ABSTRACT
Introduction: Many patients treated with Natalizumab experience end of dose interval (EDI) symptoms towards the end of the administration cycle. Objectives and aims: During the pandemic, to minimize patients accesses to the hospital and reduce exposure to Sars-CoV-2, we advised and asked patients undergoing treatment with Natalizumab if they wanted to be shifted from a Standard Interval Dosing (SID of 4 weeks) to and Extended Interval Dosing (EID of 5-6 weeks), regardless of their JCV index. Our main objective was to study prevalence and incidence of End of Dosing Interval (EDI) symptoms when Extended Interval Dosing (EID) was adopted, considering the variable prevalence of the wearing off effect. Method(s): We enrolled 87 patients, from May 2020 to January 2021, evaluated at baseline and during a 6 months follow-up with a survey focused on End of Dosing Interval Symptoms(EDIs), Fatigue Severity Scale (FSS), Expanded Disability Status Scale (EDSS) and Magnetic Resonance Imaging. Result(s): Among the 87 patients, 32(36.8%) reported End of Dose Interval (EDI) symptoms. Most common EDI symptom was fatigue (93.7%). Of note, among the patients with an EID (71), 16.9% patients reported a new onset of fatigue, where none was present before adopting the EID. Mean EDSS was higher in the group reporting EDI symptoms (3.6 EDI vs 2.2 non-EDI, p<0.05).Sphincterial functions were the ones that differed the most between the EDIsymptoms group and the non-EDI-symptoms group (1.4 EDIs vs 0.62 non-EDIs, p<0.05), among EDSS different components. Conclusion(s): The present study confirms that fatigue is the most common Natalizumab wearing-off symptom and 16.9% of patients develop a new onset of fatigue adopting an EID. Interestingly, there is a strong correlation between higher EDSS and fatigue in an EID setting. An increase of people suffering from fatigue is to be expected after adopting an EID, especially in the people with a higher EDSS and impairment of sphincterial functions. EID in our study does not compromise safety and efficacy of Natalizumab.
ABSTRACT
Background and aims: Many patients treated with Natalizumab experience End of Dose Interval (EDI) symptoms towards the end of the administration cycle. During the pandemic, due to the unknown effects of SARS-CoV-2 infection on patients undergoing treatment with Natalizumab (NTZ), we decided to shift patients on NTZ from a Standard Interval Dosing (SID of 4 weeks) to an Extended Interval Dosing (EID of 5–6 weeks). Our main objective was to study the prevalence and incidence of EDI symptoms in our MS center, along with its efficacy and safety. Methods We reviewed 102 patients in our MS center treated with natalizumab for at least 12 months using EID. When tolerated/possible, patients were shifted from a SID of 4 weeks to an EID of 5–6 weeks. Patients were asked to report any worsening of their symptoms during the administration cycle, fatigue was assessed right before the administration of NTZ, with surveys and Fatigue Severity Scale (FSS). Results: Among the 102 patients, 41 (40.19%) reported end of dose interval (EDI) symptoms, and the most common one was fatigue. Among those 41 patients: 26 (63%) had a Relapsing Remitting (RR) course while 15 (37%) had a Secondary Progressive (SP) course. Of note, 15 (36.58%) patients reported a new onset of fatigue where none was present before the EID. Our data suggest that with EID efficacy is still preserved since only 6 patients showed new lesions on follow-up-MRI and with little clinical significance. Conclusions: Our study shows that when EID was adopted, fatigue was higher in the RR course group, with efficacy still preserved.