Paris, July 04, 2019, 7pm

Validation of the AB8939 clinical development plan through
regulatory authority Scientific Advice procedure

AB Science will host a live webcast on 8 July to present the validated
clinical plan of AB8939 in AML and case report of a dog suffering
from leukemia treated with AB8939

AB8939 is a new generation microtubule destabilizer,
100% owned by AB Science, that has promising potential in oncology

AB Science SA (NYSE Euronext - FR0010557264 - AB) announces today that the European Medicine Agency (EMA) has validated the clinical development program for its new compound AB8939 in acute myeloid leukemia (AML) through a Scientific Advice procedure.

AB Science will host a live webcast on AB8939, focusing on the Scientific Advice procedure with EMA and resulting validated clinical development program of AB8939 in acute myeloid leukemia (AML).

The webcast will be held on July 8, 2019 from 5:30 pm to 6:30 pm CET. To participate, please send an email to contact@ab-science.com.

AB8939 is a new microtubule destabilizer that differs from other drugs of this class because it is a synthetic, as opposed to being derived from nature, and because it is not transported by the Pgp protein; thereby, overcoming Pgp-dependent multidrug resistance (a problem for many anthracycline drugs that are used in standard AML treatment).

AB8939 is initially being developed in AML because cancer cells proliferate rapidly in this disease. AB8939 is 100 times more potent than doxorubicin (adriamycin), which is a reference drug in AML. Furthermore, AB8939 is not deactivated by myeloperoxidase enzyme, which is an advantage over vinca alkaloids (vincristine or vinblastine).

The web conference will provide the opportunity to understand:

• The pharmacological properties of AB8939 and its key differentiating factors
• The rationale to develop AB8939 in AML and its potential in other oncology indications
• The completed non-clinical regulatory studies, which are deemed sufficient by EMA to start phase 1/2 clinical studies
• The clinical development program that has been validated by EMA though Scientific Advice, and in particular:
  • The design of phase 1/2 studies
  • The efficacy criteria to be met to be eligible for accelerated approval base on non-controlled phase 2 study, as validated by EMA
• The proof of concept data available in animal to support the claim of potential efficacy in advanced malignancies, and in particular:
  • Data from PDX mice transplanted with doxorubicin-resistant cancerous tumors from aggressive acute megakaryoblastic leukemia (AMKL) patients
  • A positive case report of a dog suffering from an acute lymphoblastic leukemia and resistant to standard treatments (vincristine, L-asparaginase, prednisone). This data is key in validating the potential activity of AB8939 in human, because this disease is similar in dogs and humans

It will be followed by a Q&A session.
The speaker will be Pr Olivier Hermine, MD, PhD. Olivier Hermine is co-founder of AB Science, Professor of Hematology at Paris V-René Descartes University, chief of adults Hematology staff at Hospital Necker (Paris), and member of the French Académie des Sciences in France.

About AB Science
Founded in 2001, AB Science is a pharmaceutical company specializing in the research, development and commercialization of protein kinase inhibitors (PKIs), a class of targeted proteins whose action are key in signaling pathways within cells. Our programs target only diseases with high unmet medical needs, often lethal with short term survival or rare or refractory to previous line of treatment.
AB Science has developed a proprietary portfolio of molecules and the Company’s lead compound, masitinib, has already been registered for veterinary medicine and is developed in human medicine in oncology, neurological diseases, and inflammatory diseases. The company is headquartered in Paris, France, and listed on Euronext Paris (ticker: AB).

Further information is available on AB Science’s website: www.ab-science.com.

Forward-looking Statements - AB Science
This press release contains forward-looking statements. These statements are not historical facts. These statements include projections and estimates as well as the assumptions on which they are based, statements based on projects, objectives, intentions and expectations regarding financial results, events, operations, future services, product development and their potential or future performance.

These forward-looking statements can often be identified by the words "expect", "anticipate", "believe", "intend", "estimate" or "plan" as well as other similar terms. While AB Science believes these forward-looking statements are reasonable, investors are cautioned that these forward-looking statements are subject to numerous risks and uncertainties that are difficult to predict and generally beyond the control of AB Science and which may imply that results and actual events significantly differ from those expressed, induced or anticipated in the forward-looking information and statements. These risks and uncertainties include the uncertainties related to product development of the Company which may not be successful or to the marketing authorizations granted by competent authorities or, more generally, any factors that may affect marketing capacity of the products developed by AB Science, as well as those developed or identified in the public documents filed by AB Science with the Autorité des Marchés Financiers (AMF), including those listed in the Chapter 4 "Risk Factors" of AB Science reference document filed with the AMF on November 22, 2016, under the number R. 16-078. AB Science disclaims any obligation or undertaking to update the forward-looking information and statements, subject to the applicable regulations, in particular articles 223-1 et seq. of the AMF General Regulations.

For additional information, please contact:

AB Science
Financial Communication & Media Relations
investors@ab-science.com

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• AB8939 SA VEng VF