Accumulated pre-switch resistance to more recently introduced one-pill-once-a-day antiretroviral regimens impacts HIV-1 virologic outcome.

BACKGROUND: One-pill-once-a-day regimens (OPODs) appeal to providers and patients. The impact of resistance to OPODs in routine clinical care is important yet unclear, particularly in treatment-experienced patients.

OBJECTIVES: We hypothesized that resistance to any OPOD component impacts treatment success and that historical, vs. most recent, resistance better predicts it.

STUDY DESIGN: In the largest RI HIV Center, we identified all patients starting/switching to Complera/Stribild, evaluated their 12-month viral load (VL) suppression, and examined the impact of demographic, clinical and laboratory data on it, focusing on recent-only vs. accumulated significant resistance, defined as low-, intermediate- or high-level predicted resistance to any OPOD component. Associations with outcomes were evaluated using Fisher exact and Wilcoxon rank sum tests. Hypotheses were tested using logistic regression.

RESULTS: Of 1624 patients, 224 started/switched to Complera or Stribild, mean age 44 years, 8 years post-diagnosis, CD4 468 cells/μL; 183 treatment-experienced (140 with genotypes; 61% suppressed at switch). Significant OPOD-associated resistance was in 30% by recent-only genotypes, and 38% by all genotypes. 12-month VL suppression was in 83% of treatment-experienced participants: 96% of suppressed at switch, associated with older age, higher CD4, fewer prior genotypes, less accumulated resistance, and better adherence; and 61% of unsuppressed at switch, associated with better adherence. Accumulated resistance independently predicted 12-month failure, better than most-recent resistance only.

CONCLUSION: 12-month VL suppression with Complera/Stribild was high, suggesting that OPODs remain options even for experienced patients. Clinicians should consider resistance history before switching to OPODs and continue to focus on improving adherence.