Sofosbuvir
| 證據等級: L5 | 預測適應症: 8 個 |
目錄
Sofosbuvir: From Chronic Hepatitis C Virus Infection to Hepatitis B Virus Infection
One-Sentence Summary
Sofosbuvir is a nucleotide analog NS5B polymerase inhibitor originally developed for chronic hepatitis C virus (HCV) infection. The TxGNN model predicts it may also be effective for Hepatitis B Virus Infection, but the surrounding evidence pack (50 clinical trials, 19 publications referencing this pairing) is dominated by reports of HBV reactivation during sofosbuvir-based HCV therapy rather than direct antiviral efficacy against HBV, with only one small Phase 2 pilot trial testing the drug in HBV-monoinfected patients.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Chronic Hepatitis C Virus (HCV) infection (well-established drug identity; local license-level indication text unavailable — see below) |
| Predicted New Indication | Hepatitis B Virus Infection |
| TxGNN Prediction Score | 99.77% |
| Evidence Level | L3 |
| US Market Status | Not marketed |
| Number of NDAs | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism-of-action data is not available in the regulatory record for this product. Based on well-established pharmacology, sofosbuvir is a nucleotide prodrug that is metabolized intracellularly to its active triphosphate form, which acts as a chain terminator when incorporated by the HCV NS5B RNA-dependent RNA polymerase (RdRp). This mechanism is specific to viruses that replicate their genome using an RdRp — a hallmark of RNA viruses such as HCV and other Flaviviridae members.
Hepatitis B virus, however, is a DNA virus that replicates via reverse transcription of an RNA pregenome using a viral reverse transcriptase, not an RdRp. This is a fundamental structural mismatch with HCV’s replication machinery, and the evidence pack itself flags this mismatch as the primary concern for this prediction (“HBV為DNA病毒，複製依賴反轉錄酶而非RdRp，與sofosbuvir主要作用標的機轉不匹配”).
Despite this mismatch, one open-label Phase 2 pilot study (NCT03312023 / PMID 36045503) tested ledipasvir/sofosbuvir in HBV-monoinfected patients, motivated by a retrospective observation of modest HBsAg decline in HBV/HCV-coinfected patients treated for HCV. It reported a measurable but modest reduction in HBsAg and HBV DNA at 12 weeks — not a cure. Meanwhile, a larger and more consistent body of literature in this same evidence pack describes the opposite phenomenon: HBV reactivation during or after sofosbuvir-based DAA therapy for HCV in coinfected patients. This suggests any HBsAg changes seen may reflect complex coinfection/immune dynamics rather than a direct antiviral effect on HBV, and that much of the “evidence” attached to this predicted indication is actually a safety signal rather than an efficacy signal.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT03312023 | Phase 2 | Completed | 21 | Open-label pilot of ledipasvir/sofosbuvir for 12 weeks in HBV-monoinfected patients; assessed decline in HBsAg and HBV DNA — the only direct test of antiviral activity against HBV in this pack. |
| NCT02613871 | Phase 3 | Completed | 111 | Ledipasvir/sofosbuvir FDC for 12 weeks in HCV genotype 1/2 patients coinfected with HBV (Taiwan); efficacy/safety in the coinfection setting, not HBV monotherapy. |
| NCT02555943 | Phase 2/3 | Completed | 23 | Prospective study of incidence, morbidity and predictors of HBV reactivation during direct-acting antiviral treatment of HCV/HBV-coinfected patients. |
| NCT02349048 | Phase 2 | Completed | 68 | Simeprevir + daclatasvir + sofosbuvir in HCV genotype 1 patients; the evidence pack links this trial to HBV literature (PMID 36045503), but the trial population itself is HCV, not HBV — relevance uncertain. |
Note: The remaining ~46 trials captured for this indication in the evidence pack are HCV mono-infection studies with no direct bearing on HBV and were excluded from this table.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 36045503 | 2023 | Phase 2 (single-arm) | Journal of Medical Virology | Open-label pilot of ledipasvir/sofosbuvir for 12 weeks in HBV-monoinfected subjects; modest decline in HBsAg and HBV DNA at week 12. |
| 31632097 | 2019 | Cohort | Infection and Drug Resistance | Role of HBV antiviral therapy in patients with HBV reactivation after DAA treatment in HCV/HBV coinfection. |
| 29334502 | 2018 | Cohort | Journal of Clinical Gastroenterology | Risk of HBV reactivation among patients treated with ledipasvir-sofosbuvir for HCV infection. |
| 33523503 | 2021 | Prospective cohort | Journal of Viral Hepatitis | HBV reactivation in cancer patients receiving DAAs for HCV infection with HBV/HCV coinfection. |
| 33031326 | 2020 | Case report | Medicine | HBV reactivation after successful HCV treatment with sofosbuvir and ribavirin. |
| 31542053 | 2019 | Case report | Journal of Medical Case Reports | HBV reactivation via an HBsAg immune-escape mutant in an anti-HBc-positive patient during sofosbuvir/velpatasvir treatment for HCV. |
| 27621502 | 2015 | Case report / ADR feature | Hospital Pharmacy | Reported case of hepatitis B reactivation with hepatitis C treatment using simeprevir and sofosbuvir. |
US Market Information
Sofosbuvir currently has no active marketing authorization on file in this jurisdiction — market status is recorded as “Not marketed,” with 0 licenses. No product listing, brand name, dosage form, or approved-indication text is available to summarize in a table.
Safety Considerations
No formal key warnings, contraindications, or drug–drug interaction data are available in this record for sofosbuvir.
Please refer to the package insert for safety information.
Note from the evidence base: although not part of the formal safety dataset, the literature and trial evidence attached to this specific predicted indication (HBV) repeatedly documents HBV reactivation in HBV/HCV-coinfected patients during or after sofosbuvir-based DAA therapy for HCV (PMIDs 33031326, 29334502, 31632097, 33523503, 31542053, 27621502). This is a clinically important signal that should inform any future safety evaluation of sofosbuvir in HBV-related populations.
Conclusion and Next Steps
Decision: Hold
Rationale:
- The proposed mechanism is biologically implausible as a direct antiviral effect — sofosbuvir targets an RNA-dependent RNA polymerase, but HBV replicates via reverse transcriptase, not RdRp.
- The bulk of available evidence for this indication describes a safety concern (HBV reactivation risk during sofosbuvir-based HCV therapy) rather than a therapeutic benefit signal; the single efficacy-oriented Phase 2 pilot (NCT03312023) showed only a modest, non-curative reduction in HBsAg/HBV DNA.
To proceed, the following is needed:
- Nonclinical/mechanistic studies clarifying whether sofosbuvir has any direct activity against HBV replication (e.g., polymerase or cccDNA assays), given the RdRp/reverse-transcriptase mismatch
- A larger, randomized, adequately powered trial in HBV-monoinfected patients with virologic-cure endpoints (HBsAg seroconversion)
- TFDA/DrugBank-sourced MOA and package-insert warnings data (currently unavailable) to support an S1 safety pre-screening
- A dedicated safety review addressing HBV reactivation risk, since this currently appears more clinically significant than any efficacy signal
- A local regulatory dossier, as the product is not currently marketed in this jurisdiction
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.