Exhibit 99.(a)(1)(O)

[AAA Letterhead]

[Name / address of holder]

By international courier service and email

December 7, 2017

Object: notification of your right to exercise your stock options

Dear Sir / Madam,

On December 5, 2017, Advanced Accelerator Applications S.A. (the “Company”) announced that it recommended the cash tender offer by Novartis Groupe France S.A., a société anonyme organized under the laws of France and a direct and indirect wholly-owned subsidiary of Novartis AG, a company organized under the laws of Switzerland, to acquire all of the outstanding ordinary shares, nominal value €0.10 per share (each, an “Ordinary Share” and, collectively, the “Ordinary Shares”), including Ordinary Shares represented by American Depositary Shares (each of which represents two Ordinary Shares) (each, an “ADS” and, collectively, the “ADSs”) of the Company for U.S. $41.00 per Ordinary Share and U.S. $82.00 per ADS (each such amount, the “Offer Price”), in each case, payable net to the seller in cash, without interest, less any withholding taxes that may be applicable, upon the terms and subject to the conditions set forth in the Offer to Purchase enclosed herewith, that you are strongly encouraged to read (the “Offer”).

The Offer commenced on December 7, 2017 and will expire at 12:00 midnight, New York City time on January 19, 2018 (which is the end of the day on January 19, 2018), unless extended in accordance with the terms of the Offer, which are described in more detail in the Offer to Purchase (the “First Offer” and the latest time and date at which the First Offer will expire, the “Expiration Date”). The closing of the First Offer is subject to the satisfaction or waiver of various conditions precedent, which are also described in more detail in the Offer to Purchase. In the event of the successful closing of the First Offer, a subsequent offer period, the dates of which are to be fixed and will be communicated through a press release issued by Novartis after the closing of the First Offer, will be commenced (the “Subsequent Offer”).

The Company has granted to you a total number of stock options equal to [·], which are subject to terms and conditions provided for in the stock option plan rules dated November 10, 2015 (the “Stock Option Plan”). You will find attached to this notification the list of stock options granted to you under the Stock Option Plan and outstanding as of November 20, 2017 with their corresponding exercise price in EUR or USD, respectively.

Pursuant to article 4.3(b) of the Stock Option Plan, all of your non-vested options become exercisable in the event of the occurrence of a “Transaction” (“Opération”), as defined in the Stock Option Plan. The Company hereby notifies you that the Offer qualifies as such.

Therefore, as from the commencement of the First Offer and until the closing of the Subsequent Offer, you have the right to exercise all your stock options, and tender the underlying shares into the Offer.

Please note that pursuant to article 4.3 of the Stock Option Plan, the stock options which are not exercised before the closing of the Subsequent Offer will become definitely null and void as of that date. We therefore recommend that, should you wish (i) to exercise your options and participate in the Offer, you should do so as soon as possible and (ii) to opt for the Cashless Exercise (as defined below), you shall do so in any event during the First Offer.

The Company and Novartis appointed Banque Transatlantique S.A. for processing the exercise of stock options, centralizing instructions to tender Company’s shares and all related payments and tax withholdings, as applicable. You will find all relevant operational details in the “AAA Shareholder or LTI Plan Participant Tender Participation Guide”.

Please note that irrespective of whether you opt or do no opt for the cashless exercise, Banque Transatlantique S.A. will charge a transaction fee of USD 5 cents per share for each tendered Ordinary Share resulting from the exercise of your stock options.

In particular, the Company and Novartis have arranged a cashless exercise (the “Cashless Exercise”) for all stock options holders, pursuant to which you have the opportunity to mandate and instruct Banque Transatlantique S.A. to process the exercise of your options and tender the underlying shares into the Offer, with the exercise price being deducted from the Offer Price. Subject to the successful closing of the First Offer, the actual issuance of shares and their tender will take place during the Subsequent Offer. Following the closing of the Subsequent Offer, you will receive from Banque Transatlantique S.A. the Offer Price less the exercise price, applicable withholding taxes and transaction fees, for each ordinary share underlying your stock options (the “Cashless Exercise Proceeds”). The Cashless Exercise is proposed during the First Offer only.

Please note that all actions referred to below can be completed through the online tool made available by Banque Transatlantique S.A. that you are encouraged to use. You can

also submit paper forms enclosed but in such case, you shall ensure the timely submission of your instructions to Banque Transatlantique S.A. (Stockplan Department) at the following address: 26, avenue Franklin Delano Roosevelt, 75372 Paris Cedex 08, France.

If you OPT for the Cashless Exercise facility, you must instruct Banque Transatlantique S.A. online (recommended) or return to Banque Transatlantique S.A. the Cashless Exercise and Tender Notice provided in Annex I to this letter, duly completed and executed, before the Expiration Date of the First Offer.

Please note that:

(i) the exercise will concern all of your stock options and be conditional upon the successful closing of the First Offer, failing which you will retain your rights to your stock options that will continue to be subject to the Stock Option Plan rules,

(ii) the exercise procedure will be settled by Banque Transatlantique S.A. during the Subsequent Offer (which includes the issuance and tender of the shares underlying your stock options into the Offer and, following the closing of the Subsequent Offer, payment to you of the Cashless Exercise Proceeds), and

(iii) you may withdraw your election for the Cashless Exercise facility by delivering a written notice of withdrawal to Banque Transatlantique S.A. (Stockplan Department) at 26, avenue Franklin Delano Roosevelt, 75372 Paris Cedex 08, France, prior to the Expiration Date. As a result of such withdrawal, your stock options will not be exercised as part of the Cashless Exercise facility and your Cashless Exercise and Tender Notice will be null and void.

If you do NOT opt for the Cashless Exercise facility, you may complete the exercise procedure individually by returning to Banque Transatlantique S.A. (i) the enclosed Exercise Notice provided in Annex II, accompanied by payment of the exercise price by wire transfer to the bank account opened in your name with Banque Transatlantique S.A. (whose number is indicated directly in Annex II) for remittance to the Company; you will have to make sure to credit this account before the Expiration Date of the First Offer or the closing date of the Subsequent Offer which date is to be communicated through a press release issued by Novartis), and (ii) if you decide to participate in the Offer, the enclosed Share Acceptance Form, which is provided in Annex II, to be duly completed and executed, and transmitted before the Expiration Date of the First Offer or on the closing date of the Subsequent Offer which date is to be communicated through a press release issued by Novartis. These actions can also be handled online.

Please note that upon the payment by you of the exercise price, your stock options will be definitely exercised and the shares underlying your stock options will be issued, irrespective of the successful closing of the Offer.

Please refer to the Offer to Purchase for additional information regarding the Offer, including a description of the terms of the Offer and the procedures for participating in the Offer.

List of your Stock Options outstanding as of November 20, 2017 which are exercisable under the Offer to the extent they remain outstanding as of December 7, 2017:

Date of Grant	Number of Stock Options outstanding	Exercise price per option
xxx	xxx	€xxx
xxx	xxx	US$xxx

ANNEX I - To be completed if you opt for cashless exercise

Cashless Exercise and Tender Notice

In order to be processed, this form must be submitted to Banque Transatlantique S.A. by the Expiration Date, at the latest, through the online remittance process (please refer to the “AAA Shareholder or LTI Plan Participant Tender participation Guide”):

You also have the possibility to send your instructions by letter with acknowledgement of receipt or delivery in person to the following address, but you are recommended to use the online process:

Banque Transatlantique S.A.

Stockplan Department

26, avenue Franklin Delano Roosevelt

75372 Paris Cedex 08

France

, on

Object: cashless exercise of my stock options and tender of underlying shares into the Offer

I, the undersigned, declare that I opt for the cashless exercise facility in respect of all my stock options and tender all the ordinary shares of Advanced Accelerator Applications S.A. (the “Company”) issued as the result of the exercise of my stock options to the cash tender offer by Novartis Groupe France S.A., a société anonyme organized under the laws of France and a direct and indirect wholly-owned subsidiary of Novartis AG, a company organized under the laws of Switzerland, to acquire all of the outstanding ordinary shares, nominal value €0.10 per share (each, an “Ordinary Share” and collectively, the “Ordinary Shares”), including Ordinary Shares represented by American Depositary Shares (each of which represents two Ordinary Shares) (the “ADSs”) of the Company, for U.S. $41.00 per Ordinary Share and U.S. $82.00 per ADS, in each case, payable net to the seller in cash, without interest, less any withholding taxes that may be applicable (the “Offer”).

I hereby declare to exercise my options as follows:

Number of exercised options	Corresponding exercise price per option	Total exercise price
xxx	€xxx	€xxx
xxx	US$xxx	US$xxx

Please note that your exercise instruction will be proceeded up to the number of options per grant date that are outstanding prior to the start of the Offer and that have vested as the result of the Offer.

Total shares to be issued upon exercise of my options:

xxx ordinary shares
of Advanced Accelerator Applications S.A.

I hereby mandate and instruct Banque Transatlantique S.A. to process the exercise of my stock options, including the share subscription, and tender into the Offer all of the Ordinary Shares of Advanced Accelerator Applications S.A. issued as the result of the exercise of my options at the price of US$ 41.00 per share (“Offer Price”) and in particular, I agree by submitting this instruction that ownership of these Ordinary Shares be transferred to Novartis Groupe France S.A. For this purpose:

(i) I acknowledge that the Ordinary Shares issued pursuant to the exercise of my stock options will be inscribed in my name in administered form (nominatif administré) in my account maintained by Banque Transatlantique S.A., AND

(ii) I further irrevocably order Banque Transatlantique S.A. to transfer the ownership of all Ordinary Shares referred to in (i) above from my individual shareholder’s account to Novartis Groupe France S.A.’s individual shareholder’s account.

I hereby instruct Banque Transatlantique S.A. to make the payment of the amount of the exercise price for my stock options to Advanced Accelerator Applications S.A. in my name and on my behalf, by deducting the corresponding amount from the Offer Price and I will receive the balance, net of any applicable withholding taxes and transaction fees(1), through Banque Transatlantique S.A. This amount will be paid to me by wire in US dollars, promptly after the closing of the Offer and the tender of my Ordinary Shares into the Offer, on my cash account opened with Banque Transatlantique S.A. I will be able to liaise thereafter with Banque Transatlantique S.A. to convert this amount into Euros and transfer this USD or EUR amount to any other bank account opened with any bank.

I acknowledge that:

(1) Banque Transatlantique S.A. will charge a transaction fee of USD 5 cents per share for each tendered Ordinary Share resulting from the exercise of your stock options

· pursuant to article 4.3 of the Stock Option Plan, the stock options which are not exercised before the closing of the Subsequent Offer will definitely become null and void at that date;

· the exercise of my stock options will be conditional upon the successful closing of the First Offer, failing which I will retain my rights to my stock options that will continue to be subject to the Stock Option Plan rules;

· the tender of Ordinary Shares is made subject to all the terms and conditions of the Offer, and I hereby make all the representations, warranties and undertakings of tendering holders that are set forth in the Offer to Purchase, which I acknowledge I have received;

· undertake to assume the tax and social consequences of the exercise of my stock options, and in particular, as the case may be, authorize Banque Transatlantique S.A., acting on behalf of my employer or in its role as paying agent, to withdraw from the Offer Price any withholding tax or social security contributions that I owe and remit these amounts to my employer (or my former employer) or directly to the relevant authorities (please see “Tax Information Notice” below). If such withholding cannot be made, I will remain liable towards my employer/paying agent for the corresponding amount.

Tax Information Notice

Depending on the tax and social security rules applicable in your current country of employment or in the country where you were employed during the vesting period of the options, Banque Transatlantique S.A., acting either on behalf of your employer or your former employer or in its role as paying agent, may have withholding obligations for the amount of tax/social charges that you owe on the gain that you would make through the exercise of your options.

I recognize that I am urged to consult my tax advisor on the tax consequences applicable to my cashless exercise.

All my instructions provided herein become final and irrevocable at the Expiration Date. Until that time, I have the right to withdraw my instruction to cashless exercise of my options. In order to proceed with such withdrawal, I shall contact Banque Transatlantique S.A., Stockplan Department, 26, avenue Franklin Delano Roosevelt, 75372 Paris Cedex 08, France.

I have retained a copy of this form for my personal files.

ANNEX II — To be completed if you do not opt for Cashless Exercise

ADVANCED ACCELERATOR APPLICATIONS S.A.

French Société Anonyme with a share capital of EUR 8,851,565.70

Registered address: 20, rue Diesel — 01630 SAINT-GENIS-POUILLY

441 417 110 RCS BOURG-EN-BRESSE

(the “Company”)

Exercise Notice of the Stock Options (the “Exercise Notice”)

1) Issuance of the New Shares Resulting from the Exercise of the Stock Options

Subject to the delivery of this Exercise Notice of the stock options and the payment of the exercise price, the share capital of the Company will be increased by an amount equal to EUR 0.1 per ordinary share issued upon the exercise of each option (the “New Shares”) (one stock option giving right to subscribe to one ordinary share).

The New Shares will be inscribed in my name in administered form (nominatif administré) in my account maintained by Banque Transatlantique S.A. The right of the stockholder will be represented by an entry into the shareholders’ account held by the Company. The New Shares will have to be fully paid upon the day of their subscription. The New Shares will be submitted to all the provisions of the by-laws of the Company and will be assimilated to the outstanding ordinary shares as from the date of their issuance.

I must pay the exercise price by wire transfer, on the account opened in my name into the books of Banque Transatlantique S.A., for remittance to the Company, whose number is indicated here below (this wire transfer must be received before the Expiration Date of the First Offer or the closing date of the Subsequent Offer which date is to be communicated through a press release issued by Novartis - any transfer received after that date will not be taken into account).

Number of my account in the books of Banque Transatlantique S.A.: [·]

[Alternative if we do not have the account number for participants before launching the communication: Where can I find my Banque Transatlantique S.A. account number? In section “Your accounts” of the website ww.transatplan.com, using personal access codes.]

Banque Transatlantique S.A. will charge a transaction fee of USD 5 cents per share for each tendered Ordinary Share resulting from the exercise of your stock options.

2) Subscription Notice

I, [first name, last name, address],

Holder of [·] stock options,

After having reviewed and acknowledged the (i) by-laws of the Company, (ii) Stock Option Plan, (iii) Notification Letter, (iv) above described conditions of the share capital increase of the Company and (v) Exercise Notice dated today,

Confirm the exercise of(2):

o All my stock options;

o stock options, and in such case, acknowledge that, pursuant to article 4.3 of the Stock Option Plan rules dated November 10, 2015, the stock options which are not exercised before the closing of the Subsequent Offer will definitely become null and void at that date;

Declare the subscription of:

· the New Shares;

Confirm that I initiated a wire transfer to be received before the Expiration Date of the First Offer or the closing date of the Subsequent Offer, for payment of the exercise price to the Company to the bank account mentioned under 1) above and enclose proof hereof.

I declare that I kept an original of the Exercise Notice for myself.

, on

(3)

(2) Please tick the box according to your choice and fill-in the related blank as necessary

(3) Signature to be preceded by the written mention « Subscription of the New Shares »

Share Acceptance Form

ORDINARY SHARE ACCEPTANCE FORM

TO TENDER ORDINARY SHARES

ADVANCED ACCELERATOR APPLICATIONS S.A.

U.S. $41.00 PER ORDINARY SHARE

PURSUANT TO THE OFFER TO PURCHASE DATED DECEMBER 7, 2017

NOVARTIS GROUPE FRANCE S.A.

A DIRECT AND INDIRECT WHOLLY-OWNED SUBSIDIARY

NOVARTIS AG

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY TIME, ON JANUARY 19, 2018 (WHICH IS THE END OF THE DAY ON JANUARY 19, 2018),

UNLESS THE OFFER IS EXTENDED.

Online remittance process to Banque Transatlantique S.A.
(please see the AAA Shareholder or LTI Plan Participant Tender Participation Guide)

Novartis Groupe France S.A., a société anonyme organized under the laws of France (“Purchaser”) and a direct and indirect wholly-owned subsidiary of Novartis AG, a company organized under the laws of Switzerland, is offering to purchase all of the outstanding ordinary shares, nominal value €0.10 per share (each, an “Ordinary Share” and, collectively, the “Ordinary Shares”), including Ordinary Shares represented by American Depositary Shares (each of which represents two Ordinary Shares) (each, an “ADS” and, collectively, the “ADSs”), of Advanced Accelerator Applications S.A., a société anonyme organized under the laws of France (“AAA”), for U.S. $41.00 per Ordinary Share and U.S. $82.00 per ADS (each such amount, the “Offer Price”), in each case, payable net to the seller in cash, without interest, less any withholding taxes that may be applicable, upon the terms and subject to the conditions set forth in the Offer to Purchase, dated December 7, 2017 (together with any amendments or supplements thereto, the “Offer to Purchase”) and in this Ordinary Share Acceptance Form (together with any amendments or supplements hereto, the “Ordinary Share Acceptance Form” and, together with the Offer to Purchase, the American Depositary Share Letter of Transmittal and other related materials, as each may be amended or supplemented from time to time, the “Offer”), as applicable.

PLEASE REVIEW AND COMPLETE (IF NECESSARY) THE FOLLOWING INFORMATION

Full name and address of the holder of Ordinary Shares (hereinafter, the “Shareholder”):

	Name:


	Address:


	Town/City:


	Postal/ZIP Code:


	Country:


	Telephone number:


	E-mail address:

The Shareholder hereby tenders the following number of Ordinary Shares:

Number of Ordinary Shares:

The Shareholder orders Banque Transatlantique S.A. (the “Ordinary Shares Agent”) to transfer the ownership of all its tendered Ordinary Shares from the Shareholder’s individual account to Purchaser’s individual account.

The tender of Ordinary Shares is subject to all the terms and conditions of the Offer, and the Shareholder hereby makes all the representations, warranties and undertakings of tendering holders that are set forth in the Offer to Purchase, which the Shareholder acknowledges it has received.

The Shareholder (i) acknowledges that all payments of the Offer Price will be made by Purchaser in cash, in the form of a wire payment, in U.S. dollars, into his/her/its account with the Ordinary Shares Agent, which the Shareholder will have opened in connection with tendering the Shareholder’s Ordinary Shares into the Offer (if the Shareholder wishes to receive the Offer Price in euros, the Shareholder should refer to the AAA Shareholder or LTI Plan Participant Tender Participation Guide) and (ii) expressly authorizes the Ordinary Shares Agent to withdraw from the Offer Price any withholding tax or social charge contribution that may be due by the Shareholder and pay it directly to the relevant tax administration (see Instructions below).

Name of Shareholder:



Signature of Shareholder:



Name of signer (if Shareholder is a legal entity):



Title of signer (if applicable):

PLEASE READ THE INSTRUCTIONS ACCOMPANYING THIS ORDINARY SHARE ACCEPTANCE FORM CAREFULLY BEFORE COMPLETING THIS ORDINARY SHARE ACCEPTANCE FORM.

INSTRUCTIONS

Forming Part of the Terms and Conditions of the Offer

1. Requests for Assistance or Additional Copies. Questions or requests for assistance may be directed to the Ordinary Shares Agent at its address and telephone number set forth below. Additional copies of the Offer to Purchase, this Ordinary Share Acceptance Form and other tender offer materials may be obtained from the Ordinary Shares Agent as set forth below, subject to applicable law, and will be furnished at Purchaser’s expense.

2. Withholding. Shareholders who have received their Ordinary Shares pursuant to a stock-option plan or a free share plan and who tender their Ordinary Shares into the Offer may be subject to withholding taxes and/or social charges that may have to be withheld at source by the Ordinary Shares Agent.

IMPORTANT TAX INFORMATION

With respect to Shareholders who have received their Ordinary Shares pursuant to a stock-option plan or a free share plan, the Ordinary Shares Agent, acting either on behalf of the Shareholders’ current or former employer or in the Ordinary Shares Agent’s role as paying agent, may have withholding obligations for the amount of tax and/or social charges that these Shareholders owe on a portion of the gains that they would make in the Offer. Shareholders who have received their Ordinary Shares pursuant to a stock-option plan or a free share plan are urged to consult their tax advisor on the tax consequences applicable to their participation in the Offer.

The Ordinary Shares Agent for the Offer is:

Banque Transatlantique S.A.

Stockplan Department

26, avenue Franklin Delano Roosevelt

75372 Paris Cedex 08

France

Email:

adacap@banquetransatlantique.com

Phone number:

+33 1 56 88 72 02

Yours faithfully,


Stefano Buono
Chief Executive Officer


Name		Signature (please write “Read and approved”)