Lysogene announces changes in the composition of its Board of Directors

CAMBRIDGE, MA and PARIS, France, – September 13, 2018, at 08.30am CET – Lysogene (FR0013233475 – LYS) (the “Company”), a pioneering biopharmaceutical company specializing in gene therapy targeting central nervous system (CNS) diseases, announced today that it has been informed of the resignation of Bpifrance Investissement from its mandate as director of the Company.

The permanent representative of Bpifrance Investissement within the Board of Directors is replaced at

the Audit Committee by Mr. Peter Lichtlen, independent member of Lysogene’s Board of Directors.

About Lysogene

Lysogene is a gene therapy company focused on the treatment of orphan diseases of the central nervous system (CNS). The company has built a unique capability to enable a safe and effective delivery of gene therapies to the CNS to treat lysosomal diseases and other genetic disorders of the CNS. A pivotal clinical trial in MPS IIIA and a phase 1- 2 clinical trial in GM1 Gangliosidosis are in preparation, while we are currently collaborating with a major partner to define the strategy of development for the treatment of Fragile X syndrome, a genetic disease related to autism. www.lysogene.com.

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Forward looking statement

This press release may contain certain forward-looking statements. Although the Company believes its expectations are based on reasonable assumptions, all statements other than statements of historical fact included in this press release about future events are subject to (i) change without notice, (ii) factors beyond the Company’s control and

(iii) the financial capabilities of the Company. These statements may include, without limitation, any statements preceded by, followed by or including words such as “target,” “believe,” “expect,” “aim,” “intend,” “may,” “anticipate,” “estimate,” “plan,” “project,” “will,” “can have,” “likely,” “should,” “would,” “could” and other words and terms of similar meaning or the negative thereof. Forwardlooking statements are subject to inherent risks and

uncertainties beyond the Company’s control that could cause the Company’s actual results, performance or achievements to be materially different from the expected results, performance or achievements expressed or implied by such forward-looking statements. A further list and description of these risks, uncertainties and other risks can be found in the Company’s regulatory filings with the French Autorité des Marchés Financiers, including in the 2017 registration document (Document de référence), registered with the French Markets Authorities on June 4, 2018, under number R. 18-047, and future filings and reports by the Company. Except as required by law, the Company assumes no obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in the forward-looking statements, even if new information becomes available in the future.