A RANDOMIZED, DOUBLE BLIND, PLACEBO-CONTROLLED, PARALLEL-GROUP, MULTICENTER

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。本研究的主要目的是确定与添加安慰剂相比，在Avonex标准方案中添加那他珠单抗是否有效：-降低1年时的临床复发率和-减缓2年时的残疾进展，如通过以下指标测量的：扩展残疾状态量表（EDSS）较基线EDSS ≥ 1.0增加至少1.0分，持续12周或EDSS从基线EDSS = 0增加至少1.5点，持续12周。- 在1年时，确定在Avonex的标准方案中加入那他珠单抗与加入安慰剂相比是否有效：-减少脑磁共振成像（MRI）扫描中钆增强病变的数量; -减少脑MRI扫描中新的或新扩大的T2高信号病变的数量;和-增加无复发受试者的比例。- 在2年时，确定当与添加安慰剂相比时，将那他珠单抗添加到Avonex的标准方案中是否在以下方面有效：-降低临床复发率; -减弱脑MRI扫描上T1低信号病变数量的增加; -减弱脑MRI扫描上T2高信号病变体积的增加;- 减缓残疾的进展，如通过每个治疗组中多发性硬化功能复合量表（MSFC）的变化所确定的。MSFC包括定时25英尺步行、九孔桩测试（9 HPT）和3秒起搏听觉连续加法测试（PASAT 3）;在至少1200总患者-年的观察后，以及在所有留在研究中的受试者至少完成方案第24周访视后确定。在至少75%的受试者接受了120周的研究后确定。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The primary objective of this study are to determine whether adding natalizumab to the standard regimen of Avonex, when compared with adding placebo, is effective in: -reducing the rate of clinical relapses at 1 year and -slowing the progression of disability at 2 years, as measured by: at least a 1.0 point increase on the Expanded Disability Status Scale (EDSS) from baseline EDSS>= 1.0, that is sustained for 12 weeds or at least a 1.5 point increase on the EDSS from baseline EDSS = 0 that is sustained for 12 weeks. The secondary objectives of this study are: - at 1 year, to determine whether adding natalizumab to the standard regimen of Avonex when compared with adding placebo, is effective in: -reducing the number of gadolinium-enhancing lesions on brain magnetic resonance imaging (MRI) scans; -reducing the number of new or newly enlarging T2 hyperintense lesions on brain MRI scans; and -increasing the proportion of relapse-free subjects. -at 2 years, to determine whether adding natalizumab to the standard regimen of Avonex, when compared with adding placebo, is effective in: -reducing the rate of clinical relapses; -attenuating the increase in T1 hypointense lesion number on brain MRI scans; - attenuating the increase in T2 hyperintense lesion volume on brain MRI scans; - slowing the progression of disability, as determined by the change in the Multiple Sclerosis Functional Composite Scale (MSFC) in each treatment group. The MSFC consists of the Timed 25-Foot Walk, Nine-Hole Peg Test (9HPT), and 3-Second Paced Auditory Serial Addition Test (PASAT 3); and dtermined after at least 1200 total patient-years of observation, and after all subjects remaining in the study have completed at least the Week 24 visit of the protocol. determined after at least 75% of subjects have been studied for 120 weeks.