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CORPORATE PRESENTATIONJUNE 2019

Subject to closing of CytoSen acquisition

Euronext: KDS

Patient-specific cell therapy in hemato-oncology to improve outcomes of hematopoietic stem cell transplantation

Leveraging the natural strengths of humanity and our collective immune systems to source the

best cells for life

Disclaimer

These slides and the accompanying oral presentation contain forward-looking statements and information. Forward-looking statements are subject to known and unknown risks, uncertainties, and other factors that may cause our or our industry’s actual results, levels or activity, performance or achievements to be materially different from those anticipated by such statements. The use of words such as “may”, “might”, “will”, “should”, “could”, “expect”, “plan”, “anticipate”, “believe”, “estimate”, “project”, “intend”, “future”, “potential” or “continue”, and other similar expressions are intended to identify forward looking statements. For example, all statements we make regarding (i) the initiation, timing, cost, progress and results of our preclinical and clinical studies and our research and development programs, (ii) our ability to advance product candidates into, and successfully complete, clinical studies, (iii) the timing or likelihood of regulatory filings and approvals, (iv) our ability to develop, manufacture and commercialize our product candidates and to improve the manufacturing process, (v) the rate and degree of market acceptance of our product candidates, (vi) the size and growth potential of the markets for our product candidates and our ability to serve those markets, and (vii) our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates, are forward looking. All forward-looking statements are based on current estimates, assumptions and expectations by our management that, although we believe to be reasonable, are inherently uncertain. All forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially from those that we expected. Any forward-looking statement speaks only as of the date on which it was made. We undertake no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. This presentation is not, and nothing in it should be construed as, an offer, invitation or recommendation in respect of our securities, or an offer, invitation or recommendation to sell, or a solicitation of an offer to buy, any of our securities in any jurisdiction. Neither this presentation nor anything in it shall form the basis of any contract or commitment. This presentation is not intended to be relied upon as advice to investors or potential investors and does not take into account the investment objectives, financial situation or needs of any investor.

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Kiadis: Combining T-cell and NK-cell platforms to fight cancer

Patient specific cell therapy in hemato-oncology,

combining innate and adaptive immune system

Strong US presence, e.g., BMT-CTN and SAB

Key medical and finance functions in US

ATIR101 US FDA RMAT and US/EU Orphan drug designations

ATIR101: phase 3 enrolling; MAA on file in EU

CSTD002: clinical trials to start in 2020

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HSCT: hematopoietic stem cell transplantation; Haplo: haploidentical (genetically half matched); allodepleted T-cells: T-cells without patient specific T-cells that could cause GVHD; GVHD: Graft versus Host disease; RMAT: Regenerative Medicine Advanced Therapy (‘breakthrough designation’); PTCy: post transplant cyclophosphamide

Develop cancer NK-cell therapies (e.g., treat

AML R/R)

Potential to Revolutionize haplo HSCT with

combination of T-cell and NK-cell therapies

Two platforms: ATIR101: allodepleted T-cells

CSTD002: potent NK cells

Kiadis to acquire CytoSen in all stock transaction

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Consideration • 1.94 million shares of Kiadis stock to be paid to CytoSen shareholders

Potential milestones • Up to an additional 5.82 million shares of Kiadis stock based on successful achievement of six clinical development and regulatory milestones, through first FDA approval

Lock-up • The majority of Kiadis shares issued to the CytoSen shareholders at closing, including to its Executive Chairman, CEO and founders, will be subject to a lock-up for a period of two years

Closing • Shareholder approvals received, expected to closing in the coming days

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Leveraging natural strengths of human immune system

“… the fields of NK-cells and T-cells are enormously synergistic and the combination could potentially

help patients with devastating diseases.”

“NK-cell therapy could significantly advance the field of immuno-oncology.”

Dr. Carl JuneCAR-T pioneer & future member of Kiadis’ SAB

The human immune system uses both the innate and adaptive arms

5Illustration Source: Smyth, NATURE Reviews: Cancer; November 2002, Volume 2.

Kiadis pipeline

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Orphan Drug & RMAT Designations

Orphan Drug Designation

Indication Development Phase 3 Filing CatalystsCommercial

Rights Status

ATIR101 ‘Safe’ T-cells

Adjunct to HSCT (EU)

• EU Approval (2019)• EU Launch (first

patient, late 2019)

• Responding to EMA Day 180 questions end May 2019

Adjunct to HSCT (US)

• Phase 3 enrollment and interim read out (2021)

• RMAT ‘breakthrough’ designation

CSTD002Potent

NK-cells

Adjunct to HSCT

• Start trial with BMT-CTN (2020)

• Proof-of-concept at MDACC (25 patients)

Cancer treatment

• Start AML R/R trial (2020)

• Proof-of-concept at MDACC for AML R/R (8 patients)

Kiadis’ first programs: help people with blood cancer

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people living with LEUKEMIAS

Globally

~400,000

Sources: Deschler B et al. Acute Myeloid Leukemia: Epidemiology and Etiology. Cancer. 2006. 2009-2107; World Health Organization. 2014 Review of Cancer Medicines on the WHO List of Essential Medicines. Available at: http://www.who.int/selection_medicines/committees/expert/20/applications/AML_APL.pdf.; Passweg, NATURE 06Feb19 (nature.com/articles/s41409-019-0465-9); D’Souza A, Fretham C.: CIBMTR summary slides, 2017. Available at: http://www.cibmtr.org

are diagnosed with ACUTE LEUKEMIAS

– acute myeloid leukemia (AML),

acute lymphoblastic leukemia (ALL) and

myelodysplastic syndrome (MDS)

– which are AGGRESSIVE

and OFTEN FATAL

~55%OF PATIENTS

Leukemia is CANCER of

IMMUNE system CELLS that

compromises immune function

HSCTs(US and EU)

AUTOLOGOUS (~55%) (utilizing patient

stem cells)OR

ALLOGENEIC (~45%)(utilizing donor

stem cells)

~65,000 Allogeneic HSCT often the onlyPOTENTIALLY

CURATIVE APPROACH available;

kills the diseased immune system

of the patient and REPLACES WITH

THE HEALTHY IMMUNE SYSTEM

of the donor

Allogeneic HSCTs: Outcomes need to improve

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GVHD • T-cells from donor recognizing patient tissue as foreign and attacking patient, due to genetic differences

Implications of GVHD

• Skin, eye, mouth or GI tract disease; immunodeficiency, muscle constriction, bone loss, pulmonary disease, thyroid disfunction, solid tumors, sleep deprivation, depression

Treatment • Immunosuppression

Impact of severe GVHD

• 2-4x higher rate of death / lower overall survival• Quality of life worse than vision impairment, MS• Side effects immunosuppression (diabetes, renal failure)• 75% of patients lose 3 years earnings, 25% permanently

The ‘ideal’ transplant: give T-cells and NK-cells that protect; avoid T-cells that attack; avoid immunosuppressants.

OF ALLO HSCT PATIENTS*

ONLY

have long term survival without severe GVHD or

relapse

GRAFT HOSTvs

Mortality/morbidity Relapse GVHD

CHALLENGES

Infections

Sources: McCurdy SR, et al. Haematologica 2017; 102:391–400; Solh M, et al. Biol Blood Marrow Transplant 2016.; Pidala et al 2011, Pasquini 2018, Khoury 2017, Solh 2018; Jones 2016; Koreth 2013;

~30%

Allogeneic HSCT: Haplo-identical transplants growing

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MATCHED (UN)RELATED DONOR (MRD / MUD)

HAPLOIDENTICAL WITH PTCy (Post Transplant Cyclophosphamide)

Patients relapse during donor search; Only half of patients get transplanted

Relapse after transplant; Immunosuppression and toxicity

Availability varies with ethnicity Almost always available (half matched, e.g., parent or child)

~27,000 PER YEAR ~4,200 PER YEAR

Sources: Passweg, NATURE 06Feb19 (nature.com/articles/s41409-019-0465-9); D’Souza A, Fretham C.: CIBMTR summary slides, 2017. Available at: http://www.cibmtr.org*Weighted average of 5 PTCy/MUD comparison publications in review Fuchs E 2017 (n=463 PTCy and n=2647 MUD)

38%

53%

38%

51%

26% 27%

45%49%

Acute GVHD II-IV

Chronic GVHD

Relapse Survival

Haplo with PTCyMatched Unrelated Donor

Haplo PTCy versus Matched Unrelated Donor(up to 3 yr follow up)*

Suppress GVHD causing T-cells (but also protective NK/T-cells) with

cyclophosphamide and immunosuppression

Does not reflect additional survival benefit of haplo due to (faster) availability of donor

ATIR101 T-cell therapy program

After T-cell depleted Haplo HSCT

ATIR101: allodepleted T-cells after T-Cell depleted haplo HSCT

Apheresis of patient and donor and

centralproduction

Conditioning of patient, apheresis of donor, graft manipulation,

graft infusionATIR101

Produce ATIR101 5 days

(14 days to interim release)

Infuse ATIR101 30 days after graft infusion

T-cell depleted Haplo HSCT

T-cells removed from graft

Conditioning of patient, apheresis of donor,

graft infusion

Haplo HSCTUnmanipulated graft,

with T-cells

Cyclophos-phamide and

immuno-suppression

Cyclo-phosphamide3-5 days after graft infusion

No immuno-suppression (no T-cells in

graft)

ATIR101 ‘Safe’ T-cells

Haplo HSCT with PTCy

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ATIR101: allo-depleted T-cell therapy, alloreactive T-cells removed ex vivo

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Mix donor immune cells with patient material; alloreactive (GVHD

causing) T-cells become activated

Add light sensitive compound that gets trapped in activated

(GVHD causing) T-cells

Then kill activated (GVHD causing) T-cells with green light; ATIR101 contains

remaining allo-depleted T-cells

ATIR101: kill cells that attack ex vivo; infuse cells that protect; avoid immunosuppressants

ATIR (n=37) Historical controls; n=64)

ATIR101: Phase 2 versus T-cell depleted haplo HSCT

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58%[44-77*]

All data at 1 year; Matched patients; ATIR ITT: all patients undergoing HSCT; ATIR status 1 June 2018 (3 patients at risk) single dose; *95% confidence interval.

23%[14-37*]

Overall Survival

Severe chronic GVHD 0% 7%

Acute grade III/IV GVHD 5% 6%

ATIR101: Protective and safe T-

cells that:

Improve overall survival

(p=0.005)

T-cell depleted HSCTT-cell depleted HSCT plus ATIR101

Do not cause (increase in) severe GVHD

Basis for ATIR101 Phase 3 design: GRFS versus PTCy

14Sources: Sohl 2016; McCurdy 2017 (Johns Hopkins); Solh 2016 (Northside); ATIR ITT: all patients undergoing HSCT; ATIR status 1 June 2018 (3 patients at risk) single dose; *ASH Poster, Steven Devine, CIBMTR; *Disease Risk Index largest prognostic factor for OS/GRFS, normalization based on GRFS for each DRI category in papers

PTCy (Johns Hopkins, single

site, 372 patients*)40%

PTCy (Northside, single site,

128 patients*)30%

GRFS for ATIR and PTCy1 year; normalized for Disease Risk Index*

GRFS for MRD/MUD/PTCySurvival without Relapse, Grade III/IV GVHD, chronic

GVHD requiring systemic immunosuppression

ATIR101 (phase 2, 37

patients)53%

ATIR101: Phase 3 (CR-AIR-009), versus PTCy

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RRandomized / Controlled(1:1)80% power to detect 16% GRFS treatment effect

Haplo HSCT (TCD) plus ATIR: T-cell deplete CD34+HSCT plus ATIR 2 mln cells/kg at 30 days

Haplo HSCT with PTCy: T-cell replete HSCT with 50 mg/kg cyclophosphamide at days 3 and 5 post HSCT & prophylactic immunosuppressants

OBJECTIVE: Demonstrate superior clinical benefit and collect pharmacoeconomic data

PRIMARY ENDPOINT: GVHD-Free & Relapse-Free Survival (GRFS)- Primary analysis: at 156 events (11,4% GRFS

treatment effect)- Interim analysis: at 105 events (17,6% GRFS

treatment effect, hazard ratio 0.61)

SECONDARY ENDPOINTS: Overall Survival (OS), Progression Free Survival (PFS), Relapse, Non Relapse Mortality (NRM)

OTHER:Randomized at enrollment; Balanced conditioning regimens; Stratification for Disease Risk Index, disease and treatment site

AML / ALL / MDS

250

CENTERS

~50EU, US, Canada

and Israel

PATIENTS

ATIR101: EMA filing and EU Launch Preparation

• Building medical and commercial teams- Medical affairs- Marketing, market access,

commercial operations, account directors

• Developing reimbursement dossiers

• Establishing own Amsterdam manufacturing facility and patient specific supply chain

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EMA FILING AND LAUNCH PREPARATION

Belgium

Spain Italy

Germany

Sweden

LAUNCH COUNTRIES (ACCESS ON PHASE 2)

• Filed based on Phase 2 with historical control• Submitting answers to EMA day 180 2nd list of

questions end of May• Building medical and commercial teams

- Medical affairs- Marketing, market access, commercial operations,

account directors

• Developing reimbursement dossiers (countries with market access possible on Phase 2 data)

• Establishing own manufacturing (Amsterdam) and patient specific supply chain

CSTD002 NK-cell therapy program

After Haplo HSCT with PTCy

CSDT002: potent NK-cells after haplo HSCT with PTCy

Conditioning of patient, apheresis of donor,

graft infusion

Haplo HSCTUnmanipulated graft,

with T-cells

Cyclophos-phamide and

immuno-suppression

Cyclo-phosphamide3-5 days after graft infusion

Collection of donor blood and central production

Produce CSTD00214 days

CSTD002

Infuse CSTD002-2, +7 and +28days after graft

infusion

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CSTD002Potent NK cells

Conditioning of patient, apheresis of donor,

graft infusion

Haplo HSCTUnmanipulated graft,

with T-cells

Cyclophos-phamide and

immuno-suppression

Cyclo-phosphamide3-5 days after graft infusion

Haplo HSCT with PTCy

NK-cell program – strong scientific roots (CSTD002)

Dean Lee, M.D., Ph.D.Co-founder of CytoSenDirector of the Cellular Therapy and Cancer Immunotherapy Program for Nationwide Children’s Hospital’s Division of Hematology/Oncology/BMT andCenter for Childhood Cancer and Blood Diseases

Robert Igarashi, Ph.D.Co-founder and Chief Science Officer of CytoSen Former Assistant Professor in the Department of Chemistry at the University of Central Florida, with a joint appointment in the Burnett School of Biomedical Sciences

Stefan O. Ciurea, M.D.Co-founder of CytoSenAssociate Professor, Department of Stem Cell Transplantation, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center

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Best-in-class potential for high dose potent NK-cell platform

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Dosing High doses (10x endogenous levels possible)

In vivo persistence Limited telomere shortening, zero senescence

Anti-tumor activity High cytotoxicity (ADCC, IFNγ and TNFα)

Breadth of response Effective response in over 10 cancer targets

Activation Upregulated activating receptors (e.g., NKG2D, CD16)

Cryopreservation Industry standard cryopreservatives and thawing

Manufacturing Scalable, wave bags, closed system

Regulatory Irradiated nanoparticle stimulation, not with tumor feeder cell line

mbIL21

4-1bbL

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Expansion and activation of natural haplo donor NK-cells with patented PM21 nanoparticles with mbIL21 and 41bbl

antigens

High dosing, cytotoxicity, persistence and activation

CSDT002: MDACC proof-of-concept* as adjunct to HSCT-PTCy

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Size Dose levels Timing Follow up Outcomes

n=25 104 to 108

cells/kgDay -2, +7, +28

from graft infusion28 months

(0.9-48)

• Improvement in relapse rate, PFS and OS• Reduction in reactivation of CMV/BKV• No severe acute and chronic GVHD

Improvement versus matched contemporaneous MDACC control and versus CIBMTR

control

*NK-cells produced with feeder cells expressing mbIL21 and 41bbl, not with nanoparticles; n=13 Phase 1 dose finding (published in Blood), n=12 Phase 2 at highest dose (presented at ASCO and Haplo2018); Ciurea SO, et. al. Blood 2017, (link to paper); Ciurea SO EMBT Mar2018; Ciurea SO, Haplo2018, Nov2018

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8%

45%

CSDT002: PoC* for treatment of AML (R/R, 2nd line salvage)

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Site Size Patients: AML R/R 2nd line salvage

Timing of dose Follow up Outcomes

MD Anderson n=8

• 4 median prior treatments• 3/8 prior HSCT• 43% median BM blasts

6 doses (11 days)

329 days(71-730)

• CR/CRi: 75% (day 30)• HSCT: 50%• Survival: 37,5% (1 year)

MD Anderson and Brazil

N=13• 4 median prior treatments• 7/13 prior HSCT • 45% median BM blasts

6 doses (11 days)

202 days (39-590) • CR/CRi: 69%

* NK-cells produced with feeder cells expressing mbIL21 and 41bbl, not with nanoparticles; Ciurea SO, et. al. ASCO June2018; Ciurea SO Haplo2018. Nov2018 22

Case example (AML, male, 25 yrs):• 8 lines of prior treatment, incl prior failed HSCT• Active disease, 90% BM blasts• Treated with NK cells plus FLAG, no subsequent HSCT• No treatment side effects• Complete response• Ongoing MRD decrease and immunologic activity (at 120 days)• Alive at 1 year; Relapsed/death at 2 years

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Multiple generations with potential to revolutionize haplo HSCT

Potentially suitable for even wider group of patients

Adjunctive dose

Haplo HSCT with PTCy T-Cell depleted with PTCy T-Cell depleted

Status Standard of care Phase 3 and EU registration

MDACC Proof of concept

Potential future standard of care

‘Safe’ T-cells +/- + +/- +Potent NK-cells - - + +No immunosuppression - + - +

Potential benefits:

GVHD & Relapse-free Survival; No immuno-suppression

Survival & relapse

Survival, relapse & GVHD;

No immuno-suppression

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ATIR101 ‘Safe T-cells’

CSTD002Potent NK-cells

ATIR101 andCSTD002

Standard of Care PTCy

Rapid growth since 2012

Strong leadership team

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ARTHUR LAHRChief Executive Officer

SCOTT A. HOLMESChief Financial Officer

DIRK de NAEYERChief Operations Officer

ANDREW SANDLER, MDChief Medical Officer

ROBERT FRIESENChief Scientific Officer

MARK WEGTER, ChairmanPartner LSP

BERNDT MODIGFormer CFO Prosensa

OTTO SCHWARZFormer COO, Actelion

ROBERT SOIFFER, MDProf Harvard, Director HSCT Dana Farber, Chair CIBMTR, board member NMDP

MARTIJN KLEIJWEGTFounder of LSP

SUBHANU SAXENAFormer head of global product strategy and commercialisation, ExCom member, Novartis

SELECT MANAGEMENT TEAM MEMBERS SUPERVISORY BOARD

JONATHAN SWEETINGSr. VP, Commercial EU

Kiadis news flow

2019

2020

2021

• Potential EU approval of ATIR101

• Launch ATIR101 in EU (late 2019, first patient)

• Continued enrollment in global Phase 3 for ATIR101

• Establish Scientific Advisory Board

• Continued enrollment in global Phase 3 for ATIR101

• Initiate clinical trial of CSTD002-NK in HSCT

• Initiate clinical trial of CSTD002-NK in AML R/R

• Continued launch of ATIR101 in EU

• Initiate additional trials with ATIR and/or CSTD002-NK

• Complete enrollment in Phase 3 for ATIR101

• Interim data for Phase 3 for ATIR101 (upon 105 events)

• Interim data for clinical trial(s) with CSTD002-NK

• Continued launch of ATIR101 in EU

• Initiate additional trials with ATIR and/or CSTD002-NK

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When it comes to life-threatening diseases, we are one family. Kiadis is re-imagining medicine by leveraging the natural strengths of humanity and our

collective immune systems to source the best cells for life. Our uncompromising approach to serve patients, their families and care givers aims to minimize harm and maximize help – delivering personalized treatments for every single

patient to offer hope, reduce suffering and provide new life.

PATIENT CARE TEAMFAMILY