Corporate Presentation

July 2019

Corporate Presentation July 2019 1 IMPORTANT NOTICE AND DISCLAIMER

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Corporate Presentation July 2019 2 Past 12 months

Significant global progresses for the company

Positive and significant Phase II/III in STS, presented at ASTRO & ESMO

CE Marking in STS

Positive clinical data in STS (IO), H&N , Liver Cancer presented at major congresses

Completion of Phase I dose escalation in Head and Neck

Positive preclinical in IO showing additional potential of the product in combination with Immune Checkpoint Inhibitors

Clinical trial authorization process to begin in 2H2019 with FDA filing

Major collaboration with MD Anderson to launch nine additional clinical trials

EIB loan granted (EUR 40m) with two tranches already borrowed

Successful ISO certification

Fund raising with US & EU new & existing specialized investors(EUR 29,5m)

Corporate Presentation July 2019 3 NANOBIOTIX

Company founded in 2003 Listed on Euronext since 2012 Pioneering Nanomedicine for over 10 years

Developing first-in-class radio enhancer for oncology targeting areas of high unmet needs Demonstrated clinical Proof of Concept in randomized Phase III trial Broad ongoing clinical development in 7 clinical trials (targeting ten indications) in EU, US and Asia Accessing the oncology market with first EU market approval obtained in Soft Tissue Sarcoma

Disruptive technology targeting large unaddressed oncology market

Corporate Presentation July 2019 4 Cancer patients treated with RTx represent significant market opportunity with large unmet medical needs

Inadequate local control (invasion) Inadequate local control Head and Neck, Glioblastoma, Liver (relapse) Pancreatic, Rectum, … Pancreatic, Prostate, Lung, Colorectal, Breast, …

Cancer patients

60% RTx**

Inadequate systemic unfavorable safety profile control (dose de-escalation/re- irradiation) Liver, Lung, Brain, …

Prostate, Head and Neck, Breast, Lung, Brain, Colorectal, …

Corporate Presentation July 2019 Source: * World Health Organization (2014); ** EQUIPMENT – A global strategic business report 08/06 RTx: radiotherapy 5 Nanobiotix targets radiation therapy - one of the largest oncology markets with limited competition

Conventional radiation therapy

Around 60%* of cancer patients TUMOR receive radiotherapy as a local treatment

Destroys any cancer cell at the right dose 50 cm

20 cm 20 cm

Important limitations due to toxicity on 100 photons at 6 MEV 100 photons @ 6 MeV healthy tissues Energy deposition Xray track

How to improve the energy dose within the tumor without damaging healthy tissues?

Corporate Presentation July 2019 Source: * RADIATION THERAPY EQUIPMENT – A global strategic business report 08/2006 6 Our solution: NBTXR3 enhances Xray absorption in the tumor

Technology key features:

1 50nm Nanosized to enter cell

2 Designed to strongly absorb Xrays 3 Designed to be non-toxic HfO2 ; electron microscopy picture

50 nanometer HfO2* particles were chosen because they have the best ratio for X-ray absorption and non-toxicity

IP: technology and product candidates protected by 20 patent families until at least 2029

* HfO2: Hafnium Oxide Corporate Presentation July 2019 Source: Maggiorella et al. (2012) 7 NBTXR3 has a physical mode of action: Leveraging NanoPhysics to fight cancer

Radiotherapy Radiotherapy with NBTXR3

Dose Dose

9X Dose* around Usual dose nanoparticles delivered in the cell Usual dose delivered in the cell

XRay XRay Clusters of Nanoparticles

Local 2 µm absorption of energy

Corporate Presentation July 2019 *Note: Dose enhancement determined by montecarlo simulation (CEA Saclay, France) 8 NBTXR3 UNIVERSAL MoA triggering cellular destruction and adaptative immune response

NBTXR3 +RTx

large energy deposition in a nano-volume → physical damage

• Structural Damage Clustered • DNA damage Nanoparticles in cytoplasm • Stress • Immunogenic Cell Death Dendritic cell • Sting pathway activation activation

CD4 & CD8 activation Direct Cell Death (Apoptosis, Necrosis, …) Tumor Infiltration and Cell Killing Corporate Presentation July 2019 9 NBTXR3 First in Class Radioenhancer

Physical Mode of Action that could work across all solid tumors to enhance radiotherapy efficacy

Only one administration

Fits into existing standard of care No change in equipment No change in current patient flow No change in protocol

One product addressing areas of high unmet medical needs

CE Marking obtained in Soft Tissue Sarcoma (commercial name: Hensify®)

Corporate Presentation July 2019 10 A product with solid foundations

Validated & protected product Over 19 patent families across the world Manufacturing demonstrated & certified ISO 13485:2016

Clinical reliability Universal Mechanism of Action (transferability) Proof of Concept demonstrated in a randomized Phase III trial in Soft Tissue Sarcoma Positive initial and promising results in different Phase I/II trials (Head and neck, HCC) NBTXR3 has been well tolerated Large clinical development pipeline with 16 contemplated clinical trials across a broad range of indications

Market acceptance (US & EU) Engaged dialogues with payers across US and EU Preclinical and clinical collaborations with major hospitals, including MD Anderson and Weill Cornell Major clinical collaboration with MD Anderson >400 MDs involved in development Fitting existing standard of care and single intra-tumoral injection

Corporate Presentation July 2019 11 Pipeline

Indication Preclinical PI PII PIII Approval

Soft tissue sarcoma EU / Asia

Head and neck cancer EU (RTx alone)

Head and neck cancer Asia NBTXR3 (RTx + chemo)*

as a Liver metastasis Single Agent EU Hepatocellular carcinoma

Rectal cancer* Asia

Prostate cancer US

Recurrent NBTXR3 Head & Neck US in Lung metastasis Inhibitors IO / Combo Checkpoint

NBTXR3 9 Phase I/II or II to be started in: + H&N, LAPC, esophageal US cancer, NSCLC, Pelvic & LN soft tissue masses

Corporate Presentation July 2019 *Conducted by PharmaEngine 12 First in class product – significant market opportunity to address areas of high unmet medical needs

Product with Physical and Universal Mode of Action Transferability across solid tumors Front line treatment & metastatic treatment

Clinical PoC demonstrated in Soft Tissue Sarcoma Phase II/III CE Marking obtained Positive Phase II/III New mode of action validated in randomized trial Primary endpoint: Pathological Complete Response Rate doubled vs radiation alone (p-value = 0.0448) ➔ Target: Start diffusing the product in EU

H&N first indication to be registered in US Positive Phase I data on advanced patients Showing potential impact on OS, ORR, QoL and well tolerated ➔ Target: Demonstrate the medical value in a high unmet medical needs population

Clinical development in PD-1 resistant patients Phase I: IND granted in NSCLC & Head and Neck advanced relapsed patient ➔ Target: Demonstrate the value of NBTXR3 in metastatic disease, transforming cold tumors into hot tumors

Expansion of NBTXR3 usage Five ongoing Phase I/II in multiple solid tumors Nine additional clinical development trials planned with MD Anderson global collaboration

Corporate Presentation July 2019 13 NBTXR3 in Soft Tissue Sarcoma

Corporate Presentation July 2019 14 Soft Tissue Sarcoma: patient population

Soft Tissue Sarcoma of the extremities* and trunk wall

Locally advanced soft tissue sarcoma, newly diagnosed or relapsed tumor:

➔High risk tumor ➔Borderline unresectable tumor or unfeasible carcinological surgical resection

Preoperative radiotherapy alone is used as a Standard of Care in this population

Main advantages (long term): • Lower late morbidity (fibrosis, bone fracture, etc.) • Improved long-term functional outcome • Improved quality of life

Unmet medical need for locally advanced soft tissue sarcoma

Corporate Presentation July 2019 * Arms and legs 15 Soft Tissue Sarcoma: treatment objectives

Ideal patient outcome in preoperative setting

• Removal of tumor • No remaining tumor cells in the body after surgery

Surgically remove (resect) tumor to improve patients’ survival and quality of life

Surgery

Corporate Presentation July 2019 16 Phase II/III Study in Soft Tissue Sarcoma

Flowchart and study design Data presented ASTRO/ESMO 2018 Session of RTx according to standard of care (25 x 2 Gy) Surgery

RTx (89 patients)

End of treatment RTx + NBTXR3 (87 patients) Day 1 One time Surgery Intratumoral injection

▪ 180 patients recruited (> 30 sites) ▪ 176 treated patients / Intended-to-treat population, full analysis set (ITT-FAS) ▪ 4 patients have been excluded from the ITT-FAS (outside of eligibility criteria): • 3 patients with no sarcoma • 1 patient randomized by error (patient considered as ineligible for pre-operative radiotherapy by the investigator – untreated patient)

Corporate Presentation July 2019 17 Two important clinical end points in STS Pathological response & Surgery Margin

Primary Endpoint Pathological response*

< 5%

Secondary Endpoint Surgery (Resection) margin

R0 Negative margin

*as per EORTC guidelines (Wardelmann et al., 2016) Corporate Presentation July 2019 18 NBTXR3 impact on the standard of care (planned radiation and surgery)

No change in Median Relative Radiation therapy dose intensity*

No change in Median Duration of radiotherapy schedule (days)

No change in % of surgery performed

The study confirmed: • Feasibility of injection • No change in dosage and schedule of current radiotherapy standard of care • Good local tolerance (similar radiation safety in both arms) • Manageable acute immunological reaction occurring at the time of injection

No impact on planned radiation and surgery

*Relative radiation therapy Dose Intensity = (Actual Dose Intensity / Planned Dose Intensity) ITT FAS (Full Analysis Set)

Corporate Presentation July 2019 19 pCRR: the study met its primary end point

Pathological Complete Response p-value 0.0448* 18 16,1 16 14 12 2x 10 7,9 8 6 % of patients with pCR with patients of % 4 2 0 Complete Pathological Response NBTXR3 activated by radiotherapy (N=87) Radiotherapy alone (N=89)

*Statistically significant at an adjusted α of 0,04575 *ITT FAS (Full Analysis Set)

Corporate Presentation July 2019 20 pCR multiplied by 4 in high grade sarcoma

Pathological Complete Response <5% residual viable cancer cells 35

30

25

20 17.1

15

% of % patients 4x 10

3.9 5 3.9 1.3 0 n=15 n=16 n=61 n=61 Grade 1 Grade 2/3

NBTXR3 activated by radiotherapy Radiotherapy alone Four fold increase in pathological complete response in the NBTXR3 arm in the higher grade sarcoma subgroup

ITT Full analysis set – subgroup: patients with pR and known grade % are calculated on the total number of patients in the subgroup. Arm A: 5 missing pR, 6 pts with unknown grade. Arm B: 6 missing pR, 6 pts with unknown grade

Corporate Presentation July 2019 21 NBTXR3 for local and relapse/metastatic treatment of cancer H&N strategy

Corporate Presentation July 2019 22 Head & Neck Cancer

493,000 The number of people diagnosed with Head & Neck Cancer in US, EU & Asia-Pacific region each year

Chemoradiation The standard of care in locally advanced Head and Neck Cancer

11% The percentage of patients (i.e. elderly and/or fragile) that are not eligible for chemoradiation

MAJOR NEED TO IMPROVE SURVIVAL AND QUALITY OF LIFE

Corporate Presentation July 2019 23 H&N: 3 clinical trials to demonstrate value capturing high unmet medical needs

Cancer diagnosis… …relapse… …Late stage cancer pathway pathway

Cancer patient patient Cancer 1st Line treatment Relapse / Locoregional or Radiotherapy Metastatic alone Radiotherapy + NBTXR3-102 Nivolumab or Pembrolizumab

Radiotherapy + Local relapse Cisplatin Lung Met Liver Met PEP-503 NBTXR3-1100 (PharmaEngine)

NBTXR3 Monotherapy Checkpoint + NBTXR3

Corporate Presentation July 2019 24 Ongoing phase I/II in Locally Advanced Squamous Cell Carcinoma of the Oral Cavity or Oropharynx (H&N)

Poor prognosis patient population:

Stage III and IV

T3 / T4 - Majority of N1 N2

Not eligible for chemo (RTx alone)

> 70 years old, frail

oral cavity, oropharynx

HPV all status (positive & negative)

Radiotherapy is the only reasonable option to treat this fragile H&N cancer patient population with limited benefits: Low ORR, Short PFS, Poor QoL

Corporate Presentation July 2019 25 Literature data: NBTXR3 Phase I/II Study Population has a poor Overall Survival prognostic

Amini et al. Bourhis et al. Moye et al. 2016 2006 2015

Median OS at 12-13 months

NBTXR3 PI/II patients should have equal or poorer prognosis • Tumor location (Oropharynx & Oral cavity) • Stage III-IV only • >70 years

Amini et al., Cancer May 15, 2016 Bourhis et al., Journal of Clinical Oncology, June 2006 Moye et al.,The Oncologist 2015;20:159–165

Corporate Presentation July 2019 26 Depth of best response* (update ICHNO 2019)

9 CR, ~90% ORR at highest doses CR linked to QoL

Corporate Presentation July 2019 27 NBTXR3 expected Value in Head and Neck Cancer Cut-off date: ICHNO 2019

No SAEs related to NBTXR3/Well tolerated with no serious side effects observed

100% of disease control at all doses ➔ Potential impact on QoL for patients 9/11 CR at higher doses* (10%, 15%, 22%)

Median follow up of >20 months ➔ Potential impact on Survival

Corporate Presentation July 2019 * Excluding non-evaluable patients & those recently added in the trial 28 NBTXR3 in combination with Immune Check Point Inhibitors

Corporate Presentation July 2019 29 H&N: 3 clinical trials to demonstrate value capturing several solid tumor indications

Cancer diagnosis… …relapse… …Late stage cancer pathway pathway

Cancer patient patient Cancer 1st Line treatment Relapse / Locoregional or Radiotherapy Metastatic alone Radiotherapy + NBTXR3-102 Nivolumab or Pembrolizumab

Radiotherapy + Local relapse Cisplatin Lung Met Liver Met PEP-503 NBTXR3-1100 (PharmaEngine)

NBTXR3 Monotherapy Checkpoint + NBTXR3

Corporate Presentation July 2019 30 Example Immunotherapy Nivolumab in recurrent patients H&N

Nivolumab: Checkmate 141 Recurrent Head and Neck.

Non responder

responder

Corporate Presentation July 2019 Ferris et al. NEJM 2016 31 Why priming is needed: Many tumors are inadequately responsive to checkpoints & other IO approaches

Hot

Cold

Hot

CD8

Cold No infiltration Limited infiltration Massive infiltration of immune cell of immune cell of immune cell Corporate Presentation July 2019 Adapted from Alexandrov et al. (2013) and Gentles et al. (2015) 32 Phase I/II in NSCLC & H&N to be initiated in combination with PD-1 Inhibitors

Checkpoint inhibitors refractory patients in NSCLC & H&N

Nivolumab: Checkmate 141 Recurrent Head and Neck.

Non responder To transform the non responder into responder with NBTXR3 and RTx

responder

Corporate Presentation July 2019 Ferris et al. NEJM 2016 33 Phase I Dose Escalation

anti PD-1 non responders (pembrolizumab or nivolumab): SD for at least 12 weeks or confirmed PD at 12 weeks

Cohort 1: Locoregionally recurrent AND metastatic HNSCC

Cohort 2: Patients with lung metastasis Primary tumor from NSCLC or HNSCC

Cohort 3: Patients with liver metastasis pre-treated Primary tumor from NSCLC or HNSCC

Corporate Presentation July 2019 34 NBTXR3 increases activated CD8 tumor infiltration Phase III Soft Tissue Sarcoma biomarker data

RTx + NBTXR3 Biopsy Baseline Pre Treatment Tumor Tissue Post Treatment

RTx Alone Biopsy Baseline Pre Treatment Tumor Tissue Post Treatment

C D 8 PDP D- 11 7 log2 ≥1 log2 ≥1 7 6 6/26 (23%) 11/23 (48%) log2 ≥1 log2 ≥1 6 5 5 9/26 (35%) 9/22 (41%) 4 4 3 3 2 2 1 1 0 0 -1 -1 -2 -2 -3 Log2 (fold change) log2 ≤1 log2 ≤1 -4

-3 8/26 (31%) 4/23 (17%) Log2 (fold change) -5 log2 ≤1 log2 ≤1 -4 -6 11/26 (42%) 5/22 (23%) -7

R T a lo n e H f0 2 -NP activated by RT R T a lo n e H f0 2 -NP activated by RT

Immunorad 2018, Paris, France

Corporate Presentation July 2019 35 Global clinical collaboration with MD Anderson: 9 clinical trials planned to start this year

Clinical collaboration will initially support 9 phase I/II or phase II Multiple indications: head & neck, pancreatic, thoracic, lung, gastrointestinal and genitourinary cancers Involving around 340 patients Risk sharing funding scheme: backloaded payment & post FDA registration payment

H&N: Dose Reduction RT for HPV+ OPSCC Thoracic: H&N: Treatment naïve esophageal cancer Borderline & Unresectable H&N NSCLC: H&N: Inoperable, checkpoint inhibitor combination, w/o chemo R3+SBRT for inoperable H&N (Re-Irradiation) NSCLC: H&N: Inoperable, checkpoint inhibitor combination, w/ chemo Resected high risk oral cavity/salivary Pelvic + LN soft tissue masses: Pancreas (moonshot program): Re-Irradiation: SBRT+R3 in LAPC

Corporate Presentation July 2019 36 First in class product / addressing high unmet medical needs

• Product with Physical and Universal Mode of Action

• Clinical Proof of Concept demonstrated in Soft Tissue Sarcoma PII/III

• H&N first indication to be registered in US

• Clinical development in PD-1 resistant patients

• Expansion of NBTXR3 usage with 5 ongoing Phase I/II in multiple solid tumors + 9 clinical trials in collaboration with MD Anderson

Corporate Presentation July 2019 37 Many growth levers

Indication Preclinical PI PII PIII Approval Cancer patients Soft tissue sarcoma EU / Asia

Head and neck cancer (RTx alone) EU

Head and neck cancer NBTXR3 (RTx + chemo)* Asia Liver metastasis as a Single Agent Hepatocellular EU carcinoma 60% Rectal cancer* Asia RTx Prostate cancer US

Recurrent NBTXR3 Head & Neck Lung US in Inhibitors metastasis IO / Combo Checkpoint

NBTXR3 9 Phase I/II or II to be started in: + H&N, LAPC, esophageal US cancer, NSCLC, Pelvic & LN soft tissue masses

NBTXR3 today is developed in 10 patient & could be expanded populations (+9 with MD Anderson) to many more patients

Corporate Presentation July 2019 *Conducted by PharmaEngine/publication under PharmaEngine responsibility 38 Financials and Shareholders

Financials Shareholding Structure as of June 2019

44,87% 46,87% K€ 2018 2017 Institutional Investors Total revenue and other income 3,479 3,722

Sales Family offices 116 252 22,360,039 Services 109 229 Other sales shares 7 23 Management & Licences - - employees Other revenues Retail 3,470 Research Tax Credit 3,363 Subsidies 3,251 3,259 Other 90 154 22 57 4,55% 3,72% Research & Development (R&D) costs (incl. (20,893) (17,733) Share-based payments) Analyst Coverage Selling, General and Administrative (SG&A) (12,653) (11,255) costs (incl. Share-based payments) Jefferies – Peter Welford Operating loss (30,067) (25,267) Kempen – Anastasia Karpova Financial loss (277) (876) Gilbert Dupont – Jamila Elbougrini Income tax - - Net loss for the period (30,345) (26,143) Kepler Cheuvreux – Arsene Guekam Consolidated cash available as of 30 Jun 2019: €54.9M Stifel – Christian Glennie

H.C. Wainright – Ramakanth Swayampakula

Portzamparc – Christophe Dombu

Degroof Petercam – Benoit Louage

Corporate Presentation July 2019 39 Newsflow

✓ MD Anderson clinical collaboration ✓ Preclinical data in IO (NBTXR3 in combination with cPI) H1 ✓ FDA feedback H&N ✓ CE Marking in Europe for STS ✓ Fundraising (EUR 29,5m)

HCC Phase I/II follow up results Final H&N Phase I dose escalation results Potential early results IO combination trial H2 Multiple launch of Phase I/II or II by MD Anderson

US H&N: clinical trial authorization process to begin in 2H2019 with FDA filing + other news to come

Corporate Presentation July 2019 40