Aligos Therapeutics, Inc.

Previous wording

We are a clinical-stage biotechnology company focused on developing novel therapeutics to address unmet medical needs in liver diseases and viral infections, including in the areas of chronic hepatitis B virus (HBV) infection, metabolic dysfunction-associated steatohepatitis (MASH), and coronavirus infections (e.g., SARS‑CoV‑2, SARS‑CoV, MERS‑CoV, and other related infections) as well as obesity. The Aligos team has a demonstrated track record of success in early drug development and medicinal chemistry in liver and viral diseases, resulting in three potential best‑in‑class drug candidates currently in clinical development.

Current wording

We are a clinical-stage biotechnology company focused on developing novel therapeutics to address unmet medical needs in liver diseases and viral infections, including in the areas of chronic hepatitis B virus (HBV) infection, metabolic dysfunction-associated steatohepatitis (MASH), and coronavirus infections as well as obesity. The Aligos team has a demonstrated track record of success in drug development and medicinal chemistry in liver and viral diseases, resulting in three potential best‑in‑class drug candidates currently in clinical development.

Previous wording

Our pipeline of drug candidates includes pevifoscorvir sodium (previously known as ALG‑000184) for chronic HBV infection, ALG‑055009 for obesity and MASH, ALG‑097558 for coronavirus infections, and a portfolio of preclinical programs. Pevifoscorvir sodium is our potential best‑/first‑in‑class Capsid Assembly Modulator (CAM‑E) for chronic HBV infection which has shown in pre-clinical testing to have enhanced pharmacologic properties vs. competitor CAM‑E drugs and greater HBV DNA suppression compared to the standard of care, nucleos(t)ide analogs (NAs), and has shown multi-log 10 reductions in viral antigens in Phase 1 clinical studies conducted to date. ALG‑055009 is our potential best‑in‑class thyroid hormone receptor beta (THR‑β) agonist for obesity and MASH with pharmacologic properties that appear to be enhanced based on data to date vs. competitor THR-β agonists. Phase 2a topline data in MASH demonstrated that ALG‑055009 dose groups met the primary endpoint with statistically significant reductions in liver fat at Week 12 as measured by MRI-PDFF. ALG‑097558 is our potential best‑in‑class small molecule pan-coronavirus 3CL protease inhibitor (PI), which has been at least 3-fold more potent in cell-based assays of coronavirus infection than other approved CoV PIs and we believe can be dosed twice daily without the requirement for ritonavir co-dosing based on Phase 1 clinical studies conducted to date.

Current wording

Our pipeline of drug candidates includes pevifoscorvir sodium (previously known as ALG‑000184) for chronic HBV infection, ALG‑055009 for MASH and obesity, ALG‑097558 for coronavirus infections, and a portfolio of preclinical programs. Pevifoscorvir sodium is our potential best‑/first‑in‑class Capsid Assembly Modulator (CAM‑E) for chronic HBV infection which has shown in pre-clinical testing to have enhanced pharmacologic properties vs. competitor CAM‑E drugs and greater HBV DNA suppression compared to the standard of care, nucleos(t)ide analogs (NAs), and has shown multi-log 10 reductions in viral antigens in Phase 1 clinical studies conducted to date. Pevifoscorvir sodium recently received Fast Track Designation from the Food and Drug Administration (FDA) in chronic HBV infection. ALG‑055009 is our potential best‑in‑class thyroid hormone receptor beta (THR‑β) agonist for MASH and obesity with pharmacologic properties that appear to be enhanced based on data to date vs. competitor THR-β agonists. Phase 2a topline data demonstrated that ALG‑055009 dose groups met the primary endpoint with statistically significant reductions in liver fat at Week 12 as measured by MRI-PDFF in subjects with presumed MASH. Recently presented nonclinical data suggests synergistic fat mass loss in combination with incretin receptor agonists in diet induced obese (DIO) mice. ALG‑097558 is our potential best‑in‑class small molecule pan-coronavirus 3CL protease inhibitor (PI), which has been at least 3-fold more potent in cell-based assays of coronavirus infection than other approved CoV PIs and we believe can be dosed twice daily without the requirement for ritonavir co-dosing based on Phase 1 clinical studies conducted to date.

Previous wording

In 2018, we in‑licensed a lead drug candidate (GLP‑26) and the associated IP for a CAM‑E from the laboratory of Professor Raymond Schinazi at Emory University. Our scientists optimized this lead drug candidate to discover the highly potent CAM‑E, ALG‑001075, which was further optimized to the prodrug pevifoscorvir sodium. Based on pre-clinical data to date, pevifoscorvir sodium has superior DMPK properties with enhanced absorption and high liver uptake, with a ~2-300-fold improvement in in vitro potency compared to other known CAMs. CAM‑Es are a class of small molecule antiviral agents that accelerate HBV capsid assembly and inhibit pgRNA encapsidation (1st MOA), resulting in empty viral capsids and lower circulating HBV DNA and RNA levels. CAM‑Es are also believed to prevent the establishment of cccDNA (2nd MOA), a major factor for the persistence of HBV infection which can be assessed by circulating HBV antigen levels (HBsAg, HBcrAg, and HBeAg). In clinical trials, competitor CAM‑Es have shown reductions in HBV DNA and RNA (1st MOA), but have rarely or inconsistently shown reductions in HBV antigens (2nd MOA). There have also been observations of the emergence of viral CAM-E drug resistance with competitor compounds.

Current wording

In 2018, we in‑licensed a lead drug candidate (GLP‑26) and the associated IP for a CAM‑E from the laboratory of Professor Raymond Schinazi at Emory University. Our scientists optimized this lead drug candidate to discover the highly potent CAM‑E, ALG‑001075, which was further optimized to the prodrug pevifoscorvir sodium. Based on pre-clinical data to date, pevifoscorvir sodium has superior DMPK properties with enhanced absorption and high liver uptake, with a ~2-300-fold improvement in in vitro potency compared to other known CAMs. CAM‑Es are a class of small molecule antiviral agents that accelerate HBV capsid assembly and inhibit pgRNA encapsidation (1st MOA), resulting in empty viral capsids and lower circulating HBV DNA and RNA levels. CAM-Es have the potential to prevent HBV DNA integration by blocking the conversion of pgRNA to dslDNA, the form which integrates into the host chromosome. CAM‑Es are also believed to prevent the establishment and replenishment of cccDNA (2nd MOA), a major factor for the persistence of HBV infection which can be assessed by circulating HBV antigen levels (HBsAg, HBcrAg, and HBeAg). These three drivers, replication, integration, and the reservoir, comprise the disease pathogenesis which can lead to end-stage liver disease and liver cancer. We believe that effective therapies for chronic HBV infection must address all three drivers. In preclinical studies and clinical trials conducted to date, pevifoscorvir sodium has demonstrated the potential to not only block HBV replication and prevent HBV DNA integration, but also reduce the cccDNA reservoir, all clinically relevant markers that improve outcomes in chronic HBV infection.

Previous wording

A multi-part Phase 1 study is complete, with evaluation of the safety, tolerability, and pharmacokinetic profile of pevifoscorvir sodium in HVs. Additionally, a dose-ranging phase assessing the safety, pharmacokinetics (PK), and antiviral activity of 10‑300 mg doses of pevifoscorvir sodium administered over 28 days in untreated HBeAg+/- subjects with chronic HBV infection has also been completed. In these study phases, pevifoscorvir sodium was found to be well tolerated with a favorable PK profile and demonstrated potentially best-in-class multi-log 10 HBV DNA and RNA reductions at all doses tested, as well as HBV surface antigen (HBsAg) reductions in a subset of HBeAg+ subjects receiving 100 mg or 300 mg of pevifoscorvir sodium (Hou et al, AASLD 2022). Based on the favorable profile observed with dosing up to 300 mg of pevifoscorvir sodium for 28 days, additional Phase 1 studies evaluated the risk-benefit profile of pevifoscorvir sodium at doses of 300 mg, with or without entecavir (ETV) therapy, for up to 96 weeks in HBeAg+and HBeAg- subjects with chronic HBV infection. Preliminary data from several of these cohorts (Hou et al., EASL 2025; Yuen et al., AASLD 2024, APASL 2025, EASL 2025) have been presented, showing that pevifoscorvir sodium, administered for up to 96 weeks, was well tolerated, exhibited a favorable PK profile, and suggested potentially best-in-class potent and durable antiviral activity.

Current wording

A multi-part Phase 1 study is complete, with evaluation of the safety, tolerability, and pharmacokinetic profile of pevifoscorvir sodium in HVs. Additionally, a dose-ranging phase assessing the safety, pharmacokinetics (PK), and antiviral activity of 10‑300 mg doses of pevifoscorvir sodium administered over 28 days in untreated HBeAg+/- subjects with chronic HBV infection has also been completed. In these study phases, pevifoscorvir sodium was found to be well tolerated with a favorable PK profile and demonstrated potentially best-in-class multi-log 10 HBV DNA and RNA reductions at all doses tested, as well as HBV surface antigen (HBsAg) reductions in a subset of HBeAg+ subjects receiving 100 mg or 300 mg of pevifoscorvir sodium (Hou et al, AASLD 2022). Based on the favorable profile observed with dosing up to 300 mg of pevifoscorvir sodium for 28 days, additional Phase 1 studies evaluated the risk-benefit profile of pevifoscorvir sodium at doses of 300 mg, with or without entecavir (ETV) therapy, for up to 96 weeks in HBeAg+ and HBeAg- subjects with chronic HBV infection. Data from these cohorts (Yuen et al., AASLD 2025) have been presented, showing that pevifoscorvir sodium, administered for up to 96 weeks, was well tolerated, exhibited a favorable PK profile, and suggested potentially best-in-class potent and durable antiviral activity.

Previous wording

subjects with chronic HBV infection at Week 48 and 9/9 (100%) at Week 96. Additionally, HBV DNA level continuously declined to < LLOQ (10 IU/mL, TND) in 5 of 9 subjects at Week 96. Data from the 300 mg pevifoscorvir sodium HBeAg- monotherapy cohort demonstrated HBV DNA suppression in all 11/11 (100%) subjects by Week 24 with the HBV DNA suppression level maintained for up to 96 weeks, with further decline in HBV DNA to < LLOQ (10 IU/mL, TND) observed in all subjects (8/8) at Week 96. Importantly, no viral breakthrough was observed in any subject, and no known CAM resistant mutations were identified.

Current wording

Data from this study following an oral daily dose of 300 mg pevifoscorvir sodium monotherapy in HBeAg+ subjects demonstrated sustained HBV DNA suppression (<LLOQ (10 IU/mL, target detected (TD) or target not detected (TND)) in 6/10 (60%) subjects with chronic HBV infection at Week 48 and 9/9 (100%) at Week 96. Additionally, HBV DNA level continuously declined to < LLOQ (10 IU/mL, TND) in 5 of 10 subjects at Week 96. Data from the 300 mg pevifoscorvir sodium HBeAg- monotherapy cohort demonstrated HBV DNA suppression in all 11/11 (100%) subjects by Week 24 with the HBV DNA suppression level maintained for up to 96 weeks, with further decline in HBV DNA to < LLOQ (10 IU/mL, TND) observed in 8/9 subjects (89%) at Week 96. Importantly, no viral breakthrough was observed in any subject, and no known CAM resistant mutations were identified.

Previous wording

Compared to Phase 3 studies with the current standard of care nucleos(t)ide analogs (NAs), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) (Buti et al., Lancet Gastro, 2016; Chen et al., Lancet Gastro 2016), these Phase 1 data to date suggest, subject to confirmation via further study, that pevifoscorvir sodium treatment may be superior to NAs in HBeAg+/- subjects in achieving HBV DNA levels < LLOQ (10 IU/mL) after 48 weeks on treatment, which is the approvable endpoint for chronic suppressive therapy in chronic HBV infection (Food and Drug Administration (FDA) Guidance, Chronic Hepatitis B Virus Infection: Developing Drugs for Treatment Guidance for Industry, April 2022 – Section III.B.1.a). We have received affirmative feedback from the FDA, the Committee for Medicinal Products for Human Use (CHMP: EU) and the National Medical Products Administration (NMPA: China) supporting subsequent studies utilizing the chronic suppressive therapy pathway for pevifoscorvir sodium. Our ongoing Phase 2 B-SUPREME study is being conducted to test superiority to standard of care NA treatment (HBV DNA levels <LLOQ (10 IU/ml, TD or TND) in HBeAg+ subjects and HBV DNA levels < LLOQ (10 IU/ml, TND) in HBeAg-subjects) after 48 weeks of monotherapy treatment. Furthermore, when combined with other mechanisms of action, including other candidates in our chronic HBV infection portfolio, pevifoscorvir sodium dosing regimens have the potential to contribute to achieving higher rates of functional cure, subject to testing such endpoint, as compared with currently approved agents.

Current wording

Compared to Phase 3 studies with the current standard of care nucleos(t)ide analogs (NAs), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) (Buti et al., Lancet Gastro, 2016; Chen et al., Lancet Gastro 2016), these Phase 1 data to date suggest, subject to confirmation via further study, that pevifoscorvir sodium treatment may be superior to NAs in HBeAg+/- subjects in achieving HBV DNA levels < LLOQ (10 IU/mL) after 48 weeks on treatment. Chronic suppressive therapy of HBV DNA levels is a validated approval pathway in chronic HBV infection (Food and Drug Administration (FDA) Guidance, Chronic Hepatitis B Virus Infection: Developing Drugs for Treatment Guidance for Industry, April 2022 – Section III.B.1.a). We have received affirmative feedback from the FDA, the Committee for Medicinal Products for Human Use (CHMP: EU) and the National Medical Products Administration (NMPA: China) supporting subsequent studies utilizing the chronic suppressive therapy pathway for pevifoscorvir sodium. Our ongoing Phase 2 B-SUPREME study is being conducted to test superiority to standard of care NA treatment (HBV DNA levels <LLOQ (10 IU/ml, TD or TND) in HBeAg+ subjects and HBV DNA levels < LLOQ (10 IU/ml, TND) in HBeAg- subjects) after 48 weeks of monotherapy treatment. Furthermore, when combined with other mechanisms of action, including other candidates in our chronic HBV infection portfolio, pevifoscorvir sodium dosing regimens have the potential to contribute to achieving higher rates of functional cure, subject to testing such endpoint, as compared with currently approved agents.

Previous wording

The Phase 2 B-SUPREME study (NCT06963710) is designed as a randomized, double-blind, active-controlled multicenter study evaluating the safety and efficacy of pevifoscorvir sodium monotherapy compared with tenofovir disoproxil fumarate for 48 weeks in approximately 200 currently untreated HBeAg+ and HBeAg- adult subjects with chronic HBV infection. The primary endpoint in the HBeAg+ arm is HBV DNA <LLOQ (10 IU/mL, TD or TND) and the primary endpoint in the HBeAg- arm is HBV DNA <LLOQ (10 IU/mL, TND). The study is also evaluating safety, PK, and other secondary and exploratory HBV biomarkers, including reductions in HBV antigens and other markers of HBV infection. The Phase 2 study has obtained worldwide regulatory approvals, and is currently activating global sites, and enrolling subjects. The first subject was dosed in August 2025. Interim data is projected in both the first and second half of 2026 and topline data is anticipated in 2027.

Current wording

With the completion of the 96 week Phase 1 study, we initiated the Phase 2 B-SUPREME study (NCT06963710), which is designed as a randomized, double-blind, active-controlled multicenter study evaluating the safety and efficacy of pevifoscorvir sodium monotherapy compared with tenofovir disoproxil fumarate for 48 weeks in approximately 200 currently untreated HBeAg+ and HBeAg- adult subjects with chronic HBV infection. The primary endpoint in the HBeAg+ arm is HBV DNA <LLOQ (10 IU/mL, TD or TND) and the primary endpoint in the HBeAg- arm is HBV DNA <LLOQ (10 IU/mL, TND). The study is also evaluating safety, PK, and other secondary and exploratory HBV biomarkers, including reductions in HBV antigens and other markers of HBV infection. The Phase 2 study has obtained regulatory approvals to move forward in every country included in the study and is currently enrolling subjects. As of April 2026, there were 74 participants enrolled in the HBeAg- cohort (Part 2a), with 103 participants enrolled in the HBeAg+ cohort (Part 1a).

Previous wording

We are also exploring additional ways to potentially treat patients with chronic HBV infection, including our antisense oligonucleotide (ASO) platform which utilizes novel monomers that could potentially reduce ASO toxicity and improve ASO liver to kidney ratios.

Current wording

We are also exploring additional ways to potentially treat patients with chronic HBV infection, including our antisense oligonucleotide (ASO) platform which utilizes novel monomers that could potentially reduce ASO toxicity and improve ASO liver to kidney ratios. Along with our partner Amoytop, ALG-170675 was selected and is currently in IND-enabling studies. Current costs for development in China are being funded by Amoytop, who maintain rights in China, Taiwan, Hong Kong and Macau. This next-generation ASO works via two mechanisms of action. It targets and destroys HBsAg-encoding mRNA and activates the immune response through TLR-8 agonism.

Previous wording

ALG‑055009: Potential best-in-class small molecule THR-β agonist for obesity and metabolic dysfunction-associated steatohepatitis

Current wording

ALG‑055009: Potential best-in-class small molecule THR-β agonist for metabolic dysfunction-associated steatohepatitis and obesity

Previous wording

Based on these promising Phase 1 data, we conducted the Phase 2a HERALD study (NCT06342947) at sites across the United States. The study was a 12-week randomized, double-blind, placebo-controlled trial evaluating 4 doses (0.3 mg, 0.5 mg, 0.7 mg, and 0.9 mg) of ALG-055009 vs. placebo in 102 subjects with presumed MASH and liver fibrosis at stages 1-3 (F1-F3). The primary endpoint of this study was percent relative change in liver fat content by MRI-PDFF at Week 12. This study also evaluated the safety and PK of ALG-055009 treatment and its effect on multiple other efficacy biomarkers, including other non-invasive tests previously shown to be impacted by treatment with THR‑β agonists. We announced positive topline data from this study in 2024, demonstrating that ALG-055009 dose groups were well-tolerated and met the primary endpoint. Specifically, doses of 0.5 mg to 0.9 mg ALG-055009 demonstrated statistically significant reductions in liver fat at Week 12, with placebo-adjusted median relative reductions up to 46.2% as measured by MRI-PDFF. Up to 70% of subjects achieved ≥30% relative reduction in liver fat compared to baseline. Eighteen subjects who were on stable GLP-1 agonist therapy qualified for enrollment in the study, with liver fat content meeting the inclusion criteria of ≥10% at baseline as measured by MRI-PDFF. Notably, 11 of 14 subjects on stable GLP-1 agonists treated with ALG-055009 had liver fat decreases, whereas 4 of 4 subjects on stable GLP-1 agonists treated with placebo had increases in liver fat over the 12-week dosing period (Loomba et al, AASLD 2024).

Current wording

Based on these promising Phase 1 data, we conducted the Phase 2a HERALD study (NCT06342947) at sites across the United States. The study was a 12-week randomized, double-blind, placebo-controlled trial evaluating 4 doses (0.3 mg, 0.5 mg, 0.7 mg, and 0.9 mg) of ALG-055009 vs. placebo in 102 subjects with presumed MASH and liver fibrosis at stages 1-3 (F1-F3). The primary endpoint of this study was percent relative change in liver fat content by MRI-PDFF at Week 12. This study also evaluated the safety and PK of ALG-055009 treatment and its effect on multiple other efficacy biomarkers, including other non-invasive tests previously shown to be impacted by treatment with THR‑β agonists. We announced positive topline data from this study in 2024, demonstrating that ALG-055009 dose groups were well-tolerated and met the primary endpoint. Specifically, doses of 0.5 mg to 0.9 mg ALG-055009 demonstrated statistically significant reductions in liver fat at Week 12, with placebo-adjusted median relative reductions up to 46.2% as measured by MRI-PDFF. Up to 70% of subjects achieved ≥30% relative reduction in liver fat compared to baseline. Eighteen subjects who were on stable GLP-1 receptor agonist therapy qualified for enrollment in the study, with liver fat content meeting the inclusion criteria of ≥10% at baseline as measured by MRI-PDFF. Notably, 11 of 14 subjects on stable GLP-1 receptor agonists treated with ALG-055009 had liver fat decreases, whereas 4 of 4 subjects on stable GLP-1 receptor agonists treated with placebo had increases in liver fat over the 12-week dosing period (Loomba et al, AASLD 2024).

Previous wording

New preclinical and clinical findings reported by other companies have suggested that THR-β agonists can significantly enhance weight loss when administered in combination with incretin receptor agonists (RAs) for the treatment of obesity.

Current wording

Preclinical and clinical findings reported by other companies have suggested that THR-β agonists can significantly enhance weight loss when administered in combination with incretin receptor agonists (RAs) for the treatment of obesity.

Previous wording

Another area of focus is to develop drug candidates with pan-coronavirus antiviral activity, including against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19. In this area of focus, we are exploring small molecule coronavirus 3CL protease inhibitors (PIs) in collaboration with the Rega Institute at Katholieke Universiteit Leuven (KU Leuven), the Center for Innovation and Stimulation of Drug Discovery (CISTIM) and the Centre for Drug Design and Discovery (CD3). This collaboration led to the discovery of ALG‑097558 which has completed a Phase 1 first-in-human evaluation in healthy volunteers and advanced into a clinical trial evaluating the compound in high-risk COVID-19 patients.

Current wording

Another area of focus is to develop drug candidates with pan-coronavirus antiviral activity, including against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19. In this area of focus, we are exploring small molecule coronavirus 3CL protease inhibitors (PIs) in collaboration with the Rega Institute at Katholieke Universiteit Leuven (KU Leuven), the Center for Innovation and Stimulation of Drug Discovery (CISTIM) and the Centre for Drug Design and Discovery (CD3). This collaboration led to the discovery of ALG‑097558 which has completed a Phase 1 first-in-human evaluation in HVs and advanced into a clinical trial evaluating the compound in high-risk COVID-19 patients.

Previous wording

ALG‑097558 has been shown in preclinical studies to be at least 3-fold more potent than nirmatrelvir and other PIs in clinical development against a panel of SARS-CoV-2 variants (including Omicron). It also has demonstrated broad pan‑coronavirus activity, including against SARS-CoV-1 and MERS-CoV. In the first-in-human Phase 1 clinical study, single doses up to 2000 mg and multiple doses up to 800 mg Q12H for 7 days were well tolerated with an acceptable PK profile that suggests ritonavir boosting may not be required. Furthermore, the absence of a clinically relevant DDI with midazolam suggests that ALG‑097558 may be able to be co-administered with CYP3A4 substrates (NCT05840952). Based on these Phase 1 data (Wilkes et al., RespiDart, 2024), the projected efficacious dose range to treat SARS-CoV-2 is 200-600 mg ALG‑097558 Q12 x 5 days, without the need for ritonavir coadministration.

Current wording

ALG‑097558 has been shown in preclinical studies to be at least 3-fold more potent than nirmatrelvir and other PIs in clinical development against a panel of SARS-CoV-2 variants (including Omicron). It also has demonstrated broad pan‑coronavirus activity, including against SARS-CoV-1 and MERS-CoV in preclinical studies. In the first-in-human Phase 1 clinical study, single doses up to 2000 mg and multiple doses up to 800 mg Q12H for 7 days were well tolerated with an acceptable PK profile that suggests ritonavir boosting may not be required. Furthermore, the absence of a clinically relevant DDI with midazolam suggests that ALG‑097558 may be shown to be appropriate for co-administration with CYP3A4 substrates (NCT05840952). Based on these Phase 1 data (Wilkes et al., RespiDart, 2024), the projected efficacious dose range to treat SARS-CoV-2 is 200-600 mg ALG‑097558 Q12 x 5 days, without the need for ritonavir coadministration.

Previous wording

A Phase 2 study of ALG‑097558 began in 2024. The AGILE trial, a United Kingdom government-supported platform trial (MRC and Wellcome Trust funding), is sponsoring and performing a study in high‑risk COVID‑19 patients evaluating ALG‑097558 as monotherapy or in combination with remdesivir (NCT04746183). We expect that future development of ALG‑097558 will be funded by external sources, including public funding sources as described below.

Current wording

A Phase 2 study of ALG‑097558 began in 2024. The AGILE trial, a United Kingdom government-supported platform trial (MRC and Wellcome Trust funding), is sponsoring and performing a study in standard and high‑risk COVID‑19 patients evaluating ALG‑097558 as monotherapy or in combination with remdesivir (NCT04746183). We expect that future development of ALG‑097558 will be funded by external sources, including public funding sources as described below.

Previous wording

Preclinical activities for our coronavirus program were partially funded through a grant from the National Institutes of Health (NIH) and the National Institute of Allergy and Infectious Diseases (NIAID) Antiviral Drug Discovery (AViDD) Centers for Pathogens of Pandemic Concern program through the Metropolitan AntiViral Drug Accelerator (MAVDA) consortium. Specific clinical and nonclinical studies for the ALG-097558 program and the follow up compound, are now also being funded with federal funds from the NIAID, NIH, Department of Health and Human Services, under Contract No. 75N93023C00052. We filed an IND in the third quarter of 2024. We expect to receive approximately $15.3 million in funds across these two NIH awards and contracts to support these activities. To date, these funds have not been impacted by any changes at the NIH or NIAID. We are also seeking additional external funding (e.g., from governmental agencies) and/or collaborations (e.g., platform trials) to support future studies as we advance ALG‑097558 for the treatment of COVID‑19 and future coronavirus pandemics.

Current wording

Preclinical activities for our coronavirus program were partially funded through a grant from the National Institutes of Health (NIH) and the National Institute of Allergy and Infectious Diseases (NIAID) Antiviral Drug Discovery (AViDD) Centers for Pathogens of Pandemic Concern program through the Metropolitan AntiViral Drug Accelerator (MAVDA) consortium. Specific clinical and nonclinical studies for the ALG-097558 program are now also being funded with federal funds from the NIAID, NIH, Department of Health and Human Services, under Contract No. 75N93023C00052. We filed an IND in the third quarter of 2024. We expect to receive approximately $15.3 million in funds across these two NIH awards and contracts to support these activities. To date, these funds have not been impacted by any changes at the NIH or NIAID. We are also seeking additional external funding (e.g., from governmental agencies) and/or collaborations (e.g., platform trials) to support future studies as we advance ALG‑097558 for the treatment of COVID‑19 and future coronavirus pandemics.

Previous wording

Our operating expenses since inception have consisted solely of research and development costs and general and administrative costs.

Current wording

Our operating expenses have historically consisted of research and development costs and general and administrative costs.

Previous wording

We expect our expenses to increase substantially in connection with our ongoing clinical development activities related to our chronic HBV infection drug candidate pevifoscorvir sodium. We rely substantially on third parties to conduct our discovery activities, nonclinical studies, clinical trials and manufacturing. We estimate research and development expenses based on estimates of services performed, and rely on third party contractors and vendors to provide us with timely and accurate estimates of expenses of services performed to assist us in these estimates. A portion of our research and development expenses are based on contractual milestones. Research and development costs consist primarily of costs incurred for the identification and development of our drug candidates through our technology platforms, which include:

Current wording

We expect our research and development expenses to increase substantially in connection with our ongoing and planned clinical development activities for pevifoscorvir sodium and our other drug candidates. We rely substantially on third parties to conduct our discovery activities, nonclinical studies, clinical trials and manufacturing. We estimate research and development expenses based on estimates of services performed, and rely on third party contractors and vendors to provide us with timely and accurate estimates of expenses of services performed to assist us in these estimates. A portion of our research and development expenses are based on contractual milestones. Research and development costs consist primarily of costs incurred for the identification and development of our drug candidates through our technology platforms, which include:

Previous wording

Comparison of the three and nine months ended September 30, 2025 and 2024

Current wording

Comparison of the three months ended March 31, 2026 and 2025

Previous wording

The following table summarizes our operating expenses for the three and nine months ended September 30, 2025 and 2024 (in thousands):

Current wording

The following table summarizes our operating expenses for the three months ended March 31, 2026 and 2025 (in thousands):

Previous wording

Research and development expenses increased by $7.2 million during the three months ended September 30, 2025, compared to the same period in 2024. The increase in the three-month period was primarily due to a $6.7 million increase in third-party expenses due to increased clinical study costs as a result of the beginning of enrollment and dosing in the pevifoscorvir sodium Phase 2a clinical trial. This included a payment of $9.0 million to Emory related to milestone payments due to the first subject dosed in a Phase 2 clinical trial. Partially offsetting this was a decrease in MASH spend due to the completion of the Phase 2a clinical trial with topline data announced in Q3 2024. Further, there was a $0.4 million increase in employee-related costs, and a $0.1 million increase in facility and other expenses.

Current wording

Research and development expenses increased by $8.9 million during the three months ended March 31, 2026, compared to the same period in 2025. The increase in the three-month period was primarily due to a $6.2 million increase in third-party expenses due to increased clinical study costs as a result of the beginning of enrollment and dosing in the pevifoscorvir sodium Phase 2 B‑SUPREME clinical trial. Further, there was a $2.2 million increase in employee-related costs, and a $0.4 million increase in facility and other expenses.

Previous wording

We expect research and development expenses will increase in future periods as we continue to focus on advancing clinical trials for pevifoscorvir sodium and MASH.

Current wording

We expect research and development expenses will increase in future periods as we continue to focus on advancing clinical trials for pevifoscorvir sodium.

Previous wording

General and administrative expenses increased by $0.5 million during the three months ended September 30, 2025, compared to the same period in 2024. This was primarily due to a $0.4 million increase in third party expenses due to increased legal and intellectual property spend, and a $0.2 million increase in employee-related costs, partially offset by a $0.1 million increase in facility, travel and entertainment costs.

Current wording

General and administrative expenses increased by $1.4 million during the three months ended March 31, 2026, compared to the same period in 2025. This was primarily due to a $0.7 million increase in employee-related costs, as well as a $0.4 million increase in third party expenses due to increased legal and intellectual property spend.

Previous wording

Interest and other income, net remained relatively flat during the three months ended September 30, 2025 as compared to the same period in the prior year. Interest and other income decreased by $0.7 million during the nine months ended September 30, 2025 as compared to the same period in the prior year due primarily to a decrease in the accretion of short-term investments.

Current wording

Interest and other income, net remained relatively flat during the three months ended March 31, 2026 as compared to the same period in the prior year.

Previous wording

The change in fair value of 2023 common warrants was a decrease of $4.1 million and an increase of $43.0 million for the three and nine months ended September 30, 2025 compared to the same period ended September 30, 2024. The change was due to a change in the fair value of the 2023 common warrants measured using the Black Scholes option pricing model remeasured at each reporting period, principally due to a change in the stock price between reporting periods.

Current wording

The change in fair value of 2023 Common Warrants was a decrease of $58.1 million for the three months ended March 31, 2026 compared to the same period ended March 31, 2025. The change was due to a change in the fair value of the 2023 Common Warrants measured using the Black Scholes option pricing model remeasured at each reporting period, principally due to a change in the stock price between reporting periods.

Previous wording

We have incurred net losses and negative cash flows from operations in each year since our formation in February 2018. Our net loss was $4.3 million for the nine months ended September 30, 2025 and net loss was $49.1 million for the nine months ended September 30, 2024, and our net losses were $131.2 million for the year ended December 31, 2024. As of September 30, 2025, we had an accumulated deficit of $622.3 million.

Current wording

We have incurred net losses in each year since inception. Our net losses were $23.0 million for the three months ended March 31, 2026 and $24.2 million for the year ended December 31, 2025. As of March 31, 2026, we had an accumulated deficit of $665.2 million.

Previous wording

As of September 30, 2025 and December 31, 2024, we had an accumulated deficit of $622.3 million and $618.0 million, respectively, and cash, cash equivalents and short-term investments of $99.1 million and $56.9 million, respectively. Our current operating plan and projected cash outflows for the upcoming periods raise doubt about our ability to continue as a going concern for at least 12 months from the issuance of the financial statements included elsewhere in this Quarterly Report. We plan to raise additional capital to fund continued operations beyond the third quarter of 2026. We are taking steps to identify access to future capital and expect to be able to access capital in the future. However, there can be no assurance that any additional funding will be available to us on acceptable terms, if at all. If events or circumstances occur such that we do not obtain additional funding, it may be necessary to significantly reduce the scope of operations to reduce the current rate of spending, which could include reductions in staff and the need to delay, limit, reduce or terminate current or future product development, which could have a material adverse effect on our business, results of operations and financial condition. Moreover, even if financing efforts are successful and additional capital is obtained, available liquidity may still be insufficient to eliminate the aforementioned substantial doubt regarding our ability to continue as a going concern.

Current wording

As of March 31, 2026, we had an accumulated deficit of $665.2 million, and cash, cash equivalents and short-term investments of $54.9 million. Our current operating plan and projected cash outflows for the upcoming periods raise doubt about our ability to continue as a going concern for at least 12 months from the issuance of the financial statements included elsewhere in this Quarterly Report. We plan to raise additional capital to fund continued operations beyond the fourth quarter of 2026. We are taking steps to identify access to future capital and expect to be able to access capital in the future. However, there can be no assurance that any additional funding will be available to us on acceptable terms, if at all. If events or circumstances occur such that we do not obtain additional funding, it may be necessary to significantly reduce the scope of operations to reduce the current rate of spending, which could include reductions in staff and the need to delay, limit, reduce or terminate current or future product development, which could have a material adverse effect on our business, results of operations and financial condition. Moreover, even if financing efforts are successful and additional capital is obtained, available liquidity may still be insufficient to eliminate the aforementioned substantial doubt regarding our ability to continue as a going concern.

Previous wording

Our primary use of cash is to fund operating expenses, which consist primarily of research and development costs related to our drug candidates and our discovery programs, and to a lesser extent, general and administrative expenditures. Our current operating plan and projected cash outflows for the upcoming periods raise doubt about our ability to continue as a going concern for at least 12 months from the issuance of the financial statements. If we are successful with our ability to access additional funding, we expect our expenses to increase substantially in connection with our ongoing clinical development activities related to our chronic HBV infection drug candidate pevifoscorvir sodium, which we have initiated clinical trials, as well as our research and development of our other drug candidates.

Current wording

Our primary use of cash is to fund operating expenses, which consist primarily of research and development costs related to our drug candidates and our discovery programs, and to a lesser extent, general and administrative expenditures. Our current operating plan and projected cash outflows for the upcoming periods raise doubt about our ability to continue as a going concern for at least 12 months from the issuance of the financial statements. If we are successful with our ability to access additional funding, we expect our expenses to increase substantially in connection with our ongoing clinical development activities related to our chronic HBV infection drug candidate pevifoscorvir sodium, for which has an ongoing Phase 2 trial, as well as our research and development of our other drug candidates.

Previous wording

hire and retain additional clinical, quality control and scientific personnel;

Current wording

hire and retain additional clinical, quality control, manufacturing, medical affairs and scientific personnel;

Previous wording

our ability to establish and maintain strategic licenses or other arrangements and the financial terms of such agreements including milestone payments to our licensors;

Current wording

our ability to establish and maintain strategic licenses or other arrangements and the financial terms of such agreements including milestone payments to our licensors and payments received from our licensees;

Previous wording

Adequate additional funds may not be available to us on acceptable terms, or at all. We do not currently have any committed external source of funds. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest may be diluted, and the terms of these securities may include liquidation or other preferences and anti-dilution protections that could adversely affect your rights as a common stockholder. Additional debt or preferred equity financing, if available, may involve agreements that include restrictive covenants that may limit our ability to take specific actions, such as incurring debt, making capital expenditures or declaring dividends, which could adversely constrain our ability to conduct our business, and may require the issuance of warrants, which could potentially dilute your ownership interest.

Current wording

Adequate additional funds may not be available to us on acceptable terms, or at all. We do not currently have any committed external source of funds. To the extent that we raise additional capital through the sale of equity or convertible debt securities, ownership interest may be diluted, and the terms of these securities may include liquidation or other preferences and anti-dilution protections that could adversely affect the rights of a common stockholder. Additional debt or preferred equity financing, if available, may involve agreements that include restrictive covenants that may limit our ability to take specific actions, such as incurring debt, making capital expenditures or declaring dividends, which could adversely constrain our ability to conduct our business, and may require the issuance of warrants, which could potentially dilute ownership interest.

Previous wording

During the nine months ended September 30, 2024, investing activities used $38.3 million of cash, primarily due to $108.1 million of purchase of short-term investments partially offset by $70.0 million related to maturities of short-term investments.

Current wording

During the three months ended March 31, 2026, investing activities provided $34.9 million of cash, primarily due to $35.0 million related to maturities of short-term investments.

Previous wording

During the nine months ended September 30, 2025, investing activities used $35.8 million of cash, primarily due to $125.5 million of purchase of short-term investments, partially offset by $90.0 million related to maturities of short-term investments.

Current wording

During the three months ended March 31, 2025, investing activities used $44.1 million of cash, primarily due to $64.0 million of purchase of short-term investments partially offset by $20.0 million related to maturities of short-term investments.

Previous wording

During the nine months ended September 30, 2024, net cash provided by financing activities was $0.3 million, consisting primarily due to proceeds from the ESPP purchase.

Current wording

During the three months ended March 31, 2026, net cash used by financing activities was $62.0 thousand, primarily due to payments on finance leases.

Previous wording

During the nine months ended September 30, 2025, net cash provided by financing activities was $101.5 million, primarily due to proceeds from the 2025 PIPE financing.

Current wording

During the three months ended March 31, 2025, net cash provided by financing activities was $101.7 million, primarily due to proceeds from the 2025 PIPE financing.

Previous wording

For a description of the expected impact of recently adopted accounting pronouncements, see Note 2. Summary of significant accounting policies in the “Notes to Unaudited Condensed Consolidated Financial Statements” contained in Part I, Item 1 of this report.

Current wording

For a description of the expected impact of recently adopted accounting pronouncements, see Note 2. Summary of significant accounting policies in the “Notes to consolidated financial statements” contained in Part I, Item 8 in our Annual Report on Form 10-K, filed with the SEC on March 5, 2026.