#1FREELNE FLT201: Initial Clinical Data October 6, 2023#2#3Creating better gene therapies for chronic debilitating diseases Potential first- and best-in-class lead program Highly differentiated gene therapy candidate FLT201 for Gaucher disease type 1 in first-in-human clinical trial Extending innovation into Parkinson's disease Lead research program leveraging our novel GCase variant for GBA1- linked Parkinson's disease Fol - Compelling initial clinical data Robust enzyme activity and favorable safety and tolerability in first two patients treated with FLT201 Experienced management team Seasoned leaders with the experience and expertise to drive progress and execution Our approach is to optimize all components of our product candidates to unlock the true potential of gene therapy FREELNE 3#4Lead clinical program with first- and best-in-class potential with research extending innovation into larger disease area Indication Gaucher Disease Type 1 FLT201 GBA1-linked Parkinson's Disease Approximate patient # ~18K ~190K Research Preclinical Phase 1/2 Phase 3 Worldwide rights Wholly owned $1B-plus peak sales potential Wholly owned Estimated patient numbers for Gaucher disease Type 1 are for US, UK, EU4 and Israel (Hematology. 2017 Mar;22(2):65-73. doi: 10.1080/10245332.2016.1240391; this figure represents the total theoretical genetic prevalence of the indication. The seroprevalence of antibodies against the AAVS3 capsid renders some patients ineligible for AAV gene therapy. We estimate approximately 60% would be eligible for AAVS3 gene therapy. Company estimate of patient numbers for GBA1-linked PD are for US, UK and EU4. FREELNE 4#5FLT201 in Gaucher Disease#6Gaucher disease type 1 is a debilitating, chronic and progressive disorder with life-altering symptoms Deficiency of GCase enzyme needed to metabolize Gb-1 in the lysosome Normal GCase function Normal metabolism of Gb-1 GCase deficiency Gb-1 not metabolized Harmful accumulation of Gb-1 and its substrate lyso-Gb1 in cells ¹Weinreb, et al., 2008 GCase = glucocerebrosidase. Gb-1 = glucosylceramide. Lyso-Gb-1 = glucosylsphingosine. Affects multiple organs, leading to wide range of symptoms and shortening life span¹ Bone pain and fractures Enlarged liver Reduced lung function *** Anemia and thrombocytopenia Enlarged spleen FREELNE 6#7Existing therapies poorly address certain aspects of disease LENGTHY INFUSION EVERY TWO WEEKS PEAKS AND TROUGHS in enzyme levels between infusions allow harmful substrates to build back up of ERT Enzyme replacement therapy current standard of care Easier to reach organs: liver, spleen Harder to reach organs: bone, lung X DOES NOT ADEQUATELY PENETRATE deeper organs, including bone and lung FREELNE7#8#9SRT offers an oral treatment option, but tolerability, compliance and perceived lack of efficacy limit its use Substrate reduction therapy (SRT) represents less than 20% of the market in Gaucher disease In study of 1388 patients who were either on SRT or ERT: 36% of patients on SRT switched to or went back to ERT 80% cited adverse events or lack of efficacy Physicians report compliance with 2-3x/day SRT is worse than for ERT Hughes, et al J. Clin. Med. 2022, 11, 5158. https://doi.org/10.3390/jcm11175158; FREELNE 9#10FLT201 has potential to deliver continuous level of enzyme and penetrate deeper tissues that existing therapies do not reach SINGLE DOSE Potent liver-directed AAVS3 capsid N Novel transgene for longer-acting engineered GCase variant Easier to reach organs: liver, spleen Harder to reach organs: bone, lung O O 00 O O 00 GCase variant 85 with prolonged half-life = more enzyme available to be delivered to cell and longer time in the cell itself FREELNE 10#11#12#13#14FLT201 demonstrates persistent coverage, while ERT is rapidly eliminated Spleen Bone marrow Lung Untreated Anti-GCase - DAB, Haematoxylin counterstain, AAV8 ERT (1h post-dose) ERT=Velaglucerase alfa ERT (24h post-dose) GBA1 var85 (steady state) FREELNE 14#15#16#17#18#19#20#21#22#23#24#25#26#27#28