Table 3.
HIV-1 Amino Acid Changesa From Pretreatment to Virologic Failure, Comparing Tenofovir/Emtricitabine vs Abacavir/Lamivudine Virologic Failures
| With EFV |
With ATV/r |
||||
|---|---|---|---|---|---|
| TDF/FTC (n = 32) | ABC/3TC (n = 38) | TDF/FTC (n = 29) | ABC/3TC (n = 35) | ||
| A: Screening plasma HIV-1 RNA<100 000 copies/mL (n = 134) | |||||
| Protease changes (%) | Median (Q1, Q3) | 0.51 (0, 1.35) | 0.51 (0, 1.01) | 1.01 (0, 1.52) | 0.00 (0.00, 0.58) |
| Absence of any protease AA change | n (%) | 12 (38%) | 17 (45%) | 8 (28%) | 18 (51%) |
| P = .5 | P = .006 | ||||
| RT changes (%) | Median (Q1, Q3) | 1.09 (0.65, 1.96) | 0.87 (0.43, 1.74) | 0.22 (0, 0.65) | 0.22 (0, 0.79) |
| Absence of any RT AA change | n (%) | 2 (6%) | 6 (16%) | 8 (28%) | 11 (31%) |
| P = .2 | P = .9 | ||||
| With EFV |
With ATV/r |
||||
| TDF/FTC (n = 11) | ABC/3TC (n = 25) | TDF/FTC (n = 15) | ABC/3TC (n = 32) | ||
| B: Screening plasma HIV-1 RNA ≥100 000 copies/mL, limited through the time of the DSMB recommendations (n = 83) | |||||
| Protease changes (%) | Median (Q1, Q3) | 0 (0, 1.52) | 0.51 (0, 1.01) | 0 (0, 1.01) | 0.51 (0, 1.01) |
| Absence of any protease AA change | n (%) | 7 (64%) | 10 (40%) | 8 (53%) | 11 (34%) |
| P = .3 | P = .3 | ||||
| RT changes (%) | Median (Q1, Q3) | 1.75 (0.22, 2.39) | 1.96 (1.12, 2.39) | 0.43 (0.22, 0.65) | 0.54 (0.22, 0.87) |
| Absence of any RT AA change | n (%) | 2 (18%) | 0 (0%) | 2 (13%) | 4 (13%) |
| P = .2 | P = .4 | ||||
Abbreviations: AA, amino acid; ABC/3TC, abacavir/lamivudine; ATV/r, atazanavir/ritonavir; DSMB, data safety and monitoring board; EFV, efavirenz; HIV-1, human immunodeficiency virus type 1; RT, reverse transcriptase; TDF/FTC, tenofovir DF/emtricitabine.
a Indicates the percentage of amino acid codons changed from pretreatment to virologic failure, with mixture changes assigned weight = 0.5 change.