NON-CONFIDENTIAL

Building Japan’s Next Generation Pharma
42nd Annual J.P. Morgan Healthcare Conference
January 2024 | Sosei Group Corporation (TSE: 4565)

Disclaimer
The material that follows is a presentation of general background information about Sosei Group Corporation and its subsidiaries (collectively, the “Company”) as of the date of this presentation. This material has been
prepared solely for informational purposes and is not to be construed as a solicitation or an offer to buy or sell any securities and should not be treated as giving investment advice to recipients. It is not targeted to the specificinvestment objectives, financial situation or particular needs of any recipient. It is not intended to provide the basis for any third party evaluation of any securities or any offering of them and should not be considered as arecommendation that any recipient should subscribe for or purchase any securities.
The information contained herein is in summary form and does not purport to be complete. Certain information has been obtained from public sources. No representation or warranty, either express or implied, by theCompany is made as to the accuracy, fairness, or completeness of the information presented herein and no reliance should be placed on the accuracy, fairness, or completeness of such information. The Company takes noresponsibility or liability to update the contents of this presentation in the light of new information and/or future events. In addition, the Company may alter, modify or otherwise change in any manner the contents of thispresentation, in its own discretion without the obligation to notify any person of such revision or changes.
This presentation contains “forward-looking statements,” as that term is defined in Section 27A of the U.S. Securities Act of 1933, as amended, and Section 21E of the U.S. Securities Exchange Act of 1934, as amended. The
words “believe”, “expect”, “anticipate”, “intend”, “plan”, “seeks”, “estimates”, “will” and “may” and similar expressions identify forward looking statements. All statements other than statements of historical facts included inthis presentation, including, without limitation, those regarding our financial position, business strategy, plans and objectives of management for future operations (including development plans and objectives relating to ourproducts), are forward looking statements. Such forward looking statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to bematerially different from any future results, performance or achievements expressed or implied by such forward looking statements. Such forward looking statements are based on numerous assumptions regarding ourpresent and future business strategies and the environment in which we will operate in the future. The important factors that could cause our actual results, performance or achievements to differ materially from those in theforward looking statements include, among others, risks associated with product discovery and development, uncertainties related to the outcome of clinical trials, slower than expected rates of patient recruitment,
unforeseen safety issues resulting from the administration of our products in patients, uncertainties related to product manufacturing, the lack of market acceptance of our products, our inability to manage growth, thecompetitive environment in relation to our business area and markets, our inability to attract and retain suitably qualified personnel, the unenforceability or lack of protection of our patents and proprietary rights, ourrelationships with affiliated entities, changes and developments in technology which may render our products obsolete, and other factors. These factors include, without limitation, those discussed in our public reports filedwith the Tokyo Stock Exchange and the Financial Services Agency of Japan. Although the Company believes that the expectations and assumptions reflected in the forward-looking statements are reasonably based on
information currently available to the Company's management, certain forward looking statements are based upon assumptions of future events which may not prove to be accurate. The forward looking statements in thisdocument speak only as at the date of this presentation and the company does not assume any obligations to update or revise any of these forward statements, even if new information becomes available in the future.
This presentation does not constitute an offer, or invitation, or solicitation of an offer, to subscribe for or purchase any securities. Neither this presentation nor anything contained herein shall form the basis of any contract orcommitment whatsoever. Recipients of this presentation are not to construe the contents of this summary as legal, tax or investment advice and recipients should consult their own advisors in this regard.
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This presentation contains non-GAAP financial measures. The non‐GAAP financial measures contained in this presentation are not measures of financial performance calculated in accordance with IFRS and should not be
considered as replacements or alternatives profit, or operating profit, as an indicator of operating performance or as replacements or alternatives to cash flow provided by operating activities or as a measure of liquidity (ineach case, as determined in accordance with IFRS). Non-GAAP financial measures should be viewed in addition to, and not as a substitute for, analysis of the Company's results reported in accordance with IFRS.
References to "FY" in this presentation for periods prior to 1 January 2018 are to the 12-month periods commencing in each case on April 1 of the year indicated and ending on March 31 of the following year, and the 9 month
period from April 1 2017 to December 31 2017. From January 1 2018 the Company changed its fiscal year to the 12-month period commencing in each case on January 1. References to "FY" in this presentation should beconstrued accordingly.
© Sosei Group Corporation. Sosei Heptares is the corporate brand and trade mark of Sosei Group Corporation. Sosei, Heptares, the logo and StaR® are trade marks of Sosei Group companies.

2Building Japan’s Next-Generation Pharma Company
TOKYO STOCK EXCHANGE
PRIME
TSE: 4565
350+ FTE EMPLOYEESCUTTING-EDGE SCIENCEPROGRAMS BY DESIGNREAL HUMAN OUTCOMES

WORLD-LEADERS IN GPCRSTRUCTURE-BASEDDRUG DESIGN• STRONG FOCUS ON GPCRTARGETS – SOLVED 375+MOLECULAR STRUCTURES

30+ ACTIVE PROGRAMSPROTECTING LIVES EVERYDAY

CNS
39%

GI
33%

IMM
9%

OTHER
18%

••10,300+ PATIENTS HAVERECEIVED PIVLAZ® (JAPANAND SHORTLY STH KOREA)+4 OTHER PARTNEREDMARKETED PRODUCTSWORLD-CLASS SCIENCE DELIVERING LIFE-CHANGING MEDICINES

3TOKYO, JAPAN (HQ)CAMBRIDGE, UK
LONDON, UK
SEOUL, SOUTH KOREA
BASEL, SWITZERLAND
REVENUE-GENERATING$350M+ CASH IN HAND
(DEC-2023)

Multiple strategic steps towards an integrated biopharma company
1990s

2000s

2015

2023
JAPANKOREA

Founded by current Chairman,
Shinichi Tamura (‘90)

Tokyo Stock Exchange IPO (’04)

Acquired Heptares Therapeutics¥100m Series A financing (’92)

Acquired Arakis (’05)••¥400m Series B financing (’94)•Added respiratory assets
out-licensed to Novartis
and launched in 2012

Royalties from ROW sales of •Ultibro®, Seebri®
and Enerzair® Breezhaler®* •Added a proprietary SBDD
platform, drug discovery
and early clinicaldevelopment capabilities
30+ programs across multiple
therapeutic areas
20+ partnerships with worldleading pharma and emerging
tech disruptors

Acquired Idorsia Pharmaceuticals
Japan and Korea•

Added late-stage clinicaldevelopment capabilities andcommercial operations inJapan•

Japan and APAC (ex-China)**rights to Pivlaz™ anddaridorexant plus exclusive
rights to 7 additional clinicalstage programs

NEW CORPORATE NAME AND BRANDING TO BE LAUNCHED LATE MARCH 2024
Note: *Seebri®, Ultibro®, Enerzair® and Breezhaler® are registered trademarks of Novartis AG.
**APAC (ex-China) territory includes Japan, South Korea, Australia, Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, New Zealand, Philippines, Singapore, Taiwan, Thailand and Vietnam

4Core focus on Japan & APAC, global partners for the US/EU5/ROW
DISCOVERYEARLY CLINICALDEVELOPMENTCOMMERCIAL

INTERNAL PRODUCTS
APAC

EXTERNAL IN-LICENSED PRODUCTS

R&D
ENGINEDISCOVERY COLLABS

OUT-LICENSED / CO-OWNEDDIVERSIFICATION OF A PHARMA COMPANY, WITH THE UPSIDE OF A BIOTECH

52023 in review – a transformative year
CORPORATEMILESTONES

IN-HOUSEDEVELOPMENTPARTNERED PROGRAMPROGRESSUp-listed to Tokyo Stock
Exchange Prime Segment

PIVLAZ® receives Marketing
Approval in South Korea



Acquisition of Idorsia
Pharmaceuticals Japan &APAC (ex-China)Japan NDA submission ofdaridorexant for insomnia

HTL’149 (GPR52 Ag) entered
Ph 1 trials for schizophrenia

HTL’723 (EP4 Ant) entered
Ph 1/2a trials for advancedsolid tumorsLandmark investment fromJapan Govt JIC VGI fundNeurocrine initiates / willinitiate Ph 1 trials ofmuscarinic compounds(M1/M4, M1, M4 agonists) inneuropsychiatry
Pfizer initiates Ph 1 of once
daily oral GLP-1 Ag (PF’522)
Tempero Bio receives Ph 1 FDA
clearance of TMP-301 (mGlu5NAM) for substance abuse

2023 A YEAR OF CORPORATE ACTION AND INVESTMENT FOR FUTURE GROWTH

6

Our mission – world-leading science, life-changing medicines

CUTTING-EDGESCIENCE

7

PROGRAMS BY
DESIGN

LIFE-CHANGING
MEDICINESOur first commercially available medicine (PIVLAZ®)
is protecting Japanese lives every day
JP GUIDELINES INCLUSION FOR MANAGEMENT OF STROKE1•Aug-23: Authorized and recommended by theJapanese Stroke Society•

Demonstrated the true endpoints of Subarachnoid
Hemorrhage (SAH) with higher level of evidence•Provides confidence to neurosurgeons to prescribe
PIVLAZ® as a new standard of care for SAH based onstrong evidence it can prevent delayed cerebral
ischemia and poor outcomes

LIFE-CHANGING MEDICINES

10,377

Cum. patients to have received PIVLAZ®

Q1Q2

Q3

Q4

Q5

Q6

Q7FY2023
JPY 13.4 BN

NHI-based Sales

MARKETING APPROVAL FOR SOUTH KOREA•Dec-23: Received Marketing Approval in South Korea•Early 2025: Commercially available to patients

Q1Q2Q3Q4Q5Q6PIVLAZ® RAPIDLY BUILDING REAL WORLD EVIDENCE MITIGATING THE RISK OF CEREBRAL VASOSPASM
1 Japanese Stroke Society Guideline 2021 for the Management of Stroke (Revised Version 2023)

8Q7

Daridorexant J-NDA filed; expected launch in late 2024
will contribute significantly to Japanese society
Impact of Insomnia on Japanese Society

15 TRILLION YEN (3% GDP)ECONOMIC LOSSDue to decreased productivity
604,000
LOST WORKING DAYS / YEAR
Due to absences and sick leave
10%
HIGHER MORTALITY RISK
If average <6 hrs sleep per nightQ4 2024 POTENTIAL LAUNCH IN JAPAN•Oct-23: J-NDA submitted for the approval ofdaridorexant, a dual orexin receptor antagonist, forthe treatment of adult patients with insomnia•

NDA includes robust Ph 3 trial data demonstrating
improved Total Sleep Time and Latency for Sleep
Onset, while maintaining a favorable safety profile•Daridorexant is marketed in the U.S. and Europe as
QUVIVIQ™ by Idorsia Pharmaceuticals Ltd (Switzerland)•In Japan, Idorsia Pharmaceuticals Japan and MochidaPharmaceutical Co., Ltd have co-developed and plan toco-market daridorexant pending Japan approval

THE IMPACT OF SLEEP DISORDERS ON JAPANESE SOCIETY IS SIGNIFICANT.
DARIDOREXANT IS A BEST-IN-CLASS SOLUTION FOR INSOMNIA
Source: “Why sleep matters – the economic costs of insufficient sleep” (2016) RAND Research Reports

9

LIFE-CHANGING MEDICINES

Clinically exposed to some of the fastest-growing areas ofmetabolic and neuropsychiatric disorders
PARTNERED PROGRAMS
Schizophrenia
Phase 2

M4 ag
GLP-1 ag

IN-HOUSE PROGRAMS
Metabolic
Phase 1

 Schizophrenia
GPR52 agPhase 1
 Solid tumours
EP4 ant
Phase 1/2a

Neuropsychiatry
Phase 1MC4 ant

Malnutrition
Phase 1

M4 ag

 Neuropsychiatry
Phase 1

CCR6 ant

IBD
Phase 1M1 ag

Neuropsychiatry
Phase 1-readyM1M4 ag

PROGRAMS BY DESIGN Substance abusemGlu5 NAM

Phase 1EP4 ag

IBD
Phase 1-ready

GPR35 Ag1

IBD
Phase 1-ready Clinical start in 2023

TOGETHER WITH OUR PARTNERS WE ACHIEVED SIX CLINICAL STARTS IN 2023
Note: 1 Sosei Heptares to regain full ownership of GSK4381406 from GSK (announced 24-Nov-2023)

10

Our partner Neurocrine has the largest portfolio ofmuscarinic compounds in development
M4 agonist

Phase 2Schizophrenia•

NBI-568 is an investigational, oral, muscarinic M4
selective acetylcholine receptor agonist for the potential
treatment of adults with schizophrenia•Anticipating Phase 2 top-line data in 2H 2024

M4 agonist

Phase 1

M1/M4 dual agonist

Phase 1PROGRAMS BY DESIGN

Neuropsychiatry•NBI-570 is an investigational, oral, muscarinic M1/M4
selective dual agonist, studied for the treatment ofsymptoms of psychosis and cognition in neurological andneuropsychiatric conditions•

Ongoing Phase 1 study
M1 agonist

Neuropsychiatry

Phase 1-ready

Neuropsychiatry•

NBI-569 is an investigational, oral, muscarinic M4preferring agonist studied for the treatment ofneurological and neuropsychiatric conditions•

NBI-567 is an investigational, oral, muscarinic M1preferring agonist studied for the treatment ofneurological and neuropsychiatric conditions•

Ongoing Phase 1 study•Phase 1 study confirmed to be initiated in 2024

MUSCARINIC AGONISM VALIDATED BY KARUNA/KARXT IN SCHIZOPHRENIA11

PROGRAMS BY DESIGN

Rapidly advancing in-house programs into the clinic
IMMUNOSUPPRESSION
IN SOLID TUMORS
EP4 ANTAGONISTSCHIZOPHRENIAAND PSYCHOSISGPR52 AGONISTINFLAMMATORYBOWEL DISEASE
EP4 AGONIST• Once daily oral small molecule• Once daily oral small molecule• Oral GI restricted• Combination with checkpoint inhibitors• 24hr target engagement• Good potency and selectivity• Collaboration with Cancer Research UK• Minimal GI systemic exposure

ONGOING PHASE 1/2A STUDYONGOING PHASE 1 STUDYPHASE 1-READY• Participants: 150 patients• Participant: 104 healthy volunteers• Estimated duration: 8/2023 - 9/2026• Estimated duration: 6/2023 - 11/2024• Regulatory submission to commencetrial completed• No DLTs or SUSARs reported• Clinical trial showing good progress
through dose escalation• Three clinical sites currently open

• Anticipated Phase 1 start 1H 2024

NEXT WAVE OF POTENTIAL BLOCKBUSTER PROGRAMS ADVANCING INTO THE CLINIC

12Note: DLT: Dose Limiting Toxicities, SUSAR: Suspected Unexpected Serious Adverse Reactions
EP4 Ant study link: https://clinicaltrials.gov/study/NCT05944237?term=Heptares&viewType=Table&page=2&rank=15
GPR52 Ag study link: https://www.isrctn.com/ISRCTN17231793?q=&filters=&sort=&offset=58&totalResults=23608&page=6&pageSize=10

Regaining full ownership of GPR35 agonist programfrom GSK, a genetically validated target

PROGRAMS BY DESIGNGPR35 AGONIST OFFERS A DIFFERENTIATED MOA TO CURRENT SOC:GPR35 AGONIST• Novel first-in-class, oral GI-restricted GPR35 agonist

GPR35
A novel target with an establishedgenetic association to IBD• Preclinical data supports potential to improve gutbarrier function and reduce visceral pain
hypersensitivity
PHASE 1-READY• GSK had received prior UK MHRA regulatory
approval to commence Phase 1 studies1• Discontinued by GSK as a result of a reprioritizationof its immunology pipeline• Once regained, intention to initiate Phase 1 study
as planned and determine optimal strategy forfurther clinical development and/or re-partnering

SIGNIFICANT UNMET NEED REMAINS IN IBD NO EXISTING THERAPIES DIRECTLY ADDRESS BARRIER FUNCTION OR PAIN HYPEREXCITABILITY
Illustration source: GSK
Note: 1 GPR35 Agonist study link (now withdrawn for strategic business reasons): https://clinicaltrials.gov/study/NCT05999708?term=GSK4381406&rank=113

PROGRAMS BY DESIGN

Deep exposure to the high-growth metabolic space
GLP-1

BEYOND GLP-1

NEXT-GENERATIONBROAD UPSTREAM OF
INCRETIN TARGETS

PF’522Phase 1

Multiple Pre-discovery/ Discovery

Pre-discovery/ Discovery

METABOLIC DISEASES - DIABETES AND OBESITY ARE JUST THE BEGINNING.
EMERGING RESEARCH SUGGESTS BENEFITS IN HEART, LIVER AND KIDNEY DISEASES
14Impact

Approach

Broadly applying AI & ML techniques across ourproprietary technology and discovery platform

CUTTING-EDGE SCIENCE

StaR® technology

Structure

Molecule Design

Translational Medicine• GPCR rich mutagenesis
datasets are mined using
ML algorithms to predict
future StaR® enablingmutations• AI used to predict GPCR
binding site/mode using
database of proprietaryinternal/external structures• Hit ID through AI- • ML based QSAR models
assisted medicinal
based on proprietarychemistry expertise internal and public
datasets• AI led analysis of large patient
datasets to identify biomarkers
and stratify patients• Accelerates StaR®
generation• Improves breadth and depth • Supportsof GPCR homology models toidentification of
support molecule
novel chemical
optimization and virtual
seriesscreening.

15 QSAR: Quantitative Structure Activity Relationship• Supports optimizationof chemical series toimprove drug like
properties• Enables the design of the 'right'
clinical studies

Robust cash balance greater than ~¥50bn ($350m) at year-end• Issuance of new shares and convertible bonds• Buyback of existing convertible bonds• 3rd party allotment to JIC VGI (see next slide)¥40bn($284m)¥67bn($473m)¥65bn($461m)Long-term,
low-rate
corporateloan¥10bn($74m)>¥50bn(>$350m)

Acquisition of IPJ/IPK
22-DecCorporate loan

Purchase of IPJ/IPKNet Financing

Other Cashflow*

FINANCIAL CAPACITY TO EXECUTE ON STRATEGIC GROWTH INITIATIVESIPJ: Idorsia Pharmaceuticals Japan, IPK: Idorsia Pharmaceuticals Korea* Illustrative only16

Dec-23 (E)Several catalysts on-track to be achieved over the next 12 months
PROGRAM

TIMINGEVENTCenerimod

1H 2024

Exclusive opt-in decision

Lucerastat

1H 2024

Exclusive opt-in decision

EP4 Ag

1H 2024

Phase 1 start

Daridorexant (Sth Korea)

2H 2024

Phase 3 start

2H 2024

Approval

PIVLAZ® (Sth Korea)

2H 2024

LaunchGPR35 Ag2H 2024

Program reversion

NBI-568 (M4 Ag)

2H 2024

Phase 2 completion

NBI-567 (M1 Ag)

2024

Phase 1 start

TMP-301 (Mglu5 NAM)

2024

Phase 2 start

ORX750 (Ox2 Ag)

2024

Phase 1 start

Daridorexant (Japan)

1 Co-development and co-promotion agreement with Mochida

17PARTNER

1Our mission, in progress
CUTTINGEDGESCIENCEPROGRAMSBY DESIGN

LIFECHANGING
MEDICINES

18✓

World-leader in SBDD, utilizing AI/ML tools for accelerating drug discovery✓

Exposure to fastest growing area of healthcare, revolutionizing treatments for metabolic diseases✓

Exclusive opt-ins for Phase 3-ready products, building our commitment to healthcare in Japan✓Additional pipeline of 30+ medicines by design, adding new programs and partners every year

✓PIVLAZ® launch ongoing, protecting patients daily✓Daridorexant NDA filing submitted to PMDA, transforming the management of sleep disorders

Thank You!
Chris Cargill
Chief Executive Officer
19

Broad, Diversified and Balanced Pipeline

Pioneering novel and differentiated therapies across multiple therapeutic areas
Pre-Discovery / Discovery

PreclinicalAPAC*

M1 ag. NBI’567

EP4 ant. HTL’732

Cenerimod

APAC*

Lucerastat

APAC*

IN-HOUSE

Neurology

Schizophrenia

PARTNEREDMultiple

GI

Inflammatory Diabetes
Neurology Metabolic

Advanced solid tumors

Systemic lupus erythematosus

ROFR/ROFN for up to five additional APAC*
programs from Idorsia’s global portfolio1

Cerebral vasospasm

Oravi®

Mouth candidiasis

Fabry disease

CXCR4 mAb KY1051

CCR6 ant. PF’894

Seebri® Breezhaler®

OX2 Ag ORX-750

MC4 ant. PF’669

Enerzair® Breezhaler®

MetabolicM4 ag. NBI’568
Schizophrenia

IBDAnorexia

M1M4 ag. NBI’570
Neurology

M4 ag. NBI’569
NeurologymGlu5 NAM TMP-301
Substance abuse

20

APAC*

GLP-1 ag. PF’532

Neurology

Narcolepsy

Ongoing technology collabs.

Insomnia (Filed Q4 ‘23)

PIVLAZ®

M1 ag. NBI’567

Immuno-oncology
Multiple

Commercial

Daridorexant

IBD

Previous and ongoing discovery collabs.

Phase 3

GPR52 ag.

GPR352 ag. GSK’406

15+ PROGRAMS

Phase 2EP4 ag.

Inflammatory Bowel Disease

10+ PROGRAMS

Phase 1

Note: Seebri®, Ultibro®, Enerzair® and Breezhaler® are registered trademarks of Novartis AG.
*APAC (ex-China) territory includes Japan, South Korea, Australia, Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, New Zealand, Philippines, Singapore, Taiwan, Thailand and Vietnam
1 ROFR = Right of First Refusal / ROFN = Right of First Negotiation in the APAC (ex-China) territory for Selatogrel, ACT-1004-1239, ACT-1014-6470, IDOR-1117-2520, ACT-777991
2 Sosei Heptares to regain full ownership of GSK4381406 from GSK (announced 24-Nov-2023)

Ultibro® Breezhaler®
COPD

COPD

Asthma~¥8bn ($54m) investment from new OPF1 fund of JIC VGIJIC Venture Growth Investments is an affiliate of govt-backed Japan Investment Corporation (JIC)JIC VGI OPPORTUNITY
FUND NO.1 (OPF1)

INVESTMENT IN SOSEI GROUP CORPORATION• One of the JIC initiatives included in theJapan Government's “StartupDevelopment Five-year Plan”• JIC VGI has invested in many growth companies in thehealthcare and life sciences sector and has intrinsic
knowledge of biotech companies• Launched in Sept-23 to support the growthand sustainable development ofinnovative companies listed on the Tokyo
Stock Exchange• Investment due diligence process conducted over severalmonths, including site visits in the UK and Japan• Engages in next-generation industries ofsignificant economic and social benefit toJapan, such as healthcare and life sciences• As a government-supported fund, OPF1 serves as along-term investor, typically holding investments for 3-5
years on average• Sosei Group Corporation was the first investment projectfrom JIC VGI OPF1, accounting for 20% of its total fund size

OPF1’S INVESTMENT RECOGNIZES THE POSITION OF SOSEI HEPTARES AS AN
EMERGING GLOBAL CHAMPION FOR THE GROWING BIOPHARMACEUTICAL SECTOR IN JAPANSource: Japan Investment Corporation21

Locations
SOSEI GROUPPMO Hanzomon 11F

Midtown East,

F17, 410 Teheran-Ro

Steinmetz Building

North West HouseVISCHER AG

2-1 Kojimachi,Chiyoda-ku

9-7-2 Akasaka Minatoku

GangHam-Gu

Granta Park,

119 Marylebone Road

Aeschenvorstadt 4

Tokyo 102-0083

Tokyo 107-0052

Seoul 06192

Cambridge CB21 6DG

London NW1 5PU

4051 Basel

Japan

Japan

South Korea

United Kingdom

United Kingdom

Switzerland