icon-folder.gif   Conference Reports for NATAP  
  42nd ICAAC Meeting
San Diego, Sept 27-31, 2002
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3TC Once Daily: equivalent to 3TC twice daily
Reported by Jules Levin
  3TC was recently approved by the FDA to be used 300 mg once daily. The current use is 150 mg twice a day. The once daily 3TC is expected to be available in the pharmacy soon. Tenofovir and D4T and ddI are also FDA approved to be used once daily. Two studies were reported at ICAAC using 3TC once daily. The first study below was used by the FDA to grant approval. Tim not reporting the second study here in detail because it was only 12 weeks of data and too preliminary, but the data at week 12 was similar to these study findings.
This is a randomized phase II/III, double-blind, controlled 48-week randomizing 554 ART-na´ve individuals to 3TC 300 mg once daily/3TC bid placebo, AZT twice daily, and efavirenz once daily vs 3TC once daily placebo/3TC 150 mg bid, AZT twice daily, and efavirenz once daily. Average viral load was the same in both groups (4.64 log); Cd4s were also about the same, 350.
The discontinuation rate was 28% in the 3TC once daily group and 31% in the 3TC twice daily group. Although the adverse events profile were similar in both groups the study authors reported 6% in the 3TC once daily group and 12% in the 3TC twice daily group discontinued treatment due to adverse events. The authors said that due to the study design (using AZT bid so regimens were not truly once daily, double blind nature study design) they could not assess the potential benefits of adherence to a once daily regimen. The viral responses (ITT m=f) through week 48 were about the same for both 3TC once daily & twice daily: <400 copies (once daily: 64%; bid 63%). <50 copies (once daily: 59%; bid 61%). The viral failure rates in the study were low and similar between the 2 study groups. Interestingly, when looking at patients with >100,000 copies/ml before starting study drugs the 3TC once daily regimen showed better viral responses: <400 copies (68% 3TC once daily; 53% 3TC twice daily); <50 copies (59% 3TC once daily, 48% 3TC twice daily). The authors did not comment if this difference was significant. But the authors concluded that 3TC once daily was equivalent to 3TC twice daily.