Time Sensitive Materials Depositary's Notice of Combined General Meeting of Nanobiotix S.A. ADSs: American Depositary Shares. ADS CUSIP No.: 63009J107. ADS Record Date

Depositary's Notice of

Combined General Meeting

To be counted, your Voting Instructions need to be received by the

Depositary prior to 10:00 A.M. (New York City time) on April 22, 2021.

* ADS holders must deliver their voting instructions in good form, to be received by the Depositary by this date - April 22, 2021 - 10:00 A.M. (New York City

time) in order to be counted. The Company's enclosed Notice of Meeting refers to voting deadlines as per local market regula- tions. The attached important notice is specific to all holders holding ADSs as of the ADS Record Date and the French Record

The Company has announced that the Meeting will be held at the date, time and location identified above. The meeting agenda has been repro- duced on page 3 hereof. Copies of some Company materials such as the procedures for obtaining preparatory documents and the statutory audi- tors report will be posted on April 7, 2021 and the Company's Notice of Meeting on April 7, 2021 at the

Company's website: https://www.nanobiotix.com/annual-general-meetings/. The information with respect to the Meeting and the ADS Voting Instructions contained herein and in any related materials

may change after the date hereof as a result of a change in circumstances (e.g. an adjournment or cancellation of the Meeting, a change in location and/or manner of holding the Meeting). The Company intends to announce any changes and updates only on

its website https://www.nanobiotix.com/annual-general-meetings/. We encourage you to check the referenced Company website for any updates to the information with respect to the Meeting and the ADS Voting Instructions as it is not expected

that any additional information will be distributed to you via mail or email.

The enclosed materials are provided to allow you to vote at the Meeting. The Company has requested the Depositary to provide you with instructions on the voting process.

As set forth in Section 4.10 of the Deposit Agreement and the Form of ADR, Holders of record of ADSs as of the close of business on the ADS Record Date who continue to hold

their ADS as of the French Record Date will be entitled, subject to any applicable law, the provisions of the Deposit Agreement, French law and the By-Laws of the Company and the provisions of or governing the Deposited Securities, to instruct the

Depositary as to the exercise of the voting rights, if any, pertaining to the Shares represented by such Holders' ADSs.

If you do not wish to vote as an ADS holder but rather wish to vote as a holder of the Company's Shares, you will need to arrange for the can- cellation of your ADSs and become

a Share holder in France before the French Record Date. You are advised to proceed with the cancellation of your ADSs well in advance of the French Record Date as the cancellation of ADSs and the delivery of the corresponding Shares in France may be

subject to unexpected processing delays.

Please note that the Company has informed the Depositary that under French company law and the Company's By-Laws, in order to exercise voting rights holders of Shares in

registered form must have their Shares registered in their own name, or where applicable in the name of a registered financial intermediary, in a share account maintained by or on behalf of the Company by the Share Registrar as of the French Record

Date. In order to exercise voting rights holders of Share in bearer form are required to have their Shares registered in their own name, or where applicable, in the name of a registered financial intermediary and obtain from an accredited financial

intermediary, and provide to the Company, an attendance certificate attesting to the registration of such Shares in the financial intermediary's account as of the French Record Date.

Please further note that a holder as of the ADS Record Date who desires to exercise its voting rights with respect to ADSs representing Shares in registered or bearer form is

required to: (a) be a holder of the ADSs as of the French Record Date, (b) deliver voting instructions to the Depositary by the ADS Voting Deadline, (c) instruct the Depositary to request that the Custodian deliver a voting form to the Company prior

to the deadline established by the Company, and (d) in the case of ADSs representing Shares in bearer form, instruct the Depositary to request that the Custodian deposit the requisite attendance certificate with the Company. The delivery of voting

instructions by an ADS Holder to the Depositary shall be deemed instructions to request delivery of the voting form and the attendance certificate.

If the Depositary receives from a Holder voting instructions which fail to specify the manner in which the Depositary is to vote the Deposited Securities represented by such

Holder's ADSs, the Depositary will deem such Holder to have instructed the Depositary to vote in favor of all resolutions endorsed by the Company's supervisory board. Deposited Securities represented by ADSs for which no timely voting instructions

are received by the Depositary from the Holder, the Depositary shall (unless otherwise specified in the notice distributed to Holders) deem such Holder, to have instructed the Depositary to give a discretionary proxy to a person designated by the

Company to vote the Deposited Securities; provided, however, that no such discre- tionary proxy shall be given by the Depositary with respect to any matter to be voted upon as to which the Company informs the Depositary that (i) the Company does not

wish such proxy to be given, (ii) substantial opposition exists, or (iii) the right of Holders of Deposited Securities may be materially adversely effected. Additionally, the Company has informed the Depositary that, under French company law,

shareholders holding a certain percentage of the Company's Shares, the workers' council or the supervisory board may submit a new resolution and the supervisory board may also modify the resolu- tions proposed in the Company's Notice of Meeting. In

such case, ADS Holders who have given prior instructions to vote on such resolutions shall be deemed to have voted in favor of the new or modified resolutions if approved by the supervisory board and against if not approved by the Company's

The attached document entitled Questions and Answers ("Q&A") should answer most of your questions on the voting process and instruct you on the proper use of the Voting

Upon receipt from a Holder (as of the ADS Record Date and who continues to hold the ADS as of the French Record Date) of a signed and completed Voting Instructions Card prior

to the ADS Voting Instructions Deadline, the Depositary shall endeavor, insofar as practicable and permitted under any applicable provisions of French law and the Company's By-Laws, to cause to be voted the Shares represented by such ADSs.

Please note that Voting Instructions may be given only in respect of a number of ADSs representing an integral number of Shares.

The information enclosed herewith with respect to the Meeting has been provided by the Company. Citibank, N.A. is forwarding this informa- tion to you solely as depositary and

in accordance with the terms of the Deposit Agreement and disclaims any responsibility with respect to the accuracy or completeness of such information. Citibank, N.A. does not, and should not be deemed to, express any opinion with respect to the

proposals to be con- sidered at the Meeting. If you wish to receive a copy of the Deposit Agreement, please contact the Depositary at the number set forth below.

If you have any questions concerning the enclosed material or if you need further explanation of the questions covered therein, please

call Citibank, N.A. - ADR Shareholder Services toll-free at 877-CITI-ADR (877-248-4237).

Citibank, N.A., as Depositary

Agenda for the Ordinary General Meeting

Agenda for the Extraordinary General Meeting

Agenda for the Ordinary General Meeting