Charcot-Marie-Tooth Disease, Type 2A

Expanded strategic collaboration with University of Pennsylvania’s Gene Therapy Program to advance genetic medicines for large CNS diseases, initially focused on Alzheimer’s Disease and Temporal Lobe Epilepsy Expect to deliver three key clinical milestones in second half of 2021: Dose first patients in global Phase 1/2 trials for PBFT02 and PBKR03 in 3Q21 Report initial safety and 30-day biomarker data from Imagine-1 global Phase 1/2 trial of PBGM01 for the treatment of infantile GM1 in 4Q21 Opened new CMC research and development site in Hopewell, N.J. Appointed three new executives – chief commercial officer, chief financial officer and chief medical officer Management to host conference call today at 8:30 a.m. ET PHILADELPHIA, Aug. 05, 2021 (GLOBE NEWSWIRE) -- Passage Bio, Inc. (Nasdaq: PASG), a clinical-stage genetic medicines company focused on developing transformative therapies for central nervous system (CNS) disorders, today reported financial results for the second quarter ended June 30, 2021 and provided recent business highlights. “As we advance our pipeline and invest in our capabilities, we are committed to becoming a leader in developing transformative genetic medicines for people with CNS disorders,” said Bruce Goldsmith, Ph.D., president and chief executive officer of Passage Bio. “I am extremely excited about the opportunity that the expanded partnership with Penn’s Gene Therapy Program creates for us to address the significant unmet needs of not only rare but also larger patient populations impacted by devastating CNS disorders. Our expanded research collaboration will include the identification of relevant biological targets for genetic modulation. We also have continued to build the talent of our company so that we can efficiently and effectively execute our clinical programs and new research opportunities. I’m also very pleased with our recent executive appointments.” James M. Wilson, M.D., Ph.D., chief scientific advisor for Passage Bio; Rose H. Weiss professor and director, Orphan Disease Center; professor in Departments of Medicine and Pediatrics, Perelman School of Medicine; and director of University of Pennsylvania’s Gene Therapy Program (GTP), said: “We are delighted with the progress that has been made through our collaborative R&D relationship with Passage Bio. Extending the scope of our collaboration is a logical next step and will allow us to deploy our gene therapy technologies into potential treatments for even larger patient populations that suffer from severe disabling and lethal neurological diseases.” Eliseo Salinas, M.D., MSc., chief R&D officer of Passage Bio, added: “As we broaden our CNS pipeline, we also continue to prioritize execution against our three lead clinical development programs. We are making steady progress opening our global network of clinical sites across nine countries and three continents and managing through lingering COVID-19 pandemic impacts. We continue to expect to dose the first patients in the third quarter for our clinical trials for frontotemporal dementia with granulin mutations, upliFT-D; and Krabbe disease, GALax-C. We also expect to report initial safety and 30-day biomarker data in the fourth quarter for our ongoing Imagine-1 global trial for GM1 gangliosidosis. We’re excited by the momentum we’re building in our journey to deliver life-transforming therapies for patients with rare CNS disorders.” Recent Highlights Passage Bio and Penn’s GTP expanded strategic collaboration and license agreement to advance genetic medicines for large patient populations : The agreement establishes new research programs to discover and develop new genetic medicines for Alzheimer’s Disease and Temporal Lobe Epilepsy as well as additional large CNS indications upon mutual agreement. These new programs include a collaborative initial discovery phase focused on identifying relevant biological targets for these two diseases. The collaboration term has also been extended by an additional year to 2026. As part of the expansion, Penn will receive a $5.0 million upfront payment as well as additional royalties and milestone payments for products that may arise from the newly added research programs. : The agreement establishes new research programs to discover and develop new genetic medicines for Alzheimer’s Disease and Temporal Lobe Epilepsy as well as additional large CNS indications upon mutual agreement. These new programs include a collaborative initial discovery phase focused on identifying relevant biological targets for these two diseases. The collaboration term has also been extended by an additional year to 2026. As part of the expansion, Penn will receive a $5.0 million upfront payment as well as additional royalties and milestone payments for products that may arise from the newly added research programs. Global Phase 1/2 clinical trials for both PBFT02 and PBKR03 on track to dose first patients in third quarter of 2021: The company expects to report initial safety and 30-day biomarker data in the first half of 2022 for the global clinical trials upliFT-D for PBFT02 for frontotemporal dementia with granulin mutations (FTD-GRN), and GALax-C for PBKR03 for Krabbe disease. Genetic testing to help identify FTD patients is being offered through InformedDNA, a leading genetics services organization; and through Invitae, a leading medical genetics company, for patients suspected of having Krabbe disease. The company expects to report initial safety and 30-day biomarker data in the first half of 2022 for the global clinical trials upliFT-D for PBFT02 for frontotemporal dementia with granulin mutations (FTD-GRN), and GALax-C for PBKR03 for Krabbe disease. Genetic testing to help identify FTD patients is being offered through InformedDNA, a leading genetics services organization; and through Invitae, a leading medical genetics company, for patients suspected of having Krabbe disease. Imagine-1 global Phase 1/2 clinical trial of PBGM01 for the treatment of infantile GM1 gangliosidosis progressing toward initial safety and 30-day biomarker data readout in 4Q21: In April 2021, the company announced that the first patient was dosed for the treatment of infantile GM1 gangliosidosis (GM1) in the global Imagine-1 trial. During the second quarter of 2021, the company advanced clinical site activation efforts and plans to open additional sites in the third quarter. In April 2021, the company announced that the first patient was dosed for the treatment of infantile GM1 gangliosidosis (GM1) in the global Imagine-1 trial. During the second quarter of 2021, the company advanced clinical site activation efforts and plans to open additional sites in the third quarter. PBFT02 received European Commission Orphan Designation for the treatment of FTD-GRN: This designation provides Passage Bio with certain potential benefits, including clinical protocol assistance, reduced regulatory fees, research grants and up to 10 years of market exclusivity following regulatory approval. This designation provides Passage Bio with certain potential benefits, including clinical protocol assistance, reduced regulatory fees, research grants and up to 10 years of market exclusivity following regulatory approval. New gene therapy R&D lab opened in Hopewell, N.J.: The Chemistry, Manufacturing and Controls (CMC) laboratory, called Princeton West, will support analytical development, clinical product testing and assay validation for Passage Bio’s novel gene therapy candidates. The Chemistry, Manufacturing and Controls (CMC) laboratory, called Princeton West, will support analytical development, clinical product testing and assay validation for Passage Bio’s novel gene therapy candidates. New executive leadership appointments announced: Maria Törnsén joined Passage Bio as chief commercial officer, effective July 19. Ms. Törnsén, who has nearly 20 years of global commercial experience, was most recently at Sarepta Therapeutics, where she was senior vice president, general manager, U.S. Simona King will join Passage Bio as chief financial officer (CFO), effective August 23. Ms. King, former executive vice president and CFO at Tmunity Therapeutics, has more than 20 years of pharmaceutical and biotech strategic finance experience. Mark Forman, M.D., Ph.D. , joined Passage Bio as chief medical officer, effective July 30, from the Alzheimer’s Drug Discovery Foundation, where he oversaw the drug discovery and development portfolio. Dr. Forman has nearly 20 years of experience in translational research for neurological disorders in both corporate and academic settings, having worked at Acadia, Merck and the University of Pennsylvania. Derrell D. Porter M.D., elected to Passage Bio board of directors in May 2021. Dr. Porter, who brings strong corporate strategy, product development and commercial experience, serves on the Audit Committee of the board. He is founder and chief executive officer of Cellevolve Bio, a cell therapy company focused on transforming investigational CNS, oncology and transplant therapies into commercial products. Anticipated Upcoming Milestones Dose first patient in Phase 1/2 FTD-GRN trial in 3Q21; report initial safety and 30-day biomarker data in 1H22. Dose first patient in Phase 1/2 Krabbe trial in 3Q21; report initial safety and 30-day biomarker data in 1H22. Report initial safety and 30-day biomarker data from Phase 1/2 PBGM01 trial in 4Q21. Continue to advance early-stage programs for PBML04 (Metachromatic leukodystrophy), PBLA05 (Amyotrophic lateral sclerosis) and PBCM06 (Charcot-Marie-Tooth Disease Type 2A), and an undisclosed adult CNS program. Second Quarter 2021 Financial Results Cash Position: Cash, cash equivalents and marketable securities were $407.8 million as of June 30, 2021, as compared to $304.8 million as of December 31, 2020. The company expects current cash and cash equivalents to fund operations for at least the next 24 months. Cash, cash equivalents and marketable securities were $407.8 million as of June 30, 2021, as compared to $304.8 million as of December 31, 2020. The company expects current cash and cash equivalents to fund operations for at least the next 24 months. Research and Development (R&D) Expenses: R&D expenses were $33.1 million for the second quarter ended June 30, 2021, compared to $19.9 million for the same quarter in 2020. R&D expenses were $33.1 million for the second quarter ended June 30, 2021, compared to $19.9 million for the same quarter in 2020. General and Administrative (G&A) Expenses : G&A expenses were $15.4 million for the second quarter ended June 30, 2021, compared to $7.4 million for the same quarter in 2020. : G&A expenses were $15.4 million for the second quarter ended June 30, 2021, compared to $7.4 million for the same quarter in 2020. Net Loss: Net loss was $48.4 million, or a net loss of $0.90 per basic and diluted share, for the second quarter ended June 30, 2021, compared to $27.2 million, or a net loss of $0.60 per basic and diluted share, for the same quarter in 2020. Conference Call Details Passage Bio will host a conference call and webcast today at 8:30 a.m. ET. To access the live conference call, please dial 833-528-0605 (domestic) or 830-221-9711 (international) and reference conference ID number 4037236. A live audio webcast of the event will be available on the Investors & News section of Passage Bio’s website at investors.passagebio.com. The archived webcast will be available on Passage Bio's website approximately two hours after the completion of the event and for 30 days following the call. About Passage Bio At Passage Bio (Nasdaq: PASG), we are on a mission to provide life-transforming genetic medicines for patients with CNS diseases that replace their suffering with boundless possibility, all while building lasting relationships with the communities we serve. Based in Philadelphia, PA, our company has established a strategic collaboration and licensing agreement with the renowned University of Pennsylvania’s Gene Therapy Program to conduct our discovery and IND-enabling preclinical work. This provides our team with enhanced access to a broad portfolio of gene therapy candidates and future gene therapy innovations that we then pair with our deep clinical, regulatory, manufacturing and commercial expertise to rapidly advance our robust pipeline of optimized gene therapies into clinical testing. As we work with speed and tenacity, we are always mindful of patients who may be able to benefit from our therapies. More information is available at . Penn Financial Disclosure Dr. Wilson is a chief scientific advisor, collaborator, consultant and co-founder of Passage Bio. As such, he holds an equity stake in the company, his laboratory at Penn receives sponsored research funding from Passage Bio, and as an inventor of certain Penn intellectual property that is licensed to Passage Bio, Dr. Wilson may receive additional financial benefits in the future. The University of Pennsylvania receives sponsored research funding from Passage Bio and has licensed intellectual property to the company that may result in future financial returns to Penn. Forward-Looking Statements This press release contains “forward-looking statements” within the meaning of, and made pursuant to the safe harbor provisions of, the Private Securities Litigation Reform Act of 1995, including, but not limited to: our expectations regarding our new research program with Penn’s Gene Therapy Program in large indications, including whether the expanded collaboration will result in any new product candidates in the selected targets or other indications; our expectations about timing and execution of anticipated milestones, including initiation of clinical trials and the availability of clinical data from such trials; our expectations about our collaborators’ and partners’ ability to execute key initiatives; our expectations about manufacturing plans and strategies; our expectations about cash runway; and the ability of our lead product candidates to treat their respective target CNS disorders. These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “might,” “plan,” “potential,” “possible,” “will,” “would,” and other words and terms of similar meaning. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including: our ability to develop and obtain regulatory approval for our product candidates; the timing and results of preclinical studies and clinical trials; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; the occurrence of adverse safety events; the risk that positive results in a preclinical study or clinical trial may not be replicated in subsequent trials or success in early stage clinical trials may not be predictive of results in later stage clinical trials; failure to protect and enforce our intellectual property, and other proprietary rights; our dependence on collaborators and other third parties for the development and manufacture of product candidates and other aspects of our business, which are outside of our full control; risks associated with current and potential delays, work stoppages, or supply chain disruptions caused by the coronavirus pandemic; and the other risks and uncertainties that are described in the Risk Factors section in documents the company files from time to time with the Securities and Exchange Commission (SEC), and other reports as filed with the SEC. Passage Bio undertakes no obligation to publicly update any forward-looking statement, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information, please contact: Investors: Stuart Henderson Passage Bio 267.866.0114 shenderson@passagebio.com Media: Gwen Fisher Passage Bio 215.407.1548 gfisher@passagebio.com Passage Bio, Inc. Balance Sheets (Unaudited) Passage Bio, Inc. Statements of Operations and Comprehensive Loss (Unaudited)

- On track to initiate three Phase 1/2 clinical programs in the first half of 2021: PBGM01 for GM1 gangliosidosis (GM1), PBFT02 for frontotemporal dementia with granulin mutations, and PBKR03 for Krabbe disease - - Opened first U.S. site for PBGM01’s Imagine-1 global clinical program and actively recruiting patients; other site activations in progress - - Opening new CMC research and development site to support analytics, assay development, and product testing in 2Q 2021 - - Strengthened financial position with recent public offering that raised $166M in net proceeds - - Management to host conference call today at 8:30 a.m. ET - PHILADELPHIA, March 03, 2021 (GLOBE NEWSWIRE) -- Passage Bio, Inc. (Nasdaq: PASG), a genetic medicines company focused on developing transformative therapies for rare, monogenic central nervous system disorders, today reported financial results for the fourth quarter and full year ended December 31, 2020 and provided recent business highlights. “At Passage Bio, we are on a mission to provide life-transforming therapies to patients with devastating CNS diseases, and we are pleased with the foundational work we accomplished in 2020 as we transition to a clinical-stage company in 2021,” said Bruce Goldsmith, Ph.D., president and chief executive officer of Passage Bio. “In the year ahead, our priorities are progressing three clinical development programs, all set to begin in the first half of 2021, and continuing to expand our pipeline and internal operations. We are confident that with the expertise of our talented internal team, our partnership with University of Pennsylvania’s Gene Therapy Program, and our relationships with patient and physician groups that we are well positioned for strong execution across all our upcoming milestones.” Recent Corporate Highlights On track to dose first patient in Imagine-1 trial evaluating PBGM01 for the treatment of infantile GM1 gangliosidosis: In January 2021, the company announced that U.S. Food and Drug Administration (FDA) cleared its Investigational New Drug (IND) application for PBGM01 for the treatment of infantile GM1 gangliosidosis (GM1), a rare and often life-threatening CNS disorder with no approved disease-modifying therapies. The company has activated its first site in the United States and is currently recruiting patients. PGBM01 has also received regulatory clearance to begin studies in the United Kingdom and Canada. Site activation efforts are in progress in these countries as well as for additional sites in the United States. The company continues to expect to dose the first patient in the trial in first quarter of 2021 and to report initial 30-day safety and biomarker data mid-year 2021. The investigational therapy has also received orphan drug and rare pediatric disease designations from FDA, as well as an orphan drug designation from the European Medicines Agency for the treatment of GM1. In January 2021, the company announced that U.S. Food and Drug Administration (FDA) cleared its Investigational New Drug (IND) application for PBGM01 for the treatment of infantile GM1 gangliosidosis (GM1), a rare and often life-threatening CNS disorder with no approved disease-modifying therapies. The company has activated its first site in the United States and is currently recruiting patients. PGBM01 has also received regulatory clearance to begin studies in the United Kingdom and Canada. Site activation efforts are in progress in these countries as well as for additional sites in the United States. The company continues to expect to dose the first patient in the trial in first quarter of 2021 and to report initial 30-day safety and biomarker data mid-year 2021. The investigational therapy has also received orphan drug and rare pediatric disease designations from FDA, as well as an orphan drug designation from the European Medicines Agency for the treatment of GM1. IND cleared and preparations on track to initiate Phase 1/2 trial for PBKR03 for treatment of patients with Krabbe disease, a rare pediatric disease: The company announced FDA clearance of the IND application for PBKR03 for Krabbe disease, a rare lysosomal storage disease, in February 2021. PBKR03 was also previously granted both orphan drug and rare pediatric disease designations for the treatment of Krabbe disease by FDA. The European Medicines Agency has also recently adopted a positive opinion for an orphan drug designation for PBKR03. Final endorsement of the designation by the European Commission is expected later in the first quarter. Passage Bio anticipates the start of the PBKR03 clinical program in the first half of 2021 with an initial 30-day safety and biomarker data readout planned for late 2021 or early 2022. The company announced FDA clearance of the IND application for PBKR03 for Krabbe disease, a rare lysosomal storage disease, in February 2021. PBKR03 was also previously granted both orphan drug and rare pediatric disease designations for the treatment of Krabbe disease by FDA. The European Medicines Agency has also recently adopted a positive opinion for an orphan drug designation for PBKR03. Final endorsement of the designation by the European Commission is expected later in the first quarter. Passage Bio anticipates the start of the PBKR03 clinical program in the first half of 2021 with an initial 30-day safety and biomarker data readout planned for late 2021 or early 2022. IND cleared and preparations on track to initiate Phase 1/2 trial for PBFT02 for treatment of patients with frontotemporal dementia with granulin mutations (FTD-GRN), an adult indication: In January, the company announced that FDA cleared its IND application for PBFT02 for FTD-GRN, a devastating form of early onset dementia. FDA has recently granted fast track designation for PBFT02. Fast track is a process designed to facilitate the development and expedite the review of drugs to treat conditions and fill unmet medical need. PBFT02 was also granted orphan drug designation by FDA earlier this year for the treatment of FTD-GRN. Passage Bio anticipates the start of PBFT02 clinical program in the first half of 2021 with initial data readouts planned late 2021 or early 2022. In January, the company announced that FDA cleared its IND application for PBFT02 for FTD-GRN, a devastating form of early onset dementia. FDA has recently granted fast track designation for PBFT02. Fast track is a process designed to facilitate the development and expedite the review of drugs to treat conditions and fill unmet medical need. PBFT02 was also granted orphan drug designation by FDA earlier this year for the treatment of FTD-GRN. Passage Bio anticipates the start of PBFT02 clinical program in the first half of 2021 with initial data readouts planned late 2021 or early 2022. Raised $166M in net proceeds via a public offering of common stock: In January 2021, the company announced a public offering of 7,000,000 shares of its common stock at a price of $22 per share. The underwriters also exercised their option to purchase an additional 1,050,000 shares of common stock for a total offering net proceeds of $166 million. In January 2021, the company announced a public offering of 7,000,000 shares of its common stock at a price of $22 per share. The underwriters also exercised their option to purchase an additional 1,050,000 shares of common stock for a total offering net proceeds of $166 million. Continue to license and advance assets through partnership with the University of Pennsylvania (Penn)’s Gene Therapy Program (GTP): The company recently advanced PBML04 for the treatment of metachromatic leukodystrophy (MLD) into IND-enabling studies in partnership with Penn GTP. Through its partnership with GTP, the company also licensed a seventh unnamed program for the treatment of an adult neurodegenerative rare monogenic CNS disorder. Passage Bio has licensing options for a total of 17 gene therapy research programs focused on rare monogenic CNS disorders and continues to evaluate additional programs for further development. The company recently advanced PBML04 for the treatment of metachromatic leukodystrophy (MLD) into IND-enabling studies in partnership with Penn GTP. Through its partnership with GTP, the company also licensed a seventh unnamed program for the treatment of an adult neurodegenerative rare monogenic CNS disorder. Passage Bio has licensing options for a total of 17 gene therapy research programs focused on rare monogenic CNS disorders and continues to evaluate additional programs for further development. Establishing internal and external manufacturing capabilities to meet the needs of growing pipeline : In December 2020, Passage Bio announced that it had completed construction and initiated vector manufacturing at its dedicated Current Good Manufacturing Practices (CGMP) manufacturing suite at Catalent Cell & Gene Therapy’s facility in Maryland. The company also announced its plans to open a Chemistry, Manufacturing and Controls (CMC) research and development site at the Princeton West Innovation Campus in Hopewell, New Jersey, for CMC laboratory operations to support analytics, assay development, and product testing for the company’s gene therapy programs in the second quarter of 2021. The company has completed clinical supply and established global clinical distribution to support clinical development of PBGM01 as well manufactured clinical supplies to initiate clinical trials for PBFT02 for FTD-GRN and PBKR03 for Krabbe disease. : In December 2020, Passage Bio announced that it had completed construction and initiated vector manufacturing at its dedicated Current Good Manufacturing Practices (CGMP) manufacturing suite at Catalent Cell & Gene Therapy’s facility in Maryland. The company also announced its plans to open a Chemistry, Manufacturing and Controls (CMC) research and development site at the Princeton West Innovation Campus in Hopewell, New Jersey, for CMC laboratory operations to support analytics, assay development, and product testing for the company’s gene therapy programs in the second quarter of 2021. The company has completed clinical supply and established global clinical distribution to support clinical development of PBGM01 as well manufactured clinical supplies to initiate clinical trials for PBFT02 for FTD-GRN and PBKR03 for Krabbe disease. Strengthened patient identification and engagement efforts, including : Sponsorship of ScreenPlus pilot program, in which GM1 has been added to the New York newborn screening pilot program led by Melissa Wasserstein, M.D. Collaboration with Invitae, a leading genetic testing company, to support its Detect Lysosomal Storage Disorders program to encourage early diagnosis of GM1 and to provide educational information to patients and clinicians regarding clinical trials. Engagement with Informed DNA to design and support a genetic screening and counselling program that will be free of charge to patients with FTD. Working with investigators participating in the ALL FTD study and the Genetic Frontotemporal Dementia Initiative and supporting the Bluefield Project to Cure FTD. : Anticipated Upcoming Milestones Dose the first patient in the global Phase 1/2 trial for PBGM01, Imagine-1, for the treatment of infantile GM1 in the first quarter of 2021. Report initial 30-day safety and biomarker data mid-year 2021. Open CMC research and development site in Hopewell, NJ, in the second quarter of 2021. Initiate Phase 1/2 trial for PBKR03 for the treatment of early infantile Krabbe disease in the first half of 2021. Report initial 30-day safety and biomarker data in late 2021 or early 2022. Initiate Phase 1/2 trial for PBFT02 for the treatment of FTD-GRN in the first half of 2021. Report initial 30-day safety and biomarker data in late 2021 or early 2022. Continue to advance preclinical programs for PBML04 (Metachromatic leukodystrophy), PBAL05 (Amyotrophic lateral sclerosis) and PBCM06 (Charcot-Marie-Tooth Disease Type 2A), and an undisclosed adult CNS program. Fourth Quarter and Full Year 2020 Financial Results Cash Position: Cash, cash equivalents and marketable securities were $304.8 million as of December 31, 2020 as compared to $158.9 million as of December 31, 2019. In January of 2021, the company raised an additional $166 million in net proceeds from a public offering. Cash, cash equivalents and marketable securities were $304.8 million as of December 31, 2020 as compared to $158.9 million as of December 31, 2019. In January of 2021, the company raised an additional $166 million in net proceeds from a public offering. Research and Development (R&D) Expenses: R&D expenses were $27.9 million for the quarter and $81.8 million for the full year ended December 31, 2020, compared to $10.0 million and $29.7 million for the same quarter and year in 2019. R&D expenses were $27.9 million for the quarter and $81.8 million for the full year ended December 31, 2020, compared to $10.0 million and $29.7 million for the same quarter and year in 2019. General and Administrative (G&A) Expenses : G&A expenses were $10.1 million for the quarter and $30.1 million for the full year ended December 31, 2020, compared to $3.6 million and $7.0 million for the same quarter and year in 2019. : G&A expenses were $10.1 million for the quarter and $30.1 million for the full year ended December 31, 2020, compared to $3.6 million and $7.0 million for the same quarter and year in 2019. Net Loss: Net loss was $38.9 million, or a net loss of $0.85 per basic and diluted share, for the quarter and $112.2 million, or a net loss of $2.91 per basic and diluted share, for the year ended December 31, 2020, compared to $13.2 million, or a net loss of $3.07 per basic and diluted share, for the quarter and $45.6 million, or a net loss of $10.77 per basic and diluted share, for the year ended December 31, 2019. Conference Call Details Passage Bio will host a conference call and webcast today at 8:30 a.m. ET. To access the live conference call, please dial 833-528-0605 (domestic) or 830-221-9711 (international) and reference conference ID number 6758094. A live audio webcast of the event will be available on the Investors & Media section of Passage Bio’s website at investors.passagebio.com. The archived webcast will be available on Passage Bio's website approximately two hours after the completion of the event and for 30 days following the call. About Passage Bio At Passage Bio (Nasdaq: PASG), we are on a mission to provide life-transforming gene therapies for patients with rare, monogenic CNS diseases that replace their suffering with boundless possibility, all while building lasting relationships with the communities we serve. Based in Philadelphia, PA, our company has established a strategic collaboration and licensing agreement with the renowned University of Pennsylvania’s Gene Therapy Program to conduct our discovery and IND-enabling preclinical work. This provides our team with unparalleled access to a broad portfolio of gene therapy candidates and future gene therapy innovations that we then pair with our deep clinical, regulatory, manufacturing and commercial expertise to rapidly advance our robust pipeline of optimized gene therapies into clinical testing. As we work with speed and tenacity, we are always mindful of patients who may be able to benefit from our therapies. More information is available at . Forward-Looking Statements This press release contains “forward-looking statements” within the meaning of, and made pursuant to the safe harbor provisions of, the Private Securities Litigation Reform Act of 1995, including, but not limited to: our expectations about timing and execution of anticipated milestones, including initiation of clinical trials and the availability of clinical data from such trials; our expectations about our collaborators’ and partners’ ability to execute key initiatives; our expectations about manufacturing plans and strategies; our expectations about cash runway; and the ability of our lead product candidates to treat their respective target monogenic CNS disorders. These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “might,” “plan,” “potential,” “possible,” “will,” “would,” and other words and terms of similar meaning. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including: our ability to develop and obtain regulatory approval for our product candidates; the timing and results of preclinical studies and clinical trials; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; the occurrence of adverse safety events; the risk that positive results in a preclinical study or clinical trial may not be replicated in subsequent trials or success in early stage clinical trials may not be predictive of results in later stage clinical trials; failure to protect and enforce our intellectual property, and other proprietary rights; our dependence on collaborators and other third parties for the development and manufacture of product candidates and other aspects of our business, which are outside of our full control; risks associated with current and potential delays, work stoppages, or supply chain disruptions caused by the coronavirus pandemic; and the other risks and uncertainties that are described in the Risk Factors section in documents the company files from time to time with the Securities and Exchange Commission (SEC), and other reports as filed with the SEC. Passage Bio undertakes no obligation to publicly update any forward-looking statement, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information, please contact: Investors: Stuart Henderson Passage Bio shenderson@passagebio.com Media: Gwen Fisher Passage Bio 215.407.1548 gfisher@passagebio.com Passage Bio, Inc. Balance Sheets (unaudited) Statements of Operations and Comprehensive Loss (unaudited)

– Investigational New Drug Applications (IND) submitted for PBFT02 for Frontotemporal Dementia with Granulin Mutation (FTD-GRN) and PBKR03 for Krabbe Disease – – Three clinical programs to begin in 1H21 – – Metachromatic leukodystrophy program, PBML04, advanced to IND-enabling phase – – Additional option exercised from Penn’s world-class Gene Therapy Program for undisclosed program focused on an adult CNS disorder – – New manufacturing laboratory to support analytical capabilities, clinical product testing and assay validation slated to open in 2Q21 – – PBFT02 for FTD-GRN becomes latest of company’s three most advanced programs to receive FDA orphan drug designation – PHILADELPHIA, Jan. 11, 2021 (GLOBE NEWSWIRE) -- Passage Bio, Inc. (Nasdaq: PASG), a genetic medicines company focused on developing transformative therapies for rare, monogenic central nervous system (CNS) disorders, today provided a corporate outlook detailing the expansion of the company’s pipeline, new regulatory filings, projected program milestones, and research and development progress. Bruce Goldsmith, Ph.D., president and chief executive officer of Passage Bio, will highlight the company’s recent progress and plans for the future in his presentation today at the 39th Annual J.P. Morgan Healthcare Conference. In his remarks, Dr. Goldsmith will highlight several components of the Company’s progress and timelines, including: Planned initiation of patient dosing in clinical studies for three novel adeno-associated virus (AAV) gene therapies: - Received FDA and MHRA clearance for PBGM01 for infantile GM1 gangliosidosis (GM1) - Submitted IND for PBKR03 for the treatment of Krabbe disease - Submitted IND for PBFT02 for treatment of Frontotemporal Dementia (FTD) with granulin (GRN) mutation. - Received FDA and MHRA clearance for PBGM01 for infantile GM1 gangliosidosis (GM1) - Submitted IND for PBKR03 for the treatment of Krabbe disease - Submitted IND for PBFT02 for treatment of Frontotemporal Dementia (FTD) with granulin (GRN) mutation. Advancement of PBML04 for the treatment of metachromatic leukodystrophy (MLD) into IND-enabling studies License of a seventh program from the University of Pennsylvania (Penn) for the treatment of an adult rare monogenic CNS disorder Planned opening of a manufacturing laboratory to support analytical capabilities, clinical product testing and assay validation “It is widely reported that there are approximately 7,000 rare diseases. Less discussed is that out of these 7,000 rare diseases, there are more than 790 rare monogenic CNS diseases, the area where we are focused,” said Dr. Goldsmith. “The diseases we are targeting are particularly devastating and have no approved disease-modifying treatment options, which means there is tremendous opportunity to make a difference for patients. At Passage Bio, we believe we are well positioned with our collaboration with Penn’s Gene Therapy Program, our corporate model, robust pipeline, manufacturing capability, strong cash position, and experienced team to succeed in our mission to deliver on the promise of gene therapies for patients with rare monogenic CNS disorders.” Passage Bio’s collaboration with Penn’s world-class Gene Therapy Program (GTP) provides the company with access to cutting-edge research, expertise and next-generation technologies. GTP is recognized worldwide for its innovative gene therapy capabilities, AAV vector technology manufacturing, and IND expertise. Through the Penn GTP collaboration, Passage Bio has licensing options for a total of 17 gene therapy research programs focused on rare monogenic disorders of the CNS through 2025. The company has exercised seven options to date, including four programs for pediatric and three programs for adult rare monogenic CNS disorders. “Through our relationship with GTP coupled with our business model, we have a well-defined path for clinical success,” explained Dr. Goldsmith. “We believe our pipeline has a higher probability of technical and regulatory success, in part because we are able to optimize delivery approaches, select candidates based on empirical research findings and integrate next-generation innovations from GTP as appropriate. Additionally, all our current therapies are designed for direct delivery to the CNS, which we believe offers a number of benefits, including avoiding crossing the blood brain barrier, better CNS biodistribution and lower dosing compared to systemic delivery.” Dr. Goldsmith added: “We spent 2020 establishing a solid foundation for our company to execute seamlessly against our ambitious future plans. Our progress has laid the groundwork for clinical trial preparedness and manufacturing readiness, which will be critical to successfully deliver on several meaningful catalysts this year.” The company’s three most advanced programs are: PBGM01 for infantile GM1 and PBKR03 for Krabbe disease, which are pediatric programs; and PBFT02 for FTD-GRN, which is an adult program. Passage Bio is also continuing to progress preclinical pediatric programs PBCM06 for Charcot-Marie-Tooth neuropathy type 2A (CMT2A) and PBML04 for MLD, which was recently advanced into IND-enabling studies. The company’s additional adult preclinical programs are PBAL05 for amyotrophic lateral sclerosis (ALS) and a seventh program, for which the company recently exercised an option and has not yet disclosed the therapeutic target. Significant Pipeline and Corporate Advancement The company’s lead program PBGM01 is entering the clinic to study its safety and efficacy in addressing infantile GM1, a rare and often life-threatening CNS disorder with no approved disease-modifying therapies. The global Phase 1/2 study, Imagine-1, is expected to enroll the first patient in the first quarter of 2021 and is expected to report initial 30-day safety and biomarker data mid-year 2021. PBGM01 has received regulatory agency clearance from FDA and MHRA. The investigational therapy has also received orphan drug and rare pediatric disease designations from FDA, as well as orphan drug designation from the European Medicines Agency for the treatment of GM1. The company has submitted investigational new drug (IND) applications to FDA for Phase 1/2 clinical studies of PBFT02 in FTD-GRN, a devastating form of early onset dementia; and PBKR03 in Krabbe disease, a pediatric disease with rapid progression, typically resulting in death by 2 years old. The company recently received orphan drug designation from FDA for PBFT02 for FTD-GRN. PBKRO3 has orphan drug and rare pediatric disease designations from FDA for treatment of Krabbe disease. Passage Bio anticipates the start of both clinical programs in the first half of 2021. Initial data from these trials are anticipated to potentially readout in late 2021 or early 2022, depending on the timing of first patient treated in each study. In parallel with pipeline advancement, the company has focused on establishing manufacturing and global distribution from clinical development through initial commercialization. Clinical supply for PBGM01 for our phase 1 / 2 global trial, manufactured through our partnership with Catalent, is already in place. We have also manufactured clinical supplies to initiate clinical trials for our next two most advanced programs – PBKRO3 for Krabbe disease and PBFT02 for FTD-GRN. In December, Passage Bio announced that it had completed construction and started production at its dedicated Current Good Manufacturing Practices (CGMP) manufacturing suite at Catalent Cell & Gene Therapy’s facility in Maryland. The company also announced the planned opening in the second quarter of 2021 of a gene therapy manufacturing research and development site at the Princeton West Innovation Campus in Hopewell, New Jersey, for Chemistry, Manufacturing and Controls (CMC) laboratory operations to support analytics, assay development, and product testing for the company’s gene therapy programs. About Passage Bio At Passage Bio (Nasdaq: PASG), we are on a mission to provide life-transforming gene therapies for patients with rare, monogenic CNS diseases that replace their suffering with boundless possibility, all while building lasting relationships with the communities we serve. Based in Philadelphia, PA, our company has established a strategic collaboration and licensing agreement with the renowned University of Pennsylvania’s Gene Therapy Program to conduct our discovery and IND-enabling preclinical work. This provides our team with access to a broad portfolio of gene therapy candidates and future gene therapy innovations that we then pair with our deep clinical, regulatory, manufacturing and commercial expertise to rapidly advance our robust pipeline of optimized gene therapies into clinical testing. As we work with speed and tenacity, we are always mindful of patients who may be able to benefit from our therapies. More information is available at . Forward-Looking Statements This press release contains “forward-looking statements” within the meaning of, and made pursuant to the safe harbor provisions of, the Private Securities Litigation Reform Act of 1995, including, but not limited to: our expectations about timing and execution of anticipated milestones, including our planned IND submissions, initiation of clinical trials and the availability of clinical data from such trials; our expectations about our collaborators’ and partners’ ability to execute key initiatives; our expectations about manufacturing plans and strategies; our expectations about cash runway; and the ability of our lead product candidates to treat the underlying causes of their respective target monogenic CNS disorders. These forward-looking statements may be accompanied by such words as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “might,” “plan,” “potential,” “possible,” “will,” “would,” and other words and terms of similar meaning. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements, including: our ability to develop and obtain regulatory approval for our product candidates; the timing and results of preclinical studies and clinical trials; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; the occurrence of adverse safety events; the risk that positive results in a preclinical study or clinical trial may not be replicated in subsequent trials or success in early stage clinical trials may not be predictive of results in later stage clinical trials; failure to protect and enforce our intellectual property, and other proprietary rights; our dependence on collaborators and other third parties for the development and manufacture of product candidates and other aspects of our business, which are outside of our full control; risks associated with current and potential delays, work stoppages, or supply chain disruptions caused by the coronavirus pandemic; and the other risks and uncertainties that are described in the Risk Factors section in documents the company files from time to time with the Securities and Exchange Commission (SEC), and other reports as filed with the SEC. Passage Bio undertakes no obligation to publicly update any forward-looking statement, whether written or oral, that may be made from time to time, whether as a result of new information, future developments or otherwise. For further information, please contact: Passage Bio Investors: Sarah McCabe and Zofia Mita Stern Investor Relations, Inc. 212-362-1200 sarah.mccabe@sternir.com Zofia.mita@sternir.com Passage Bio Media: Gwen Fisher Passage Bio 215-407-1548 gfisher@passagebio.com