A randomized clinical trial comparing ritonavir-boosted lopinavir versus raltegravir each with tenofovir plus emtricitabine for post-exposure prophylaxis for HIV infection.

OBJECTIVES: The objective of this study was to assess post-exposure prophylaxis (PEP) non-completion at day 28, comparing two regimens.

METHODS: A prospective, open, randomized clinical trial was conducted at a tertiary hospital in Barcelona, Spain. Individuals attending the emergency room because of potential sexual exposure to HIV were randomized to tenofovir disoproxil/emtricitabine (245/200 mg) plus either ritonavir-boosted lopinavir (400/100 mg) or raltegravir (400 mg). The primary endpoint was PEP non-completion at day 28. Secondary endpoints were adherence, adverse events and rate of seroconversions. This study was registered in ClinicalTrials.gov: NCT01576731.

RESULTS: One-hundred-and-twenty-one individuals were randomized to receive ritonavir-boosted lopinavir and 122 to raltegravir (n = 243). PEP non-completion at day 28 was 43% with no significant difference between arms. We performed a modified ITT analysis including only those patients who attended on day 1 (n = 191). PEP non-completion in this subgroup was higher in the ritonavir-boosted lopinavir arm than in the raltegravir arm (34.6% versus 20.4%, P = 0.04), as was the number of patients lost to follow-up at day 28 (32.6% versus 21.6%, P = 0.08) and the proportion of patients with low adherence (49.2% versus 30.8%, P = 0.03). Adverse events were significantly more common in the ritonavir-boosted lopinavir arm (73.4% versus 60.2%, P = 0.007). There was an HIV seroconversion at day 90 in the raltegravir arm in a patient who had multiple potential sexual risk exposures before and after receiving PEP.

CONCLUSIONS: Although we found no differences between arms regarding PEP non-completion, poor adherence and adverse events were significantly higher in patients allocated to tenofovir disoproxil/emtricitabine plus ritonavir-boosted lopinavir. These data support the use of raltegravir as the preferred third drug in current PEP recommendations.