ProQR Corporate PresentationProQR inherited blindness platform ProQR Therapeutics – Corporate Presentation 6 Intravitreal delivery is routine procedure • Long half -life in the

CREATING MEDICINESfor patientsin need

Date:October 2018

Nasdaq:PRQR

Forward looking statements

ProQR Therapeutics – Corporate Presentation 2

This presentation contains forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts, contained in this presentation, including but not limited to, statements regarding our strategy, future operations, future preclinical and clinical trial plans and related timing of trials and results, research and development, future financial position, future revenues, projected costs, prospects, therapeutic potential of our product candidates, plans and objectives of management, are forward-looking statements. The words “aim,” “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

Forward-looking statements represent our management’s beliefs and assumptions only as of the date of this presentation. We may not actually achieve the plans, intentions or expectations

disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. The forward-looking statements contained in this presentation reflect our current views with respect to future events, and we assume no obligation to update any forward-looking statements except as required by applicable law. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including those that may be described in greater detail in the annual report filed on Form 20-F for the year ended December 31, 2017 that we have filed with the U.S. Securities and Exchange Commission (the “SEC”) and any subsequent filings we have made with the SEC. We have included important factors in the cautionary statements included in that annual report, particularly in the Risk Factors section, and subsequent filings with the SEC that we believe could cause actual results or events to differ materially from the forward-looking statements that we make.

ProQR at a glancePlatform for therapies targeting inherited blindness

QR-110 for LCA10 with positive clinical data

• Phase 1/2 trial expected to complete H2 2019• Phase 2/3 ILLUMINATE trial expected to start H1 2019

QR-421a for Usher syndrome Exon 13

• Completed pre-IND meeting• Initiate STELLAR trial around YE 2018, data expected

mid 2019• Multiple dose adaptive trial, data expected H2 2020

QR-1123 for P23H adRP (in-licensed from Ionis)

• Preclinical activities and natural history study completed by Ionis

• Phase 1/2 trial expected to start in 2019

Pursuing deep pipeline in ophthalmology with many targets that can progress into clinical development rapidly


Patient-centric RNA THERAPEUTICS platform company, developing drugs for ORPHAN DISEASES with well understood causality

Broad RNA platform in other therapeutic areas

Dystrophic Epidermolysis Bullosa

• QR-313 in active clinical trial with interim analysis data expected late 2018 / early 2019

Partnership with Galapagos on fibrosis targets using Axiomer®

RNA editing platform

Majority ownership in CNS spin-out company Amylon

ProQR development pipeline


DISCOVERY PRECLINICAL DEVELOPMENT PROOF OF CONCEPT TRIALS

LATE STAGE/REGISTRATIONAL

TRIALS

OphthalmologyQR-110 for LCA10 p.Cys998XQR-421a for Usher syndrome 2A exon 13QR-1123 for P23H adRP - discovered by IonisQRX-504 for FECD3QR-411 for Usher syndrome 2A PE-40QRX-1011 for Stargardt’s disease c.5461-10T>C

Dystrophic Epidermolysis BullosaQR-313 for DEB exon 73QRX-323 for DEB exon 80QRX-333 for DEB exon 3

Cystic FibrosisEluforsen (QR-010) for F508del

FibrosisPartnered with Galapagos NVUndisclosed targets

Central Nervous SystemAmylon TherapeuticsAT-010 for HCHWA-D

PARTNERED PROGRAMS

RNA oligo therapies for inherited blindness


Wild-type Disease Disease + oligo

RNA

DNA

Protein

RNA

DNA

Protein

RNA

DNA

Protein

ProQR inherited blindness platform


Intravitreal delivery is routine procedure• Long half-life in the eye allows

for dosing quarterly or less frequent

• Chemical modification enables naked delivery

• QR-110 has shown placebo-like clean safety profile

Predictive optic cup model• Sophisticated organoid model

for retinal dystrophies• Accurately predicted in QR-

110 trial:• Clinically efficacious

intravitreal dose level • Response to treatment• Time to onset of response

Broad distribution allows for targeting of central and peripheral diseases• Oligo’s distribute broadly to all

different cell types• Allowing for targeting central

and peripheral disease

Targeted RNA oligo therapies• RNA oligo designed to

specifically address the mutations causing the disease

• >300 genetic eye diseases described

UNIQUE PLATFORM FOR PRECISION MEDICINE

QR-110 for LCA10


LCA10

Lose sight in first years of life

No therapy available

p.Cys998X mutation affects ~2,000 patients in the Western World

QR-110

Goal: Restore vision/ prevent vision loss in patients with LCA10

Locally adminis-tered in the eye. Routine intra-vitreal procedure

Anticipated infrequent dosing of 4 times a year or less

√ Established modality in eye√ Strong preclinical proof of

concept in human retina in preclinical models

√ Orphan drug designation√ Fast track designation

√ Phase 1/2 interim analysis showed rapid and sustained efficacy and favorable safety

• Pivotal phase 2/3 trial expected to start in H1 2019

Clinical study design – PQ-110-001


Open label, multiple dose, dose escalation study, Phase 1/2

• Up to twelve p.Cys998X LCA10 patients; adults and children (≥6yrs)

• Intravitreal injections in one eye

• Participating sites: major sites in EU (UGhent) and US (UPenn, UIowa)

• Primary endpoints:

• Safety, tolerability

• Secondary endpoints and exploratory efficacy:

• Visual acuity, mobility course, FST, OCI, pharmacokinetics, OCT, PRO, ERG, pupilometry

• IND and CTA (BE)

• Orphan drug designation in EU and US

• FDA Fast-track designation

1 loading dose & 3 maintenance doses over 1 year:

• 160 µg loading dose / 80 µg maintenance dose

• 320 µg loading dose / 160 µg maintenance dose

= DSMC review

Adult Mid dose

Adult Low dose

Adult High dose

Pediatric Low dose

Pediatric Mid dose

Pediatric High dose

Observation of early efficacy at low and mid dose led to:• Accelerated interim analysis• No escalation to the high dose

• Plan to start a pivotal Phase 2/3 ILLUMINATE trial in H1 2019 with parallel pediatric study

Interim results summary• The trial met its primary and secondary objectives Safe and well tolerated in >1500 subject treatment-days analyzed Mechanistic proof-of-concept confirmed by improvement in FST Clinical proof-of-concept confirmed by BCVA and supported by

improvement in mobility course The four analyzed outcome measures showed concordant improvement

• Enrollment has been completed

• 12 month data in all subjects is expected in H2 2019

• Plan to start a Phase 2/3 trial in H1 2019• Double-blind, controlled, dose range finding adaptive design• Could serve as the sole pivotal registration trial• Parallel trial in pediatric <6 years old


Baseline Demographics


Pediatric and adult patients (8-44 age range), with severely impaired vision

Sex 2nd CEP290 Allele Age / Group Baseline VA(logMAR)

TreatedEye

Dose(µg)

M c.2506_2507delGA 19 / A LP / LP RE 160/80

M c.4723A>T 41 / A LP / LP RE 160/80

M c.5668G>T 44 / A 2.3 / 2.4 LE 160/80

F c.4438‐3delC 16 / P 2.5 / 2.5 RE 160/80

M c.6277delG 8 / P 1.9 / 2.1 LE 160/80

F c.3167_3168insA 21 / A LP / LP RE 320/160

F c.4723A>T 27 / A 1.1 / 0.7 RE 320/160

F c.4393C>T 24 / A LP / LP RE 320/160

M c.6277delG 10 / P 1.9 / 1.4 RE 320/160

F c.547_550delTACC 15 / P LP / LP RE 320/160

F c.2991+1655A>G 14 / P 0.6/0.6 - 320/160

Disposition and Safety Results

Safety findings:

• Generally well tolerated with occasional mild AEs related to injection, typical to IVT.

• No SAEs.

• No early discontinuations.

• Independent DSMC agreed that there were no safety concerns.


10 subjects enrolled, no early terminations or SAEs

Subjects 1 2 4 3 1

# doses 0 1 2 3 4

Screened 12

> 1 month follow-up 10




Dosed 10

Top Line Efficacy Results


Concordant improvement in all outcome measures

Direction of improvement

Responder threshold

Change from baseline at Month 3Mean (SEM)

Treated Untreated

Visual Acuity (ETDRS/BRVT) – LogMAR (n=8) ↓= improved > -0.3 -0.67 (0.32) 0.02 (0.05)

Mobility Course – level (n=7) ↑ = improved >2 2.57 (1.19) 1.36 (1.04)

Full field stimulus red (FST red) - cd/m2 (n=7) ↓= improved -0.74 (0.35) -0.23 (0.18)

Full field stimulus blue (FST blue) - cd/m2 (n=7) ↓= improved -0.91 (0.38) -0.02 (0.11)

Nystagmus tracking (OCI) - Log10mm (n=7) ↓= improved -0.14 (0.08) -0.04 (0.06)

Best Corrected Visual Acuity (BCVA)


Majority of subjects had clinically meaningful improvement

Clinically meaningful (-0.3 LogMAR)

Individual subject responses

Chan

ge fr

om b

asel

ine

(Log

MAR

)

Impr

ovem

ent

p=0.011

EDTRS (LogMAR -0.3 - 1.6)

BRVT (LogMAR 1.4 - 4.0)

BCVA effect was maintained for at least 6 months


Dose 1 Dose 2 Dose 3

Clinically meaningful (-0.3 LogMAR)Im

prov

emen

t

Mobility Course for LCA10


• Large dynamic range to accommodate lower visual acuity.

• Measures functional visual performance using a series of courses at increasing difficulty and multiple light intensities.

• > 2 levels considered meaningful.

Course Light level Score

Fail all courses 0

BRE 100% LED 1

BRE 10% LED 2

HCRE 400 lux 3

HCRE 50 lux 4

HCRE 1 lux 5

HCVNC 400 lux 6

HCVNC 250 lux 7

HCVNC 125 lux 8

HCVNC 50 lux 9

HCVNC 10 lux 10

HCVNC 4 lux 11

HCVNC 1 lux 12

LCVNC 400 lux 13

LCVNC 250 lux 14

LCVNC 125 lux 15

LCVNC 50 lux 16

LCVNC 10 lux 17

LCVNC 4 lux 18

LCVNC 1 lux 19

Low-Contrast Visual Navigation Challenge at 1, 4, 10, 50, 125, 250, 400 lux (Ora, Inc. LCVNC™)

High-Contrast Visual Navigation Challenge at 1, 4, 10, 50, 125, 250, 400 lux (Ora, Inc. HCVNC™)

High-Contrast Room Exitat 1, 50, 400 lux (Ora, Inc. HCRE™)

Backlit Room Exit at 10% and 100% backlighting intensity (Ora, Inc. BRE™)

Grading scores:

Mobility Course


Improved at month 3 and month 6

Clinically Meaningful(2 levels)

Treated Eye Contralateral Eye

Impr

ovem

ent

Dose 1 Dose 2

Individual subject responses

Change in BCVA tracks with change in Mobility


Responder

Non-responder

Full Field Stimulus Test (FST)


Impr

ovem

ent

Measured with blue and red light

BlueTreated Eye

BlueContralateral Eye

RedTreated Eye

RedContralateral Eye

Ocular instability (OCI)


Measuring nystagmus (involuntary eye movement)

Treated Eye Contralateral Eye Individual subject responses

Impr

ovem

ent

EZ line in normal retina shows outer segments by EZ-line, as detected by OCT

ProQR Therapeutics – Corporate Presentation

20

EZ line is missing in LCA10 retina due to lack of outer segments

Month 1

Month 2

Month 3

Baseline

Example of restoration of anatomy detected by OCTRestoration of EZ-line in subjectNormal retina

LCA10 retina

ProQR Therapeutics – Corporate Presentation

Summary of Phase 1/2 interim analysis• QR-110 was safe and well tolerated.

• Approximately 60% of subjects demonstrated improvement in BCVA and performance on mobility course.

• Improvement was seen within two months of the first dose and has been maintained throughout ongoing dosing and monitoring.

• Improvement in physiological endpoints including full field stimulation test and ocular instability was also observed.

• General concordance between all 4 endpoints

21ProQR Therapeutics – Corporate Presentation

2 scales to measure vision:

Normal visionNo light perception

Sensitivity and Range of endpoints


020/20

1.020/200

2.0Countingfingers

3.0Hand

motion

4.0Light

perception

0.720/100

LogMARSnellen

1.620/800

Ranges are illustrative, not exact

AverageAverage

LCA2 patientsVision at baseline


Normal visionNo light perception

Sensitivity and Range of endpoints


020/20

1.020/200

2.0Countingfingers

3.0Hand

motion

4.0Light

perception

0.720/100

LogMARSnellen

1.620/800

OCI

Ranges are illustrative, not exact

Ocular Instability (OCI)



Functional vision assessed by mobility course(s)

Spark

ETDRSVision measured by BRVT or ETDRS is the gold standard

BRVT

2 scales to measure vision:

ProQR Mobility course

FSTFull Field Stimulus Test expected to be most sensitive endpoint

QR-110 Phase 1/2 in LCA10, Luxturna in LCA2


QR-110 Phase 1/2 in LCA10 Luxturna Phase 1 in LCA2 Luxturna Phase 3 in LCA2

Visual Acuity(ETDRS/BRVT)

Mean improvement of -0.67 LogMAR (p=0.01)62.5% improved > 0.3 LogMAR

Mean is not reported• 46% improved• 38% stable• 6% worseSource: BLA clinical review memo

Mean improvement of -0.16 LogMAR (p=0.17)

Source: FDA AdCom

Mobility course

Mean of 2.6 levels improvement57% of patients improved >2 levels

8/11 eyes showed improvement

Source: FDA AdCom

1.6 light levels improvement compared to placeboSource: FDA AdCom

FST red light

Mean Improvement of -0.74 logAAV-RPE 65-15 patient study. Mean improvement of -0.45 logJacobson et al., 2012

Improvement of -1.29 log

Source: ICER report

FST Blue light

Mean Improvement of -0.91 logAAV-RPE 65-15 patient study. Mean improvement of -1.59 logJacobson et al., 2012

AAV-RPE 65-15 patient study. Mean improvement of-1.96 logJacobson et al., 2012

OCImean change of log -0.14 mm 4 out of 7 patients improved

8 out of 12 patients improvedSource: A. M. Maguire et al 2009

Not reported

Not assessed in a head-to-head clinical trial

Preliminary design pivotal Phase 2/3 trial


Control group

Treatment group (dose level 2)

0 month 3 month 6 month 9 month 12 month

Treatment group (dose level 1)

• Double-blind, controlled, 12-month, dose range finding study in adaptive design

• Could serve as the sole registration trial• Sites in US and select EU countries• 30+ patients >6 years old• Multiple IVT injections initially in one eye

• Primary (registration) endpoints: • Visual Acuity (ETDRS, BRVT) • Mobility course

• Expected to start in H1 2019

• Preliminary design pending regulatory feedback

• Planning to start pediatric trial in <6 years old

Ophthalmology pipeline

• Clean safety profile (QR-110)

• Durable response with infrequent dosing

• Intravitreal administration delivers to the retina

• Clinically meaningful vision improvement in a majority of low vision patients

• Optic cup accurately predicted:

• Clinically efficacious intravitreal dose level

• Response to treatment

• Time to onset of response

• To be further validated in future trials of QR-110 and other IRD programs


Building on success of QR-110



TRIALS

OphthalmologyQR-110 for LCA10 p.Cys998X

QR-421a for Usher syndrome 2A exon 13

QR-1123 for P23H adRP - discovered by Ionis

QRX-504 for FECD3

QR-411 for Usher syndrome 2A PE-40

QRX-1011 for Stargardt’s disease c.5461-10T>C

QR-421a for Usher syndrome


Designed to treat genetic eye disease in Usher syndrome

Ushers

Develop hearing loss and blindness in childhood and turn completely blind by mid adulthood

Exon 13 mutations affect ~16,000 patients in western world.

√ RNA is established modality in eye√ Strong preclinical proof of concept

in patient retina√ Orphan drug designation√ Completed pre-IND meeting

STELLAR Phase 1/2 trial• Expect to dose a first patient with QR-

421a around YE 2018 with safety and efficacy results in mid 2019

• Expect results from multiple dose adaptive trial in H2 2020

Partnership

Awarded $7.5M financial support from FFB to conduct trial

For Usher exon 13 no therapy available

Unmet need

QR-421a produced functional ∆exon 13 Ush2a protein in optic cups and zebra fish


AON treated zebrafish showed b-wave ERG amplitude restoration

Time (ms)

Wild-type range

Ampl

itude

AON treated Exon 13 mutant

Erwin van Wijk, Radboudumc, Nijmegen, the Netherlands

AON treated optic cups from c.2299delG homozygous patient


Phase 1/2Single

Ascending Dose

STELLAR Phase 1/2 trial• Single dose, dose-escalation double blind controlled trial• Goals include safety and efficacy PoC and dose interval• Up to 12 adult patients with severe eye disease• Inclusion criteria: Visual field of >10o, visual acuity of 20/32 or worse• Single Intravitreal injection in one eye, or sham treatment• Key efficacy endpoints: Medmont DAC Perimetry, Static VF, microperimetry, OCT• First dose at YE 2018, data expected in Mid 2019

Meeting of independent DSMC

QR-421a Phase 1/2 trial in Usher 2a patients

Low dose (n=2-4)

Mid dose (n=2-4)

High dose (n=2-4)

Multiple dose adaptive trial

Open label extension

Multiple dose adaptive trial• Potentially pivotal• Repeated intravitreal injections, or sham

procedures in one eye• Goal: efficacy and safety• Up to 15 sites in US and select EU countries• First dose expected in mid 2019• Data expected in H2 2020

Washout informs dosing interval

QR-1123 for P23H adRP

Announced licensing agreement in October 2018• Upfront equity payment of $2.5 million at 20% premium ($22,23 per share)• Milestone payments (cash or equity, at ProQR’s discretion) • Royalties of 20% on net sales

High confidence in RNA therapies for eye diseases• Recent clinical proof of concept for QR-110 in LCA10• Solid pre-clinical proof of concept for QR-1123 adds another high quality

program to the ophthalmology pipeline • Success in this program would allow targeting other autosomal dominant

eye diseases


Exclusive worldwide license from Ionis Pharma


QR-1123 for P23H adRPGapmer targeting autosomal dominant RP due to the P23H mutation in RHO

P23H adRP

Progressive reduction in night & peripheral vision. Blindness is frequent in mid-adulthood

No therapy available

~2,500 patients with P23H adRP in United States

QR-1123

Goal: Restore vision/prevent vision loss in patients with P23H adRP

Locally adminis-tered in the eye. Routine intra-vitreal procedure

Anticipated infrequent dosing of 4 times a year or less

√ Established modality in eye√ Strong preclinical proof of concept in vivo√ In-licensed from Ionis Pharmaceuticals√ Majority of IND enabling activities completed√ 2 year Natural History Study is completed and

will be used to accelerate clinical development



• P23H mutation in the rhodopsin (RHO) gene causes autosomal dominant Retinitis Pigmentosa (adRP)• Rhodopsin is the light sensitive pigment in

rods in the retina• P23H mutant rhodopsin is misfolded and

toxic, causing progressive loss of rods (night and peripheral vision affected)

• Eventual loss of cones (central vision) causes patients to become legally blind by ~40-50 years of age

• P23H is the most prevalent mutation associated with adRP in the US, accounting for ~2,500 patients

• QR-1123 inhibits the formation of toxic mutant version of rhodopsin protein• QR-1123 selectively binds to the mutant

RHO mRNA• Gapmer structure causes RNase H

mediated cleavage of mutant mRNA without affecting the WT mRNA

• QR-1123 slows retinal degeneration in aggressive humanized mouse models of adRP

• Potential to reverse toxic effect and restore vision in P23H adRP patients


Disease Background & Clinical Phenotype

Rhodopsin Rhodopsin

QR-1123

Rhodopsin

MoA QR-1123QR-1123 blocks expression of toxic P23H mutant RHO protein

Healthy people inherit two wild type copies of the rhodopsin gene

P23H mutant rhodopsin is misfolded and toxic, causing progressive loss of rods

QR-1123 suppresses P23H mRNA with an allele specific mechanism


mRNA Rhodopsin

protein

Rhodopsin

Outersegment

Innersegment

Nucleus

Connectingcilium

RNA

DNA

DNA

Rhodopsin

QR-1123 is specific for P23H allele


Strong and specific suppression of P23H in cells QR-1123 is selective for P23H in vivo

QR-1123 preserves ONL and improves ERG in P23H rat model


Murray et al., 2015 IOVS 56: 6362

QR-1123 surrogate improves ERG in P23H Tg ratstrong correlation with ONL preservation

QR-1123 surrogate preserves ONLIn P23H Tg rat

mRHO AS03 PBS QR-1123 surrogate Control oligo

Light level Light level

Ampl

itude

(µV)

Ampl

itude

(µV)

QR-1123 reduces retinal degeneration in humanized P23H mice


Optic Nerve Head (ONH)

Superior retina

Inferiorretina

Lens

Optic NerveHead

Superior Inferior

Preliminary Phase 1/2 trial in adRPP23H patients


Preliminary Phase 1/2 trial design• Multiple dose, dose-escalation double-masked

controlled trial• Goals include safety and efficacy PoC and dose interval• Up to 12 adult patients with progressed eye disease

• Intravitreal injection in one eye, or sham treatment• Key efficacy endpoints: Medmont DAC Perimetry, Static

VF, microperimetry, OCT• Pending IND acceptance study start expected in 2019

Meeting of independent DSMC

Low dose

Mid dose

High dose

Open label extension

QR-411 for Usher syndrome


Designed to treat genetic eye disease in Usher syndrome

Ushers

Develop hearing loss and blindness in childhood and turn completely blind by mid adulthood

PE-40 mutation affects ~1,000 patients in western world

√ RNA is established modality in eye√ Strong pre-clinical proof of

concept in patient retina√ Orphan drug designation

Next steps • Progression into development after

validation of ophthalmology pipeline in QR-110 and QR-421a

QR-411

For Usher PE-40no therapy available

Strong pre-clinical PoCin human models. Development candidate selected

Strong PoC

QRX-1011 for Stargardt disease


Stargardt disease

Develop blindness in childhood and turn completely blind by mid adulthood

~7,000 patients with c.5461-10T>C in ABCA4in Western world

√ RNA is established modality in eye√ Strong pre-clinical proof of

concept


clinical validation of ophthalmology pipeline in QR-110 and QR-421a

QR-1011

For Stargardt c.5461-10T>C in ABCA4 no therapy available

Strong pre-clinical PoCin human models.

Strong PoC

QR-504 for FECD3


Fuchs’ Endothelial Corneal Dystrophy

Front of the eye disease leading to blindness in 50+ years of age

>250,000 patients with Repeat expansion in TCF4in Western world

√ RNA is established modality in eye√ Rapid delivery to corneal cells√ Strong pre-clinical proof of

concept in human primary cell models


clinical validation of ophthalmology pipeline in QR-110 and QR-421a

QR-504

For FECD3 Repeat expansion in TCF4No therapy available

Strong pre-clinical PoCin human primary models. Development candidate selected

Strong PoC

Inherited blindness pipeline beyond LCA10 and Usher

• QR-110 Phase 1/2 trial is expected to complete in H2 2019

• Phase 2/3 pivotal ILLUMINATE trial is expected to start enrollment in H1 2019

• QR-421a STELLAR Phase 1/2 trial is expected to readout in mid 2019

• QR-1123 Phase 1/2 trial expected to start in 2019

• Rapidly advancing several undisclosed discovery stage ophthalmology programs into developmentand clinical trials




TRIALS

OphthalmologyQR-110 for LCA10 p.Cys998X

QR-421a for Usher syndrome 2A exon 13

QR-1123 for P23H adRP - discovered by Ionis

QRX-504 for FECD3

QR-411 for Usher syndrome 2A PE-40

QRX-1011 for Stargardt’s disease c.5461-10T>C

QR-313 for dystrophic epidermolysis bullosa


DEB

Limited life expectancy

Blistering from birth

First product tar-gets most common mutation affecting ~2,000 patients in western world

QR-313

Molecular targeting with potential disease-modification due to long protein half-life

√ Strong preclinical proof of concept

√ Topical formulation based on existing hydrogel

√ FDA & EMA granted orphan drug designation

Next steps • Clinical trial initiated• Report interim data from

trial expected in late 2018 / early 2019

• Report full results expected in 2019

Topically applied. Commonly used hydro-gel, containing QR-313 RNA therapy

Anticipated convenient application at home. Maximum frequency every other day

Aims to heal wounds, restore skin and improve quality of life

QR-313 phase 1/2 trial in DEB patients

• IND enabling studies completed

• Placebo controlled, double-blinded phase 1/2 trial

• 4-8 RDEB exon 73 patients, >2yo (possibility of expansion

to 15 patients for adaptive repowering)

• 10 sites in US and select EU countries

• Independent DSMC

• Dosing 4 weeks, follow-up 8 weeks

• 2 or 3 doses per week depending on bandage change

frequency, 5gram gel (50mg QR-313) per 100cm2 area

• Endpoints

• Primary: safety, tolerability and exon skip

• Secondary: C7 protein detection (IF), anchoring fibrils (TEM),

wound healing (imaging), skin strength, time to re-blistering

• Orphan drug designation in EU and US

• Readouts:

• Exon skip in 4 or more patients in late 2018 / early 2019• Wound healing, re-blistering, IF, TEM in 2019


4 weeks treatment 8 weeks follow up

End of treatment

biopsy

End of follow-up

biopsy

Monitor wound healing and re-blistering

Potential broad applicability• >20,000 G-to-A mutations

described in literature• Proprietary Axiomer platform

technology can target G-to-A mutations

• Potentially broader applicability in protein modulation and stop-codon mutations

Strong IP protection• Invented in house at ProQR

laboratories• Protected with 5 patents families,

protecting Axiomer as a platform• Key collaborations with ADAR

experts in the world

Unique A-to-I RNA editing• A-to-I editing in RNA• Using endogenous ADAR• ADAR is recruited by a single

stranded Editing OligoNeucleotide (EON)

• I is translated as a G, allowing to target G-to-A mutations

Axiomer® RNA editing platform


Editing Oligonucleotide (EON) mediated A-to-I editing

Endogenous editing

EONs designed to recruit natural ADARs


Axiomer® EON-directed therapeutic editing

RNAEON

I

RNAEON

A

RNA

I

A

ADAR

RNA

E O N 1 E O N 2 E O N 3

I D U A e n z y m a t i c a c t i v i t y

( % c h a n g e o v e r c o n t r o l )

0 %

2 5 %

5 0 %

E O N 1 E O N 2 E O N 3

G A G r e d u c t i o n o v e r c o n t r o l

0 %

- 2 0 %

- 4 0 %

- 6 0 %

Robust Proof of Concept in Vivo


Readouts for restored function in IDUA Hurler mouse model

Enzymatic activity

GAG accumulation

RNA sequence correction

GAG reduction(% change over control)

Enzymatic activity (% change over control)

Axiomer® platform technology

Current status

• Discovered and developed in house

• 5 patent family applications filed protecting the full platform

• In vitro PoC in many other models, including CFTR class I mutations

• In vivo PoC in Hurler animal model

• >20,000 disease causing G>A mutations identified

Strategy

• Axiomer® platform technology has the potential to yield large number of new medicines for currently untreatable diseases

• ProQR plans to apply Axiomer® technology in core therapeutic areas

• Active business development strategy to capture value of platform

• First partnership with Galapagos N.V. on the application of Axiomer® technology in select fibrosis targets


Next steps and strategy

Strong team with proven track record


Management and leadership team Supervisory board

Daniel de Boer*Chief Executive Officer

Honorary former board member

Gerard Platenburg*Chief Innovation Officer

Smital ShahChief Financial Officer

René BeukemaChief Corp. Development Officer & General Counsel

David RodmanExecutive Vice President ofResearch & Development

Dinko Valerio*Chairman

Alison Lawton

Paul Baart

Antoine Papiernik

Henri Termeer*

James Shannon

* Founding team

Peter AdamsonSenior Vice President Opthalmology Franchise

World-class Scientific Advisory Committee

49ProQR Therapeutics – Corporate Presentation

Scott A. ArmstrongMD, PhD

Phillip D. ZamorePhD

Thaddeus DryjaMD

Cy SteinMD

NUCLEIC ACID THERAPEUTICS

Peter A. BealPhD

Annemieke Aartsma RusPhD

Art LevinPhD

Yi-Tao YuPhD

Broad IP estate• ProQR built a broad IP estate consisting of:

• 20 fully owned patent families• 6 licenses from academia (MGH, INSERM, Radboud University and Leiden University)

• Patent terms (excluding possible extension):• Eluforsen for F508del through 2033• QR-110 for LCA10 through 2036• QR-313 for DEB exon 73 through 2036• QR-411 for Usher PE-40 through 2037• QR-421a for Usher exon 13 through 2037• Axiomer® platform technology through 2037


Several upcoming milestonesQR-110 for LCA10

• Complete readout Phase 1/2 in H2 2019

• Start Phase 2/3 in H1 2019

QR-421a for Usher Syndrome exon 13

• STELLAR Phase 1/2 trial to start around YE 2018, safety and efficacy data readout in mid 2019

• Expected readout multiple dose adaptive trial in H2 2020



Pipeline

• Rapidly advancing several discovery and non-clinical stage ophthalmology programs to mature into development and clinical trials

QR-313 for Dystrophic EB exon 73

• WINGS Phase 1/2 Interim data readout in late 2018/early 2019, full data in 2019

Axiomer® RNA editing platform technology

• Strong potential for product and business development


ProQR since 2012

• Based in Leiden, the Netherlands

• 130 employees (30 nationalities)

• 2014 IPO NASDAQ: PRQR

• FD Shares outstanding: ~43 million (post September 2018 financing)

• Cash position (Q2 2018): € 33.0 million; no debt

• $104.1 million financing in September 2018

• $7.5M grant funding awarded by Foundation Fighting Blindness in February 2018

• $5M grant funding awarded by EBRP and EBMRF in June 2018

• Projected cash runway into 2021


Facts and figures as of September 2018

IT’S INOUR RNA

Documents

ProQR Corporate PresentationProQR inherited blindness platform ProQR Therapeutics – Corporate Presentation 6 Intravitreal delivery is routine procedure • Long half -life in the