ENANTA PHARMACEUTICALS INC

Previous wording

We are a biotechnology company that uses our robust, chemistry-driven approach and drug discovery capabilities to discover and develop small molecule drugs with an emphasis on virology and immunology.

Current wording

We are a biotechnology company that uses our robust, chemistry-driven approach and drug discovery capabilities to discover and develop small molecule drugs for virology and immunology indications.

Previous wording

We discovered glecaprevir, the second of two antiviral protease inhibitors discovered and developed through our collaboration with AbbVie for the treatment of chronic infection with hepatitis C virus, or HCV. Glecaprevir is co-formulated as part of AbbVie’s leading brand of direct-acting antiviral, or DAA, combination treatment for HCV, which has been marketed under the tradenames MAVYRET®(U.S.) and MAVIRET® (ex-U.S.) (glecaprevir/pibrentasvir) since 2017.

Current wording

We discovered glecaprevir, the second of two antiviral protease inhibitors developed through our collaboration with AbbVie for the treatment of chronic infection with hepatitis C virus, or HCV. Glecaprevir is co-formulated as part of AbbVie’s leading brand of direct-acting antiviral, or DAA, combination treatment for HCV, which has been marketed under the tradenames MAVYRET®(U.S.) and MAVIRET® (ex-U.S.) (glecaprevir/pibrentasvir) since 2017.

Previous wording

Our active development programs in virology are focused on respiratory syncytial virus, or RSV, the most common cause of bronchiolitis and pneumonia and leading cause of U.S. hospitalization in young children and a significant cause of respiratory illness in older adults, with estimates suggesting that on average each year RSV leads to three million hospitalizations globally in children under 5 years old and 177,000 hospitalizations in the U.S. in adults over the age of 65.

Current wording

Our active development programs in virology are focused on respiratory syncytial virus, or RSV, the most common cause of bronchiolitis and pneumonia and leading cause of U.S. hospitalization in young children and a significant cause of respiratory illness in older adults. Estimates suggest that, on average, each year RSV leads to three million hospitalizations globally in children under 5 years old and 177,000 hospitalizations in the U.S. in adults over the age of 65. Populations at high risk for severe RSV infection include infants and young children, adults older than 65 years of age, and those with comorbidities such as chronic heart or lung disease.

Previous wording

We also have development programs in virology for the following disease targets:

Current wording

We also have development stage programs in virology for the following disease targets:

Previous wording

SARS-CoV-2, the virus that causes COVID-19, with estimates suggesting that COVID-19 continues to have a disease burden greater than influenza, including persistent cases of infection often referred to as long COVID and hospitalization and death among the elderly and those with comorbidities, while new variants continue to emerge on a regular basis; and

Current wording

SARS-CoV-2, the virus that causes COVID-19, with estimates suggesting that COVID-19 continues to have a disease burden greater than influenza, with hospitalization and death among the elderly and those with comorbidities, persistent symptoms referred to as long COVID, and new variants emerging on a regular basis; and

Previous wording

In immunology, we are designing and developing highly potent and selective, oral small molecule inhibitors for the treatment of inflammatory disease by targeting key mechanisms of immune response. Our initial focus has been on mechanisms involved in an overactive type 2 immune response, which is the reaction of the body's immune system when the body detects infections or allergens and sends out immune cells to fight them. An overactive response is a primary driver of a number of inflammatory diseases.

Current wording

In immunology, we are designing and developing highly potent and selective, oral small molecule inhibitors for the treatment of inflammatory disease by targeting key mechanisms of immune response. Our initial focus has been on mechanisms involved in an overactive type 2 immune phenotype, which is the response of the immune system upon encountering infections or allergens. An overactive response is a primary driver of a number of inflammatory diseases.

Previous wording

The receptor tyrosine kinase, known as KIT, which is critical for regulating mast cell activity; and

Current wording

The receptor tyrosine kinase, known as KIT, which is critical for regulating mast cell activity, a primary driver of inflammation in the skin and implicated in multiple allergic diseases; and

Previous wording

STAT6, a transcription factor uniquely responsible for interleukin-4 (IL-4)/interleukin-13 (IL-13) cell signaling, the factors that play important roles in regulating the responses of lymphocytes, myeloid cells, and non-hematopoietic cells within the immune system.

Current wording

STAT6, a transcription factor uniquely responsible for interleukin-4 (IL-4)/interleukin-13 (IL-13) cell signaling, which drives a type 2 dominant phenotype and downstream inflammation.

Previous wording

These mechanisms are implicated, along with others, in several diseases, and it is not uncommon for an efficacious treatment for one disease to be tested and approved for other immunology indications. We currently plan to focus our immunology drug development efforts on the following disease indications:

Current wording

These mechanisms are implicated, along with others, in several diseases, and it is not uncommon for an efficacious treatment for one disease to be tested and approved for other immunology indications. We currently plan to focus our initial immunology drug development proof-of-concept efforts on the following disease indications:

Previous wording

As of December 31, 2024, we had $216.7 million in cash, cash equivalents and short-term marketable securities. We expect that our existing cash, cash equivalents, short-term marketable securities, as well as the cash flows from our retained portion of future HCV royalties and our forthcoming federal tax refund, will enable us to fund our operating expenses and capital expenditure requirements into fiscal 2028.

Current wording

As of March 31, 2025, we had $193.4 million in cash, cash equivalents and short-term marketable securities. We expect that our existing cash, cash equivalents, short-term marketable securities, as well as the cash flows from our retained portion of future HCV royalties and our $33.8 million federal tax refund received in April 2025, will enable us to fund our operating expenses and capital expenditure requirements into fiscal 2028.

Previous wording

RSV. In virology, we have two clinical stage product candidates for RSV – zelicapavir (formerly EDP-938) and EDP-323. Both of these compounds are replication inhibitors that work by shutting down replication and the production of new virions, as opposed to the other mechanism in development of fusion inhibition that only blocks viral entry. Zelicapavir, which has Fast Track designation from the U.S. Food and Drug Administration, or FDA, is a potent inhibitor of the RSV N-protein for both major subgroups of RSV, referred to as RSV-A and RSV-B. Zelicapavir is being studied in two Phase 2 studies, each in a different high risk patient population. EDP-323, which also has a Fast Track designation from the FDA, is an inhibitor of the RSV L-protein for both major subgroups of RSV that has recently completed a Phase 2 challenge study.

Current wording

RSV. In virology, we have two clinical stage candidates for RSV – zelicapavir (formerly EDP-938) and EDP-323. Both of these compounds are replication inhibitors that work by shutting down replication and the production of new virions, as opposed to the other mechanism in development of fusion inhibition that only blocks viral entry. Zelicapavir, which has Fast Track designation from the U.S. Food and Drug Administration, or FDA, is a potent inhibitor of the RSV N-protein for both major subgroups of RSV, referred to as RSV-A and RSV-B. Zelicapavir is being studied in two Phase 2 studies, each in a different high risk patient population. EDP-323, which also has a Fast Track designation from the FDA, is an inhibitor of the RSV L-protein for both major subgroups of RSV that has recently completed a Phase 2 challenge study. We will evaluate potential partnership opportunities to advance our RSV programs to the next stage of clinical development.

Previous wording

Zelicapavir - N-protein Inhibitor Candidate: We have studied zelicapavir in two Phase 2 studies that were designed to be proof-of-concept and exploratory studies in otherwise healthy young adults (not at high-risk for serious outcomes with RSV) to understand the viral response in the context of RSV infection. With these studies, zelicapavir has demonstrated a favorable safety profile, consistent with that observed in over 500 subjects exposed to zelicapavir to date. We believe that zelicapavir has the greatest potential to show optimal efficacy in high-risk populations since these patients have reduced RSV immunity, which manifests in a higher and longer duration of viral load and greater disease severity, allowing a bigger window to realize the full potential of zelicapavir. Based on its growing safety profile, we are continuing to evaluate zelicapavir in high-risk populations, including pediatric patients and high-risk adults, all of which have significant unmet need:

Current wording

Zelicapavir - N-protein Inhibitor Candidate: Zelicapavir is a once-daily, oral, direct-acting antiviral selectively targeting the N-protein that demonstrated statistically significant reductions in RSV viral load and symptoms in a human challenge model, Phase 2 clinical study. Zelicapavir was also tested in another Phase 2 exploratory study of otherwise healthy young adults (not at high-risk for serious outcomes with RSV) to understand viral response to treatment in community-acquired RSV infection. With these studies, zelicapavir has demonstrated a favorable safety profile, consistent with that observed in over 500 subjects exposed to zelicapavir to date. We believe that zelicapavir has the greatest potential to show optimal efficacy in high-risk populations since these patients have reduced RSV immunity, which manifests in a higher and longer duration of viral load and greater disease severity, allowing a bigger window to realize the full potential of zelicapavir. Based on its growing safety profile, we are continuing to evaluate zelicapavir in high-risk populations, including pediatric patients and high-risk adults, all of which have significant unmet need:

Previous wording

Pediatric Study of Zelicapavir: On December 9, 2024, we announced positive topline results from the first-in-pediatrics Phase 2 study evaluating zelicapavir in hospitalized and non-hospitalized children aged 28 days to 36 months with RSV. This Phase 2 study was a randomized, double-blind, dose ranging, placebo-controlled study in hospitalized and non- hospitalized pediatric patients with RSV aged 28 days to 36 months.

Current wording

Pediatric Study of Zelicapavir: In December 2024, we announced positive topline results from the first-in-pediatrics Phase 2 randomized, double-blind, placebo-controlled study evaluating zelicapavir in approximately 90 hospitalized and non-hospitalized children aged 28 days to 36 months with RSV. This Phase 2 study was a randomized, double-blind, dose ranging, placebo-controlled study in hospitalized and non- hospitalized pediatric patients with RSV aged 28 days to 36 months. The first part of the study included dose ranging in two different age cohorts, focused on safety and pharmacokinetics (PK), and the second part of the study focused on virology outcomes from a single dose selected from the first part of the study.

Previous wording

High-Risk Adults Study of Zelicapavir: We also have an ongoing Phase 2b study in high-risk adults, including those who are older than 65 years of age and those who have asthma, chronic obstructive pulmonary disease, or COPD, or congestive heart failure. Approximately 180 patients will be treated with zelicapavir or placebo for five days with a primary endpoint of time to resolution of RSV lower respiratory tract disease symptoms. Enrollment is progressing and we are targeting enrollment completion in the current Northern Hemisphere RSV season with topline data expected in the third quarter of 2025.

Current wording

High-Risk Adults Study of Zelicapavir: We also have an ongoing Phase 2b study in high-risk adults, including those who are older than 65 years of age and those who have asthma, chronic obstructive pulmonary disease, or COPD, or congestive heart failure. Patients enrolled in the study are treated with zelicapavir or placebo for five days, and the primary endpoint is time to resolution of RSV lower respiratory tract disease symptoms. We recently met our target enrollment of 180 patients and we are continuing enrollment to capture the remainder of the Northern Hemisphere RSV season. Enrollment will complete before the end of May 2025, with topline data expected in late third quarter of 2025.

Previous wording

EDP-323 - L-protein Inhibitor Candidate: Our second clinical RSV candidate, EDP-323, is a novel oral, direct-acting antiviral selectively targeting the RSV L-protein, a viral RNA-dependent RNA polymerase enzyme that contains multiple enzymatic activities required for RSV replication. EDP-323 has sub-nanomolar potency against RSV-A and RSV-Bin vitro and protected mice in a dose-dependent manner from RSV infection as demonstrated by both virological and pathological endpoints. EDP-323 is not expected to have cross-resistance to other classes of inhibitors and has the potential to be used alone, or in combination with other RSV mechanisms, to broaden the treatment window or addressable patient populations.

Current wording

EDP-323 - L-protein Inhibitor Candidate: Our second clinical RSV candidate, EDP-323, is an oral, direct-acting antiviral selectively targeting the RSV L-protein, a viral RNA-dependent RNA polymerase enzyme that contains multiple enzymatic activities required for RSV replication. EDP-323 has sub-nanomolar potency against RSV-A and RSV-Bin vitro and protected mice in a dose-dependent manner from RSV infection as demonstrated by both virological and pathological endpoints. EDP-323 is not expected to have cross-resistance to other classes of inhibitors and has the potential to be used alone, or in combination with other RSV mechanisms, to broaden the treatment window or addressable patient populations.

Previous wording

KIT Inhibitors. We have a preclinical stage program to develop oral KIT inhibitors to treat CSU and potentially other indications by depleting mast cells, thereby addressing a primary driver of these diseases. We have discovered novel, potent and selective oral KIT inhibitors, which are in preclinical development. In the fourth quarter of 2024, we selected our lead development candidate, EPS-1421. This candidate demonstrates potent nanomolar activity in both binding and cellular function assays, with sub-nanomolar activityin vivo, and is highly selective for KIT versus other kinases. This inhibitor also demonstrates strongin vitro andin vivo absorption, distribution, metabolism and excretion (ADME) properties. We expect to conduct scale-up activities and IND-enabling studies for this program in 2025.

Current wording

KIT Inhibitors. We have a preclinical stage program to develop oral KIT inhibitors to treat CSU and potentially other indications by depleting mast cells, thereby addressing a primary driver of these diseases. We have discovered novel, potent and selective oral KIT inhibitors, which are in preclinical development. In the fourth quarter of 2024, we selected our lead development candidate, EPS-1421. This candidate demonstrates potent nanomolar activity in both binding and cellular function assays, with sub-nanomolar activityin vivo, and is highly selective for KIT versus other kinases. This inhibitor also demonstrates strongin vitro andin vivo absorption, distribution, metabolism and excretion (ADME) properties. We are conducting scale-up activities and IND-enabling studies for this program in 2025.

Previous wording

STAT6 Inhibitors. We have a discovery stage program to develop oral STAT6 inhibitors for the treatment of type 2 immune driven diseases, initially focusing on AD and potentially other indications by blocking the IL-4/IL-13 signaling pathway, thereby addressing a primary driver of these diseases. We have discovered novel, potent and selective oral STAT6 inhibitors, which are being optimized in the discovery stage. Our prototype inhibitors demonstrate potent activity and high selectivity for STAT6 over other STATs in both biochemical and cellular assays, including SH2 domain selectivity against non-STAT proteins, and also demonstrate systemicin vivo target engagement after ex vivo IL-4 stimulation. We are continuing to evaluate multiple compounds in preclinical studies, including toxicology studies, and conducting lead optimization activities. Our goal is to select a lead development candidate in the second half of 2025.

Current wording

STAT6 Inhibitors. We have a discovery stage program to develop oral STAT6 inhibitors for the treatment of type 2 immune driven diseases, initially focusing on AD and potentially other indications by blocking the IL-4/IL-13 signaling pathway, thereby addressing a primary driver of these diseases. We have discovered novel, potent and selective oral STAT6 inhibitors, which are being optimized in the discovery stage. Our prototype inhibitors demonstrate nanomolar potency and high selectivity for STAT6 over other STATs in both biochemical and cellular assays, with good intrinsic permeability and oral bioavailability. Importantly, a prototype inhibitor resulted in complete inhibition of phosphorylated STAT6, or pSTAT6, in a mouse model, demonstratingin vivo STAT6 target engagement after a single dose with rapid and complete inhibition of pSTAT6. We are continuing to evaluate multiple compounds in preclinical studies, including toxicology studies, and conducting lead optimization activities. Our goal is to select a lead development candidate in the second half of 2025.

Previous wording

To date, we have funded our operations primarily through royalty payments received under our collaboration agreement with AbbVie, a $200.0 million payment received in April 2023 from our royalty sale agreement, and our existing cash, cash equivalents, and short-term marketable securities. We believe that our existing cash, cash equivalents and short-term marketable securities, as well as the cash flows from our retained portion of future HCV royalties and our forthcoming federal tax refund, will enable us to fund our operating expenses and capital expenditure requirements into fiscal 2028.

Current wording

To date, we have funded our operations primarily through milestone and royalty payments received under our collaboration agreement with AbbVie, a $200.0 million payment received in April 2023 from our royalty sale agreement, and our existing cash, cash equivalents, and short-term marketable securities. We believe that our existing cash, cash equivalents and short-term marketable securities, as well as the cash flows from our retained portion of future HCV royalties and our $33.8 million federal tax refund received in April 2025, will enable us to fund our operating expenses and capital expenditure requirements into fiscal 2028.

Previous wording

The following table is a summary of revenue recognized for the three months ended December 31, 2024 and 2023:

Current wording

The following table is a summary of revenue recognized for the three and six months ended March 31, 2025 and 2024:

Previous wording

At any given time, we have later stage programs in clinical development as well as several active early-stage research and drug discovery projects. Our internal resources, employees and infrastructure are utilized across multiple projects, including our early-stage discovery projects. As such, we report information regarding costs incurred based on our programs (i.e., disease area) rather than on a project specific basis. All indirect costs are allocated to programs based on headcount and square footage of our facilities. We expect that our research and development expenses will fluctuate from period to period as we advance our research and development programs. However, in the next 12 months, we anticipate a reduction in our external research and development expenses, primarily driven by the completion of the Phase 2a human challenge study of EDP-323 and the Phase 2b study of zelicapavir in pediatric patients. These milestones, along with strategic adjustments, have positioned us to reduce spending in 2025 while maintaining our commitment to advancing key programs. To date, we have not identified any significant impact of inflation on spending in research and development, but it is uncertain whether there will be inflationary impacts in future periods.

Current wording

At any given time, we have later stage programs in clinical development as well as several active early-stage research and drug discovery projects. Our internal resources, employees and infrastructure are utilized across multiple projects, including our early-stage discovery projects. As such, we report information regarding costs incurred based on our programs (i.e., disease area) rather than on a project specific basis. All indirect costs are allocated to programs based on headcount and square footage of our facilities. We expect that our research and development expenses will fluctuate from period to period as we advance our research and development programs. However, in the next 12 months, we anticipate a reduction in our external research and development expenses, primarily driven by the completion of the Phase 2a human challenge study of EDP-323 and the Phase 2b study of zelicapavir in pediatric patients. These milestones, along with strategic adjustments, have positioned us to reduce spending in 2025 while maintaining our commitment to advancing key programs. To date, we have not identified any significant impact of inflation on spending in research and development, but it is uncertain whether there will be inflationary impacts, including as a result of tariffs, in future periods.

Previous wording

We recognized revenue of $17.0 million during the three months ended December 31, 2024 as compared to $18.0 million during the three months ended December 31, 2023. The $1.0 million decrease in revenue was primarily due to AbbVie’s lower reported HCV sales as compared to the comparable period in 2023.

Current wording

We recognized revenue of $14.9 million during the three months ended March 31, 2025 as compared to $17.1 million during the three months ended March 31, 2024. The $2.1 million decrease in revenue was primarily due to AbbVie’s lower reported HCV sales as compared to the comparable period in 2024.

Previous wording

Research and development expenses for the three months ended December 31, 2024 decreased by $8.7 million compared to the same period in 2023.

Current wording

Research and development expenses for the three months ended March 31, 2025 decreased by $7.5 million compared to the same period in 2024.

Previous wording

The costs in our immunology programs increased by $2.5 million primarily due to the scale-up and IND-enabling activities related to our KIT program and the initiation of preclinical studies for our STAT6 program.

Current wording

The costs in our immunology programs increased by $2.6 million primarily due to the initiation of preclinical studies and lead optimization activities for our STAT6 program.

Previous wording

Other program costs decreased by $2.2 million primarily due to the completion of the discovery and optimization activities related to our STAT6 program.

Current wording

Other program costs decreased by $1.7 million primarily due to the completion of the discovery-stage activities related to our STAT6 program.

Previous wording

General and administrative expenses decreased by $3.7 million for the three months ended December 31, 2024 compared to the same period in 2023. The change was primarily due to a decrease in legal expenses related to our patent infringement suit against Pfizer.

Current wording

General and administrative expenses decreased by $2.8 million for the three months ended March 31, 2025 compared to the same period in 2024. The change was primarily due to a decrease in legal expenses related to our patent infringement suit against Pfizer.

Previous wording

Interest expense decreased $1.5 million for the three months ended December 31, 2024, as compared to the same period in 2023 due to the paydown of our obligation associated with our royalty sale agreement entered into during April 2023 with an affiliate of OMERS.

Current wording

Interest expense decreased $0.8 million for the three months ended March 31, 2025, as compared to the same period in 2024 due to the paydown of our obligation associated with our royalty sale agreement entered into during April 2023 with an affiliate of OMERS.

Previous wording

The costs in our virology program decreased $9.0 million primarily due to timing of our clinical trials in our RSV program and to a lesser extent, a decrease in costs associated with our COVID-19 program as we stopped further internal development and will only progress the program in the context of one or more collaborations.

Current wording

The costs in our virology program decreased $17.5 million primarily due to the timing of our clinical trials in our RSV program and to a lesser extent, a decrease in costs associated with our COVID-19 program as we stopped further internal development and will only progress the program in the context of one or more collaborations.

Previous wording

We fund our operations with cash flows from our retained portion of our royalty revenue and our existing financial resources. At December 31, 2024, our principal sources of liquidity were cash and cash equivalents and short-term marketable securities of $216.7 million.

Current wording

We fund our operations with cash flows from our retained portion of our royalty revenue and our existing financial resources. At March 31, 2025, our principal sources of liquidity were cash and cash equivalents and short-term marketable securities of $193.4 million.

Previous wording

Cash used in operating activities was $16.8 million for the three months ended December 31, 2024 as compared to cash used in operating activities of $25.0 million for the same period in 2023. Our cash used in operating activities decreased $8.2 million primarily due to lower research and development payments, offset by lower cash receipts associated with our AbbVie agreement.

Current wording

Cash used in operating activities was $30.3 million for the six months ended March 31, 2025 as compared to cash used in operating activities of $53.6 million for the same period in 2024. Our cash used in operating activities decreased $23.3 million primarily due to lower research and development payments, offset by lower cash receipts associated with our AbbVie agreement.

Previous wording

Net cash provided by (used in) investing activities

Current wording

Net cash provided by investing activities

Previous wording

Cash provided by investing activities was $68.9 million for the three months ended December 31, 2024 as compared to cash used in investing activities of $13.1 million for the same period in 2023. Our cash provided by investing activities increased $82.0 million, driven by the timing of maturities of marketable securities in 2024 compared to 2023.

Current wording

Cash provided by investing activities was $64.5 million for the six months ended March 31, 2025 as compared to cash provided by investing activities of $45.5 million for the same period in 2024. Our cash provided by investing activities increased $19.0 million, driven by the timing of maturities of marketable securities in 2025 compared to 2024.

Previous wording

Cash used in financing activities was $5.0 million for the three months ended December 31, 2024 as compared to cash used in financing activities of $7.4 million for the same period in 2023. Our cash used in financing activities decreased $2.4 million, driven primarily by lower payments on our royalty sale agreement with OMERS.

Current wording

Cash used in financing activities was $11.9 million for the six months ended March 31, 2025 as compared to cash used in financing activities of $13.8 million for the same period in 2024. Our cash used in financing activities decreased $1.9 million, driven primarily by lower payments on our royalty sale agreement with OMERS.

Previous wording

As of December 31, 2024, we had $216.7 million in cash, cash equivalents and short-term marketable securities. We believe that our existing cash, cash equivalents and short-term marketable securities as of December 31, 2024, as well as the cash flows from our retained portion of future HCV royalties and our forthcoming federal tax refund, will enable us to fund our operating expenses and capital expenditure requirements into fiscal 2028. However, our projection of the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially.

Current wording

As of March 31, 2025, we had $193.4 million in cash, cash equivalents and short-term marketable securities. We believe that our existing cash, cash equivalents and short-term marketable securities as of March 31, 2025, as well as our $33.8 million federal tax refund received in April 2025 and our retained portion of future HCV royalties, will enable us to fund our operating expenses and capital expenditure requirements into fiscal 2028. However, our projection of the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially.

Previous wording

Total estimated minimum lease payments for the next 5 years and thereafter under our existing facility and leased equipment agreements are $6.7 million for the remainder of 2025, $8.5 million in 2026, $8.7 million in 2027, $9.0 million in 2028, $9.3 million in 2029, and $50.6 million thereafter.

Current wording

Total estimated minimum lease payments for the next 5 years and thereafter under our existing facility and leased equipment agreements are $4.6 million for the remainder of 2025, $8.5 million in 2026, $8.7 million in 2027, $9.0 million in 2028, $9.3 million in 2029, and $50.6 million thereafter.