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6
•  In October 2017 we presented data supporting opicinumab as a potential therapy to repair damage to the 
central nervous system caused by MS. These data were presented at the seventh Joint Meeting of the 
European Committee for Treatment and Research in MS and Americas Committee for Treatment and Research 
in MS (ECTRIMS-ACTRIMS).
Neuromuscular Disorders
SPINRAZA (nusinersen)
•  In January 2017 we presented new data from the Phase 3 ENDEAR study of SPINRAZA, which demonstrated a 
statistically significant reduction in the risk of death or permanent ventilation in SPINRAZA-treated infants with 
SMA compared to untreated infants. The data were presented at the British Pediatric Neurology Association 
annual conference in Cambridge, U.K.
•  In April 2017 the CHMP of the EMA adopted a positive opinion recommending the granting of a marketing 
authorization in the E.U. for SPINRAZA to treat patients with SMA.
•  In April 2017 we presented Phase 3 end of study SPINRAZA data from CHERISH, which demonstrated a highly 
statistically significant and clinically meaningful improvement in motor function in children with later-onset 
(most likely to develop Type 2 or Type 3) SMA compared to untreated children. The overall findings continued to 
support the efficacy and favorable safety profile of SPINRAZA across a broad range of individuals with SMA.  
We also presented interim data from the Phase 2 NURTURE study evaluating SPINRAZA for the treatment of 
infants under six weeks old with genetically diagnosed SMA who were presymptomatic at treatment initiation. At 
the time of the interim analysis, infants (n=20) were enrolled for a median of 317.5 days, and all infants were 
alive and none required respiratory intervention (chronic non-invasive ventilation, invasive ventilation or 
tracheostomy). Further, most infants achieved motor milestone and growth parameter gains generally 
consistent with normal development, such as head control, independent sitting, standing and walking 
independently, as measured by validated scales.
These data were presented at the 69
th
 annual meeting of AAN in Boston, MA.
•  In June 2017 the EC granted a marketing authorization for SPINRAZA for the treatment of 5q SMA in pediatric 
and adult patients in the E.U. SPINRAZA is the first approved treatment in the E.U. for SMA. SPINRAZA was 
reviewed under the EMA’s accelerated assessment program.
•  In June 2017 we presented robust efficacy and safety data from Phase 2 and Phase 3 SPINRAZA studies at the 
Cure SMA 2017 Annual SMA Conference in Orlando, FL. Data demonstrated motor function improvements in 
infants on permanent ventilation and no increase in the risk of adverse events in children with scoliosis.
•  In July 2017 the Japanese Ministry of Health, Labor and Welfare approved the use of SPINRAZA for the 
treatment of infantile SMA.
•  In September 2017 the Japanese Ministry of Health, Labor and Welfare approved the use of SPINRAZA for the 
treatment of pediatric and adult patients with SMA.
•  In October 2017 we presented new data at the 22
nd
 International Congress of the World Muscle Society 
demonstrating that earlier initiation of treatment with SPINRAZA may improve motor function outcomes in 
infants and children with SMA. Results demonstrated the favorable efficacy and safety profile of SPINRAZA.
•  In October 2017 we and Ionis were awarded the 2017 Prix Galien USA Award for Best Biotechnology Product for 
SPINRAZA.
•  In November 2017 the end of study results from ENDEAR, the Phase 3 study of SPINRAZA, were published in 
The New England Journal of Medicine.
Alzheimer's Disease and Dementia
Aducanumab (BIIB037)
•  In March 2017 we presented data from research of aducanumab at the 13
th
 International Conference on 
Alzheimer’s and Parkinson’s Diseases (AD/PD™) in Vienna, Austria.
•  In April 2017 we presented data from a Phase 1b study of aducanumab at the 69
th
 annual meeting of the AAN 
in Boston, MA. This data was previously presented at the Clinical Trials on Alzheimer’s Disease (CTAD) meeting 

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in December 2016 and included interim results from the titration cohort of the placebo-controlled period of the 
Phase 1b study as well as data from the first year of the long-term extension (LTE).
•  In May 2017 we announced that we had amended the protocol of the Phase 3 trials of aducanumab. ApoE4 
carriers that previously would be on a high dose of 6 mg/kg may now be titrated up to 10 mg/kg. This 
amendment is being reviewed by regulatory bodies and clinical study ethic independent review boards globally 
and may be implemented on a country by country basis. The change has already been incorporated in the U.S.
•  In July 2017 we presented a new post-hoc analysis of the Phase 1b PRIME study of aducanumab at the 
Alzheimer’s Association International Conference in London, U.K. Data presented included changes in the 
cognitive and functional subscores of the clinical dementia rating score. Aducanumab slowed decline on both 
the cognitive and functional assessments compared to placebo, and the results of all subgroups studied were 
consistent with the overall study population.
•  In August 2017 we announced results from a recently conducted analysis of the LTE of our ongoing Phase 1b 
study of aducanumab. The updated analyses include data from the placebo-controlled period and the LTE for 
patients treated with aducanumab up to 24 months in the titration cohort and up to 36 months in the fixed-
dose cohorts. The results are consistent with previously reported analyses from this ongoing Phase 1b study 
and support the design of the ongoing Phase 3 studies of aducanumab for early AD.
•  In November 2017 we presented new data from the LTE of our ongoing Phase 1b study of aducanumab at the 
CTAD meeting in Boston, MA. The data included results from patients in the Phase 1b study who were treated 
with a gradually increased dose of aducanumab for up to 24 months and those who were treated with a fixed 
dose of 3, 6 or 10 mg/kg aducanumab for up to 36 months. The results are consistent with previously reported 
analyses from the Phase 1b study and support the design of the ongoing Phase 3 studies of aducanumab for 
early AD.
BAN2401 (A  mAb)
•  In December 2017 we announced that an Independent Data Monitoring Committee determined that BAN2401 
did not meet the criteria for success based on a Bayesian analysis at 12 months as the primary endpoint in an 
856-patient Phase 2 clinical study. Following the predefined study protocol, the blinded study will continue and 
a comprehensive final analysis will be conducted at 18 months seeking to demonstrate clinically significant 
results. The results of the final analysis are expected to be obtained during the second half of 2018.
BIIB076
•  In January 2017 we initiated a Phase 1 trial of BIIB076, an anti-tau monoclonal antibody, in healthy volunteers 
and participants with AD.
BIIB092
•  In June 2017 we dosed our first patient in our Phase 2 study of BIIB092 for PSP.
BIIB080 (also known as Ionis-MAPT
Rx
)
•  In October 2017 our collaboration partner Ionis announced the initiation of a Phase 1/2a clinical study of 
IONIS-MAPT
Rx
 in patients with mild AD. IONIS-MAPT
Rx
 is an antisense drug designed to selectively reduce the 
production of microtubule-associated protein tau (MAPT), or tau protein, in the brain. We have an option to 
develop and commercialize IONIS-MAPT
Rx
.
Movement Disorders
BIIB054 (anti-alpha-synuclein antibody)
•  In March 2017 we presented data from research of BIIB054, our investigational treatment for Parkinson’s 
disease, at the 13
th
 International Conference on Alzheimer’s and Parkinson’s Diseases (AD/PD™) in Vienna, 
Austria.
•  In July 2017 we completed enrollment in the Phase 1 study of BIIB054 in both healthy volunteers and patients 
with early onset Parkinson’s disease.
•  In January 2018 we dosed our first patient in our Phase 2 SPARK study of BIIB054 in Parkinson's disease.

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