Passage BIO, Inc.

Previous wording

We are currently studying PBFT02 in FTD-GRN, for which there are currently no approved disease-modifying therapies. In addition to the continued clinical development of PBFT02 to treat FTD-GRN, we intend to pursue PBFT02 in additional adult neurodegenerative diseases where we believe increasing PGRN levels could provide benefit. Third-party preclinical studies have shown that increased PGRN levels reduce the pathologic accumulation of TAR DNA binding protein 43, or TDP-43. TDP-43 pathology is a hallmark of multiple neurodegenerative conditions, including FTD due to mutations in theC9orf72 gene, or FTD-C9orf72, approximately 95% of sporadic amyotrophic lateral sclerosis, or ALS, and approximately 50% of sporadic FTD. Additionally, we believe restoration of PGRN has the potential to modulate Alzheimer’s disease, or AD, in patients who are carriers of the PGRN-loweringGRN rs5848 single nucleotide polymorphism, or SNP. Individuals with this polymorphism have reduced PGRN levels and are at an increased risk for AD. We have received positive regulatory feedback on the clinical pathway to treating FTD-C9orf72 patients and ALS patients with PBFT02. We are proceeding with clinical development of PBFT02 in FTD-C9orf72 patients and plan to initiate dosing in the first half of 2025.

Current wording

We are currently studying PBFT02 in FTD-GRN, for which there are currently no approved disease-modifying therapies. In addition to the continued clinical development of PBFT02 to treat FTD-GRN, we intend to pursue PBFT02 in additional adult neurodegenerative diseases where we believe increasing PGRN levels could provide benefit. Third-party preclinical studies have shown that increased PGRN levels reduce the pathologic accumulation of TAR DNA binding protein 43, or TDP-43. TDP-43 pathology is a hallmark of multiple neurodegenerative conditions, including FTD due to mutations in theC9orf72 gene, or FTD-C9orf72, approximately 95% of sporadic amyotrophic lateral sclerosis, or ALS, and approximately 50% of sporadic FTD. Additionally, we believe restoration of PGRN has the potential to modulate Alzheimer’s disease, or AD, in patients who are carriers of the PGRN-loweringGRN rs5848 single nucleotide polymorphism, or SNP. Individuals with this polymorphism have reduced PGRN levels and are at an increased risk for AD. We have received positive regulatory feedback on the clinical pathway to treating FTD-C9orf72 patients and ALS patients with PBFT02. We are proceeding with clinical development of PBFT02 in FTD-C9orf72 patients, and plan to begin patient enrollment upon site review and acceptance of the amended upliFT-D clinical trial protocol.

Previous wording

We have entered into a series of sublicense agreements with Gemma Biotherapeutics, Inc., or Gemma, a newly formed genetic medicines company co-founded by Dr. James Wilson in connection with the outlicensing of PBGM01 for the treatment of GM1 gangliosidosis, or GM1, PBKR03 for the treatment of Krabbe disease, and PBML04 for the treatment of metachromatic leukodystrophy, or MLD, collectively the Outlicensed Programs, and such agreements, the Gemma Sublicenses. In addition, we have entered into a Transition Services Agreement, as amended, and a research, collaboration and license agreement, or the Gemma Collaboration Agreement, with Gemma. We refer to the Gemma Sublicenses, the Transition Services Agreement, and the Gemma Collaboration Agreement, collectively, as the Outlicense Transaction Agreements.

Current wording

We are party to a series of sublicense agreements, as amended, with Gemma Biotherapeutics, Inc., or Gemma, a newly formed genetic medicines company co-founded by Dr. James Wilson in connection with the outlicensing of PBGM01 for the treatment of GM1 gangliosidosis, or GM1, PBKR03 for the treatment of Krabbe disease, and PBML04 for the treatment of metachromatic leukodystrophy, or MLD, collectively the Outlicensed Programs, and such agreements, the Amended Gemma Sublicenses. In addition, we have entered into a Transition Services Agreement, as amended, and a research, collaboration and license agreement, or the Gemma Collaboration Agreement, with Gemma. We refer to the Amended Gemma Sublicenses, the Transition Services Agreement, and the Gemma Collaboration Agreement, collectively, as the Outlicense Transaction Agreements.

Previous wording

Prior to the execution of the Outlicense Transaction Agreements, we progressed four product candidates from preclinical to clinical stage development and had one active preclinical program in Huntington’s disease through our research

Current wording

Prior to the execution of the Outlicense Transaction Agreements, we progressed four product candidates from preclinical to clinical stage development and had one active preclinical program in Huntington’s disease through our research collaboration with the Trustees of the University of Pennsylvania’s, or Penn’s, Gene Therapy Program, or GTP. This collaboration provided access to differentiated scientific expertise for the conduct of rigorous preclinical studies to

Previous wording

collaboration with Penn’s Gene Therapy Program, or GTP. This collaboration provided access to differentiated scientific expertise for the conduct of rigorous preclinical studies to generate promising product candidates. Gemma is comprised of a core research team from GTP and is continuing the same approach to preclinical development to support the continued development of our preclinical Huntington’s disease program.

Current wording

generate promising product candidates. Gemma is comprised of a core research team from GTP and is continuing the same approach to preclinical development to support the continued development of our preclinical Huntington’s disease program.

Previous wording

In January 2025, we reported biomarker data from patients in our upliFT-D trial who received Dose 1 of PBFT02 (3.3e10 genome copies/g estimated brain weight, or 4.50e13 total genome copies). Dose 1 of PBFT02 resulted in robust and durable increases in CSF PGRN levels, with concentrations increasing from below 3.0 ng/mL at baseline to 8.0 to 17.3 ng/mL at 30 days post-treatment (n=6), 13.2 to 27.3 ng/mL at six months post-treatment (n=4), and 22.3 to 34.0 ng/mL at 12 months post-treatment (n=2). CSF PGRN levels generally plateaued by 6 months post-treatment and have remained durable through the longest available follow-up of 18 months post-treatment (n=1). These levels of CSF PGRN are higher than the range found in healthy adult controls of 3.3 to 8.2 ng/mL (mean=4.8 ng/mL; n=61). In contrast, following PBFT02 administration, plasma PGRN levels were unaltered, remaining similar to baseline concentrations and

Current wording

In June 2025, we reported biomarker data from patients in our upliFT-D trial. Dose 1 of PBFT02 (3.3e10 genome copies/g estimated brain weight, or 4.5e13 total genome copies) resulted in robust and durable increases in CSF PGRN levels, with concentrations increasing from below 3.0 ng/mL at baseline to a mean of 12.4 ng/mL at one month (n=7), 19.4 ng/mL at six months (n=6), 25.9 ng/mL at 12 months (n=4), and 23.8 ng/mL at 18 months (n=2). These levels of CSF PGRN are higher than the range found in healthy adult controls of 3.3 to 8.2 ng/mL (mean=4.8 ng/mL; n=61). CSF PGRN levels for the first patient treated with Dose 2 of PBFT02 (1.6e10 genome copies/g estimated brain weight, or 2.2e13 total genome copies) increased substantially from 1.5 ng/mL at baseline to 7.6 ng/mL at one month, approaching the upper limit of the range found in healthy adult controls. In contrast, following PBFT02 administration, plasma PGRN levels were unaltered, remaining similar to baseline concentrations and below mean levels found in healthy adult

Previous wording

below levels found in healthy adult controls. Dose 1 of PBFT02 also resulted in an average 13% decrease in plasma neurofilament light chain, or NfL, levels, a biomarker associated with disease progression, compared to baseline at 12 months post-treatment (n=2). This reduction in plasma NfL after PBFT02 administration contrasts with an expected increase in plasma NfL levels of approximately 29% per year among untreated, symptomatic FTD-GRN patients, according to published natural history data (Saracino 2021).

Current wording

controls. Dose 1 of PBFT02 resulted in an average 4% increase in plasma neurofilament light chain, or NfL, levels, a biomarker associated with disease progression, compared to baseline at 12 months post-treatment (n=4). This change in plasma NfL after PBFT02 administration contrasts with an expected increase in plasma NfL levels of approximately 28% and 29% per year among untreated, symptomatic FTD-GRN patients, based on analysis of the ALLFTD natural history data and published natural history data (Saracino 2021), respectively.

Previous wording

As of April 2025, interim safety highlights from Dose 1 of PBFT02 in FTD-GRN patients (n=7) included:

Current wording

As of June 2025, interim safety highlights from PBFT02 in FTD-GRN patients (n=8) included:

Previous wording

The potential for benefit of increased PGRN in disorders with TDP-43 pathology has been demonstrated by third-party preclinical studies in mice and zebrafish which showed that increased PGRN levels reduced TDP-43 pathology and associated toxicities. We anticipate that elevating neuronal PGRN levels in diseases with TDP-43 pathology may provide significant benefits to patients. We have initiated preclinical studies to extend these initial observations.

Current wording

The potential for benefit of increased PGRN in disorders with TDP-43 pathology has been demonstrated by third-party preclinical studies in mice and zebrafish which showed that increased PGRN levels reduced TDP-43 pathology and associated toxicities. We anticipate that elevating neuronal PGRN levels in diseases with TDP-43 pathology may provide significant benefits to patients.

Previous wording

enrolled sequentially. Each cohort will consist of three to five symptomatic FTD patients withC9orf72 gene mutations and patients will initially receive Dose 2 PBFT02. We expect to initiate dosing of FTD-C9orf72 patients in the first half of 2025. There are no disease modifying therapies approved for the treatment of FTD-C9orf72. Based on available literature, we estimate the prevalence of FTD-C9orf72 in the United States and Europe is approximately 21,000. We are currently enrolling FTD-C9orf72 patients in our upliFT-D trial.

Current wording

We received positive regulatory feedback on the clinical pathway to treating FTD-C9orf72 with PBFT02 in the ongoing upliFT-D trial and revised the study to include two cohorts. Cohorts 4 and 5 will consist of three to five symptomatic FTD patients withC9orf72 gene mutations who will initially receive Dose 2 PBFT02. There are no disease modifying therapies approved for the treatment of FTD-C9orf72. Based on available literature, we estimate the prevalence of FTD-

Previous wording

We also have a research program through the Gemma Collaboration Agreement for TLE, which was previously conducted by Penn under the Penn Agreement. In order to reduce operating expenses, we have paused development of this program.

Current wording

We also have a research program through the Gemma Collaboration Agreement for TLE, which was previously conducted under the research, collaboration and licensing agreement with Penn, as amended, previously the Penn Agreement and now referred to as the Penn License Agreement. In order to reduce operating expenses, we have paused development of this program.

Previous wording

We were incorporated in July 2017 under the laws of the State of Delaware. Since inception, our operations have consisted primarily of conducting preclinical studies, developing licensed technology, conducting clinical trials, and manufacturing clinical supply to support clinical trials. We have incurred recurring losses, the majority of which are attributable to research and development activities, and negative cash flows from operations. Historically, we have funded our operations through the sale of convertible preferred stock and public offerings of common stock. Our net losses were $15.4 million and $16.7 million for the three months ended March 31, 2025 and 2024, respectively. As of March 31, 2025, we had an accumulated deficit of $674.6 million. Our primary use of cash is to fund operating expenses, which consist primarily of research and development expenditures, and to a lesser extent, general and administrative expenditures. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our current or future product candidates. We expect to continue to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates through all stages of development and clinical trials and, ultimately, seek regulatory approval. In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant

Current wording

an accumulated deficit of $684.0 million. Our primary use of cash is to fund operating expenses, which consist primarily of research and development expenditures, and to a lesser extent, general and administrative expenditures. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our current or future product candidates. We expect to continue to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates through all stages of development and clinical trials and, ultimately, seek regulatory approval. In addition, if we obtain marketing approval for any of our product candidates, we expect to incur significant commercialization expenses related to product manufacturing, marketing, sales and distribution. Our net losses may fluctuate significantly from quarter to quarter and year to year, depending on the timing of our clinical trials and our expenditures on other research and development activities.

Previous wording

As of March 31, 2025, we had cash and cash equivalents of $63.4 million. We expect our existing cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2027.

Current wording

As of June 30, 2025, we had cash and cash equivalents of $57.6 million. We expect our existing cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2027.

Previous wording

For our licensed programs in FTD, GM1, Krabbe and MLD, the Penn License Agreement requires that we make payments of up to $16.5 million per product candidate. Each payment will be due upon the achievement of specific development milestone events by such licensed product for a first indication, reduced development milestone payments for the second and third indications and no development milestone payments for subsequent indications. In addition, on a product-by-product basis, we are obligated to make up to $55.0 million in sales milestone payments on each licensed product based on annual worldwide net sales of the licensed product in excess of defined thresholds. Pursuant to the Gemma Sublicenses, Gemma is responsible for the payments to Penn related to the Outlicensed Programs.

Current wording

For our licensed programs in FTD, GM1, Krabbe and MLD, the Penn License Agreement requires that we make payments of up to $16.5 million per product candidate. Each payment will be due upon the achievement of specific development milestone events by such licensed product for a first indication, reduced development milestone payments for the second and third indications and no development milestone payments for subsequent indications. In addition, on a product-by-product basis, we are obligated to make up to $55.0 million in sales milestone payments on each licensed product based on annual worldwide net sales of the licensed product in excess of defined thresholds. Pursuant to the Amended Gemma Sublicenses, Gemma is responsible for the payments to Penn related to the Outlicensed Programs.

Previous wording

Upon successful commercialization of a product using the licensed technology, we are obligated to pay to Penn, on a licensed product-by-licensed product and country-by-country basis, tiered royalties (subject to customary reductions) in the mid-single digits percentage on annual worldwide net sales of such licensed product. In addition, other than the Gemma Sublicenses, we are obligated to pay to Penn a percentage of sublicensing income, ranging from the mid-single digits to low double digits, for sublicenses under the Penn License Agreement. The agreement will expire on a licensed product-by-licensed product and country-by-country basis upon the later of (i) the expiration of the last valid claim of the licensed patent rights that covers the exploitation of such licensed product in such country, and (ii) the expiration of the royalty period. Pursuant to the Gemma Sublicenses, Gemma is responsible for the payments to Penn related to the Outlicensed Programs.

Current wording

Upon successful commercialization of a product using the licensed technology, we are obligated to pay to Penn, on a licensed product-by-licensed product and country-by-country basis, tiered royalties (subject to customary reductions) in the mid-single digits percentage on annual worldwide net sales of such licensed product. In addition, other than the Amended Gemma Sublicenses, we are obligated to pay to Penn a percentage of sublicensing income, ranging from the mid-single digits to low double digits, for sublicenses under the Penn License Agreement. The agreement will expire on a licensed product-by-licensed product and country-by-country basis upon the later of (i) the expiration of the last valid claim of the licensed patent rights that covers the exploitation of such licensed product in such country, and (ii) the

Previous wording

Agreement, (i) Gemma will conduct certain preclinical and IND-enabling work for our active research program in Huntington’s disease and a currently paused research program in TLE, which were previously being conducted by Penn under the Penn Agreement and (ii) Gemma will grant us options to conduct mutually agreed research programs in four new CNS indications.

Current wording

In connection with the transfer of the Outlicensed Programs, on July 31, 2024, we entered into a research, collaboration and license agreement with Gemma, or the Gemma Collaboration Agreement. Pursuant to the Gemma Collaboration Agreement, (i) Gemma will conduct certain preclinical and IND-enabling work for our active research program in Huntington’s disease and a currently paused research program in TLE, which were previously being conducted by Penn under the Penn Agreement and (ii) Gemma will grant us options to conduct mutually agreed research programs in four new CNS indications.

Previous wording

In connection with the transfer of the Outlicensed Programs to Gemma, we have entered into the Gemma Sublicenses, pursuant to which, we will receive (i) initial payments of an aggregate of $10.0 million for licenses and clinical product supply; (ii) up to an additional $10.0 million contingent on the completion by Gemma of certain business milestones; (iii) up to an additional $114.0 million in development and commercial milestone payments; and (iv) single digit royalties as a percentage of annual worldwide net sales in exchange for sublicenses to relevant intellectual property, transfer of regulatory dossiers and transfer of clinical trial materials and product supply related to the Outlicensed Programs. In addition, Gemma is responsible for all payments to Penn related to the Outlicensed Programs under the Penn License Agreement.

Current wording

In connection with the transfer of the Outlicensed Programs to Gemma, on July 2024, we entered into the Gemma Sublicenses. On May 7, 2025, we agreed to amend each of the Gemma Sublicenses to revise certain financial terms related to the Outlicensed Programs, or the Amended Gemma Sublicenses. Pursuant to the Amended Gemma Sublicenses, we are entitled to receive (i) an aggregate total of $15.0 million in initial payments for licenses and clinical product supply, of which $5.0 million was previously received and $5.0 million of which was due in May 2025; (ii) an additional $5.0 million contingent on Gemma completing certain business milestones; (iii) up to an additional $114.0 million in development and commercial milestone payments; and (iv) single digit royalties as a percentage of annual worldwide net sales in exchange for sublicenses to relevant intellectual property, transfer of regulatory dossiers and transfer of clinical trial materials and product supply related to the Outlicensed Programs. In addition, Gemma is responsible for all payments to Penn related to the Outlicensed Programs under the Penn License Agreement.

Previous wording

In addition, we entered into the Transition Services Agreement, as amended by the First Amendment to the Transition Services Agreement, dated January 31, 2025, pursuant to which, we will provide transitional services at cost to Gemma through May 31, 2025, unless terminated earlier, and be entitled to reimbursement for transitional services performed retroactively from March 1, 2024, related to the transfer of the Outlicensed Programs. As of March 31, 2025, we have collected $5.0 million in initial payments and $3.7 million in transition services payments under these agreements. Subsequent to March 31, 2025, we have received an additional $0.4 million in transition services payments.

Current wording

In addition, we entered into the Transition Services Agreement, as amended by the First Amendment to the Transition Services Agreement, dated January 31, 2025, pursuant to which, we provided transitional services at cost to Gemma through May 31, 2025, and are entitled to reimbursement for transitional services performed retroactively from March 1, 2024, related to the transfer of the Outlicensed Programs. As of June 30, 2025, we have collected $5.0 million in initial payments and $4.7 million in transition services payments under these agreements. Subsequent to June 30, 2025, we have applied $0.7 million in amounts owed to Gemma for the Huntington’s disease program against amounts due to us for transition services.

Previous wording

We track outsourced development expenses and other external research and development expenses to specific product candidates on a program-by-program basis, such as fees paid to CROs, CDMOs and research laboratories in connection with our preclinical development, process development, manufacturing and clinical development activities, expenses incurred under our prior collaboration with Penn, and future expenses incurred under the Gemma Collaboration Agreement. However, we do not track our internal research and development expenses on a program-by-program basis as they primarily relate to compensation, lab operations and lab facility costs, and other expenses which are deployed across multiple projects under development.

Current wording

We track outsourced development expenses and other external research and development expenses to specific product candidates on a program-by-program basis, such as fees paid to CROs, CDMOs and research laboratories in connection with our preclinical development, process development, manufacturing and clinical development activities, expenses incurred under our prior collaboration with Penn, and expenses incurred under the Gemma Collaboration Agreement. However, we do not track our internal research and development expenses on a program-by-program basis as they primarily relate to compensation, lab operations and lab facility costs, and other expenses which are deployed across multiple projects under development.

Previous wording

General and administrative expenses consist primarily of personnel expenses, including salaries, benefits and share-based compensation expense, for employees and consultants in executive, finance, accounting, legal, information technology, product strategy, quality, regulatory, operations and human resource functions. General and administrative expenses also include professional and consulting services, headquarters facility costs, including rent, utilities, depreciation, amortization and maintenance, legal expenses related to intellectual property, litigation and corporate matters, insurance expense, expenses related to contract modifications or terminations, software expenses, expenses incurred to engage with patient advocacy organizations, and recruitment related expenses. We expect our general and administrative expenses to decrease in the near future in connection with the reduction of our overall workforce by 55% in January 2025.

Current wording

General and administrative expenses consist primarily of personnel expenses, including salaries, benefits and share-based compensation expense, for employees and consultants in executive, finance, accounting, legal, information technology, product strategy, quality, regulatory, operations and human resource functions. General and administrative expenses also include professional and consulting services, headquarters facility costs, including rent, utilities, depreciation, amortization and maintenance, legal expenses related to intellectual property, litigation and corporate matters, insurance expense, expenses related to contract modifications or terminations, software expenses, expenses incurred to engage with patient advocacy organizations, and recruitment related expenses. We expect our general and administrative expenses to remain consistent in the near future.

Previous wording

Impairment of long-lived assets consists of non-cash impairment charges recorded to our assets. We review long-lived assets, such as the right of use assets, or ROU assets, or property and equipment, for impairments when events or changes in circumstances indicate the carrying amount of the assets may not be recoverable. During the three months ended March 31, 2025, we recognized impairment expenses related to property and equipment and certain other assets in connection with the announcement to reduce our workforce by 55% and cease our lab operations in Hopewell, New Jersey. We reassessed asset groups at the lab in Hopewell, New Jersey, and evaluated such asset groups for impairment. We determined the laboratory equipment was a separate asset group based on management’s implemented plans to sell the laboratory equipment and estimated the fair value of the laboratory equipment based on the estimated future cash flows from the sale of such equipment.

Current wording

Impairment of long-lived assets consists of non-cash impairment charges recorded to our assets. We review long-lived assets, such as the right of use assets, or ROU assets, or property and equipment, for impairments when events or changes in circumstances indicate the carrying amount of the assets may not be recoverable. During the six months ended June 30, 2025, we recognized impairment expenses related to property and equipment and certain other assets in connection with the announcement to reduce our workforce by 55% and cease our lab operations in Hopewell, New Jersey. We reassessed asset groups at the lab in Hopewell, New Jersey, and evaluated such asset groups for impairment. We determined the laboratory equipment was a separate asset group based on management’s implemented plans to sell the laboratory equipment and estimated the fair value of the laboratory equipment based on the estimated future cash flows from the sale of such equipment.

Previous wording

General and administrative expenses decreased by $0.4 million to $6.1 million for the three months ended March 31, 2025 from $6.5 million for the three months ended March 31, 2024. The decrease was primarily due to the following:

Current wording

General and administrative expenses decreased by $2.0 million to $4.5 million for the three months ended June 30, 2025 from $6.5 million for the three months ended June 30, 2024. The decrease was primarily due to the following:

Previous wording

Other income (expense), net decreased by $0.2 million to $1.1 million for the three months ended March 31, 2025 from $1.3 million for the three months ended March 31, 2024. The decrease was primarily due to the following:

Current wording

Other income (expense), net decreased by $0.4 million to $1.0 million for the three months ended June 30, 2025 from $1.4 million for the three months ended June 30, 2024. The decrease was primarily due to the following:

Previous wording

During the three months ended March 31, 2025, we recorded $2.6 million of impairment expense related to laboratory equipment and certain other assets which were revalued and subsequently sold from the Hopewell Laboratory Space.

Current wording

During the six months ended June 30, 2025, we recorded $2.6 million of impairment expense related to laboratory equipment and certain other assets which were revalued and subsequently sold from the Hopewell Laboratory Space.

Previous wording

As of March 31, 2025, we had $63.4 million in cash and cash equivalents and had an accumulated deficit of $674.6 million. We expect our existing cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2027.

Current wording

As of June 30, 2025, we had $57.6 million in cash and cash equivalents and had an accumulated deficit of $684.0 million. We expect our existing cash and cash equivalents will enable us to fund our operating expenses and capital expenditure requirements into the first quarter of 2027.

Previous wording

On March 5, 2021, we entered into a Sales Agreement, or the Sales Agreement, with Cowen and Company, LLC, or Cowen, relating to the applicable terms of at-the-market equity offerings, or the ATM Facility, pursuant to which we may, but are not obligated to, offer and sell, from time to time, shares of our common stock with an aggregate offering price up to $125.0 million through Cowen, as sales agent in the ATM Facility. We issued 6,000,000 shares of common stock under the ATM Facility, resulting in net proceeds of $8.7 million, after deducting offering costs of $0.3 million in March 2024. We are limited to $15.8 million in our capacity to offer and sell shares of our common stock under this sales agreement pursuant to the prospectus supplement to our shelf registration statement on Form S-3, filed on March 5, 2025. As of March 31, 2025, $15.8 million of capacity remains available to be sold under the ATM Facility.

Current wording

On March 5, 2021, we entered into a Sales Agreement, or the Sales Agreement, with Cowen and Company, LLC, or Cowen, relating to the applicable terms of at-the-market equity offerings, or the ATM Facility, pursuant to which we may, but are not obligated to, offer and sell, from time to time, shares of our common stock with an aggregate offering price up to $125.0 million through Cowen, as sales agent in the ATM Facility. We issued 6,000,000 shares (300,000 shares adjusted for the Reverse Stock Split) of common stock under the ATM Facility, resulting in net proceeds of $8.7 million, after deducting offering costs of $0.3 million in March 2024. We are limited in our capacity to offer and sell shares of our common stock under this sales agreement pursuant to the prospectus supplement to our shelf registration statement on Form S-3, filed on March 5, 2025. As of June 30, 2025, $15.8 million of capacity remains available to be sold under the ATM Facility.

Previous wording

During the three months ended March 31, 2025, we used $13.8 million of net cash in operating activities. Cash used in operating activities reflected a net loss of $15.4 million and a decrease in our operating assets of $2.2 million, partially offset by non-cash charges of $3.8 million related to depreciation, amortization, share-based compensation, amortization of premium and discount, net, and impairment of long-lived assets. The primary use of cash was to fund our operations related to the development of our product candidates.

Current wording

During the six months ended June 30, 2025, we used $20.2 million of net cash in operating activities. Cash used in operating activities reflected a net loss of $24.8 million and a decrease in our operating assets of $0.3 million, partially offset by non-cash charges of $4.9 million related to depreciation, amortization, share-based compensation, amortization of premium and discount, net, and impairment of long-lived assets. The primary use of cash was to fund our operations related to the development of our product candidates.

Previous wording

During the three months ended March 31, 2024, we used $18.9 million of net cash in operating activities. Cash used in operating activities reflected a net loss of $16.7 million and a net increase in our operating assets of $4.2 million, partially offset by net non-cash charges of $2.0 million related to depreciation, amortization, share-based compensation, and amortization of premium and discount, net. The primary use of cash was to fund our operations related to the development of our product candidates.

Current wording

During the six months ended June 30, 2024, we used $32.1 million of net cash in operating activities. Cash used in operating activities reflected a net loss of $32.7 million and a net increase in our operating assets of $3.8 million, partially offset by non-cash charges of $4.4 million related to depreciation, amortization, share-based compensation, and amortization of premium and discount, net, and impairment of long-lived assets. The primary use of cash was to fund our operations related to the development of our product candidates.

Previous wording

Duringthe three months ended March 31, 2025, we had sales and maturities of $39.0 million in marketable securities and received cash proceeds of $0.6 million related to the sale of property and equipment and certain other assets.

Current wording

Duringthe six months ended June 30, 2025, we had sales and maturities of $39.0 million in marketable securities and received cash proceeds of $1.2 million related to the sale of property and equipment and certain other assets.

Previous wording

During the three months ended March 31, 2024, we purchased $13.8 million in marketable securities, and had sales and maturities of $39.1 million in marketable securities. We did not make any purchases of property and equipment for the three months ended March 31, 2025 and 2024.

Current wording

During the six months ended June 30, 2024, we purchased $50.8 million in marketable securities, and had sales and maturities of $77.1 million in marketable securities. We did not make any purchases of property and equipment for the six months ended June 30, 2025 and 2024.

Previous wording

During the three months ended March 31, 2024, we received $8.7 million in net proceeds from the issuance of common stock under the ATM Facility. We received gross proceeds of $9.0 million, net of offering costs of $0.3 million.

Current wording

During the six months ended June 30, 2024, we received $8.7 million in net proceeds from the issuance of common stock under the ATM Facility. We also received gross proceeds of $9.0 million, net of offering costs of $0.3 million. We received $0.1 million in proceeds from the issuance of common stock under the ESPP and exercises of employee stock options.

Previous wording

We lease approximately 37,000 square feet of office space in Philadelphia, Pennsylvania, or the 2005 Market Street Lease Agreement. The lease will expire in December 2031. We have an option to extend the term of the lease by up to two additional five-year terms. The aggregate estimated rent payments due over the initial term of the lease is $11.8 million, with rent payments that began in 2022. Our sublease agreements do not relieve us from our primary obligations under the 2005 Market Street Lease Agreement, however, we do expect cash inflows from the agreements to partially offset our future obligations for the duration of the sublease agreements.

Current wording

We lease approximately 37,000 square feet of office space in Philadelphia, Pennsylvania, or the 2005 Market Street Lease Agreement. The lease will expire in December 2031. We have an option to extend the term of the lease by up to two additional five-year terms. Our sublease agreements do not relieve us from our primary obligations under the 2005 Market Street Lease Agreement, however, we do expect cash inflows from the agreements to partially offset our future obligations for the duration of the sublease agreements.

Previous wording

We sublease approximately 16,000 square feet of office space in Philadelphia, Pennsylvania, or the 1835 Market Street Sublease Agreement. The sublease will expire in August 2025. We have an option to extend the term of the sublease by three and a half years through February 2029. The aggregate estimated rent payments due over the initial term of the sublease is approximately $0.5 million, with rent payments that began in 2024.

Current wording

We sublease approximately 16,000 square feet of office space in Philadelphia, Pennsylvania, or the 1835 Market Street Sublease Agreement. The sublease will expire in August 2025. We have an option to extend the term of the sublease by three and a half years through February 2029.

Previous wording

We lease approximately 62,000 square feet of laboratory space in Hopewell, New Jersey, or the Laboratory Lease Agreement. The lease will expire in March 2036. The aggregate estimated rent payments due over the initial term of the lease is approximately $40.3 million, with rent payments that began in 2021. Our sublease agreement does not relieve us from our primary obligations under the Laboratory Lease Agreement, however, we do expect cash inflows from the agreement to partially offset our future obligations for the duration of the sublease agreement.

Current wording

We lease approximately 62,000 square feet of laboratory space in Hopewell, New Jersey, or the Laboratory Lease Agreement. The lease will expire in March 2036. Our sublease agreement does not relieve us from our primary obligations under the Laboratory Lease Agreement, however, we do expect cash inflows from the agreement to partially offset our future obligations for the duration of the sublease agreement.

Previous wording

The contractual obligations and commitments above do not include any potential milestone or royalty payments that we may be required to make under the Penn License Agreement. Under the Gemma Sublicenses, Gemma will be responsible for all potential milestone and royalty payments to Penn for the Outlicensed Programs.

Current wording

The contractual obligations and commitments above do not include any potential milestone or royalty payments that we may be required to make under the Penn License Agreement. Under the Amended Gemma Sublicenses, Gemma will be responsible for all potential milestone and royalty payments to Penn for the Outlicensed Programs.

Previous wording

During the three months ended March 31, 2025, there were no material changes to our critical accounting policies and estimates from those described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Estimates” in our 2024 Annual Report filed on Form 10-K.

Current wording

During the six months ended June 30, 2025, there were no material changes to our critical accounting policies and estimates from those described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Estimates” in our 2024 Annual Report filed on Form 10-K.