Letter to AB Science stakeholders on COVID-19 pandemic impact on AB Science clinical studies

Paris, April 07, 2020, 6.15pm

A letter to our stakeholders on COVID-19 pandemic impact on AB Science clinical studies

Dear Stakeholders,

At this time, we expect that the COVID-19 pandemic will have limited impact on our clinical development program, as this crisis struck at a time when most of our on-going clinical studies were completed and new confirmatory studies were not yet initiated.

Data integrity is not affected for any of our programs as a result of the pandemic. The only trial with patients still under treatment is our phase 3 trial in prostate cancer (AB12003). In this study, we continue to work closely with our contract research organizations to monitor the safety of patients who are participating in the study. We have not observed any discontinuations nor deaths due to COVID-19.

For the studies to be read out, phase 2b/3 Alzheimer’s Disease AB9004, phase 3 Severe Asthma with High Eosinophils AB14001, phase 3 Pancreatic Cancer AB12005 and phase 3 Metastatic Prostate Cancer AB12003, the potential impact could be a delay of up to a couple of months in study read-out timing, due to more difficult access to the clinical sites to perform quality control checks before the database lock.

For the new phase 3 Mastocytosis (AB15001) and ALS (AB19001) confirmatory studies, patient enrollment will start once post-pandemic conditions permit proper access to the sites, which may delay the enrollment date initially planned in March 2020 by up to 3 months. This decision is necessary to ensure the safety and well-being of our employees, the patients and the healthcare professionals involved in our clinical trials, and to ensure the integrity of these trials.

AB Science remains in constant contact with our global network of key suppliers, manufacturing partners, and contract research organizations to identify potential risks and take appropriate measures to avoid any disruption. At this time, we do not anticipate any supply disruptions.

We have put into place remote operations and new policies to maintain the safety and well-being of our employees, in line with international COVID guidelines, while working to maintain business continuity.

We wish you well in these difficult times.

Alain Moussy

CEO

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: .

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

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