A higher number of gadolinium-enhancing lesions at baseline was the only risk factor for loss of NEDA-3 during follow-up. Cladribine was more efficacious in switchers from first-line therapies or naïves. Grade I lymphopenia was more frequent at month 3 and 15. No grade IV lymphopenia cases were observed. Independent predictors of grade III lymphopenia were a lower baseline lymphocyte count and a higher number of previous treatments. Sixty-two patients presented at least one side effect and globally 111 adverse events were recorded, none of them was serious. CONCLUSIONS: Our study confirms previous data on cladribine effectiveness and safety. Cladribine is more effective when placed early in the treatment algorithm. Real-world data on larger populations with longer follow-up are needed to confirm our findings.

Sexual Dysfunction in People with Multiple Sclerosis: The Role of Disease Severity, Illness Perception, and Depression.

Despite being a common issue in people with multiple sclerosis (pwMS), sexual dysfunction is still underinvestigated. This work aims to assess the potential determinants of sexual dysfunction in pwMS by considering its relationship with disease severity (in terms of global disability), illness perception, and depressive symptoms. In this multicenter study, 1010 pwMS responded to an online survey. A serial mediation model considering negative illness perception and depressive symptoms as mediators of the relationship between disease severity and sexual dysfunction was conducted using the SPSS PROCESS Macro with bias-corrected bootstrapping (5000 samples). Disease severity exerts an indirect effect on sexual dysfunction via illness perception, both independently and through depressive symptoms. However, the results indicated that illness perception plays a more crucial role in sexual dysfunction in pwMS with mild disability than in pwMS with moderate-severe disability. This study suggests that higher disability increases its magnitude by enhancing negative illness perception, that, in turn, affects sexual dysfunction both directly and through depressive symptoms, especially in pwMS with mild disability. Modulating the effect of illness perception by favoring adaptive coping strategies might represent a valid approach to mitigate sexual dysfunction symptoms in MS.

Modifiable risk factors of COVID-19 in patients with multiple sclerosis: a single-centre case-control study.

BACKGROUND: Disease and treatment-associated immune system abnormalities may confer higher risk of Coronavirus disease 2019 (COVID-19) to people with multiple sclerosis (PwMS). We assessed modifiable risk factors associated with COVID-19 in PwMS. METHODS: Among patients referring to our MS Center, we retrospectively collected epidemiological, clinical and laboratory data of PwMS with confirmed COVID-19 between March 2020 and March 2021 (MS-COVID, n = 149). We pursued a 1:2 matching of a control group by collecting data of PwMS without history of previous COVID-19 (MS-NCOVID, n = 292). MS-COVID and MS-NCOVID were matched for age, expanded disability status scale (EDSS) and line of treatment. We compared neurological examination, premorbid vitamin D levels, anthropometric variables, life-style habits, working activity, and living environment between the two groups. Logistic regression and Bayesian network analyses were used to evaluate the association with COVID-19. RESULTS: MS-COVID and MS-NCOVID were similar in terms of age, sex, disease duration, EDSS, clinical phenotype and treatment. At multiple logistic regression, higher levels of vitamin D (OR 0.93, p < 0.0001) and active smoking status (OR 0.27, p < 0.0001) emerged as protective factors against COVID-19. In contrast, higher number of cohabitants (OR 1.26, p = 0.02) and works requiring direct external contact (OR 2.61, p = 0.0002) or in the healthcare sector (OR 3.73, p = 0.0019) resulted risk factors for COVID-19. Bayesian network analysis showed that patients working in the healthcare sector, and therefore exposed to increased risk of COVID-19, were usually non-smokers, possibly explaining the protective association between active smoking and COVID-19. CONCLUSIONS: Higher Vitamin D levels and teleworking may prevent unnecessary risk of infection in PwMS.

Neural stem cell transplantation in patients with progressive multiple sclerosis: an open-label, phase 1 study.

Innovative pro-regenerative treatment strategies for progressive multiple sclerosis (PMS), combining neuroprotection and immunomodulation, represent an unmet need. Neural precursor cells (NPCs) transplanted in animal models of multiple sclerosis have shown preclinical efficacy by promoting neuroprotection and remyelination by releasing molecules sustaining trophic support and neural plasticity. Here we present the results of STEMS, a prospective, therapeutic exploratory, non-randomized, open-label, single-dose-finding phase 1 clinical trial ( NCT03269071 , EudraCT 2016-002020-86), performed at San Raffaele Hospital in Milan, Italy, evaluating the feasibility, safety and tolerability of intrathecally transplanted human fetal NPCs (hfNPCs) in 12 patients with PMS (with evidence of disease progression, Expanded Disability Status Scale ≥6.5, age 18-55 years, disease duration 2-20 years, without any alternative approved therapy). The safety primary outcome was reached, with no severe adverse reactions related to hfNPCs at 2-year follow-up, clearly demonstrating that hfNPC therapy in PMS is feasible, safe and tolerable. Exploratory secondary analyses showed a lower rate of brain atrophy in patients receiving the highest dosage of hfNPCs and increased cerebrospinal fluid levels of anti-inflammatory and neuroprotective molecules. Although preliminary, these results support the rationale and value of future clinical studies with the highest dose of hfNPCs in a larger cohort of patients.