United states securities and exchange commission

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54
capital expenditures of up to $170.0 million, primarily 
in 2018, and our goal is to redirect resources of up to 
$400.0 million annually by 2020 to prioritized 
research and development and other value creation 
opportunities.
Tax Reform
The 2017 Tax Act has resulted in significant 
changes to the U.S. corporate income tax system. 
These changes include a federal statutory rate 
reduction from 35% to 21%, the elimination or 
reduction of certain domestic deductions and credits 
and limitations on the deductibility of interest expense 
and executive compensation. The 2017 Tax Act also 
transitions international taxation from a worldwide 
system to a modified territorial system and includes 
base erosion prevention measures on non-U.S. 
earnings, which has the effect of subjecting certain 
earnings of our foreign subsidiaries to U.S. taxation 
as GILTI. These changes are effective beginning in 
2018.
The 2017 Tax Act also includes the Transition 
Toll Tax, which is a one-time mandatory deemed 
repatriation tax on accumulated foreign subsidiaries' 
previously untaxed foreign earnings. 
Changes in tax rates and tax laws are accounted 
for in the period of enactment. Therefore, during the 
year ended December 31, 2017, we recorded a 
charge totaling $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. The Transition Toll Tax will be paid 
over an eight-year period, starting in 2018, and will 
not accrue interest.
The 2017 Tax Act will provide us with flexibility in 
deploying our cash resources to advance our 
business interests. We expect that it will have a 
modest positive effect on our income tax rate in 2018 
and a potential incremental benefit thereafter.
Hemophilia Spin-Off
On February 1, 2017, we completed the spin-off 
of our hemophilia business, Bioverativ, as an 
independent, publicly traded company trading under 
the symbol "BIVV" on the Nasdaq Global Select 
Market. The spin-off was accomplished through the 
distribution of all the then outstanding shares of 
common stock of Bioverativ to Biogen shareholders, 
who received one share of Bioverativ common stock 
for every two shares of Biogen common stock they 
owned. The separation and distribution was 
structured to be tax-free for shareholders for federal 
income tax purposes. Bioverativ assumed all of our 
rights and obligations under our collaboration 
agreement with Sobi and our collaboration and 
license agreement with Sangamo.
Our consolidated results of operations and 
financial position included in this report reflect the 
financial results of our hemophilia business for all 
periods through January 31, 2017.
For additional information on the spin-off of our 
hemophilia business, please read Note 3, Hemophilia 
Spin-Off, to our consolidated financial statements 
included in this report.
Financial Highlights
Diluted earnings per share attributable to Biogen 
Inc. were $11.92 for 2017, representing a decrease 
of 29.6% versus the same period in 2016.
As described below under “Results of 
Operations,” our income from operations for the year 
ended December 31, 2017 reflects the following:
•  Total revenues were $12,273.9 million for 2017, 
representing an increase of 7.2% over the same 
period in 2016.
•  Product revenues, net totaled $10,354.7 million 
for 2017, representing an increase of 5.5% over 
the same period in 2016. This increase was 
primarily driven by revenues from SPINRAZA, 
TECFIDERA and BENEPALI, partially offset by the 
elimination of worldwide ALPROLIX and 
ELOCTATE revenues resulting from the spin-off of 
our hemophilia business on February 1, 2017 
and a net decrease in total Interferon sales. 

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•  Revenues from anti-CD20 therapeutic programs 
totaled $1,559.2 million for 2017, representing 
an increase of 18.6% over the same period in 
2016. This increase was primarily driven by 
royalty revenues on sales of OCREVUS and 
Biogen's share of pre-tax profits on RITUXAN.
•  Other revenues totaled $360.0 million for 2017, 
representing an increase of 13.8% from the 
same period in 2016. This increase was 
primarily driven by an increase in other royalty 
and corporate revenues.
•  Total cost and expenses totaled $6,929.7 
million for 2017, representing an increase of 
10.0%, compared to the same period in 2016. 
This increase was primarily driven by $444.2 
million of amortization and impairment charges 
related to our U.S. and rest of world licenses to 
Forward Pharma's intellectual property, including 
Forward Pharma's intellectual property related to 
TECFIDERA, a 14.2% increase in research and 
development primarily related to higher 
milestone and upfront expenses, a 10.2% 
increase in cost of goods sold, a $120.0 million 
pre-tax charge to acquired in-process research 
and development for an upfront payment made 
to Remedy upon the closing of the asset 
purchase transaction for BIIB093 and an 
increase in collaboration profit sharing. These 
increases were partially offset by a $454.8 
million litigation settlement charge in the prior 
year.
As described below under "Financial Condition, 
Liquidity and Capital Resources":
•  We generated $4,551.0 million of net cash flows 
from operations for 2017, which were primarily 
driven by earnings. 
•  Cash, cash equivalents and marketable 
securities totaled approximately $6,746.3 
million as of December 31, 2017.
•  We repurchased approximately 4.9 million 
shares of common stock at a cost of $1.4 billion 
during 2017 under our share repurchase 
programs. 
Acquisitions
BIIB093 Acquisition
In May 2017 we completed an asset purchase of 
the Phase 3-ready candidate BIIB093 (intravenous 
glibencamide) (formerly known as CIRARA) from 
Remedy. The target indication for BIIB093 is LHI, a 
severe form of ischemic stroke where cerebral edema 
often leads to a disproportionately large share of 
stroke-related morbidity and mortality. The FDA 
recently granted BIIB093 Orphan Drug Designation for 
severe cerebral edema in patients with acute 
ischemic stroke. The FDA has also granted BIIB093 
Fast Track designation.
Under this agreement, we are responsible for the 
future development and commercialization of 
BIIB093. Remedy will share in the cost of 
development for the target indication for BIIB093 in 
LHI stroke.
For additional information on our transaction with 
Remedy, please read Note 2, Acquisitions, to our 
consolidated financial statements included in this 
report.
Collaborative and Other Relationships
BIIB092 License Agreement
In June 2017 we completed an exclusive license 
agreement with BMS for BIIB092 (formerly known as 
BMS-986168), a Phase 2-ready experimental 
medicine with potential in AD and PSP. BIIB092 is an 
antibody targeting tau, the protein that forms the 
deposits, or tangles, in the brain associated with AD 
and other neurodegenerative tauopathies such as PSP. 
Under this agreement, we received worldwide 
rights to BIIB092 and are responsible for the full 
development and global commercialization of BIIB092 
in AD and PSP. 
For additional information on our collaboration 
arrangement with BMS, please read Note 20, 
Collaborative and Other Relationships, to our 
consolidated financial statements included in this 
report.
Eisai Collaboration Agreement
In October 2017 we entered into a new 
collaboration agreement with Eisai for the joint 
development and commercialization of aducanumab 
(the Aducanumab Collaboration Agreement). Under 
the Aducanumab Collaboration Agreement, we will 
continue to lead the ongoing Phase 3 development of 
aducanumab and will remain responsible for 100% of 
development costs for aducanumab until April 2018. 
Eisai will then reimburse us for 15% of aducanumab 
development expenses for the period April 2018 
through December 2018, and 45% thereafter. Upon 
commercialization, both companies will co-promote 
aducanumab with a region-based profit split.
In addition, we and Eisai will continue to jointly 
develop BAN2401 and E2609.
We and Eisai will co-promote AVONEX, TYSABRI 
and TECFIDERA in Japan in certain settings and Eisai 
will distribute AVONEX, TYSABRI, TECFIDERA and 
PLEGRIDY in India and other Asia-Pacific markets, 
excluding China.

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