United states securities and exchange commission

Table of Contents
52
settlement and license agreement with Forward Pharma and related intangible assets, please read Note 7, 
Intangible Assets and Goodwill, to our consolidated financial statements included in this report.
(d)  Income tax expense for the year ended December 31, 2017, includes $1,173.6 million related to our current 
estimate of the provisions of the 2017 Tax Act, including a $989.6 million expense under the Transition Toll Tax. 
For additional information on the 2017 Tax Act, please read Note 17, Income Taxes, to our consolidated 
financial statements included in this report.
(e)  Total cost and expenses for the years ended December 31, 2017, 2016 and 2015, include restructuring 
charges of $0.9 million, $33.1 million and $93.4 million, respectively. In addition, total cost and expenses for 
the year ended December 31, 2016, also include charges to cost of sales totaling $52.4 million of expenses 
incurred as a result of our determination to cease manufacturing and vacate our small-scale biologics facility in 
Cambridge, MA as well as close and vacate our warehouse in Somerville, MA. Total cost and expenses for the 
years ended December 31, 2017 and 2016, also includes $19.2 million and $18.1 million, respectively, of 
costs incurred directly related to the spin-off of our hemophilia business into an independent, publicly traded 
company. 
(f)  Net income attributable to Biogen Inc. for the year ended December 31, 2015, includes a pre-tax charge to 
noncontrolling interest of $60.0 million for a milestone payment due to Neurimmune upon the enrollment of the 
first patient in a Phase 3 trial for aducanumab.
(g)  Commencing in the second quarter of 2013 product and total revenues include 100% of net revenues related 
to sales of TYSABRI as a result of our acquisition of all remaining rights to TYSABRI from Elan Pharma 
International, Ltd (Elan), an affiliate of Elan Corporation, plc. Upon closing of this transaction, our collaboration 
agreement was terminated. 

---

Table of Contents
53
Item 7.  
Management’s Discussion and 
Analysis of Financial Condition and Results 
of Operations
The following discussion should be read in 
conjunction with our consolidated financial 
statements and related notes beginning on page F-1 
of this report. Certain totals may not sum due to 
rounding.
Executive Summary
Introduction
Biogen is a global biopharmaceutical company 
focused on discovering, developing and delivering 
worldwide innovative therapies for people living with 
serious neurological and neurodegenerative diseases, 
including in our core growth areas of MS and 
neuroimmunology, AD and dementia, movement 
disorders and neuromuscular disorders, including 
SMA and ALS. We also plan to invest in emerging 
growth areas such as pain, ophthalmology, 
neuropsychiatry and acute neurology. In addition, we 
are employing innovative technologies to discover 
potential treatments for rare and genetic disorders, 
including new ways of treating diseases through gene 
therapy in the previously mentioned areas. We also 
manufacture and commercialize biosimilars of 
advanced biologics.
Our marketed products include TECFIDERA, 
AVONEX, PLEGRIDY, TYSABRI, ZINBRYTA and FAMPYRA 
for the treatment of MS, SPINRAZA for the treatment 
of SMA and FUMADERM for the treatment of severe 
plaque psoriasis. We also have certain business and 
financial rights with respect to RITUXAN for the 
treatment of non-Hodgkin's lymphoma, CLL and other 
conditions, GAZYVA for the treatment of CLL and 
follicular lymphoma, OCREVUS for the treatment of 
PPMS and RMS, and other potential anti-CD20 
therapies under a collaboration agreement with 
Genentech.
Our current revenues depend upon continued 
sales of our principal products and, unless we 
develop, acquire rights to and/or commercialize new 
products and technologies, we may be substantially 
dependent on sales from our principal products for 
many years. 
In the longer term, our revenue growth will be 
dependent upon the successful clinical development, 
regulatory approval and launch of new commercial 
products as well as additional indications for our 
existing products, our ability to obtain and maintain 
patents and other rights related to our marketed 
products, assets originating from our research and 
development efforts and/or successful execution of 
external business development opportunities.
Our innovative drug development and 
commercialization activities are complemented by our 
biosimilar therapies, which expand access to 
medicines and reduce the cost burden for healthcare 
systems. We are leveraging our manufacturing 
capabilities and know-how to develop, manufacture 
and market biosimilars through Samsung Bioepis, our 
joint venture with Samsung Biologics. Under our 
commercial agreement, we market and sell BENEPALI, 
an etanercept biosimilar referencing ENBREL, and 
FLIXABI, an infliximab biosimilar referencing 
REMICADE, in the E.U.
2017 Corporate Strategy
In July 2017 we announced an updated strategic 
framework to optimize the value of our MS business 
while investing for the future across our core growth 
areas of MS and neuroimmunology, AD and dementia, 
movement disorders, and neuromuscular diseases, 
including SMA and ALS. We also plan to invest in 
emerging growth areas such as pain, ophthalmology, 
neuropsychiatry, and acute neurology. 
We expect the continued performance of our 
commercial assets and the expiration of the 
contingent payments related to TECFIDERA, discussed 
further in the “Contractual Obligations and Off-Balance 
Sheet Arrangements” section of this report, to enable 
us to invest in and build an industry leading 
neuroscience pipeline. We view investment in growth 
as our top priority, but also recognize the value of 
opportunistically returning excess capital to 
shareholders through share repurchases.
In order to deliver positive results in the near 
term while investing in the next stages of our growth, 
we will focus on the following strategic priorities:
•  maximizing the resilience of our MS core 
business;
•  accelerating efforts in SMA as a significant new 
growth opportunity;
•  developing and expanding our neuroscience 
portfolio;
•  focusing our capital allocation efforts to drive 
investment for future growth; and
•  creating a leaner and simpler operating model to 
streamline our operations and reallocate 
resources towards prioritized research and 
development and commercial value creation 
opportunities.
In October 2017, in connection with creating a 
leaner and simpler operating model, we approved a 
corporate restructuring program intended to 
streamline our operations and reallocate resources. 
We expect to make total non-recurring operating and 

---