Case Study #5 Lamivudine (LMV) Resistance
+ Adefovir (ADV) non-response

LMV Resistance + ADV non-response

  • 66 year old Chinese male
  • Routine health check – positive serum HBsAg
  • HBeAg -ve, anti-Hbe +ve
  • Liver Biopsy - cirrhotic
  • Commenced LMV 200mg , developed LMV resistance after 15 months of therapy
  • ADV added - initial response followed by HBV DNA plateau at 6.3 log10 IU/ml
  • Patient commenced Tenofovir (TDF) – good response,currently undetectable HBV DNA

LMV Resistance

  1. Patient commenced LMV mono therapy,
    • HBV DNA levels reduced by almost two logs initially
  2. No further suppression of viral replication
  3. Virological breakthrough on LMV
  4. ADV was added to the treatment protocol

LMV Resistance

Drug resistance testing:

  1. Antiviral drug resistance testing was performed following virological breakthrough on LMV
The primary resistance mutations to LMV rtL180M and rtM204V were detected

ADV non response

  1. ADV was added to the treatment protocol
    • Serum ALT levels dropped to almost normal
    • Serum HBV DNA levels dropped initially but then remained elevated
  2. Patient was switched to Tenofovir (TDF) and LMV combination therapy
    • Effective suppression of viral replication
    • ALT levels returned to normal

LMV resistance & ADV non response

Drug resistance testing:

  1. Antiviral drug resistance testing was performed following virological breakthrough on LMV
    • The primary resistance mutations to LMV rtL180M and rtM204V were detected
  2. Antiviral drug resistance testing was performed due to elevated HBV DNA levels during ADV therapy
    • The primary resistance mutations to LMV rtL180M and rtM204V were detected
    • No mutations associated with resistance to ADV or combination therapy were detected – Sub-optimal response to ADV