A Pilot Study of Raltegravir Plus Combination Antiretroviral Therapy in Early Human Immunodeficiency Virus Infection: Challenges and Lessons Learned

Virological and Immunological Outcomes of an Intensified Four-Drug versus a Standard Three-Drug Antiretroviral Regimen, Both Integrase Strand Transfer Inhibitor-Based, in Primary HIV Infection

The optimal therapeutic approach for primary HIV infection (PHI) is still debated. We aimed to compare the viroimmunological response to a four- versus a three-drug regimen, both INSTI-based, in patients with PHI. This was a monocentric, prospective, observational study including all patients diagnosed with PHI from December 2014 to April 2018. Antiretroviral therapy (ART) was started, before genotype resistance test results, with tenofovir/emtricitabine and either raltegravir plus boosted darunavir or dolutegravir. Cumulative probability of virological suppression [VS] (HIV-1 RNA< 40 cp/mL), low-level HIV-1 DNA [LL-HIVDNA] (HIV-1 DNA < 200 copies/106PBMC), and CD4/CD8 ratio ≥1 were estimated using Kaplan−Meier curves. Factors associated with the achievement of VS, LL-HIVDNA, and CD4/CD8 ≥ 1 were assessed by a Cox regression model. We enrolled 144 patients (95.8% male, median age 34 years): 110 (76%) started a four-drug-based therapy, and 34 (24%) a three-drug regimen. Both treatment groups showed a comparable high probability of achieving VS and a similar probability of reaching LL-HIVDNA and a CD4/CD8 ratio ≥1 after 48 weeks from ART initiation. Higher baseline HIV-1 RNA and HIV-1 DNA levels lowered the chance of VS, whereas a better preserved immunocompetence increased that chance. Not statistically significant factors associated with LL-HIVDNA achievement were found, whereas a higher baseline CD4/CD8 ratio predicted the achievement of immune recovery. In PHI patients, the rapid initiation of either an intensified four-drug or a standard three-drug INSTI-based regimen showed comparable responses in terms of VS, viral reservoir size, and immunological recovery.

Impact of Integrase Inhibition Compared With Nonnucleoside Inhibition on HIV Reservoirs in Lymphoid Tissues

BACKGROUND

HIV is produced in lymphoid tissues (LT) and stored on the follicular dendritic cell network in LT. When antiretroviral therapy is started, plasma viremia decays in 2 phases; the first within days of starting therapy and the second over weeks. Raltegravir (RAL), an integrase inhibitor, has been associated with only a single rapid phase of decay, and we speculated this may be due to higher intracellular concentration (IC) of RAL in LT. We have previously measured suboptimal ICs of antiretroviral therapy agents in LT, which were associated with slower decay of both vRNA+ cells and the follicular dendritic cell network pool.

SETTING

Outpatient clinic at the Joint Clinical Research Center in Kampala, Uganda.

METHODS

We compared the rate of decay in LT in people starting RAL with those starting efavirenz (EFV).

RESULTS

There was no difference in the rate of virus decay in LT. The ratio of the ICs of RAL and EFV in lymph node to the concentration of drug that inhibits 95% of virus in blood was 1 log lower in lymph node for EFV and >3 logs lower for RAL.

CONCLUSION

These data further highlight the challenges of drug delivery to LT in HIV infection and demonstrate that RAL is not superior to EFV as judged by direct measurements of the source of virus in LT.

Impact of Different Antiretroviral Strategies on Total HIV-DNA Level in Virologically Suppressed HIV-1 Infected Patients

Background:

Total HIV-DNA load in peripheral blood cell (PBMCs) reflects the global viral reservoir that seems not to be affected by antiretroviral treatment. However, some studies report-ed a different permeability of different drugs in cellular compartments.

Objective:

To investigate the relation between the amount of total HIV-1 DNA and different treatment strategies.

Methods:

Total HIV-1 DNA was quantified by real time PCR in PBMCs collected from 161 patients with long-term undetectable HIV-RNA receiving different therapy schedules (3-drug regimens or 2-drug regimen containing Raltegravir as integrase inhibitor).

Results:

Overall, HIV patients who started therapy with a median pre-ART CD4+ cell count >400 cells/mm3 and HIV viral load of 3 log10 copies/ml, achieved a lower amount of HIV total DNA. No significant correlation was found in DNA size when patients were stratified on the basis of different therapeutic protocols. However, HIV DNA load analysis, when only performed in HIV patients with a median pre-ART CD4+ cell count >200 cells/mm3 and HIV viral load < 3 log10 copies/ml, showed a significative DNA decrease in Raltegravir treated group with respect to the NNRTIs-treated group.

Conclusion:

The data emphasize that HIV-DNA level represents a predictive factor in long-term sup-pressive therapy patients. In addition, the diminished reservoir, only observed in patients treated with the NRTI-sparing regimen RAL plus PI/r before immunological and virological derangement, sug-gests that latest generation drugs, such as integrase inhibitors, might represent an optimal chance in the management of HIV infection.

Peering into the HIV reservoir

The main obstacle to HIV eradication is the establishment of a long-term persistent HIV reservoir. Although several therapeutic approaches have been developed to reduce and eventually eliminate the HIV reservoir, only a few have achieved promising results. A better knowledge of the mechanisms involved in the establishment and maintenance of HIV reservoir is of utmost relevance for the design of new therapeutic strategies aimed at purging it with the ultimate goal of achieving HIV eradication or alternatively a functional cure. In this regard, it is also important to take a close look into the cellular HIV reservoirs other than resting memory CD4 T-cells with key roles in reservoir maintenance that have been recently described. Unraveling the special characteristics of these HIV cellular compartments could aid us in designing new therapeutic strategies to deplete the latent HIV reservoir.

Clinical benefit of dolutegravir in HIV-1 management related to the high genetic barrier to drug resistance

This manuscript reviews the reasons why Integrase inhibitors should now routinely constitute a part of first line antiretroviral therapy for the treatment of HIV disease. The use of these drugs that are generally well tolerated has resulted in far less drug resistance than was the case with most other categories of antiviral compounds. In addition, the integrase inhibitor family of drugs has been less prone to the problem of transmitted drug resistance which is due to a wide variety of substitutions in the HIV genome that can be sexually transmitted from one person to another. However, the use of integrase inhibitors in first line therapy may unfortunately not soon happen in developing country settings where non-nucleoside reverse transcriptase inhibitors continue to be a mainstay of initial therapy, primarily for reasons of cost. As long as this situation continues, problems of drug resistance and transmitted drug resistance will be common in such settings. Current evidence also suggests that the use of dolutegravir as a first line integrase inhibitor may limit development of drug resistance to an extent that exceeds the use of other members of this family of drugs. This may be due to particular patterns of resistance involving dolutegravir, whereby the mutations that are associated with resistance against this compound may actually diminish both HIV replication capacity as well as integrase enzymatic activity in a far-reaching and unique manner. This gives potential hope that the use of dolutegravir in first line therapy could actually form part of the long-sought goal of attainment of a functional cure for HIV disease.