Lysogene: 2017 annual results

• Significant operational progress
• Higher R&D expenses with the preparation of the pivotal trial in MPS IIIA

PARIS, France, and CAMBRIDGE MA., US —March 26, 2018—06:30pm—CEST Lysogene (FR0013233475 – LYS), a gene therapy company pioneering therapies to treat diseases of the central nervous system (CNS), today announced its 2017 financial results, as approved by the Board of Directors on March 22, 2018. Audit procedures on the statutory and consolidated financial statements have been performed in accordance with professional standards applicable in France.

Karen Aiach, Founder and Chief Executive Officer, commented: “As announced at the time of our IPO, Lysogene has continued to develop its two drug candidates. We have completed the recruitment in the Natural History of MPS IIIA and we have presented our preliminary data which are in line with expectations. We are well positioned to start our phase III pivotal trial in 2018 for LYS-SAF302, our most advanced drug candidate for MPS IIIA, as we obtained the green light from the Paediatric Investigation Plan. We are also pleased with the progress of our GM1 gangliosidosis programme, with a goal to start in clinical development in 2019 and which obtained all the regulatory approvals early 2017. This implies that our second drug candidate gains recognition from the Health authorities.”

Selected financial information at December 31, 2017 (IFRS Consolidated accounts)

In € thousand	2017	2016
Revenue	–	–
Other operating revenue	2,687	1,493
R&D expenses	(15,330)	(6,329)
Administrative, sales and marketing expenses	(4,573)	(2,453)
Operating income	(17,216)	(7,289)
Net income	(17,794)	(7,484)
Net income per share (€)	(1.52)	(0.91)
Net cash flow related to operating activities	(14,615)	(6,653)
Net cash flow related to financing activities	23,149	(217)
Cash position variation (excl. forex differences)	(14,938)	(6,616)
Cash and cash equivalents at the end of the period	14,089	6,353

As expected, operating expenses rose sharply, reflecting:

• • GMP1 batch production of LYS-SAF302 and the start of GMP batch production of LYS- GM101;
  • Pre-clinical research studies (MPS IIIA and GM1);
  • Continuation of the MPS IIIA Natural History study, which will be used as a control group in the pivotal trial; and
  • Expansion of the workforce.

Alongside these developments, other operating revenues – of which the Company’s research tax credit accounts for 96% – amounted to €2.7 million versus €1.5 million in 2016. Lysogene posted a net loss of €17.8 million in 2017 compared to €7.5 million in 2016.

Losses per share increased to €1.52 in 2017 from €0.91 in 2016.

Lysogene had €14.1 million of cash and cash equivalent as of December 31, 2017. The Company is looking at various options for strengthening its financial position in the next 12 months, notably a capital increase, a debt financing or possible partnerships.

As a reminder: 2017 key operational highlights Successful IPO

• February 2017 marks an important milestone in Lysogene’s development with the successful initial public offering on Euronext Paris, raising approximately €22.6 million.

Strengthening the management team by appointing a COO and a CMO

• Dr Sophie Olivier and Mr Philippe Mendels-Flandre were respectively appointed Chief Medical Officer and Chief Operating Officer to strengthen Lysogene’s management team and support the company with its strategic growth. Sophie was previously Pediatric Coordinator at the European Medicines Agency (EMA), after holding various positions within the Wyeth group. They both have more than 15 years of experience in the healthcare industry and regulatory drug development.

LYS-SAF302, Lysogene’s most advanced drug candidate for MPS IIIA

• In March, Lysogene presented baseline data from the first International Pivotal Observational Study in MPS IIIA (SAMOS2). This study is critical as it will serve as a control group for Lysogene’s

1 Good Manufacturing Practices

2Sanfilippo A Multinational Observational Study

pivotal (phase II/III) trial. The successful recruitment of 23 patients in SAMOS was completed in May and preliminary data are in line with Lysogene’s expectations and were presented at the World Symposium 2017.

• In September, Lysogene set up its Clinical Advisory Board (“CAB”), consisting of internationally renowned experts in gene therapy, neurosurgery and metabolic diseases. The CAB will provide strategic advice to Lysogene as it continues to advance its clinical development programs and devise commercialization paths for its two orphan drug candidates in gene therapy.

Besides, Lysogene successfully held its first meeting of the Parent Advisory Board for parents and caregivers of children with MPS IIIA.

LYS-GM101, Lysogene’s second drug candidate for the treatment of GM1 gangliosidosis

• In 2017, LYS-GM101 was granted with the orphan drug designation from both the European Medicines Agency (EMA) and the U.S. Food and Drug Administration (FDA). The FDA also granted a rare pediatric disease designation to LYS-GM101 earlier in the year.
• In May, Lysogene signed a manufacturing agreement with a first-class contract manufacturing organization based in the US, for the production of LYS-GM101, using the AAVrh10 vector, to be used in clinical trials to treat patients with GM1 gangliosidosis. The manufacturing platform is one of the leading producers of cell and viral vector-based gene therapy products.

Key operational highlights since December 31, 2017

• On February 6th 2018, Lysogene obtained Paediatric Investigation Plan (PIP) green light from European Medicines Agency paving way for clinical trial application approvals on MPS IIIA pivotal study. The positive PIP opinion by the EMA’s Paediatric Committee (PDCO) is a significant milestone toward submission of Lysogene’s marketing authorization application following completion of the phase 3 trial.

Next financial milestones:

• First quarter 2018 revenue and cash position on April 16, 2018 (after market close)
• Ordinary shareholders’ meeting on June 4, 2018
• Second quarter 2018 revenue and cash position on July 16, 2018 (after market close)

About Lysogene

Lysogene is a gene therapy company focused on orphan diseases of the central nervous system (CNS), and a leader in MPSIIIA. Lysogene has generated five non-cumulative years of clinical safety data to show the efficiency of a direct delivery route to the CNS with its first gene therapy trial for MPS IIIA. The company has recently completed the enrollment for the first multi-national observational study in MPS IIIA, which

will function as the non-concurrent control for the pivotal trial for MPS IIIA that is expected to start in H1 2018. A phase 1 clinical trial for GM1 Gangliosidosis is expected to start 2019. Both programs have orphan drug designation from the EMA and the U.S Food and Drug Administration (FDA) and rare pediatric designation from the FDA.

Lysogene is listed on the Euronext regulated market in Paris (ISIN code: FR0013233475) For more information, please visit www.lysogene.com.

Contacts

Investors:

Chris Maggos

LifeSci Advisors

chris@lifesciadvisors.com

+41 79 367 6254