Discontinued development of drug candidates	6 Months Ended
Jun. 30, 2022
Discontinued Development of Drug Candidates [Abstract]
Discontinued development of drug candidates	12. Discontinued Development of Drug Candidates STOPSTM drug candidate, ALG-010133 On January 6, 2022, the Company announced that it had halted further development of its STOPSTM drug candidate, ALG‑010133, which was being developed as a potential therapy for chronic hepatitis B (CHB). This decision was based on emerging data from the Phase 1 Study ALG‑010133-101 indicating that at the projected efficacious dose (400 mg, estimated to achieve liver exposures >3 x EC90 for HBsAg inhibition) there was no meaningful HBsAg reduction. Furthermore, a higher dosage level (maximum feasible dose of 600 mg) that was planned to be evaluated in a subsequent cohort was assessed to be very unlikely to reach the 1 log10 IU/mL HBsAg reduction level that the Company had previously defined as necessary to advance the program. No dose limiting safety findings have been identified in CHB subjects dosed at any dose level. In early January, based on this information, the Company's management reviewed the data with members of the study’s Study Review Committee, and jointly concluded that the data were not sufficient to support further development of ALG‑010133. The halt of ALG‑010133 resulted in a charge of approximately $3.8 million related to non-cancelable purchase obligations that was recognized during the six months ended June 30, 2022. Antisense Oligonucleotide (ASO) drug candidate, ALG-020572 On March 22, 2022, the Company announced that it had discontinued development of its ASO drug candidate, ALG‑020572, which was being studied in subjects with CHB. Dosing in the first CHB cohort of Study ALG‑020572-401 was stopped after one subject experienced a serious adverse event (SAE) with significant increase in alanine aminotransferase (ALT) following the administration of multiple doses of 210 mg ALG‑020572 that resulted in a brief hospitalization. Four subjects in CHB Cohort 1, including the hospitalized subject, experienced significant ALT flares following multiple dosing; these were unexpected based on prior experience in nonclinical studies and single dose administration in healthy volunteers. Based on this information, the Company concluded that the program should be discontinued. In all four subjects, laboratory parameters and symptoms are improving, and the hospitalized subject has been discharged. The Company plans to use any cost savings from the discontinuation of the ALG‑020572 program to further support clinical and small molecule preclinical development programs, all of which target novel mechanisms that have the potential to enhance the care of patients with CHB, nonalcoholic steatohepatitis and COVID-19. The halt of ALG‑020572 resulted in a charge of approximately $3.4 million related to non-cancelable purchase obligations that was recognized during the six months ended June 30, 2022.

Discontinued development of drug candidates

6 Months Ended

Jun. 30, 2022

Discontinued Development of Drug Candidates [Abstract]

Discontinued development of drug candidates

12.

Discontinued Development of Drug Candidates

STOPSTM drug candidate, ALG-010133

On January 6, 2022, the Company announced that it had halted further development of its STOPSTM drug candidate, ALG‑010133, which was being developed as a potential therapy for chronic hepatitis B (CHB). This decision was based on emerging data from the Phase 1 Study ALG‑010133-101 indicating that at the projected efficacious dose (400 mg, estimated to achieve liver exposures >3 x EC90 for HBsAg inhibition) there was no meaningful HBsAg reduction. Furthermore, a higher dosage level (maximum feasible dose of 600 mg) that was planned to be evaluated in a subsequent cohort was assessed to be very unlikely to reach the 1 log10 IU/mL HBsAg reduction level that the Company had previously defined as necessary to advance the program. No dose limiting safety findings have been identified in CHB subjects dosed at any dose level. In early January, based on this information, the Company's management reviewed the data with members of the study’s Study Review Committee, and jointly concluded that the data were not sufficient to support further development of ALG‑010133. The halt of ALG‑010133 resulted in a charge of approximately $3.8 million related to non-cancelable purchase obligations that was recognized during the six months ended June 30, 2022.

Antisense Oligonucleotide (ASO) drug candidate, ALG-020572

On March 22, 2022, the Company announced that it had discontinued development of its ASO drug candidate, ALG‑020572, which was being studied in subjects with CHB. Dosing in the first CHB cohort of Study ALG‑020572-401 was stopped after one subject experienced a serious adverse event (SAE) with significant increase in alanine aminotransferase (ALT) following the administration of multiple doses of 210 mg ALG‑020572 that resulted in a brief hospitalization. Four subjects in CHB Cohort 1, including the hospitalized subject, experienced significant ALT flares following multiple dosing; these were unexpected based on prior experience in nonclinical studies and single dose administration in healthy volunteers. Based on this information, the Company concluded that the program should be discontinued. In all four subjects, laboratory parameters and symptoms are improving, and the hospitalized subject has been discharged. The Company plans to use any cost savings from the discontinuation of the ALG‑020572 program to further support clinical and small molecule preclinical development programs, all of which target novel mechanisms that have the potential to enhance the care of patients with CHB, nonalcoholic steatohepatitis and COVID-19. The halt of ALG‑020572 resulted in a charge of approximately $3.4 million related to non-cancelable purchase obligations that was recognized during the six months ended June 30, 2022.