Name: Hibsago (bepirovirsen) in Chronic hepatitis B virus infection in adults without cirrhosis: Dosage
Published: 2026-10-21T22:39:04-04:00

Recommended dosage: loading phase and maintenance phase

“HIBSAGO is for subcutaneous use only” (opens the prescribing information at this quote)
“Weeks 1 and 2” (opens the prescribing information at this quote)
“The recommended dosage of HIBSAGO is 300 mg (administered as two 150 mg subcutaneous injections) twice a week allowing 3 or 4 days between each dose.” (opens the prescribing information at this quote)
“Weeks 3 to 24” (opens the prescribing information at this quote)
“The recommended dosage of HIBSAGO is 300 mg (administered as two 150 mg subcutaneous injections) once a week on the same day each week.” (opens the prescribing information at this quote)

Treatment duration and early cessation at week 12

“The maximum recommended duration of HIBSAGO treatment is 24 weeks” (opens the prescribing information at this quote)
“Early cessation of HIBSAGO may be considered in patients who have not achieved HBsAg <1 IU/mL by Treatment Week 12” (opens the prescribing information at this quote)
“Among participants with baseline HBsAg ≤3,000 IU/mL who met this criterion, 34% (203/601) had sustained suppression of HBV DNA and HBsAg not detected at 24 weeks after cessation of all chronic HBV treatment. Participants who did not meet this criterion (who had HBsAg ≥1 IU/mL at Week 12) had a 2% (9/498) probability of having sustained suppression of HBV DNA and HBsAg not detected at 24 weeks after cessation of all chronic HBV treatment.” (opens the prescribing information at this quote)
“Among participants with baseline HBsAg ≤1,000 IU/mL who met this criterion, 42% (179/426) achieved this endpoint, and those who did not meet this criterion had a 2.5% (7/280) probability of achieving this endpoint.” (opens the prescribing information at this quote)

Patient selection: quantitative HBsAg testing and baseline laboratory tests

“Prior to initiation of HIBSAGO for treatment of chronic HBV infection, test all patients to quantify HBsAg levels in serum or plasma to identify patients with baseline HBsAg levels less than or equal to 3,000 IU/mL” (opens the prescribing information at this quote)
“In addition, test patients for HBV DNA, ALT, AST, bilirubin, platelet count, urine albumin-creatinine ratio (uACR), and estimated glomerular filtration rate (eGFR) prior to initiation of treatment and as directed while on treatment and following treatment completion” (opens the prescribing information at this quote)
“HIBSAGO therapy should be prescribed only when appropriate laboratory monitoring can be performed to manage the treatment regimen. Close laboratory monitoring is required to assess for toxicities that may necessitate dose modification, treatment interruption, or permanent discontinuation of HIBSAGO” (opens the prescribing information at this quote)

“The FDA also authorized the Roche Elecsys HBsAg II quant II RxDx assay as a companion diagnostic device to aid in the selection of patients with chronic HBV infection for treatment with antiviral therapy in accordance with the FDA approved drug labeling” (opens the source at this quote in a new tab)

“Quantitative surface antigen testing will support the diagnosis and identification of patients suitable for treatment with bepirovirsen who have baseline HBsAg levels ≤3000 IU/ml. Several tests are available, including a recently authorised FDA test.” (opens the source at this quote in a new tab)

Dosage modification by ALT and total bilirubin

ALT and total bilirubin	Dosage	ALT and total bilirubin monitoring frequency
ALT <3x ULN	“No dosage adjustments required”	“Weekly through Week 12 and every other week from Weeks 12 through 24”
Total bilirubin <1.5x ULN, ALT <10x ULN	“No dosage adjustments required”	“Weekly through Week 12 and every other week from Weeks 12 through 24”
Total bilirubin <1.5x ULN, ALT ≥10x to <12x ULN	“No dosage adjustments required”	“Increase monitoring to twice weekly until ALT is on a downward trajectory”
Total bilirubin <1.5x ULN, ALT ≥12x ULN	“Pause treatment”“When ALT<10x ULN, resume treatment at 150 mg once a week. If ALT continues to decline, increase dosage to 300 mg once a week.”	“Increase monitoring to twice weekly until ALT is on a downward trajectory”
Total bilirubin <1.5x ULN, ALT ≥10x ULN for ≥4 weeks	“Permanently discontinue treatment”	“Twice weekly until ALT is on a downward trajectory and then as clinically indicated”
Total bilirubin ≥1.5 to <2x ULN, ALT ≥3x ULN	“Pause treatment”“When ALT <10x ULN and total bilirubin <1.5x ULN, resume treatment at 150 mg once a week. If ALT is on a downward trajectory, increase dosage to 300 mg once a week.”	“Increase monitoring to twice weekly until ALT is on a downward trajectory”
Total bilirubin ≥2x ULN, ALT ≥3x ULN	“Permanently discontinue treatment”	“Twice weekly until ALT is on a downward trajectory and then as clinically indicated”

“If ALT or total bilirubin has increased markedly from the previous assessment, repeat laboratory testing and review the results before giving the next dose of HIBSAGO, even if the values have not yet reached the thresholds that require treatment interruption or discontinuation.” (opens the prescribing information at this quote)
“In all patients with abnormal values at the time of HIBSAGO discontinuation, obtain ALT and total bilirubin values at 4, 12, and 24 weeks post-treatment to assess recovery of ALT values to within the normal range, as appropriate.” (opens the prescribing information at this quote)

Dosage modification by platelet count

Platelet count (x 10^9/L)	Dosage	Platelet monitoring frequency
≥100	“No dosage adjustment required”	“Weekly”
75 to <100	“Pause treatment”“When platelet count ≥100 x 109/L, resume treatment at 300 mg once a week”	“Weekly”
50 to <75	“Pause treatment”“When platelet count ≥100 x 109/L, resume treatment at 300 mg once a week”	“Every 2-3 days until 3 consecutive platelet counts ≥75 x 109/L”
25 to <50	“Permanently discontinue treatment”	“Every 2-3 days until 3 consecutive platelet counts ≥75 x 109/L”
<25	“Permanently discontinue treatment”	“Daily until 2 consecutive platelet counts ≥25 x 109/L”

“If platelet count decreases by ≥30% between consecutive readings, repeat and review platelet count before administering further doses of HIBSAGO, even if platelet count is ≥100 x 109/L.” (opens the prescribing information at this quote)
“In all patients with abnormal values at the time of HIBSAGO discontinuation, obtain repeat platelet counts 4 and 12 weeks post-treatment to assess for platelet count recovery, as appropriate.” (opens the prescribing information at this quote)

Dosage modification by eGFR

eGFR	Dosage	eGFR monitoring frequency
No significant change from baseline	“No dosage adjustment required”	“Monitor eGFR every other week through Week 24”
Reduced by ≥30% from pretreatment levels for ≥2 consecutive readings	“Pause treatment”“When eGFR increases to within 15% of pretreatment levels, resume treatment at 300 mg once a week.”	“Monitor weekly until eGFR stabilizes or returns to pretreatment levels”

“In all patients with abnormal values at the time of HIBSAGO discontinuation, obtain eGFR at 4 weeks and 12 weeks post-treatment to monitor for renal function recovery, as appropriate.” (opens the prescribing information at this quote)

Missed doses

“If a dose of HIBSAGO is missed at any time during treatment (Weeks 1-24), the missed dose must be administered as soon as possible, unless the next scheduled dose is due in less than three days, in which case the missed dose must be skipped and the next dose administered as scheduled.” (opens the prescribing information at this quote)

Completion of treatment: nucleos(t)ide analog continuation and criteria for stopping it

“HIBSAGO must be stopped upon completion of 24 weeks of treatment, and patients must remain on their NrtI therapy for at least an additional 24 weeks. Following the 24 weeks of further NrtI treatment, stopping NrtI therapy can be considered in those patients who:” (opens the prescribing information at this quote)
“are hepatitis B e-antigen (HBeAg) negative,” (opens the prescribing information at this quote)
“have HBV DNA <LLOQ (lower limit of quantification, defined as <20 IU/mL), HBsAg not detectable (LOD = 0.05 IU/mL), and alanine aminotransferase (ALT) values ≤2x upper limit of normal (ULN), and” (opens the prescribing information at this quote)
“do not need the nucleos(t)ide analog reverse transcriptase inhibitor therapy to treat Human Immunodeficiency Virus (HIV) co-infection” (opens the prescribing information at this quote)
“If NrtI therapy is stopped, frequent monitoring of HBsAg, HBV DNA, and hepatic function is recommended for at least one year following NrtI therapy cessation, with routine monitoring as clinically indicated afterwards” (opens the prescribing information at this quote)