Onxeo

Legal Proceedings Report • Jul 7, 2016

Onxeo collaborates with the Royal College of Surgeons in Ireland for research program on Beleodaq® derivatives

Paris (France), Copenhagen (Denmark), July 7, 2016 – Onxeo S.A. (Euronext Paris, NASDAQ Copenhagen: ONXEO), an innovative company specializing in the development of orphan oncology therapeutics, today announced a collaboration with the Royal College of Surgeons in Ireland (RCSI) for a discovery-stage program on the derivatives of belinostat (Beleodaq®), a histone deacetylase (HDAC) inhibitor.

This new collaboration program aims at optimizing the pharmacokinetic profile of belinostat, in order to increase its lifetime, its efficacy and its stability. In the end, the goal is to develop conjugate molecules derived from belinostat and with distinctive features compared to existing HDAC inhibitors, which may lead to new patent opportunities. The research projects will be led by Pr. Celine Marmion, Associate Professor of Bioinorganic Chemistry at RCSI and specialized in rational drug design, synthesis and pharmacological evaluation of metal-based anti-cancer agents.

According to the terms of the agreement, research costs will be shared between Onxeo and RCSI. Onxeo will have an option to license RCSI's patents at negotiated rates. RCSI will lead compounds synthesis and in vitro testing, and Onxeo will lead the in vivo studies.

"We are excited to partner with leading research institution such as RCSI for this preclinical program which should allow us to develop new compounds derived from belinostat. This will enable us to strengthen our portfolio while capitalizing on the experience already acquired with this product. Results of these researches are expected in the course of 2017" commented Judith Greciet, CEO of Onxeo.

The concept for such a derived conjugated belinostat was validated by similar work described in a safety and efficacy presentation at the American Society of Hematology (ASH) Annual Meeting in 2011.

About Onxeo

Onxeo is a leading developer of orphan oncology drugs. The Company is focused on developing innovative therapeutics for rare cancers, one of the fastest growing markets in the healthcare industry with high, unmet medical needs. Onxeo's vision is to become a global leader and pioneer in oncology, with a focus on orphan or rare cancers, by developing advanced, effective, and safe therapeutics designed to improve the lives of patients. 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).

Onxeo's orphan oncology products are:

Livatag® (Doxorubicin Transdrug™): Currently being evaluated in a Phase III trial (ReLive) in patients with hepatocellular carcinoma (primary liver cancer); and in combination with other cancer agents in first-line HCC

• Beleodaq® (belinostat): FDA-approved in the US in 2014 under the agency's accelerated approval program as a second-line treatment for patients with peripheral T-cell lymphoma (PTCL) and currently marketed by Onxeo's partner in the US, Spectrum Pharmaceuticals; belinostat in combination with other cancer agents is currently in development in first-line treatment for patients with PTCL (BelCHOP) and in other solid tumors
• AsiDNA: The first-in-class siDNA (signal-interfering DNA) which has successfully undergone a proof-of-concept Phase I trial in metastatic melanoma
• Validive® (Clonidine Lauriad®): Positive final results from a Phase II trial in head and neck cancer patients with severe oral mucositis

In addition, Onxeo has successfully developed and registered two non-cancer products which are currently being commercialized in the U.S. and Europe.

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).

Contacts : Judith Greciet, CEO Nicolas Fellmann, CFO contact@onxeo.com +33 1 45 58 76 00

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

Kirsten Thomas / Lee Roth – The Ruth Group (U.S.) kthomas@theruthgroup.com / lroth@theruthgroup.com +1 508 280 6592 / +1 646 536 7012