Acute infusion effects in relapsing multiple sclerosis patients receiving alemtuzumab under a modified prophylaxis regimen.

BACKGROUND: Use of alemtuzumab in relapsing multiple sclerosis (RMS) is limited by safety concerns, notably risk of rare, serious vascular events. Along with other vital sign (VS) changes, acute increase in systolic blood pressure (SBP) is monitored as a marker of vascular risk. Peri-infusion prophylaxis is used to manage clinical risk by moderating cytokine release; protocols are not fully specified and vary across sites. Here, we report a modified prophylaxis regimen developed at Maritime Neurology. This single-center observational cohort study (NCT04633967) aimed to examine acute responses (VS events and infusion-associated reactions) in RMS patients receiving alemtuzumab infusion under this regimen. In a post hoc analysis, we examined incidence of acute SBP increase at this clinic versus the Bayshore network of Canadian infusion centers, where a standard prophylaxis regimen is used. METHODS: Alemtuzumab was infused on 5 consecutive days (Course 1; n = 29) and 3 consecutive days one year later (Course 2; n = 28). In addition to intravenous methylprednisolone 500mg on each infusion day, patients received daily prophylactic treatment with oral prednisone 50mg from 5 days before to 5 days after treatment (infusion days excepted) and oral H1 and H2 antihistaminics from 7 days before to 7 days after treatment. Excursions in SBP and other VS were relative to prespecified ranges; persistent excursions were those for which two sequential measurements were outside these ranges. In comparing VS events at Maritime Neurology and the Bayshore centers, acute SBP increase was defined as ≥20 mmHg increase in mean SBP, or any SBP reading ≥20% over patient's pre-course baseline. RESULTS: Mean (SD) VS were within range at pre-course and all other daily baselines. VS changes, including persistent excursions, were generally subclinical; all infusion-associated reactions were mild. One patient discontinued treatment after Course 1 due to immune thrombocytopenia purpura. Acute SBP increase occurred in 11/28 (39%) Maritime Neurology versus 367/610 (60%) Bayshore (p = 0.028). CONCLUSION: The modified peri-infusion prophylaxis regimen was well tolerated and may reduce incidence of acute SBP increase. FUNDING: This project was funded by Sanofi, Canada.

VAMP1 mutation causes dominant hereditary spastic ataxia in Newfoundland families.

Our group previously described and mapped to chromosomal region 12p13 a form of dominantly inherited hereditary spastic ataxia (HSA) in three large Newfoundland (Canada) families. This report identifies vesicle-associated membrane protein 1 (VAMP1), which encodes a critical protein for synaptic exocytosis, as the responsible gene. In total, 50 affected individuals from these families and three independent probands from Ontario (Canada) share the disease phenotype together with a disruptive VAMP1 mutation that affects a critical donor site for the splicing of VAMP1 isoforms. This mutation leads to the loss of the only VAMP1 isoform (VAMP1A) expressed in the nervous system, thus highlighting an association between the well-studied VAMP1 and a neurological disorder. Given the variable phenotype seen in the affected individuals examined here, we believe that VAMP1 should be tested for mutations in patients with either ataxia or spastic paraplegia.