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CDx, Hepatitis B Surface Antigen, Quantitative, Immunoassay
Test Code22772
Preferred Specimen
1 mL Serum; 1 mL Plasma.
Collection Instructions:
__Separate plasma or serum from cells within 24 hours of
__collection by centrifugation. Follow manufacturers
__instructions for collection tube handling.
Collection Instructions:
__Separate plasma or serum from cells within 24 hours of
__collection by centrifugation. Follow manufacturers
__instructions for collection tube handling.
Minimum Volume
0.5 mL Serum
Transport Container
Serum
__Red-top (no gel) (preferred)
__SST (red-top)
Plasma: EDTA (lavender-top)
__Red-top (no gel) (preferred)
__SST (red-top)
Plasma: EDTA (lavender-top)
Transport Temperature
Serum and Plasma: Room temperature preferred; Refrigerated
_acceptable; Frozen acceptable
_acceptable; Frozen acceptable
Specimen Stability
Serum or Plasma
__Room temperature: 72 Hours
__Refrigerated: 7 Days
__Frozen: 90 Days
__Room temperature: 72 Hours
__Refrigerated: 7 Days
__Frozen: 90 Days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
• heat-inactivated samples, samples with additives, other
than transport preservatives
than transport preservatives
Methodology
Electrochemiluminescence Immunoassay
Setup Schedule
A.M. Sets up 7 days a week.
Report Available
Reports in 3 to 5 days.
Clinical Significance
This assay is intended as a companion diagnostic to guide
treatment for bepirovirsen in patients with chronic
hepatitis B virus (HBV) infection and should be used in
accordance with approved therapeutic product labeling. This
assay is not approved for HBV screening or as a diagnostic
test to confirm HBV infection, including blood products.
Bepirovirsen is an antisense oligonucleotide HBV antiviral
drug targeting all HBV transcripts and is expected to
reduce levels of HBV DNA and hepatitis B surface antigen
(HBsAg). Quantitative measurements of hepatitis B surface
antigen can be performed at baseline and at the end of
treatment. In the B-Well 1 & 2 Phase 3 clinical trials,
patients with levels between 100 and 1,000 IU/mL
demonstrated the highest rate of functional cure (25% to
28% HBsAg loss) after a finite 24-week regimen of
bepirovirsen. Observed functional cure rates in patients
with levels between 1,000 and 3,000 IU/mL were lower (5% to
10%) compared to patients with baseline levels < or = 1,000
IU/mL. While lower baseline antigen levels are historically
associated with favorable treatment responses, clinical
data for bepirovirsen in patients with baseline HBsAg <100
IU/mL remains limited.
Values greater than 3,000 IU/mL exceed the cutoff point for
predicting response to therapy when HBsAg is tested at
baseline.
Baseline HBV DNA suppression (<90 IU/mL on oral therapy) is
recommended prior to starting bepirovirsen. Transient,
clinically silent ALT elevations (up to 10x ULN) are common
(23%) during weeks 5-10 of therapy as a sign of viral
clearance. Close liver function monitoring is recommended.
Performance characteristic for this assay has not been
established for determining clinical phase of HBV infection
or for guiding treatment with other HBV drugs. The results
of this test should be interpreted in the context of
pertinent clinical history and physical examination
findings and other laboratory results.
References:
1. Hou J, Seng-Gee L, Buti M, et al. Phase 3 Results of
Bepirovirsen Treatment for Chronic Hepatitis B Virus
Infection. N Engl J Med. 2026 Jun 25;394(24):2395-2406.
doi:10.1056/NEJMoa2515131
2. Roche Elecsys HBsAg II quant II RxDx Method Sheet (Ref:
TARP HBsAgIIqII RxDx, B-Well 1 [NCT05630807] / B-Well 2
[NCT05630820]).
treatment for bepirovirsen in patients with chronic
hepatitis B virus (HBV) infection and should be used in
accordance with approved therapeutic product labeling. This
assay is not approved for HBV screening or as a diagnostic
test to confirm HBV infection, including blood products.
Bepirovirsen is an antisense oligonucleotide HBV antiviral
drug targeting all HBV transcripts and is expected to
reduce levels of HBV DNA and hepatitis B surface antigen
(HBsAg). Quantitative measurements of hepatitis B surface
antigen can be performed at baseline and at the end of
treatment. In the B-Well 1 & 2 Phase 3 clinical trials,
patients with levels between 100 and 1,000 IU/mL
demonstrated the highest rate of functional cure (25% to
28% HBsAg loss) after a finite 24-week regimen of
bepirovirsen. Observed functional cure rates in patients
with levels between 1,000 and 3,000 IU/mL were lower (5% to
10%) compared to patients with baseline levels < or = 1,000
IU/mL. While lower baseline antigen levels are historically
associated with favorable treatment responses, clinical
data for bepirovirsen in patients with baseline HBsAg <100
IU/mL remains limited.
Values greater than 3,000 IU/mL exceed the cutoff point for
predicting response to therapy when HBsAg is tested at
baseline.
Baseline HBV DNA suppression (<90 IU/mL on oral therapy) is
recommended prior to starting bepirovirsen. Transient,
clinically silent ALT elevations (up to 10x ULN) are common
(23%) during weeks 5-10 of therapy as a sign of viral
clearance. Close liver function monitoring is recommended.
Performance characteristic for this assay has not been
established for determining clinical phase of HBV infection
or for guiding treatment with other HBV drugs. The results
of this test should be interpreted in the context of
pertinent clinical history and physical examination
findings and other laboratory results.
References:
1. Hou J, Seng-Gee L, Buti M, et al. Phase 3 Results of
Bepirovirsen Treatment for Chronic Hepatitis B Virus
Infection. N Engl J Med. 2026 Jun 25;394(24):2395-2406.
doi:10.1056/NEJMoa2515131
2. Roche Elecsys HBsAg II quant II RxDx Method Sheet (Ref:
TARP HBsAgIIqII RxDx, B-Well 1 [NCT05630807] / B-Well 2
[NCT05630820]).
