Onxeo

Declaration of Voting Results & Voting Rights Announcements • Jan 17, 2017

A Public Limited Company with Share Capital of 11 760 851 euros Registered Address 49, boulevard du Général Martial Valin – 75015 Paris Paris Trade and Companies' Register 410 910 095

DISCLOSURE OF THE TOTAL NUMBER OF VOTING RIGHTS AND SHARES COMPOSING THE SHARE CAPITAL

Pursuant to article L. 233-8 II of the French Commercial Code (Code du Commerce) and article 223-16 of the General Regulation of the French Financial Markets Authority (AMF – Autorité des Marchés Financiers)

As at December 31, 2016:

Total number of outstanding shares	47,043,404
Theoretical voting rights (1)	47,043,404

Shares without voting rights

Treasury registered shares (2)	0
Treasury bearer shares (3)	23,800
Others (4)	0

Exercisable voting rights	47,019,604
= (1) - [(2) + (3) + (4)]

The increase in capital is related to the definitive acquisition of bonus shares previously granted by the Company.

About Onxeo

Onxeo is a biopharmaceutical company specializing in the development of innovative drugs for the treatment of orphan diseases, in particular in oncology, driven by high therapeutic demand in one of the fastest growing segments of the pharmaceutical industry. Onxeo's objective is to become a major international player in the field of rare cancers. Its growth strategy is founded on the development of innovative, effective, and safe drugs based on breakthrough technologies that can make a real difference in the treatment of orphan oncology diseases and considerably improve the quality of life of patients affected by rare and aggressive cancers. Onxeo's comprehensive portfolio features a broad orphan oncology pipeline, with four independent programs in various stages of clinical development, including Onxeo's first approved orphan oncology drug, Beleodaq®. The Company is headquartered in Paris, France and has approximately 50 employees. Onxeo is listed on Euronext in Paris, France (Ticker: ONXEO, ISIN Code: FR0010095596) and Nasdaq Copenhagen, Denmark (Ticker: ONXEO).

Learn more by visiting www.onxeo.com.

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Disclaimer

This communication expressly or implicitly contains certain forward-looking statements concerning Onxeo and its business. Such statements involve certain known and unknown risks, uncertainties and other factors, which could cause the actual results, financial condition, performance or achievements of Onxeo to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Onxeo is providing this communication as of this date and does not undertake to update any forward-looking statements contained herein as a result of new information, future events or otherwise. For a discussion of risks and uncertainties which could cause actual results, financial condition, performance or achievements of Onxeo to differ from those contained in the forward-looking statements, please refer to the Risk Factors ("Facteurs de Risque") section of the 2015 Reference Document filed with the AMF on April 29, 2016, which is available on the AMF website (http://www.amf-france.org) or on the company's website (www.onxeo.com).

Onxeo Valerie Leroy, Investor Relations investors@onxeo.com +33 1 45 58 76 00

Media Relations

Caroline Carmagnol / Florence Portejoie – Alize RP onxeo@alizerp.com +33 6 64 18 99 59 / +33 6 47 38 90 04

Investor & Media Relations US Kirsten Thomas / Lee Roth – The Ruth Group kthomas@theruthgroup.com / lroth@theruthgroup.com +1 508 280 6592 / +1 646 536 7012