ACQUISITION OF AUDENTES

Establishing a leading position in gene therapy

Naoki Okamura

Representative Director, Corporate Executive Vice President,

Chief Strategy Officer and Chief Financial Officer

Astellas Pharma Inc.

December 3, 2019

This document contains “forward-looking statements” relating to the acquisition of Audentes by Astellas. Such forward-looking statements include, but are not limited to, the ability of Audentes and

Astellas to complete the transactions contemplated by the merger agreement, including the parties’ ability to satisfy the conditions to the consummation of the offer contemplated thereby and the other

conditions set forth in the merger agreement, statements about the expected timetable for completing the transaction, Astellas’ and Audentes’ beliefs and expectations and statements about the

benefits sought to be achieved in Astellas’ proposed acquisition of Audentes, the potential effects of the acquisition on both Astellas and Audentes, the possibility of any termination of the merger

agreement, as well as the expected benefits and success of Audentes’ product candidates, the timing and nature of regulatory filings for Audentes’ product candidates, the timing of Audentes’

presentation of non-clinical data and the timing and nature of Audentes’ preclinical studies, clinical trials and manufacturing activities. In some cases, forward-looking statements may be identified by

terminology such as “believe,” “may,” “will,” “should”, “predict”, “goal”, “strategy”, “potentially,” “estimate,” “continue,” “anticipate,” “intend,” “could,” “would,” “project,” “plan,” “expect,” “seek” and similar

expressions and variations thereof. These words are intended to identify forward-looking statements. Astellas and Audentes have based these forward-looking statements on current expectations and

projections about future events and trends that they believe may affect the financial condition, results of operations, business strategy, short-term and long-term business operations and objectives

and financial needs of Astellas and Audentes, but there can be no guarantee that such expectations and projections will prove accurate in the future.

All statements other than statements of historical fact are statements that could be deemed forward-looking statements. Actual results may differ materially from current expectations because of risks

associated with uncertainties as to the timing of the offer and the subsequent merger; uncertainties as to how many of Audentes’ stockholders will tender their shares in the offer; the risk that

competing offers or acquisition proposals will be made; the possibility that various conditions to the consummation of the merger and the offer contemplated thereby may not be satisfied or waived;

the effects of disruption from the transactions contemplated by the merger agreement on Audentes’ business and the fact that the announcement and pendency of the transactions may make it more

difficult to establish or maintain relationships with employees, suppliers and other business partners; and the risk that stockholder litigation in connection with the offer or the merger may result in

significant costs of defense, indemnification and liability. Moreover, Astellas and Audentes operate in very competitive and rapidly changing environments, and new risks emerge from time to time.

Although Astellas and Audentes believe that the expectations reflected in such forward-looking statements are reasonable, they cannot guarantee future events, results, actions, levels of activity,

performance or achievements, business and market conditions, the timing and results of biotechnology development and potential regulatory approval and whether the conditions to the closing of the

proposed transaction are satisfied on the expected timetable or at all. Forward-looking statements are also subject to risks and uncertainties pertaining to the business of Audentes, including those set

forth in the “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of Audentes’ Annual Report on Form 10-K for the year ended

December 31, 2018, and Quarterly Report on Form 10-Q for the quarter ended September 30, 2019, which are on file with the SEC and available on the SEC’s website at www.sec.gov. In addition to

the risks described above and in Audentes’ other filings with the SEC, other unknown or unpredictable factors could also affect Audentes’ results. No forward-looking statements can be guaranteed

and actual results may differ materially from such statements. The information contained in this document is provided only as of the date hereof, and no party undertakes any obligation to revise or

update any forward-looking statements to reflect events or circumstances after the date hereof, except as required by law.

The tender offer for the outstanding shares of common stock of Audentes has not yet commenced. This communication is for informational purposes only and is neither an offer to purchase nor a

solicitation of an offer to sell shares of Audentes common stock, nor is it a substitute for the tender offer materials that Astellas and its acquisition subsidiary will file with the SEC upon commencement

of the tender offer. At the time the tender offer is commenced, Astellas will file a tender offer statement on Schedule TO with the SEC, and thereafter Audentes will file a solicitation/recommendation

statement on Schedule 14D-9 with respect to the offer. THE TENDER OFFER STATEMENT (INCLUDING AN OFFER TO PURCHASE, A RELATED LETTER OF TRANSMITTAL AND OTHER

OFFER DOCUMENTS) AND THE SOLICITATION / RECOMMENDATION STATEMENT WILL CONTAIN IMPORTANT INFORMATION THAT SHOULD BE READ CAREFULLY AND CONSIDERED

BY AUDENTES’ STOCKHOLDERS BEFORE ANY DECISION IS MADE WITH RESPECT TO THE TENDER OFFER. Both the tender offer statement and the solicitation/recommendation statement

will be mailed to Audentes’ stockholders free of charge. A free copy of the tender offer statement and the solicitation/recommendation statement will also be made available to all stockholders of

Audentes by contacting Audentes at [email protected] or by phone at (415) 818-1033. In addition, the tender offer statement, the related letter of transmittal and certain other tender offer

documents and the solicitation/recommendation statement (and all other documents filed with the SEC) will be available at no charge on the SEC’s website: www.sec.gov, upon filing with the SEC. In

addition to these documents, Audentes files annual, quarterly and current reports and other information with the SEC. These filings with the SEC are also available to the public for free at the SEC’s

website at www.sec.gov. In addition, the solicitation/recommendation statement and the other documents filed by the Audentes with the SEC are available to all stockholders of Audentes free of

charge at http://investors.audentestx.com/sec-filings.

AUDENTES’ STOCKHOLDERS ARE ADVISED TO READ THE SCHEDULE TO AND THE SCHEDULE 14D-9 CAREFULLY, AS EACH MAY BE AMENDED OR SUPPLEMENTED FROM TIME TO

TIME, AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC WHEN THEY BECOME AVAILABLE BEFORE THEY MAKE ANY DECISION WITH RESPECT TO THE TENDER OFFER,

BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND THE PARTIES THERETO, AS WELL AS IMPORTANT INFORMATION THAT

HOLDERS OF SHARES OF AUDENTES’ COMMON STOCK SHOULD CONSIDER BEFORE MAKING ANY DECISION REGARDING TENDERING THEIR SHARES.

Important Additional Information

Cautionary Notice Regarding Forward-Looking Statements

AGENDA

Transaction Summary

III

Overview of Audentes

Strategic Rationale

TRANSACTION SUMMARY

Party

•

Audentes Therapeutics, Inc. (San Francisco); Listed on NASDAQ

Purchase

Price

•

$60.00 per share in cash

•

Premium of 110% to Audentes’ closing share price of $28.61 on

December 2, 2019

Acquisition

Amount*

•

Approximately $3 billion

Acquisition Method

•

Asilomar Acquisition Corp., a wholly-owned subsidiary of Astellas

Holding, Inc.,

will commence a tender offer for all outstanding shares

of Audentes

Financing

• Acquisition amount will be financed utilizing existing loan facilities as

bridge finance

Others

• Transaction unanimously approved by the boards of directors of both

companies

• The acquisition is expected to close during the first calendar quarter

2020, subject to customary closing conditions, including US antitrust

clearance and the tender of a majority of Audentes’ outstanding

shares of common stock

*Acquisition amount reflects amounts required to purchase all common shares, options, restricted stock units and other securities

AGENDA

Transaction Summary

III

Overview of Audentes

Strategic Rationale

COMPANY OVERVIEW

Audentes Therapeutics, Inc.

 Headquartered in San Francisco, California

 Founded in 2012; IPO on NASDAQ in July 2016

 Clinical-stage AAV-based gene therapy company focusing on rare

neuromuscular diseases

 Experienced management

 Of total 270 employees, 220 engage in R&D and manufacturing

AAV: Adeno-Associated Virus

KEY GENE THERAPY SUCCESS FACTORS

Lead Program Establishes Clinical

Proof-of-Concept for Audentes’

Know-how and Platform

AT132 for XLMTM is

in Phase 1/2 clinical stage

AAV Technology Platform

Proprietary drug design,

manufacturing, and development

capabilities enables efficient drug

development

Audentes’ Outstanding Capability

Large-scale cGMP

Manufacturing Capability

Fully integrated, in-house

cGMP manufacturing enables

agile & flexible R&D.

Commercial production

for XLMTM is ongoing

XLMTM : X-Linked Myotubular Myopathy

AT132 PROGRAM OVERVIEW

RMAT: Regenerative Medicine Advanced Therapy, BLA: Biologic License Application, MAA: Marketing Authorization Application

XLMTM : X-Linked Myotubular Myopathy

Product

XLMTM

Regulatory

 AAV8 capsid; Desmin promoter

 One-time, systemic dose

 Gene replacement of MTM1 gene encoding

myotubularin in muscle cells

 X-linked, loss of function mutations in MTM1 gene

 Rare disease; Estimated 50% mortality by 18 months

 >80% require ventilator support

 Motor milestones are substantially delayed

 No treatment available; supportive care only

 RMAT, Rare Pediatric Disease, Fast Track and Orphan

Drug designations by FDA;

 PRIME and Orphan Drug designations by EMA

 BLA and MAA submissions planned at the earliest

in mid-2020 and 2H2020, respectively

AT132 PHASE 1/2 ASPIRO STUDY

Inclusion

Criteria

Assessment

Dose

 Male subjects (<5 yrs old)

 Genetically confirmed XLMTM

 Requires ventilator support

 Safety and tolerability

 Neuromuscular function: CHOP INTEND, Developmental milestones

 Respiratory function: MIP and Ventilator use

 Cohort 1: 1 x 10

vg/kg (6 Treated / 1 Delayed Control)

 Cohort 2: 3 x 10

vg/kg (6 Treated / 1 Delayed Control)

CHOP INTEND: Children’s Hospital of Philadelphia infant Test of Neuromuscular Disorders

MIP: maximal inspiratory pressure

XLMTM : X-Linked Myotubular Myopathy

AT132 PHASE 1/2 ASPIRO STUDY

Presented in 24

International Annual Congress of the

World Muscle Society (Oct 1-5, 2019)

Age (years)

Only Patient 2 was able to sit unassisted for 30 seconds at baseline,

Patient 3 not evaluable because of halo traction device

Treated patients are achieving the ability to raise self to standing position,

walk with support or walk alone

Interim data as of August 7, 2019

AT132 PHASE 1/2 ASPIRO STUDY

Treated patients showed rapid and sustained increase in CHOP INTEND Score

CHOP INTEND: Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders

LS: least squares means estimated with Repeated Measures ANOVA Model

Bars indicate standard error, SD: Standard deviation

Weeks after ASPIRO baseline

Change from baseline in

CHOP INTEND score (LS means)

Interim data as of August 7, 2019

Presented in 24

International Annual Congress of the

World Muscle Society (Oct 1-5, 2019)

Neuromuscular Functions (CHOP-INTEND Score)

Treated (N=10)

Control (N=2)

AT132 PHASE 1/2 ASPIRO STUDY

Treated (N=10)

Control (Patient 4)

Control (Patient 11)

Ventilator use

Treated patients have achieved mean reductions in ventilator dependence

nearing 20 hours per day

Weeks after ASPIRO baseline

Presented in 24

International Annual Congress of the

World Muscle Society (Oct 1-5, 2019)

LS: least squares means estimated with Repeated Measures ANOVA Model

Bars indicate standard error, SD: standard derivation

Interim data as of August 7, 2019

Baseline:

>12 hours

ventilator

dependence

Reduction

in ventilator

dependence over

24 hours (h)

(LS means)

AT132 PHASE 1/2 ASPIRO STUDY

Increased respiratory muscle strength (MIP) observed as early as 4 weeks

Respiratory Functions (MIP)

Change from baseline in

MIP (cm H

O) (LS means)

Weeks after ASPIRO baseline

Interim data as of August 7, 2019

Presented in 24

International Annual Congress of the

World Muscle Society (Oct 1-5, 2019)

MIP: maximal inspiratory pressure

LS: least squares means estimated with Repeated Measures ANOVA Model

Bars indicate standard error, SD: standard derivation

Treated (N=10)

Control (N=2)

10,000 FOLD HIGHER DOSE IN MUSCLE COMPARED

TO EYE

Adapted from https://www.nature.com/articles/d42473-018-00307-6

x10,000 dose of eye

x1,000 dose of eye

x10 dose of eye

1x10

Established large-scale commercial manufacturing provides capacity required for

higher-dose neuromuscular indications

MANUFACTURING FACILITY TO DEVELOP MULTIPLE

PIPELINE PRODUCT CANDIDATES

Plasmid

Manufacturing

Clinical Trial

Material

Manufacturing

Process

Development

Analytical

Development

Commercial

Manufacturing

Clinical Trial Materials Supply

Internal manufacturing capability to

seamlessly supply drug product

Commercial Production of AT132

Large-scale production enabled by

Audentes’ proprietary know-how

AAV-BASED GENE THERAPY

AAV Surface

Delivery of the

transgene to a

target cell

Transgene

Therapeutic gene

that selectively

functions in a target

cell of patients

 AAV8 is Audentes’ preferred capsid serotype for delivering transgenes to target tissues

 Innovative programs targeting neuromuscular diseases can be developed in an

accelerated manner with Audentes’ proprietary gene therapy know-how

AAV platform + Transgene

Adeno Associated Virus

AAV-based gene therapies for rare neuromuscular diseases

AUDENTES’ PIPELINE

MTM1

GAA

Exons 2, 1-5

Exon 51

Exon 53

DMPK

Transgene

AT132

AT845

AT702

AT751

AT753

AT466

Code

XLMTM

Pompe Disease

DMD

Myotonic

Dystrophy (DM1)

Disease

• Ph1/2 pivotal expansion ongoing

• Preclinical

• Pre-clinical

Development Stage

MOA

Gene Replacement Vectorized Exon Skipping Vectorized RNA Knockdown

XLMTM: X-Linked Myotubular Myopathy

DMD: Duchenne muscular dystrophy

AGENDA

Transaction Summary

III

Overview of Audentes

Strategic Rationale

GENETIC REGULATION AS FIFTH PRIMARY FOCUS

Genetic Regulation to be new Primary Focus

ASIM: Antigen-specific immuno-modulation

 In-house R&D

 Asset acquisition through

business development

Mitochondria

Biology

Regeneration

& Blindness

Immuno-

oncology

ASIM

Biology

Genetic

Regulation

Primary Focus

Harvard

Medical

School

THE COMBINED CAPABILITIES OF ASTELLAS AND

AUDENTES ALLOW THE TARGETING OF MORE DISEASES

Gene Replacement

Neuromuscular

diseases

Biology

(Audentes + Astellas)

Common

diseases

Patients

AAV

Modality (Audentes)

Core

platform

 Complementary in-house

programs

 Next-generation technology

through business development

Astellas

Capsid engineering

Expansion to

+ Undisclosed partners

Gene Replacement

Audentes

Gene Regulation

Optimization to

Final products

License &

Engineering

Process dev &

Manufacturing

ACQUISITION OF AUDENTES: SUMMARY

 Transforms Genetic Regulation Primary Focus into a new growth area

for Astellas, building on a complementary technology platform and

capabilities in gene therapy to swiftly bring products to patients

 Develop innovative gene therapies that address the unmet medical

needs of patients

Acquisition of Audentes is a major step to establishing a leading position in gene therapy

ON THE FOREFRONT OF

HEALTHCARE CHANGE