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GSK3389404, an N-acetyl galactosamine-conjugated antisense oligonucleotide (ASO), was in clinical development for chronic hepatitis B (CHB) treatment. Few studies have examined ASOs in Asian participants. In this analysis, the plasma pharmacokinetics (PK) of GSK3389404 were characterized and compared in patients with CHB across the Asia-Pacific region (N = 64), including mainland China (

Chronic infection with hepatitis B virus (HBV) leads to an increased risk of death from cirrhosis and hepatocellular carcinoma. Functional cure rates are low with current treatment options (nucleos(t)ide analogs (NAs) and pegylated interferons). Bepirovirsen is an antisense oligonucleotide targeting all HBV messenger RNAs; in cell culture and animal models, bepirovirsen leads to reductions in HBV-derived RNAs, HBV DNA and viral proteins. This phase 2 double-blinded, randomized, placebo-controlled trial is the first evaluation of the safety and activity of an antisense oligonucleotide targeting HBV RNA in both treatment-naïve and virally suppressed individuals with chronic HBV infection. The primary objective was to assess the safety and tolerability of bepirovirsen in individuals with chronic hepatitis B (CHB) (NCT02981602). The secondary objective was to assess antiviral activity, including the change from baseline to day 29 in serum hepatitis B surface antigen (HBsAg) concentration. Participants with CHB infection ≥6 months and serum HBsAg ≥50 IU ml−1 were enrolled from seven centers across Hong Kong and the Republic of Korea and randomized (3:1 within each dose cohort) to receive bepirovirsen or placebo via subcutaneous injection twice weekly during weeks 1 and 2 (days 1, 4, 8 and 11) and once weekly during weeks 3 and 4 (days 15 and 22). Participants were then followed for 26 weeks. Twenty-four participants were treatment-naïve and seven were receiving stable NA therapy. Treatment-emergent adverse events were mostly mild/moderate (most commonly injection site reactions). Eleven (61.1%) and three (50.0%) treatment-naïve participants experienced one or more treatment-emergent adverse event in the bepirovirsen and placebo groups, respectively. In participants receiving NA therapy, the corresponding numbers were three (60.0%) and one (50.0%). Transient, self-resolving alanine aminotransferase flares (≥2× upper limit of normal) were observed in eight treatment-naïve participants and three participants on stable NA regimens in the bepirovirsen treatment arms. HBsAg reductions were observed and were significant versus placebo for treatment-naïve participants receiving bepirovirsen 300 mg (P = 0.001), but not for the bepirovirsen 150 mg group (P = 0.245) or participants receiving stable NA therapy (P = 0.762). Two participants in each of the 300 mg dose groups achieved HBsAg levels below the lower limit of quantitation by day 29 (n = 3) or day 36 (n = 1). Bepirovirsen had a favorable safety profile. These preliminary observations warrant further investigation of the safety and activity of bepirovirsen in a larger CHB patient population., A first-in-human study of an antisense oligonucleotide targeting hepatitis B virus (HBV) RNA provides initial insights into this potential new therapeutic modality for individuals with chronic HBV infection.

Background Bepirovirsen is an antisense oligonucleotide that targets all hepatitis B virus (HBV) messenger RNAs and acts to decrease levels of viral proteins. Methods We conducted a phase 2b, randomized, investigator-unblinded trial involving participants with chronic HBV infection who were receiving or not receiving nucleoside or nucleotide analogue (NA) therapy. Participants were randomly assigned (in a 3:3:3:1 ratio) to receive weekly subcutaneous injections of bepirovirsen at a dose of 300 mg for 24 weeks (group 1), bepirovirsen at a dose of 300 mg for 12 weeks then 150 mg for 12 weeks (group 2), bepirovirsen at a dose of 300 mg for 12 weeks then placebo for 12 weeks (group 3), or placebo for 12 weeks then bepirovirsen at a dose of 300 mg for 12 weeks (group 4). Groups 1, 2, and 3 received loading doses of bepirovirsen. The composite primary outcome was a hepatitis B surface antigen (HBsAg) level below the limit of detection and an HBV DNA level below the limit of quantification maintained for 24 weeks after the planned end of bepirovirsen treatment, without newly initiated antiviral medication. Results The intention-to-treat population comprised 457 participants (227 receiving NA therapy and 230 not receiving NA therapy). Among those receiving NA therapy, a primary-outcome event occurred in 6 participants (9%; 95% credible interval, 0 to 31) in group 1, in 6 (9%; 95% credible interval, 0 to 43) in group 2, in 2 (3%; 95% credible interval, 0 to 16) in group 3, and 0 (0%; post hoc credible interval, 0 to 8) in group 4. Among participants not receiving NA therapy, a primary-outcome event occurred in 7 participants (10%; 95% credible interval, 0 to 38), 4 (6%; 95% credible interval, 0 to 25), 1 (1%; post hoc credible interval, 0 to 6), and 0 (0%; post hoc credible interval, 0 to 8), respectively. During weeks 1 through 12, adverse events, including injection-site reactions, pyrexia, fatigue, and increased alanine aminotransferase levels, were more common with bepirovirsen (groups 1, 2, and 3) than with placebo (group 4). Conclusions In this phase 2b trial, bepirovirsen at a dose of 300 mg per week for 24 weeks resulted in sustained HBsAg and HBV DNA loss in 9 to 10% of participants with chronic HBV infection. Larger and longer trials are required to assess the efficacy and safety of bepirovirsen. (Funded by GSK; B-Clear ClinicalTrials.gov number, NCT04449029.)

Long-acting (LA) cabotegravir demonstrated superior efficacy versus daily oral standard-of-care for HIV-1 preexposure prophylaxis. This phase 1 study assessed safety, tolerability, pharmacokinetics, and acceptability of cabotegravir in 47 HIV-negative adult Chinese men at low risk of acquiring HIV-1. Participants received once-daily oral cabotegravir 30 mg for 4 weeks and, after a 1-week washout, five 600-mg (3-mL) intramuscular cabotegravir LA injections at weeks 5, 9, 17, 25, and 33. Pharmacokinetic plasma samples were intensively collected on day 27 (

Dose-dependent reductions in hepatitis B virus (HBV) RNA, DNA, and viral proteins following bepirovirsen administration were observed in HepG2.2.15 cells. In HBV-transgenic mice treated at 50 mg/kg/wk, hepatic HBV RNA and DNA were reduced by 90% and 99%, respectively. Subsequently, a phase 1 first-in-human study assessed pharmacokinetics and tolerability of single (75-450 mg) and multiple (150-450 mg on days 1, 4, 8, 11, 15, and 22) subcutaneous bepirovirsen doses in 96 healthy volunteers. Bepirovirsen at all dose levels was rapidly absorbed (maximum plasma concentration 3-8 hours after dosing), rapidly distributed to peripheral tissues, and slowly eliminated (median plasma terminal half-life: 22.5-24.6 days across cohorts). Plasma exposure (dose-proportional at 150-450 mg) and concentration-time profiles were similar following the first and sixth doses, suggesting little to no plasma accumulation (steady state achieved by day 22). Renal elimination of full-length bepirovirsen accounted for2% of the total dose. Across the single and multiple dose cohorts, 197 treatment-emergent adverse events were reported, with 99% and 65% classified as mild in severity and local injection site reactions, respectively. In conclusion, bepirovirsen showed an acceptable safety profile in humans with observed pharmacokinetics consistent with the chemical class, warranting further evaluation of bepirovirsen in chronic HBV infection.

Bepirovirsen, an antisense oligonucleotide targeting pregenomic and mRNA transcripts of HBV, has been conjugated to N-acetyl galactosamine (GSK3389404) to enhance hepatocyte delivery. This dose-finding study was the first to assess GSK3389404 for chronic HBV infection.This phase IIa, randomised, double-blind, placebo-controlled, 2-part study was conducted in 22 centres in Asia (NCT03020745). Pharmacokinetic findings from Part 1 informed Part 2 dosing. In Part 2, patients with chronic hepatitis B on nucleos(t)ide analogue therapy were randomised 11:2 to GSK3389404 (30, 60, 120 mg weekly or 120 mg bi-weekly) or placebo until Day 85. Coprimary endpoints included HBsAg response (≥1.5 logParts 1 and 2 included 12 (9 GSK3389404, 3 placebo) and 66 patients (56 GSK3389404, 10 placebo), respectively. In Part 2, one patient each in the 60 mg weekly, 120 mg weekly and 120 mg bi-weekly arms achieved a HBsAg response. HBsAg reductions were dose-dependent (Day 85: mean 0.34 [60 mg weekly] to 0.75 logGSK3389404 showed an acceptable safety profile and target engagement, with dose-dependent reductions in HBsAg. However, no efficacious dosing regimen was identified.NCT03020745.Hepatitis B virus (HBV) can result in chronic HBV infection, which may ultimately lead to chronic liver disease, primary liver cancer and death; HBV proteins may prevent the immune system from successfully controlling the virus. GSK3389404 is an investigational agent that targets HBV RNA, resulting in reduced viral protein production. This study assessed the safety of GSK3389404 and its ability to reduce the viral proteins in patients with chronic HBV infection. GSK3389404 showed dose-dependent reduction in hepatitis B surface antigen, with an acceptable safety profile. While no clear optimal dose was identified, the findings from this study may help in the development of improved treatment options for patients with chronic HBV infections.

GSK3389404 is a liver‐targeted antisense oligonucleotide that inhibits synthesis of hepatitis B surface antigen and all other hepatitis B virus proteins. This first‐in‐human, randomized, double‐blind, phase 1 study assessed the safety and pharmacokinetics of GSK3389404 administered subcutaneously (SC) in healthy subjects. Four single ascending‐dose cohorts (10 mg, 30 mg, 60 mg, and 120 mg) and 3 multiple ascending‐dose cohorts (30 mg, 60 mg, and 120 mg once weekly for 4 weeks) each comprised 6 subjects randomized to GSK3389404 and 2 subjects randomized to placebo. There were no serious adverse events (AEs) or withdrawals due to AEs. The safety profile did not worsen with repeated dosing. The most frequent treatment‐related AEs were injection site reactions (19.0% [n = 8/42], frequency unrelated to dose levels); all were mild (Grade 1) and resolved without dose modification or discontinuation. GSK3389404 administered subcutaneously was readily absorbed with a time to maximum plasma concentration (Tmax) of 1–4 hours and an elimination half‐life of 3–6 hours in plasma. Plasma area under the concentration‐time curve (AUC) and maximum observed concentration (Cmax) were dose‐proportional. Dose‐normalized plasma AUC from time 0 to infinity averaged 69.9 ng·h/(mL·mg dose) across cohorts, and Cmax 9.5 ng/(mL·mg dose). Pharmacokinetic profiles and parameters were comparable between single and multiple dosing. No accumulation was observed with once‐weekly dosing. The metabolite was undetectable in urine and plasma. In the pooled urine, GSK3389404 was estimated to account for

A strong synergy can result from China-US antimicrobial resistance (AMR) collaborations given similarities and differences between their respective healthcare systems and research infrastructures. The Antibacterial Resistance Leadership Group has employed a model of realistic growth, starting with a feasible, relatively low-resource observational study in a critical priority pathogen. This and other observational studies will provide vital scientific information required for the rational design of future interventional trials. In addition, it provides a mutual, low-risk opportunity for determining the strengths and opportunities of the research collaboration. Issues identified during the observational studies can be addressed prior to the initiation of high-resource interventional studies. Collaborative clinical AMR studies between China and the United States have tremendous potential to decrease AMR rates, improve responsible antibiotic use, and ultimately improve the lives of patients in both countries.

A gradient anion-exchange high-performance liquid chromatographic assay was developed for the simultaneous determination and quantitation of the cytotoxic triphosphates of arabinosylguanine (ara-GTP) and fludarabine (F-ara-ATP). The method was validated with respect to selectivity, recovery, linearity, precision, and accuracy using authentic standards. To test this assay in a more complex biological matrix, perchloric acid extracts of circulating human leukemia cells spiked with known concentrations of ara-GTP and F-ara-ATP were examined. Finally, to assess the clinical utility of our method, perchloric acid extracts of circulating human leukemia cells isolated from patients treated with fludarabine and nelarabine were analyzed. The range of quantitation was 0.0125-10 nmol for the ara- and native NTPs in cellular extracts. This assay should be helpful in establishing the mechanistic rationales for drug scheduling and combinations of nelarabine and fludarabine, and for correlating the therapeutic efficacy and levels of the cytotoxic triphosphates in target cells.