Biogen : MS Portfolio

MS Portfolio

Jerome Hanna, MB BCh BAO, MRCS, MFPM, Senior Medical Director

R&D Day

September 21, 2021

Forward-looking statements

This presentation contains forward-looking statements, including statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, relating to: our strategy and plans; potential of, and expectations for, our commercial business and pipeline programs; capital allocation and investment strategy; clinical development

programs, clinical trials, and data readouts and presentations; risks and uncertainties associated with drug development and commercialization; regulatory discussions, submissions, filings, and approvals and the timing thereof; the potential benefits, safety, and efficacy of our and our collaboration partners' products and investigational therapies; the anticipated benefits and potential of investments, collaborations, and business development activities; and our future financial and operating results. These forward-looking statements may be accompanied by such words as "aim," "anticipate," "believe," "could," "estimate," "expect," "forecast," "goal," "intend," "may," "plan," "potential," "possible," "prospect," "will," "would," and other words and terms of similar meaning. Drug development and commercialization involve a high degree of risk, and only a small number of research and development

programs result in commercialization of a product. Results in early-stage clinical trials may not be indicative of full results or results from later stage or larger scale clinical trials and do not ensure regulatory approval. You should not place undue reliance on these statements or the scientific data presented.

These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including: our dependence on sales from our products; uncertainty of long-term success in developing, licensing, or acquiring other product candidates or additional indications for existing products; failure to compete effectively due to significant product competition in the markets for our products; failure to successfully execute or realize the anticipated benefits of our strategic and growth initiatives;

difficulties in obtaining and maintaining adequate coverage, pricing, and reimbursement for our products; our dependence on collaborators, joint venture partners, and other third parties for the development, regulatory approval, and commercialization of products and other aspects of our business, which are outside of our full control; risks associated with current and potential future healthcare reforms; risks related to commercialization of biosimilars; failure to obtain, protect, and enforce our data, intellectual property, and other proprietary rights and the risks and uncertainties relating to intellectual property claims and challenges; the risk that positive results in a clinical trial may not be replicated in subsequent or confirmatory trials or success in early stage clinical trials may not be predictive of results in later stage or large scale clinical trials or trials in other potential indications;

risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; the occurrence of adverse safety events, restrictions on use with our products, or product liability claims; risks relating to the distribution and sale by third parties of counterfeit or unfit versions of our products; risks relating to the use of social media for our business; risks relating to technology failures or breaches; risks relating to management and key personnel changes, including attracting and retaining key personnel; failure to comply with legal and regulatory requirements; the risks of doing business internationally, including currency exchange rate

fluctuations; risks relating to investment in our manufacturing capacity; problems with our manufacturing processes; fluctuations in our effective tax rate; the direct and indirect impacts of the ongoing COVID-19 pandemic on our business, results of operations, and financial condition; fluctuations in our operating results; risks related to investment in properties; the market, interest, and credit risks associated with our investment portfolio; risks relating to share repurchase programs; risks relating to access to capital and credit markets; risks related to indebtedness; change in control provisions in certain of our collaboration agreements; environmental risks; and any other risks and uncertainties that are described in other reports we have filed with the U.S. Securities and Exchange Commission (SEC).

These statements are based on our current beliefs and expectations and speak only as of the date of this presentation. We do not undertake any obligation to publicly update any forward-looking statements.

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For >40 years, Biogen has been a pioneer in neuroscience and developing transformative treatments for multiple sclerosis

1978	1996	2004
Biogen is founded by a	Biogen launches AVONEX, the	TYSABRI, Biogen's highly
small group of visionary	first interferon treatment for RMS	efficacious MS product,
scientists		receives FDA approval

BIIB061

2014

2013

2013

2013

FAMPYRA,

2011

Biogen's

2016

Biogen launches

BIIB061 first in

Biogen acquires

TECFIDERA

symptomatic MS

AVONEX IM

PLEGRIDY, our

human dosing

full rights to

launches and

treatment, receives

FAMPYRA,

most recent MS

TYSABRI from

becomes the most

conditional EC

Pen approved

Orela-

Biogen's

portfolio addition

Elan

prescribed oral MS

approval

by the FDA

symptomatic MS

therapy

brutinib

treatment, receives

full EC approval

BIIB107

BIIB091

2017

2017

2018

2019

2019

2020

2020

2021

Biogen partners

Biogen acquires

Reinvigorated LCM

Biogen launches

BIIB091, reversible

BIIB107, novel anti-

EU approval of

US approval of plegridy IM,

with Siemens

global rights for

trials for TYSABRI

Vumerity

BTKi first in human

VLA4 agent first in

plegridy IM

EU approval of Tysabri SC,

Healthcare to

Vumerity from

and Biogen

dosing

human dosing

acquisition of BIIB128

develop advanced

Alkermes

platform

orelabrutinib), worldwide

MS MRI tools

treatments

filing activities of Vumerity

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The Biogen MS pipeline demonstrates leadership in RMS while expanding our footprint in PMS and Neurorepair

TRANSFORMATIVE

THERAPIES FOR RMS by developing agents with improved benefit risk profile

ADVANCE CARE IN

PROGRESSIVE DISEASE

by targeting CNS-

compartmentalized immune

cells

IMPROVE DISABILITY

AND RESTORE

FUNCTION

by targeting remyelination

and neurorepair

Hit ID	Lead ID	Lead OP	R2D	Phase 1	Phase 2	Phase 3	LCM

TYSABRI IV & SC

PLEGRIDY IM & SC

VUMERITYTM

TECFIDERA

AVONEX

BIIB091 (periphBTK)

BIIB107 (anti-VLA4)

Orelabrutinib

Undisclosed Asset

Undisclosed Asset

Undisclosed Asset

Undisclosed Asset

BIIB061

Undisclosed Asset

Undisclosed Asset

CNS = central nervous system; ID = identification; OP = optimization; R2D = research to development; IM = intra-muscular; LCM = lifecycle management; PMS = progressive multiple sclerosis; RMS = relapsing multiple sclerosis; SC = subcutaneous; IV = intravenous

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Multiple Sclerosis - pathophysiology

Overview

MS involves an immune-mediated process directed against the CNS

• Aberrant inflammatory response triggered
• Immune system cells attack CNS myelin and nerve fibers
• Demyelination, nerve dysfunction, and axonal loss occurs
• Nerve impulses traveling to / from brain and spinal cord are distorted or interrupted
• Clinically characterized by episodes of acute neurological worsening (relapses) and progressive disability accumulation

CNS = central nervous system

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