48-week outcomes following switch from AZT/3TC to FTC/TDF (TVD) vs. continuing on AZT/3TC: 48-week interim analysis of the RECOMB trial

Purpose of the study

To compare changes in total limb fat by DEXA scan assessment after switching from an AZT/3TC backbone to TVD vs. maintaining an AZT/3TC regimen.

Methods

72 weeks, open label, randomised, controlled study. Virologically-suppressed HIV-infected patients (<50 c/mL) on HAART containing AZT/3TC (plus either an NNRTI or a PI) were assigned to either switch their AZT/3TC backbone to TVD or continue current AZT/3TC-containing regimen. Stratification was performed by third agent of HAART (either NNRTI or PI).

Summary of results

80 patients included (39 TVD; 41 AZT/3TC). Mean age was 44 years. Patients were predominantly male (81%). The median CD4 cell count at baseline was higher in the TVD vs AZT/3TC arm (655 vs. 504 cel/mm³; p = 0.037). (Tables 1 and 2.)

Table 1 Efficacy outcomes at Week 48.

Table 2 Week 48 median changes from BL in limb fat, haematology and lipids

Five patients discontinued due to an adverse event before week 24; one in the TVD group (upper abdominal pain) and four in AZT/3TC group (two renal cholic, one anaemia, one lactic acidosis). Changes from BL in GFR (CG) were -11.8 for TVD and -3.6 mL/min for AZT/3TC.

Conclusion

Through 48 weeks, switching from a suppressive HAART regimen containing AZT/3TC to TVD, was well tolerated, maintained efficacy and led to a significant improvement in limb fat content. Additionally, haemoglobin and hematocrit significantly improved for patients switched from AZT/3TC to TVD.