Anti-JCV Antibody Prevalence in Patients with Relapsing Multiple Sclerosis Receiving or Considering Treatment with Natalizumab: Baseline Results of STRATIFY-2 (S41.002)

Abstract

Objective: Determine the prevalence of anti-JC (JCV) antibodies in patients with relapsing multiple sclerosis (MS) using a 2-step anti-JCV antibody assay. Background JCV infection is a prerequisite for development of progressive multifocal leukoencephalopathy (PML). Assessing anti-JCV antibody status represents a means to determine JCV exposure and stratify PML risk in MS patients. Design/Methods: STRATIFY-2 is an ongoing, longitudinal, observational US study that is currently enrolling relapsing MS patients being treated or considering treatment with natalizumab. Serum is collected at baseline and annually thereafter for 2 years and tested for anti-JCV antibodies using a 2-step anti-JCV antibody assay. This interim analysis represents baseline data collected as of May 13, 2011. Results: At baseline (n=19,537), overall anti-JCV antibody prevalence was 54.7% (95% confidence interval [CI]: 54.0%–55.4%). Prevalence was lower in females (52.5% [95% CI: 51.7%–53.3%]) than in males (60.8% [95% CI: 59.4%−62.1%]) and increased with age ( Conclusions: STRATIFY-2 represents the largest data set to date to analyze anti-JCV antibody prevalence. Baseline results are consistent with other, smaller studies using this assay, which report anti-JCV antibody prevalence of 50%–60%. While anti-JCV antibody status was influenced by age and gender, natalizumab exposure use did not affect serostatus. Final study results will be used to assess PML incidence in anti-JCV antibody positive and negative MS patients. Supported by: Biogen Idec Inc. and Elan Pharmaceuticals, Inc. Disclosure: Dr. Bozic has received personal compensation for activities with Biogen Idec. Dr. Bozic holds stock and/or stock options in Biogen Idec, which sponsored research in which Dr. Bozic was involved as an investigator. Dr. Bozic holds stock and/or stock options in Biogen Idec. Dr. Richman has received personal compensation for activities with Biogen Idec as employees.Dr. Richman holds stock and/or options in Biogen Idec, which sponsored research in which Dr. Richman was involved as an investigator. Dr. Plavina has received personal compensation for activities with Biogen Idec as an employee.Dr. Plavina holds stock and/or stock options in Biogen Idec which sponsored research in which Dr. Plavina was involved as an investigator. Dr. Natarajan has received personal compensation for activities with Biogen Idec as an employee. Dr. Scanlon has received personal compensation for activities with Biogen Idec as an employee. Dr. Subramanyam has received personal compensation for activities with Biogen Idec as an employee. Dr. Subramanyam holds stock and/or stock options in Biogen Idec. Dr. Sandrock has received personal compensation for activities with Biogen Idec as an employee. Dr. Sandrock holds stock and/or stock options in Biogen Idec. Dr. Bloomgren has received personal compensation for activities with Biogen Idec as an employee.