Durable Efficacy of Switching From a 3- or 4-Drug Tenofovir Alafenamide-Based Regimen to the 2-Drug Regimen Dolutegravir/Lamivudine in the TANGO Study Through Week 196

BACKGROUND

Switching to the 2-drug regimen dolutegravir/lamivudine demonstrated durable non-inferior efficacy vs continuing 3- or 4-drug tenofovir alafenamide-based regimens for maintaining virologic suppression in people with HIV-1 through Week 144 in TANGO.

SETTING

134 centers, 10 countries.

METHODS

Adults with HIV-1 RNA <50 copies/mL for >6 months and no history of virologic failure were randomized to switch from stable tenofovir alafenamide-based regimens to dolutegravir/lamivudine on Day 1 (early-switch group) for 196 weeks. Those randomized to continue tenofovir alafenamide-based regimens on Day 1 who maintained virologic suppression at Week 144 switched to dolutegravir/lamivudine at Week 148 (late-switch group). Efficacy, safety, and tolerability (including weight and biomarker changes) of dolutegravir/lamivudine in early-switch and late-switch groups were assessed through Week 196.

RESULTS

Overall, 369 participants switched to dolutegravir/lamivudine on Day 1 (early-switch) and 298 switched at Week 148 (late-switch). In the early-switch group, 83% (306/369) maintained virologic suppression through Year 4, and 3% (11/369) reported new adverse events between Weeks 144 and 196. The late-switch group at Week 196 and early-switch group at Week 48 had comparable proportions with virologic suppression (93% each) and similar safety profiles. No late-switch participants and 1 early-switch participant met confirmed virologic withdrawal criteria through Week 196, with no resistance-associated mutations observed. Treatment continued to be well tolerated long-term.

CONCLUSION

Switching from tenofovir alafenamide-based regimens to dolutegravir/lamivudine showed durable efficacy, high barrier to resistance, and good tolerability through 4 years. These results support dolutegravir/lamivudine as a robust treatment for maintaining virologic suppression.

Long-acting cabotegravir and rilpivirine dosed every 2 months in adults with HIV-1 infection: 152-week results from ATLAS-2M, a randomized, open-label, Phase 3b, noninferiority study

BACKGROUND

Cabotegravir (CAB) + rilpivirine (RPV) dosed intramuscularly monthly or every 2 months is a complete long-acting (LA) regimen for the maintenance of HIV-1 virologic suppression. Here, we report the ATLAS-2M study Week 152 results.

METHODS

ATLAS-2M is a Phase 3b, randomized, multicenter study assessing the efficacy and safety of CAB+RPV LA every 8 weeks (Q8W) vs. every 4 weeks (Q4W). Virologically suppressed (HIV-1 RNA <50 copies/mL) individuals were randomized to receive CAB+RPV LA Q8W or Q4W. Endpoints included the proportion of participants with plasma HIV-1 RNA ≥50 copies/mL and <50 copies/mL, incidence of confirmed virologic failure (CVF; two consecutive measurements of ≥200 copies/mL), safety, and tolerability.

RESULTS

1045 participants received CAB+RPV LA (Q8W, n=522; Q4W, n=523). CAB+RPV LA Q8W demonstrated noninferior efficacy vs. Q4W dosing, with 2.7% (n=14) and 1.0% (n=5) of participants having HIV-1 RNA ≥50 copies/mL, respectively. The adjusted treatment difference in proportions was 1.7% (95% CI 0.1 to 3.3), meeting the pre-specified noninferiority threshold of 4%. At Week 152, 87% of participants maintained HIV-1 RNA <50 copies/mL (Q8W, 87% [n=456]; Q4W, 86% [n=449]). Overall, 12 (2.3%) participants in the Q8W arm and two (0.4%) participants in the Q4W arm had CVF. Eight and 10 participants with CVF had treatment-emergent resistance-associated mutations to RPV and integrase inhibitors, respectively. Safety profiles were comparable, with no new safety signals observed since Week 48.

CONCLUSIONS

These data demonstrate the durability of virologic suppression with CAB+RPV LA Q8W or Q4W for ∼3 years, and confirm the long-term efficacy, safety, and tolerability of CAB+RPV LA as a complete regimen for the maintenance of HIV-1 virologic suppression.

Efficacy and Safety of Switching to Dolutegravir/Lamivudine Versus Continuing a Tenofovir Alafenamide-Based 3- or 4-Drug Regimen for Maintenance of Virologic Suppression in Adults Living With Human Immunodeficiency Virus Type 1: Results Through Week 144 From the Phase 3, Noninferiority TANGO Randomized Trial

BACKGROUND

Switching to dolutegravir/lamivudine (DTG/3TC) was noninferior to continuing tenofovir alafenamide (TAF)-based regimens for maintaining virologic suppression at week 48 of the TANGO study. Here we present week 144 outcomes (efficacy, safety, weight, and biomarkers).

METHODS

TANGO is a randomized (1:1, stratified by baseline third agent class), open-label, noninferiority phase 3 study. Virologically suppressed (>6 months) adults with human immunodeficiency virus type 1 (HIV-1) switched to once-daily DTG/3TC or continued TAF-based regimens.

RESULTS

A total of 741 participants received study treatment (DTG/3TC, n = 369; TAF-based regimen, n = 372). At week 144, the proportion of participants with an HIV-1 RNA level ≥50 copies/mL (primary end point, Snapshot; intention-to-treat-exposed population) after switching to DTG/3TC was 0.3% (1 of 369) versus 1.3% (5 of 372) for those continuing TAF-based regimens, demonstrating noninferiority (adjusted treatment difference, -1.1 [95% confidence interval, -2.4 to .2), with DTG/3TC favored in the per-protocol analysis (adjusted treatment difference, -1.1 [-2.3 to -.0]; P = .04). Few participants met confirmed virologic withdrawal criteria (none in the DTG/3TC and 3 in the TAF-based regimen group), with no resistance observed. Drug-related adverse events were more frequent with DTG/3TC (15%; leading to discontinuation in 4%) than TAF-based regimens (5%; leading to discontinuation in 1%) through week 144, but rates were comparable after week 48 (4%; leading to discontinuation in 1% in both groups). Changes from baseline in lipid values generally favored DTG/3TC; no clinical impact on renal function and comparable changes in inflammatory and bone biomarkers across groups were observed.

CONCLUSIONS

Switching to DTG/3TC demonstrated noninferior and durable efficacy compared with continuing TAF-based regimens in treatment-experienced adults with HIV-1, with good safety and tolerability, and no resistance through 144 weeks.

Week 96 extension results of a Phase 3 study evaluating long-acting cabotegravir with rilpivirine for HIV-1 treatment

BACKGROUND

ATLAS (NCT02951052), a phase 3, multicenter, open-label study, demonstrated that switching to injectable cabotegravir (CAB) with rilpivirine (RPV) long-acting dosed every 4 weeks was noninferior at week (W) 48 to continuing three-drug daily oral current antiretroviral therapy (CAR). Results from the W 96 analysis are presented.

METHODS AND DESIGN

Participants completing W 52 of ATLAS were given the option to withdraw, transition to ATLAS-2M (NCT03299049), or enter an Extension Phase to continue long-acting therapy (Long-acting arm) or switch from CAR to long-acting therapy (Switch arm). Endpoints assessed at W 96 included proportion of participants with plasma HIV-1 RNA less than 50 copies/ml, incidence of confirmed virologic failure (CVF; two consecutive HIV-1 RNA ≥200 copies/ml), safety and tolerability, pharmacokinetics, and patient-reported outcomes.

RESULTS

Most participants completing the Maintenance Phase transitioned to ATLAS-2M (88%, n = 502/572). Overall, 52 participants were included in the W 96 analysis of ATLAS; of these, 100% (n = 23/23) and 97% (n = 28/29) in the Long-acting and Switch arms had plasma HIV-1 RNA less than 50 copies/ml at W 96, respectively. One participant had plasma HIV-1 RNA 50 copies/ml or higher in the Switch arm (173 copies/ml). No participants met the CVF criterion during the Extension Phase. No new safety signals were identified. All Switch arm participants surveyed preferred long-acting therapy to their previous daily oral regimen (100%, n = 27/27).

CONCLUSION

In this subgroup of ATLAS, 98% (n = 51/52) of participants at the Extension Phase W 96 analysis maintained virologic suppression with long-acting therapy. Safety, efficacy, and participant preference results support the therapeutic potential of long-acting CAB+RPV treatment for virologically suppressed people living with HIV-1.

Three-year durable efficacy of dolutegravir plus lamivudine in antiretroviral therapy - naive adults with HIV-1 infection

OBJECTIVE

To assess efficacy and safety of dolutegravir (DTG) + lamivudine (3TC) vs. DTG + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in treatment-naive adults with HIV-1 in the prespecified 144-week secondary analyses of GEMINI-1 and GEMINI-2.

DESIGN

Identical, multicenter, phase III, randomized, non-inferiority studies (double-blind through 96 weeks).

METHODS

Participants with HIV-1 RNA ≤500 000 copies/ml and no major viral resistance mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, or protease inhibitors were randomized 1:1 to once-daily DTG + 3TC or DTG + TDF/FTC.

RESULTS

At week 144, DTG + 3TC (N = 716) was noninferior to DTG + TDF/FTC (N = 717) in proportion of participants achieving HIV-1 RNA <50 copies/ml (Snapshot algorithm) in the pooled analysis (82% vs. 84%, respectively; adjusted treatment difference [95% confidence interval (CI)], -1.8% [-5.8, 2.1]), GEMINI-1 (-3.6% [-9.4, 2.1]), and GEMINI-2 (0.0% [-5.3, 5.3]). Twelve DTG + 3TC participants and nine DTG + TDF/FTC participants met protocol-defined confirmed virologic withdrawal (CVW) criteria; none developed treatment-emergent resistance. One DTG + 3TC participant who did not meet CVW criteria developed M184V at week 132 and R263R/K at week 144, conferring a 1.8-fold change in susceptibility to DTG; non-adherence to therapy was reported. Significantly fewer drug-related adverse events occurred with DTG + 3TC vs. DTG + TDF/FTC (20% vs. 27%; relative risk [95% CI], 0.76 [0.63-0.92]). Renal and bone biomarker changes favored DTG + 3TC.

CONCLUSIONS

Three-year durable efficacy, long-term tolerability, and high barrier to resistance support first-line use of DTG + 3TC for HIV-1 treatment (see Supplemental Digital Content 1, http://links.lww.com/QAD/C297; video abstract).

Long-acting cabotegravir and rilpivirine dosed every 2 months in adults with HIV-1 infection (ATLAS-2M), 48-week results: a randomised, multicentre, open-label, phase 3b, non-inferiority study

BACKGROUND

Phase 3 clinical studies showed non-inferiority of long-acting intramuscular cabotegravir and rilpivirine dosed every 4 weeks to oral antiretroviral therapy. Important phase 2 results of every 8 weeks dosing, and supportive modelling, underpin further evaluation of every 8 weeks dosing in this trial, which has the potential to offer greater convenience. Our objective was to compare the week 48 antiviral efficacy of cabotegravir plus rilpivirine long-acting dosed every 8 weeks with that of every 4 weeks dosing.

METHODS

ATLAS-2M is an ongoing, randomised, multicentre (13 countries; Australia, Argentina, Canada, France, Germany, Italy, Mexico, Russia, South Africa, South Korea, Spain, Sweden, and the USA), open-label, phase 3b, non-inferiority study of cabotegravir plus rilpivirine long-acting maintenance therapy administered intramuscularly every 8 weeks (cabotegravir 600 mg plus rilpivirine 900 mg) or every 4 weeks (cabotegravir 400 mg plus rilpivirine 600 mg) to treatment-experienced adults living with HIV-1. Eligible newly recruited individuals must have received an uninterrupted first or second oral standard-of-care regimen for at least 6 months without virological failure and be aged 18 years or older. Eligible participants from the ATLAS trial, from both the oral standard-of-care and long-acting groups, must have completed the 52-week comparative phase with an ATLAS-2M screening plasma HIV-1 RNA less than 50 copies per mL. Participants were randomly assigned 1:1 to receive cabotegravir plus rilpivirine long-acting every 8 weeks or every 4 weeks. The randomisation schedule was generated by means of the GlaxoSmithKline validated randomisation software RANDALL NG. The primary endpoint at week 48 was HIV-1 RNA ≥50 copies per mL (Snapshot, intention-to-treat exposed), with a non-inferiority margin of 4%. The trial is registered at ClinicalTrials.gov, NCT03299049 and is ongoing.

FINDINGS

Screening occurred between Oct 27, 2017, and May 31, 2018. Of 1149 individuals screened, 1045 participants were randomised to the every 8 weeks (n=522) or every 4 weeks (n=523) groups; 37% (n=391) transitioned from every 4 weeks cabotegravir plus rilpivirine long-acting in ATLAS. Median participant age was 42 years (IQR 34-50); 27% (n=280) female at birth; 73% (n=763) white race. Cabotegravir plus rilpivirine long-acting every 8 weeks was non-inferior to dosing every 4 weeks (HIV-1 RNA ≥50 copies per mL; 2% vs 1%) with an adjusted treatment difference of 0·8 (95% CI -0·6-2·2). There were eight (2%, every 8 weeks group) and two (<1%, every 4 weeks group) confirmed virological failures (two sequential measures ≥200 copies per mL). For the every 8 weeks group, five (63%) of eight had archived non-nucleoside reverse transcriptase inhibitor resistance-associated mutations to rilpivirine at baseline. The safety profile was similar between dosing groups, with 844 (81%) of 1045 participants having adverse events (excluding injection site reactions); no treatment-related deaths occurred.

INTERPRETATION

The efficacy and safety profiles of dosing every 8 weeks and dosing every 4 weeks were similar. These results support the use of cabotegravir plus rilpivirine long-acting administered every 2 months as a therapeutic option for people living with HIV-1.

FUNDING

ViiV Healthcare and Janssen.

Long-acting cabotegravir and rilpivirine dosed every 2 months in adults with HIV-1 infection (ATLAS-2M), 96-week results: a randomised, multicentre, open-label, phase 3b, non-inferiority study

BACKGROUND

Long-acting cabotegravir and rilpivirine administered monthly or every 2 months might address the challenges associated with daily oral antiretroviral therapy. The ATLAS-2M week 48 results showed non-inferiority of long-acting cabotegravir and rilpivirine administered every 8 weeks compared with that of every 4 weeks. In this study, we report the efficacy, safety, and tolerability results from the week 96 analysis.

METHODS

ATLAS-2M is a randomised, multicentre, open-label, phase 3b, non-inferiority trial conducted in 13 countries, evaluating the safety and efficacy of maintenance treatment with intramuscular injections of long-acting cabotegravir and rilpivirine, administered every 8 weeks versus every 4 weeks, to people living with HIV-1. Virologically suppressed adults with HIV-1, either already receiving intramuscular long-acting cabotegravir and rilpivirine every 4 weeks (ie, ATLAS study rollover participants) or oral standard of care, were randomly assigned (1:1), in an unblinded fashion, to receive either intramuscular long-acting cabotegravir (600 mg) and rilpivirine (900 mg) every 8 weeks (ie, the every 8-week dosing group) or intramuscular long-acting cabotegravir (400 mg) and rilpivirine (600 mg) every 4 weeks (ie, the every 4-week dosing group). Randomisation was generated using the GlaxoSmithKline-validated randomisation software RANDALL NG (version 1.3.3). The primary endpoint at week 48 was the proportion of participants with plasma HIV-1 RNA measurements of 50 copies per mL or more (ie, the US Food and Drug Administration [FDA] Snapshot algorithm), which has been published previously. Here, we present the week 96 results: the proportion of participants with plasma HIV-1 RNA measurements of less than 50 copies per mL (FDA Snapshot algorithm), with a non-inferiority margin of -10%; the proportion of participants with plasma HIV-1 RNA measurements of 50 copies per mL or more (FDA Snapshot algorithm), with a non-inferiority margin of 4%; the proportion of participants with protocol-defined confirmed virological failure (ie, two consecutive plasma HIV-1 RNA measurements ≥200 copies per mL); safety; pharmacokinetics; and tolerability. This study is registered with ClinicalTrials.gov, number NCT03299049, and is currently ongoing.

FINDINGS

Between Oct 27, 2017, and May 31, 2018, a total of 1149 participants were screened; of whom, 1049 (91%) were randomly assigned and 1045 (91%) initiated treatment (522 in the every 8-week dosing group and 523 in the every 4-week dosing group). The median age was 42 years (IQR 34-50). 280 (27%) of 1045 participants were assigned female at birth and 764 (73%) were white. At week 96 (FDA Snapshot algorithm), 11 (2%) of 522 participants in the every 8-week dosing group and six (1%) of 523 in the every 4-week dosing group had an HIV-1 RNA measurement of 50 copies per mL or more, with an adjusted treatment difference of 1·0 (95% CI -0·6 to 2·5), meeting the prespecified non-inferiority threshold of 4%; 475 (91%) of 522 participants in the every 8-week dosing group and 472 (90%) of 523 in the every 4-week dosing group maintained an HIV-1 RNA measurement of less than 50 copies per mL, with an adjusted treatment difference of 0·8 (95% CI -2·8 to 4·3), which met the prespecified non-inferiority threshold of -10%. One participant in the every 8-week dosing group met the confirmed virological failure criterion since the week 48 analysis at week 88, resulting in a total of nine participants in the every 8-week dosing group and two in the every 4-week dosing group having confirmed virological failure. No new safety signals were identified, and no treatment-related deaths occurred. Injection site reactions were the most common adverse event, occurring in 412 (79%) of 522 participants in the every 8-week dosing group and 400 (76%) of 523 in the every 4-week dosing group. Most injection site reactions were grade 1 or 2 (7453 [99%] of 7557 in both groups), with a median duration of 3 days (IQR 2-5).

INTERPRETATION

Long-acting cabotegravir and rilpivirine dosed every 8 weeks had non-inferior efficacy compared with that of every 4 weeks through the 96-week analysis, with both regimens maintaining high levels of virological suppression. These results show the durable safety, efficacy, and acceptability of dosing long-acting cabotegravir and rilpivirine monthly and every 2 months as maintenance therapy for people living with HIV-1.

FUNDING

ViiV Healthcare and Janssen Research & Development.

Efficacy, Safety, and Durability of Long-Acting Cabotegravir and Rilpivirine in Adults With Human Immunodeficiency Virus Type 1 Infection: 5-Year Results From the LATTE-2 Study

Background

In the Long-Acting Antiretroviral Treatment Enabling Trial 2 (LATTE-2) phase 2b study, long-acting (LA) injectable cabotegravir + rilpivirine dosed every 8 weeks (Q8W) or every 4 weeks (Q4W) demonstrated comparable efficacy with daily oral antiretroviral therapy (ART) through 96 weeks in ART-naive adults with human immunodeficiency virus type 1 (HIV-1). Here we report efficacy, tolerability, and safety of cabotegravir + rilpivirine LA over approximately 5 years.

Methods

After 20 weeks of oral cabotegravir + abacavir/lamivudine, participants were randomized to cabotegravir + rilpivirine LA Q8W or Q4W or continue oral ART through the 96-week maintenance period. In the extension period through week 256, participants continued their current LA regimen (randomized Q8W/Q4W groups) or switched from oral ART to Q8W or Q4W LA therapy (extension-switch groups). Endpoints assessed included proportion of participants with HIV-1 RNA <50 copies/mL (Snapshot algorithm) and adverse events (AEs).

Results

At week 256, 186 of 230 (81%) participants in randomized Q8W/Q4W groups and 41 of 44 (93%) participants in extension-switch groups had HIV-1 RNA <50 copies/mL. No protocol-defined virologic failures occurred after week 48. Injection wsite reactions infrequently resulted in discontinuation (4 [2%] and 1 [2%] participants in randomized Q8W/Q4W and extension-switch groups, respectively). Three participants in randomized Q8W/Q4W groups experienced drug-related serious AEs, including 1 fatal serious AE (Q4W group); none occurred in extension-switch groups. Of 25 participants with AEs leading to withdrawal, 20 were in the randomized Q4W group; no AE leading to withdrawal occurred in >1 participant.

Conclusions

Cabotegravir + rilpivirine LA exhibited long-term efficacy and tolerability, demonstrating its durability as maintenance therapy for HIV-1 infection.

Clinical Trials Registration. NCT02120352.

Cabotegravir for HIV Prevention in Cisgender Men and Transgender Women

BACKGROUND

Safe and effective long-acting injectable agents for preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection are needed to increase the options for preventing HIV infection.

METHODS

We conducted a randomized, double-blind, double-dummy, noninferiority trial to compare long-acting injectable cabotegravir (CAB-LA, an integrase strand-transfer inhibitor [INSTI]) at a dose of 600 mg, given intramuscularly every 8 weeks, with daily oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for the prevention of HIV infection in at-risk cisgender men who have sex with men (MSM) and in at-risk transgender women who have sex with men. Participants were randomly assigned (1:1) to receive one of the two regimens and were followed for 153 weeks. HIV testing and safety evaluations were performed. The primary end point was incident HIV infection.

RESULTS

The intention-to-treat population included 4566 participants who underwent randomization; 570 (12.5%) identified as transgender women, and the median age was 26 years (interquartile range, 22 to 32). The trial was stopped early for efficacy on review of the results of the first preplanned interim end-point analysis. Among 1698 participants from the United States, 845 (49.8%) identified as Black. Incident HIV infection occurred in 52 participants: 13 in the cabotegravir group (incidence, 0.41 per 100 person-years) and 39 in the TDF-FTC group (incidence, 1.22 per 100 person-years) (hazard ratio, 0.34; 95% confidence interval, 0.18 to 0.62). The effect was consistent across prespecified subgroups. Injection-site reactions were reported in 81.4% of the participants in the cabotegravir group and in 31.3% of those in the TDF-FTC group. In the participants in whom HIV infection was diagnosed after exposure to CAB-LA, INSTI resistance and delays in the detection of HIV infection were noted. No safety concerns were identified.

CONCLUSIONS

CAB-LA was superior to daily oral TDF-FTC in preventing HIV infection among MSM and transgender women. Strategies are needed to prevent INSTI resistance in cases of CAB-LA PrEP failure. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 083 ClinicalTrials.gov number, NCT02720094.).

Patient-Reported Outcomes Through 1 Year of an HIV-1 Clinical Trial Evaluating Long-Acting Cabotegravir and Rilpivirine Administered Every 4 or 8 Weeks (ATLAS-2M)

BACKGROUND

Advances in HIV-1 therapeutics have led to the development of a range of daily oral treatment regimens, which share similar high efficacy rates. Consequently, more emphasis is being placed upon the individual's experience of treatment and impact on quality of life. The first long-acting injectable antiretroviral therapy for HIV-1 (long-acting cabotegravir + rilpivirine [CAB + RPV LA]) may address challenges associated with oral treatment for HIV-1, such as stigma, pill burden/fatigue, drug-food interactions, and adherence. Patient-reported outcomes (PROs) collected in an HIV-1 clinical trial (ATLAS-2M; NCT03299049) comparing participants' experience with two dosing regimens (every 4 weeks [Q4W] vs. every 8 weeks [Q8W]) of CAB + RPV LA are presented herein.

METHODS

PRO endpoints evaluated through 48 weeks of therapy included treatment satisfaction (HIV Treatment Satisfaction Questionnaire [HIVTSQ]), treatment acceptance ("General Acceptance" domain of the Chronic Treatment Acceptance [ACCEPT^®] questionnaire), acceptability of injections (Perception of Injection [PIN] questionnaire), treatment preference (questionnaire), and reasons for switching to/continuing long-acting therapy (exploratory endpoint; questionnaire). Participants were randomized 1:1 to receive CAB + RPV LA Q8W or Q4W. Results were stratified by prior CAB + RPV exposure in either preplanned or post hoc analyses.

RESULTS

Overall, 1045 participants were randomized to the Q8W (n = 522) and Q4W (n = 523) regimens; 37% (n = 391/1045) had previously received CAB + RPV in ATLAS. For participants without prior CAB + RPV exposure, large increases from baseline were reported in treatment satisfaction in both long-acting arms (HIVTSQ status version), with Q8W dosing statistically significantly favored at Weeks 24 (p = 0.036) and 48 (p = 0.004). Additionally, improvements from baseline were also observed in the "General Acceptance" domain of the ACCEPT questionnaire in both long-acting arms for participants without prior CAB + RPV exposure; however, no statistically significant difference was observed between arms at either timepoint (Week 24, p = 0.379; Week 48, p = 0.525). Significant improvements (p < 0.001) in the "Acceptance of Injection Site Reactions" domain of the PIN questionnaire were observed from Week 8 to Weeks 24 and 48 in both arms for participants without prior CAB + RPV exposure. Participants with prior CAB + RPV exposure reported high treatment satisfaction (mean [HIVTSQ status version]: Q8W 62.2/66.0; Q4W 62.0/66.0), treatment acceptance (mean: Q8W 89.3/100; Q4W 91.2/100), and acceptance of injection site reactions (mean [5 = not at all acceptable; 1 = totally acceptable]: Q8W 1.72; Q4W 1.59) at baseline/Week 8 that were maintained over time. Participants without prior CAB + RPV exposure who received Q8W dosing preferred this regimen over oral CAB + RPV (98%, n = 300/306). Among those with prior Q4W exposure, 94% (n = 179/191) preferred Q8W dosing versus Q4W dosing (3%, n = 6/191) or oral CAB + RPV (2%, n = 4/191).

CONCLUSIONS

Both long-acting regimens provided high treatment satisfaction and acceptance, irrespective of prior CAB + RPV exposure, with most participants preferring Q8W dosing over both the Q4W regimen and their previous daily oral regimen. The PRO data collected at Week 48 support the therapeutic potential of CAB + RPV LA.

FUNDING

ViiV Healthcare and Janssen.

TRIAL REGISTRATION

ATLAS-2M: ClinicalTrials.gov NCT03299049, registered October 2, 2017.

Efficacy and Safety of Switching to Dolutegravir/Lamivudine Fixed-Dose 2-Drug Regimen vs Continuing a Tenofovir Alafenamide-Based 3- or 4-Drug Regimen for Maintenance of Virologic Suppression in Adults Living With Human Immunodeficiency Virus Type 1: Phase 3, Randomized, Noninferiority TANGO Study

Background

The 2-drug regimen dolutegravir (DTG) + lamivudine (3TC) is indicated for treatment-naive adults with human immunodeficiency virus type 1 (HIV-1). We present efficacy and safety of switching to DTG/3TC in virologically suppressed individuals.

Methods

TANGO is an open-label, multicenter, phase 3 study that randomized adults (1:1, stratified by baseline third agent class) with HIV-1 RNA <50 copies/mL to switch to once-daily fixed-dose DTG/3TC or remain on a tenofovir alafenamide (TAF)–based regimen. The primary end point was proportion of participants with HIV-1 RNA ≥50 copies/mL at week 48 (US Food and Drug Administration Snapshot algorithm) in the intention-to-treat–exposed population (4% noninferiority margin).

Results

743 adults were enrolled; 741 received ≥1 dose of study drug (DTG/3TC, N = 369; TAF-based regimen, N = 372). At week 48, proportion of participants with HIV-1 RNA ≥50 copies/mL receiving DTG/3TC was 0.3% (1/369) vs 0.5% (2/372) with a TAF-based regimen (adjusted treatment difference [95% confidence interval], −0.3 [−1.2 to .7]), meeting noninferiority criteria. No participants receiving DTG/3TC and 1 receiving a TAF-based regimen met confirmed virologic withdrawal criteria, with no emergent resistance at failure. Drug-related grade ≥2 adverse events and withdrawals due to adverse events occurred in 17 (4.6%) and 13 (3.5%) participants with DTG/3TC and 3 (0.8%) and 2 (0.5%) with a TAF-based regimen, respectively.

Conclusions

DTG/3TC was noninferior in maintaining virologic suppression vs a TAF-based regimen at week 48, with no virologic failure or emergent resistance reported with DTG/3TC, supporting it as a simplification strategy for virologically suppressed people with HIV-1.

Clinical Trials Registration

NCT03446573.

Long-acting cabotegravir plus rilpivirine for treatment in adults with HIV-1 infection: 96-week results of the randomised, open-label, phase 3 FLAIR study

BACKGROUND

There is a need for more convenient, less frequent treatment to help address challenges associated with daily oral HIV treatment in people living with HIV, including stigma, pill burden, drug-food interactions, and adherence. The phase 3 ATLAS and FLAIR studies showed non-inferiority of long-acting cabotegravir and rilpivirine dosed every 4 weeks compared with standard oral therapy for the maintenance of virological suppression in adults with HIV-1 over 48 weeks. We present the 96-week findings.

METHODS

FLAIR is a randomised, phase 3, open-label, multicentre study done in 11 countries investigating whether switching to long-acting cabotegravir and rilpivirine is non-inferior to daily dolutegravir, abacavir, and lamivudine in virologically suppressed adults living with HIV-1. Antiretroviral therapy (ART)-naive participants received induction therapy with daily oral dolutegravir (50 mg), abacavir (600 mg), and lamivudine (300 mg) for 20 weeks. After 16 weeks, participants with less than 50 HIV-1 RNA copies per mL were randomly assigned (1:1) to continue the standard of care regimen (standard care group) or switch to receive daily oral cabotegravir 30 mg and rilpivirine 25 mg for at least 4 weeks followed by long-acting cabotegravir 400 mg and rilpivirine 600 mg, administered as two 2 mL intramuscular injections, every 4 weeks for at least 96 weeks (long-acting group). Randomisation was stratified by baseline (preinduction) HIV-1 RNA (<100 000 or ≥100 000 copies per mL) and sex at birth and used GlaxoSmithKline-verified randomisation software (RandAll NG, version 1.3.3) for treatment assignment. The primary endpoint was the proportion of participants with plasma HIV-1 RNA of 50 copies per mL or more assessed as per the US Food and Drug Administration (FDA) Snapshot algorithm at week 48, which has been reported previously. Here, we report the proportion of participants with 50 or more HIV-1 RNA copies per mL using the FDA Snapshot algorithm at week 96 (intention-to-treat population; non-inferiority margin 6%). The trial is registered with ClinicalTrials.gov, NCT02938520.

FINDINGS

Between Oct 27, 2016, and March 24, 2017, 809 participants were screened. 631 (78%) participants entered the induction phase and 566 (70%) were randomly assigned to either the standard care group (283 [50%] participants) or the long-acting group (283 [50%]). Median age was 34 years (IQR 29 to 43), 62 (11%) were 50 years or older, 127 (22%) were women (sex at birth), and 419 (74%) were white. At week 96, nine (3%) participants in each arm had 50 or more HIV-1 RNA copies per mL, with an adjusted difference of 0·0 (95% CI -2·9 to 2·9), consistent with non-inferiority established at week 48. Across both treatment groups, adverse events leading to withdrawal were infrequent (14 [5%] participants in the long-acting group and four [1%] in the standard care group). Injection site reactions were the most common adverse event, reported by 245 (88%) participants in the long-acting group; their frequency decreased over time. Median injection site reaction duration was 3 days (IQR 2 to 4), and 3082 (99%) of 3100 reactions were grade 1 or 2. No deaths occurred during the maintenance phase.

INTERPRETATION

The 96-week results reaffirm the 48-week results, showing long-acting cabotegravir and rilpivirine continued to be non-inferior compared with continuing a standard care regimen in adults with HIV-1 for the maintenance of viral suppression. These results support the durability of long-acting cabotegravir and rilpivirine, over an almost 2-year-long period, as a therapeutic option for virally suppressed adults with HIV-1.

FUNDING

ViiV Healthcare and Janssen Research and Development.

Dolutegravir plus lamivudine for initial treatment of HIV-1-infected participants with HIV-1 RNA <500 000 copies/mL: week 48 outcomes from ACTG 5353

BACKGROUND

The AIDS Clinical Trials Group study A5353 demonstrated the efficacy and safety of dolutegravir and lamivudine for initial treatment of HIV-1 infection at week 24 in individuals with HIV-1 RNA 1000-500 000 copies/mL. Optimal ART for treatment-naive individuals must be durable.

OBJECTIVES

The aim of this study was to estimate the efficacy and safety of dolutegravir plus lamivudine at week 48 and compare the efficacy in participants with baseline HIV-1 RNA ≤100 000 copies/mL versus >100 000 copies/mL.

METHODS

Virological success was defined as HIV-1 RNA <50 copies/mL by FDA Snapshot criteria. Definition of virological failure included confirmed HIV-1 RNA >200 copies/mL at week 24 or later. The proportion of participants with virological success was estimated using two-sided exact Clopper-Pearson 95% CI. Comparison between screening HIV-1 RNA (≤100 000 versus >100 000 copies/mL) strata was carried out by Fisher's exact test. The study was registered with ClinicalTrials.gov, number NCT02582684.

RESULTS

A total of 120 enrolled eligible participants were included in the analysis. At week 48, 102 of the 120 participants (85%; 95% CI 77%-91%) had virological success. Virological success was similar between screening HIV-1 RNA groups. Six (5%) participants had virological non-success and one additional participant experienced virological failure while on study but off study treatment. No new drug resistance mutations were observed. Six (5%) participants had study-related grade 3 or higher adverse events and none discontinued study treatment.

CONCLUSIONS

These results add to the evidence that dolutegravir plus lamivudine is a safe and effective option for initial ART in individuals with HIV-1 RNA <500 000 copies/mL.

Long-Acting Cabotegravir and Rilpivirine after Oral Induction for HIV-1 Infection

BACKGROUND

Long-acting injectable regimens may simplify therapy for patients with human immunodeficiency virus type 1 (HIV-1) infection.

METHODS

We conducted a phase 3, randomized, open-label trial in which adults with HIV-1 infection who had not previously received antiretroviral therapy were given 20 weeks of daily oral induction therapy with dolutegravir-abacavir-lamivudine. Participants who had an HIV-1 RNA level of less than 50 copies per milliliter after 16 weeks were randomly assigned (1:1) to continue the current oral therapy or switch to oral cabotegravir plus rilpivirine for 1 month followed by monthly injections of long-acting cabotegravir plus rilpivirine. The primary end point was the percentage of participants who had an HIV-1 RNA level of 50 copies per milliliter or higher at week 48 (Food and Drug Administration snapshot algorithm).

RESULTS

At week 48, an HIV-1 RNA level of 50 copies per milliliter or higher was found in 6 of 283 participants (2.1%) who received long-acting therapy and in 7 of 283 (2.5%) who received oral therapy (adjusted difference, -0.4 percentage points; 95% confidence interval [CI], -2.8 to 2.1), a result that met the criterion for noninferiority for the primary end point (margin, 6 percentage points). An HIV-1 RNA level of less than 50 copies per milliliter at week 48 was found in 93.6% who received long-acting therapy and in 93.3% who received oral therapy (adjusted difference, 0.4 percentage points; 95% CI, -3.7 to 4.5), a result that met the criterion for noninferiority for this end point (margin, -10 percentage points). Of the participants who received long-acting therapy, 86% reported injection-site reactions (median duration, 3 days; mild or moderate severity, 99% of cases); 4 participants withdrew from the trial for injection-related reasons. Grade 3 or higher adverse events and events that met liver-related stopping criteria occurred in 11% and 2%, respectively, who received long-acting therapy and in 4% and 1% who received oral therapy. Treatment satisfaction increased after participants switched to long-acting therapy; 91% preferred long-acting therapy at week 48.

CONCLUSIONS

Therapy with long-acting cabotegravir plus rilpivirine was noninferior to oral therapy with dolutegravir-abacavir-lamivudine with regard to maintaining HIV-1 suppression. Injection-site reactions were common. (Funded by ViiV Healthcare and Janssen; FLAIR ClinicalTrials.gov number, NCT02938520.).

Long-Acting Cabotegravir and Rilpivirine for Maintenance of HIV-1 Suppression

BACKGROUND

Simplified regimens for the treatment of human immunodeficiency virus type 1 (HIV-1) infection may increase patient satisfaction and facilitate adherence.

METHODS

In this phase 3, open-label, multicenter, noninferiority trial involving patients who had had plasma HIV-1 RNA levels of less than 50 copies per milliliter for at least 6 months while taking standard oral antiretroviral therapy, we randomly assigned participants (1:1) to either continue their oral therapy or switch to monthly intramuscular injections of long-acting cabotegravir, an HIV-1 integrase strand-transfer inhibitor, and long-acting rilpivirine, a nonnucleoside reverse-transcriptase inhibitor. The primary end point was the percentage of participants with an HIV-1 RNA level of 50 copies per milliliter or higher at week 48, determined with the use of the Food and Drug Administration snapshot algorithm.

RESULTS

Treatment was initiated in 308 participants per group. At week 48, HIV-1 RNA levels of 50 copies per milliliter or higher were found in 5 participants (1.6%) receiving long-acting therapy and in 3 (1.0%) receiving oral therapy (adjusted difference, 0.6 percentage points; 95% confidence interval [CI], -1.2 to 2.5), a result that met the criterion for noninferiority for the primary end point (noninferiority margin, 6 percentage points). An HIV-1 RNA level of less than 50 copies per milliliter at week 48 was found in 92.5% of participants receiving long-acting therapy and in 95.5% of those receiving oral therapy (adjusted difference, -3.0 percentage points; 95% CI, -6.7 to 0.7), a result that met the criterion for noninferiority for this end point (noninferiority margin, -10 percentage points). Virologic failure was confirmed in 3 participants who received long-acting therapy and 4 participants who received oral therapy. Adverse events were more common in the long-acting-therapy group and included injection-site pain, which occurred in 231 recipients (75%) of long-acting therapy and was mild or moderate in most cases; 1% withdrew because of this event. Serious adverse events were reported in no more than 5% of participants in each group.

CONCLUSIONS

Monthly injections of long-acting cabotegravir and rilpivirine were noninferior to standard oral therapy for maintaining HIV-1 suppression. Injection-related adverse events were common but only infrequently led to medication withdrawal. (Funded by ViiV Healthcare and Janssen; ATLAS ClinicalTrials.gov number, NCT02951052.).

No Clinical Impact of CYP3A5 Gene Polymorphisms on the Pharmacokinetics and/or Efficacy of Maraviroc in Healthy Volunteers and HIV-1-Infected Subjects

Maraviroc is a C-C chemokine receptor type-5 antagonist approved for the treatment of HIV-1. Previous studies show that cytochrome P450 3A5 (CYP3A5) plays a role in maraviroc metabolism. CYP3A5 is subject to a genetic polymorphism. The presence of 2 functional alleles (CYP3A5*1/*1) confers the extensive metabolism phenotype, which is rare in whites but common in blacks. The effect of CYP3A5 genotype on maraviroc and/or metabolite pharmacokinetics was evaluated in 2 clinical studies: a post hoc analysis from a phase 2b/3 study (NCT00098293) conducted in 494 HIV-1-infected subjects (study 1) in which the impact on maraviroc efficacy in 303 subjects was also assessed, and a study conducted in 47 healthy volunteers (study 2). In study 2 (NCT02625207), extensive metabolizers had 26% to 37% lower mean area under the concentration-time curve compared with poor metabolizers (no CYP3A5*1 alleles). This effect diminished to 17% in the presence of potent CYP3A inhibition. The effect of CYP3A5 genotype was greatest in the formation of the metabolite (1S,2S)-2-hydroxymaraviroc. In study 1, the CYP3A5*1/*1 genotype unexpectedly had higher maraviroc area under the curve predictions (20%) compared with those with no CYP3A5*1 alleles. The reason for this disparity remains unclear. The proportions of subjects with viral loads <50 and <400 copies/mL for maraviroc were comparable among all 3 CYP3A5 genotypes. In both studies maraviroc exposures were in the range of near-maximal viral inhibition in the majority of subjects. These results demonstrate that although CYP3A5 contributes to the metabolism of maraviroc, CYP3A5 genotype does not affect the clinical response to maraviroc in combination treatment of HIV-1 infection at approved doses.

ACTG A5353: A Pilot Study of Dolutegravir Plus Lamivudine for Initial Treatment of Human Immunodeficiency Virus-1 (HIV-1)-infected Participants With HIV-1 RNA <500000 Copies/mL

Background

Limited data exist on initial human immunodeficiency virus type 1 (HIV-1) treatment with dolutegravir plus lamivudine.

Methods

A5353 is a phase 2, single-arm, pilot study of once-daily dolutegravir (50 mg) plus lamivudine (300 mg) in treatment-naive participants with HIV-1 RNA ≥1000 and <500000 copies/mL. Exclusion criteria included active hepatitis B or major protease, reverse transcriptase, or integrase resistance. The primary efficacy measure was the proportion with HIV-1 RNA <50 copies/mL (FDA [US Food and Drug Administration] Snapshot) at week 24. Virologic failure (VF) was confirmed HIV-1 RNA >400 copies/mL at week 16/20 or >200 copies/mL at or after week 24. Dolutegravir levels and drug resistance testing were performed at VF.

Results

One hundred and twenty participants (87% male, median age 30 years, 37 (31%) HIV-1 RNA >100000 copies/mL) initiated study treatment. Median entry HIV-1 RNA and CD4 count were 4.61 log10 copies/mL and 387 cells/mm3. Virologic efficacy at week 24 was 108/120 (90%, confidence interval [83%, 95%]), with comparable results in the >100000 copies/mL and ≤100000 copies/mL strata, that is, 89% (75%, 97%) and 90% (82%, 96%), respectively. Three participants with VF, had undetected plasma dolutegravir at ≥1 time points; the M184V and R263R/K mutations developed in 1 participant. Two participants experienced grade 3 possible/probable treatment-related adverse events; none discontinued treatment due to adverse events.

Conclusions

Dolutegravir plus lamivudine demonstrated efficacy in individuals with pretreatment HIV-1 RNA up to 500000 copies/mL in this pilot trial, but a participant developed resistance mutations.

Clinical Trials Registration

NCT02582684.

Efavirenz Therapeutic Range in HIV-1 Treatment-Naive Participants

BACKGROUND

Efavirenz is currently suggested as an alternative to recommended antiretroviral (ARV) regimens by the Department of Health and Human Services for the treatment of HIV-1 in ARV-naive patients. A mid-dosing interval therapeutic range between 1000 and 4000 ng/mL for efavirenz has been proposed in the literature, with patients more likely to experience virologic failure below this range and adverse effects above. The current study reports an analysis of virologic outcome between those above, below, or within the reported efavirenz therapeutic range (1000-4000 ng/mL) and within subgroups.

METHODS

This analysis examined efavirenz plasma concentrations obtained from participants enrolled in AIDS Clinical Trials Group Study A5202. This investigation divided subjects into those who experienced virologic failure and those who did not. These subjects were further separated to investigate those who had "high," "within," or "low" plasma concentrations, based on the therapeutic range. The association between virologic failure and plasma concentration was statistically examined in addition to the variables: race/ethnicity, sex, assigned nucleos(t)ide reverse transcriptase inhibitor backbone, age at study entry, history of intravenous drug use, weight, and screening HIV-1 RNA stratification level.

RESULTS

In univariate analyses, a statistically significant difference was found when comparing the efavirenz concentration groups, (22 failures among the "low" concentration group [19%], 65 failures among the "within" concentration group [12%], and 11 failures among the "high" concentration group [9%]) when evaluating virologic failure as an outcome (P = 0.04). In addition, the proportion of participants with virologic failure differed across race/ethnicity groups (P = 0.03) with black non-Hispanic participants observed to have the highest rate (17%). Efavirenz concentration group, race/ethnicity, age, weight, and the interaction between efavirenz concentration group and weight were found to be significantly associated with virologic failure in multivariable logistic regression analysis.

CONCLUSIONS

The proposed efavirenz therapeutic range, combined with the impact of a patient's weight, is associated with virologic failure in HIV-infected ARV-naive individuals in the United States. Additional analysis is recommended to determine the most appropriate concentration value that defines the lower limit of the efavirenz therapeutic range.

Long-acting intramuscular cabotegravir and rilpivirine in adults with HIV-1 infection (LATTE-2): 96-week results of a randomised, open-label, phase 2b, non-inferiority trial

BACKGROUND

Cabotegravir and rilpivirine are antiretroviral drugs in development as long-acting injectable formulations. The LATTE-2 study evaluated long-acting cabotegravir plus rilpivirine for maintenance of HIV-1 viral suppression through 96 weeks.

METHODS

In this randomised, phase 2b, open-label study, treatment-naive adults infected with HIV-1 initially received oral cabotegravir 30 mg plus abacavir-lamivudine 600-300 mg once daily. The objective of this study was to select an intramuscular dosing regimen based on a comparison of the antiviral activity, tolerability, and safety of the two intramuscular dosing regimens relative to oral cabotegravir plus abacavir-lamivudine. After a 20-week induction period on oral cabotegravir plus abacavir-lamivudine, patients with viral suppression (plasma HIV-1 RNA <50 copies per mL) were randomly assigned (2:2:1) to intramuscular long-acting cabotegravir plus rilpivirine at 4-week intervals (long-acting cabotegravir 400 mg plus rilpivirine 600 mg; two 2 mL injections) or 8-week intervals (long-acting cabotegravir 600 mg plus rilpivirine 900 mg; two 3 mL injections) or continued oral cabotegravir plus abacavir-lamivudine. Randomisation was computer-generated with stratification by HIV-1 RNA (<50 copies per mL, yes or no) during the first 12 weeks of the induction period. The primary endpoints were the proportion of patients with viral suppression at week 32 (as defined by the US Food and Drug Administration snapshot algorithm), protocol-defined virological failures, and safety events through 96 weeks. All randomly assigned patients who received at least one dose of study drug during the maintenance period were included in the primary efficacy and safety analyses. The primary analysis used a Bayesian approach to evaluate the hypothesis that the proportion with viral suppression for each long-acting regimen is not worse than the oral regimen proportion by more than 10% (denoted comparable) according to a prespecified decision rule (ie, posterior probability for comparability >90%). Difference in proportions and associated 95% CIs were supportive to the primary analysis. The trial is registered at ClinicalTrials.gov, number NCT02120352.

FINDINGS

Among 309 enrolled patients, 286 were randomly assigned to the maintenance period (115 to each of the 4-week and 8-week groups and 56 to the oral treatment group). This study is currently ongoing. At 32 weeks following randomisation, both long-acting regimens met primary criteria for comparability in viral suppression relative to the oral comparator group. Viral suppression was maintained at 32 weeks in 51 (91%) of 56 patients in the oral treatment group, 108 (94%) of 115 patients in the 4-week group (difference 2·8% [95% CI -5·8 to 11·5] vs oral treatment), and 109 (95%) of 115 patients in the 8-week group (difference 3·7% [-4·8 to 12·2] vs oral treatment). At week 96, viral suppression was maintained in 47 (84%) of 56 patients receiving oral treatment, 100 (87%) of 115 patients in the 4-week group, and 108 (94%) of 115 patients in the 8-week group. Three patients (1%) experienced protocol-defined virological failure (two in the 8-week group; one in the oral treatment group). Injection-site reactions were mild (3648 [84%] of 4360 injections) or moderate (673 [15%] of 4360 injections) in intensity and rarely resulted in discontinuation (two [<1%] of 230 patients); injection-site pain was reported most frequently. Serious adverse events during maintenance were reported in 22 (10%) of 230 patients in the intramuscular groups (4-week and 8-week groups) and seven (13%) of 56 patients in the oral treatment group; none were drug related.

INTERPRETATION

The two-drug combination of all-injectable, long-acting cabotegravir plus rilpivirine every 4 weeks or every 8 weeks was as effective as daily three-drug oral therapy at maintaining HIV-1 viral suppression through 96 weeks and was well accepted and tolerated.

FUNDING

ViiV Healthcare and Janssen R&D.

Safety and tolerability of long-acting cabotegravir injections in HIV-uninfected men (ECLAIR): a multicentre, double-blind, randomised, placebo-controlled, phase 2a trial

BACKGROUND

Cabotegravir (GSK1265744) is an HIV-1 integrase strand transfer inhibitor with potent antiviral activity and a long half-life when administered by injection that prevented simian-HIV infection upon repeat intrarectal challenge in male macaques. We aimed to assess the safety, tolerability, and pharmacokinetics of long-acting cabotegravir injections in healthy men not at high risk of HIV-1 infection.

METHODS

We did this multicentre, double-blind, randomised, placebo-controlled, phase 2a trial at ten sites in the USA. Healthy men (aged 18-65 years) deemed not at high risk of acquiring HIV-1 at screening were randomly assigned (5:1), via computer-generated central randomisation schedules, to receive cabotegravir or placebo. Participants received oral cabotegravir 30 mg tablets or matching placebo once daily during a 4 week oral lead-in phase, followed by a 1 week washout period and, after safety assessment, three intramuscular injections of long-acting cabotegravir 800 mg or saline placebo at 12 week intervals. Study site staff and participants were masked to treatment assignment from enrolment through week 41 (time of the last injection). The primary endpoint was safety and tolerability from the first injection (week 5) to 12 weeks after the last injection. We did analysis in the safety population, defined as all individuals enrolled in the study who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov identifier, NCT02076178.

FINDINGS

Between March 27, 2014, and Feb 23, 2016, we randomly assigned 127 participants to receive cabotegravir (n=106) or placebo (n=21); 126 (99%) participants comprised the safety population. Most participants were men who have sex with men (MSM; n=106 [83%]) and white (n=71 [56%]). 87 (82%) participants in the cabotegravir group and 20 (95%) participants in the placebo group completed the injection phase. Adverse events (n=7 [7%]) and injection intolerability (n=4 [4%]) were the main reasons for withdrawal in the cabotegravir group. The frequency of grade 2 or higher adverse events was higher in participants in the long-acting cabotegravir group (n=75 [80%]) than in those in the placebo group (n=10 [48%]; p=0·0049), mostly due to injection-site pain (n=55 [59%]). No significant differences were noted in concomitant medications, laboratory abnormalities, electrocardiogram, and vital sign assessments. Geometric mean trough plasma concentrations were 0·302 μg/mL (95% CI 0·237-0·385), 0·331 μg/mL (0·253-0·435), and 0·387 μg/mL (0·296-0·505) for injections one, two, and three, respectively, indicating lower than predicted exposure. The geometric mean apparent terminal phase half-life estimated after the third injection was 40 days. Two (2%) MSM acquired HIV-1 infection, one in the placebo group during the injection phase and one in the cabotegravir group 24 weeks after the final injection when cabotegravir exposure was well below the protein-binding-adjusted 90% inhibitory concentration.

INTERPRETATION

Despite high incidence of transient, mild-to-moderate injection-site reactions, long-acting cabotegravir was well tolerated with an acceptable safety profile. Pharmacokinetic data suggest that 800 mg administered every 12 weeks is a suboptimal regimen; alternative dosing strategies are being investigated. Our findings support further investigation of long-acting injectable cabotegravir as an alternative to orally administered pre-exposure prophylaxis regimens.

FUNDING

ViiV Healthcare.

Regional variation in HIV clinical trials participation in the United States

OBJECTIVES

To ensure generalizability of clinical research results, it is important to enroll a heterogeneous population that is representative of the target clinical population. Earlier studies have found regional variation in participation in human immunodeficiency virus (HIV) clinical trials, with the lowest rates seen in the southern United States. Rates of new HIV diagnoses are highest in the South, highlighting the need for in-depth understanding of disparities in clinical trial participation. We evaluated whether regional variation in study participation remains, and describe factors that facilitate or prevent HIV clinical trial participation by region.

METHODS

A one-time, anonymous, bilingual, self-administered survey was conducted among HIV-infected adults receiving HIV care at all 47 domestic AIDS Clinical Trials Group clinical research sites, with a goal of completing 50 surveys per site. χ(2) tests were used to evaluate differences in knowledge of and participation in HIV clinical trials by region, including Northeast, Midwest, South, and West regions. Multivariable logistic regression was used to estimate odds ratios and 95% confidence intervals (CIs) for the effect of region on knowledge of and participation in HIV clinical trials.

RESULTS

Of 2263 completed surveys, 2125 were included in this analysis. The proportion of respondents in the South who reported knowledge of studies (66%) was significantly lower than in the Northeast (76%), Midwest (77%), and West (73%) (P = 0.001). Respondents in the South also were the least likely group to report ever having tried to or having participated in a research study (51%) compared with respondents in the Northeast (60%), Midwest (57%), and West (69%; P < 0.001). After adjusting for age, sex, education, race/ethnicity, tobacco use, and alcohol use, the odds ratio for knowledge of and participation in clinical trials for the Northeast (1.36; 95% CI 1.07-1.72) and West (1.85; 95% CI 1.39-2.45) remained significant compared with the South. African American respondents in the South were the most likely population group to report not understanding research studies (15%) as a reason for not participating, compared with the Northeast (9%), Midwest (8%), and West (6%; P < 0.001).

CONCLUSIONS

Significant regional variations in knowledge of and participation in HIV clinical trials exist. Our results suggest that increasing awareness and understanding of research studies, particularly among African Americans in the South, may facilitate HIV clinical trial participation that is more representative of the HIV-infected population across the United States.

Sex differences in atazanavir pharmacokinetics and associations with time to clinical events: AIDS Clinical Trials Group Study A5202

OBJECTIVES

It is uncertain whether HIV-1 antiretroviral exposure and clinical response varies between males and females or different race/ethnic groups. We describe ritonavir-enhanced atazanavir pharmacokinetics in relation to virological failure, safety and tolerability in treatment-naive individuals to investigate potential differences.

METHODS

Plasma samples were collected from participants in AIDS Clinical Trials Group Study A5202 for measurement of antiretroviral concentrations. Individual estimates of apparent oral clearance of atazanavir (L/h) were calculated from a one-compartment model and divided into tertiles as slow (<7), middle (7 to <9; reference group) and fast (≥9). Associations between atazanavir clearance and clinical outcomes were estimated with a hazard ratio (HR) from Cox proportional hazards models. Interactions between atazanavir clearance and sex, race/ethnicity and NRTIs were investigated for each of the outcomes.

RESULTS

Among 786 participants, average atazanavir clearance was slower in females (n = 131) than males (n = 655). Atazanavir clearance was associated with time to virological failure (P = 0.053) and this relationship differed significantly by sex (P = 0.003). Females in the fast atazanavir clearance group had shorter time to virological failure (HR 3.49; 95% CI 1.24-9.84) compared with the middle (reference) atazanavir clearance group. Among males, the slow atazanavir clearance group had a higher risk of virological failure (HR 2.10; 95% CI 1.16-3.77).

CONCLUSIONS

Atazanavir clearance differed by sex. Females with fast clearance and males with slow clearance had increased risk of virological failure.

Minorities remain underrepresented in HIV/AIDS research despite access to clinical trials

BACKGROUND AND OBJECTIVE

The reasons for minority underrepresentation in HIV/AIDS clinical trials remain unclear. We aimed to evaluate the knowledge, experience, and factors that influence minority participation in HIV/AIDS studies in the United States.

METHODS

An anonymous, bilingual, self-administered survey on study participation was given to HIV-infected adults attending AIDS Clinical Trials Group-affiliated clinics in the United States and Puerto Rico. Chi-square tests were used to evaluate differences by race, first language, and level of education. Logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for factors associated with being talked to about participation in a study.

RESULTS

We analyzed 2,175 complete surveys (221 in Spanish). Among respondents, 31% were White, 40% were Black/African American (AA), and 21% were Hispanic. The overall rate of previous participation in any HIV/AIDS study was 48%. Hispanics were less likely to know about studies compared to Whites and AAs (67% vs 74% and 76%, respectively; P < .001). Compared to Whites, AAs and Hispanics were less likely to have been talked to about participating in a study (76% vs 67% and 67%, respectively; P < .001). The OR for being talked to about participating in a study was 0.65 (95% CI, 0.52-0.81) for AAs and 0.65 (95% CI, 0.49-0.85) for Hispanics, compared to Whites. AAs and Hispanics were more likely to state that studies were not friendly to their race (17% and 10% vs 4%; P < .001).

CONCLUSIONS

Minorities continue to face barriers for HIV/AIDS trial participation, even when clinical research is available. Enrollment strategies should better target minorities to improve recruitment in HIV/AIDS research.

Outcomes by sex following treatment initiation with atazanavir plus ritonavir or efavirenz with abacavir/lamivudine or tenofovir/emtricitabine

BACKGROUND

We aimed to evaluate treatment responses to atazanavir plus ritonavir (ATV/r) or efavirenz (EFV) in initial antiretroviral regimens among women and men, and determine if treatment outcomes differ by sex.

METHODS

We performed a randomized trial of open-label ATV/r or EFV combined with abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) in 1857 human immunodeficiency virus type 1-infected, treatment-naive persons enrolled between September 2005 and November 2007 at 59 sites in the United States and Puerto Rico. Associations of sex with 3 primary study endpoints of time to virologic failure, safety, and tolerability events were analyzed using Cox proportional hazards models. Model-based population pharmacokinetic analysis was performed using nonlinear mixed effects modeling (NONMEM version VII).

RESULTS

Of 1857 participants, 322 were women. Women assigned to ATV/r had a higher risk of virologic failure with either nucleoside reverse transcriptase inhibitor backbone than women assigned to EFV, or men assigned to ATV/r. The effects of ATV/r and EFV upon safety and tolerability risk did not differ significantly by sex. With ABC/3TC, women had a significantly higher (32%) safety risk compared to men; with TDF/FTC, the safety risk was 20% larger for women compared to men, but not statistically significant. Women had slower ATV clearance and higher predose levels of ATV compared to men. Self-reported adherence did not differ significantly by sex.

CONCLUSIONS

This is the first randomized clinical trial to identify a significantly earlier time to virologic failure in women randomized to ATV/r compared to women randomized to EFV. This finding has important clinical implications given that boosted protease inhibitors are often favored over EFV in women of childbearing potential.

CLINICAL TRIALS REGISTRATION

NCT00118898.

Racial differences in response to antiretroviral therapy for HIV infection: an AIDS clinical trials group (ACTG) study analysis

BACKGROUND

In the United States, black individuals infected with human immunodeficiency virus (HIV) have higher rates of virologic failure on antiretroviral therapy (ART) and of death compared to white individuals. The cause for these disparities is uncertain. We sought to examine differences in virologic outcomes among antiretroviral-naive clinical trial participants starting randomized ART and to investigate factors to explain the differences.

METHODS

Individual-level data from participants initiating ART in 5 AIDS Clinical Trials Group studies were analyzed. Included studies were those conducted during 1998-2006 with a primary outcome of virologic failure. The primary outcome measure was time to virologic failure, regardless of ART changes.

RESULTS

A total of 2495 individuals (1151 black; 1344 white) were included with a median follow-up of 129 weeks. Compared to whites, blacks had an increased hazard of virologic failure (hazard ratio [HR]; 1.7; 95% confidence interval [CI], 1.4-1.9; P < .001), with no evidence of heterogeneity across regimens (P = .97); the association remained after adjustment for measured confounders (HR, 1.4; 95% CI, 1.2-1.6; P < .001). Increased hazard of virologic failure was associated with younger age, higher pretreatment HIV type 1 RNA level, lower pretreatment CD4 cell count, hepatitis C antibody, less education, and recent nonadherence to treatment. Sensitivity analyses with different endpoint definitions demonstrated similar results.

CONCLUSIONS

In this analysis, blacks had a 40% higher virologic failure risk than whites that was not explained by measured confounders. The observation was consistent over a range of regimens, suggesting that the difference may be driven by social factors; however, biological factors cannot be ruled out. Further research should identify the sources of racial disparities and develop strategies to reduce them.

Community-associated methicillin-resistant Staphylococcus aureus colonization in high-risk groups of HIV-infected patients

BACKGROUND

We examined the epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) nasal colonization among 3 groups of human immunodeficiency virus (HIV)-infected and 1 group of HIV-negative outpatients.

METHODS

We determined prevalence and risk factors associated with MRSA colonization among women, recently incarcerated, and Hispanic HIV-infected patients and HIV-negative patients; isolates were typed by pulsed-field gel electrophoresis. Relative prevalence was calculated using Poisson regression, and logistic regression was used for multivariate analysis.

RESULTS

Of 601 patients, 9.3% were colonized with MRSA; 11% of HIV-infected and 4.2% of HIV-negative patients were colonized (relative prevalence, 2.6; 95% confidence interval [CI], 1.12-6.07; P = .03). Among HIV-infected patients, recently incarcerated patients had the highest colonization prevalence (15.6%) followed by women (12%); Hispanic patients had the lowest (2.8%). Eighty percent of confirmed MRSA isolates were identified as USA300. On multivariate analysis, history of incarceration or residence in alternative housing (odds ratio [OR], 2.3; 95% CI, 1.1-4.7; P = .03) was associated with MRSA colonization; Hispanic ethnicity was negatively associated (OR, 0.3; 95% CI, .11-.98; P = .045). There was a trend (OR, 1.6; 95% CI, .9-3.0; P = .097) toward geographic location of residence being associated with colonization. After controlling for incarceration, residence, and geography, HIV status was no longer significantly associated with colonization.

CONCLUSIONS

The CA-MRSA and HIV epidemics have intersected. Examination of networks of individuals released from incarceration, both HIV positive and negative, is needed to assess the role of social networks in spread of CA-MRSA and inform prevention strategies.

Challenges and successes in linking HIV-infected women to care in the United States

Women currently account for 27% of new human immunodeficiency virus (HIV) infections in the United States, the majority of which are acquired through heterosexual transmission. In the United States, black and Latino persons are disproportionately affected by the HIV epidemic, a disparity that is most dramatically present among HIV-infected women. Many of these women face significant discrimination as a result of race or ethnicity and sex, and they suffer disproportionately from poverty, low health literacy, and lack of access to high-quality HIV care. As a consequence, despite the availability of highly active antiretroviral therapy (HAART), women with HIV often have delayed entry into care and experience poor outcomes. This article reviews risk factors for HIV infection in women, barriers to engagement in care, and strategies to improve linkage to HIV-related medical and social care.

Impact of low abundance HIV variants on response to ritonavir-boosted atazanavir or fosamprenavir given once daily with tenofovir/emtricitabine in antiretroviral-naive HIV-infected patients

Population genotyping (PG) can underestimate resistance if resistance-containing low abundance variants go undetected. PG and clonal analysis (CA) results were compared in virologic failures (VFs) from a 48-week clinical trial that evaluated once-daily fosamprenavir/ritonavir (FPV/r) 1400 mg/100 mg or atazanavir/ritonavir (ATV/r) 300 mg/100 mg, each combined with tenofovir/emtricitabine, in antiretroviral-naive patients. VF was defined as confirmed HIV-1 RNA > or =400 copies/ml at > or =24 weeks or viral rebound >400 copies/ml any time following viral suppression. All patients had baseline PG. One hundred and six patients enrolled (53/arm). Baseline resistance mutations were more prevalent in patients receiving FPV/r (10/53) than ATV/r (3/53). Seven patients (7%) were VFs-four on FPV/r and three on ATV/r. In the four FPV/r-treated VFs, baseline HIV TAMs combinations and/or PI mutations were detected in one by PG at VF (RT: L210W + T215C; PR: M46I + L76V) and three others by CA alone (RT: L210W + T215Y; RT: M41L; RT: K65R + K70R; PR: I47V); all four had study drug-associated mutations (CA detecting more HIV-1 resistance mutations than PG). In the three ATV/r VFs, no baseline drug-associated mutations were detected by PG; for one patient CA detected RT: K65R; PR: I84V. Phylogenetic analysis revealed tight clustering for FPV/r-treated VFs with highly related clones, whereas HIV-1 from ATV/r-treated VFs had no outgrowth from baseline of low abundance resistance-containing variants. In conclusion, low-abundance HIV resistance-containing variants were detected in baseline samples from patients with VF. The archived viruses that reemerged under selection pressure and acquired additional mutations were found primarily in patients in the FPV/r arm. Despite this and a baseline resistance imbalance between the two arms, FPV/r and ATV/r provided similar virologic suppression through 48 weeks; however, these findings highlight the necessity for the development of quick and inexpensive methods for detection of minority species to better guide therapy selection.

Classic pyomyositis of the extremities as an unusual manifestation of Blastomyces dermatitidis: a report of two cases

Pyomyositis is an infection of skeletal muscle that, by definition, arises intramuscularly rather than secondarily from adjacent infection. It is usually associated with bacterial infection, particularly Staphylcococcus aureus. Fungi are rare causes, and Blastomyces dermatitidis has not been reported previously. In this case series, we report two cases of pyomyositis caused by B. dermatitidis. Cases were prospectively identified through routine clinical care at a single academic referral hospital. Two patients with complaints of muscle pain and subacute cough were treated at our hospital in 2007. Both patients were found to have pyomyositis caused by B. dermatitidis- in the quadriceps muscles in one patient, and in the calf muscle in another - by radiological imaging and fungal culture. Both were also diagnosed with pneumonia caused by B. dermatitidis (presumptive in one, confirmed in the other). There was no evidence of infection of adjacent structures, suggesting that the route of infection was likely direct haematogenous seeding of the muscle. A review of the literature confirmed that although B. dermatitidis has been described as causing axial muscle infection secondary to adjacent infection such as vertebral osteomyelitis, our description of isolated muscle involvement (classic pyomyositis) caused by B. dermatitidis, particularly of the extremity muscles, is unique. We conclude that B. dermatitidis is a potential cause of classic pyomyositis.

Fosamprenavir or atazanavir once daily boosted with ritonavir 100 mg, plus tenofovir/emtricitabine, for the initial treatment of HIV infection: 48-week results of ALERT

Background

Once-daily (QD) ritonavir 100 mg-boosted fosamprenavir 1400 mg (FPV/r100) or atazanavir 300 mg (ATV/r100), plus tenofovir/emtricitabine (TDF/FTC) 300 mg/200 mg, have not been compared as initial antiretroviral treatment. To address this data gap, we conducted an open-label, multicenter 48-week study (ALERT) in 106 antiretroviral-naïve, HIV-infected patients (median HIV-1 RNA 4.9 log₁₀ copies/mL; CD4+ count 191 cells/mm³) randomly assigned to the FPV/r100 or ATV/r100 regimens.

Results

At baseline, the FPV/r100 or ATV/r100 arms were well-matched for HIV-1 RNA (median, 4.9 log₁₀ copies/mL [both]), CD4+ count (mean, 176 vs 205 cells/mm³). At week 48, intent-to-treat: missing/discontinuation = failure analysis showed similar responses to FPV/r100 and ATV/r100 (HIV-1 RNA < 50 copies/mL: 75% (40/53) vs 83% (44/53), p = 0.34 [Cochran-Mantel-Haenszel test]); mean CD4+ count change-from-baseline: +170 vs +183 cells/mm³, p = 0.398 [Wilcoxon rank sum test]). Fasting total/LDL/HDL-cholesterol changes-from-baseline were also similar, although week 48 median fasting triglycerides were higher with FPV/r100 (150 vs 131 mg/dL). FPV/r100-treated patients experienced fewer treatment-related grade 2–4 adverse events (15% vs 57%), with differences driven by ATV-related hyperbilirubinemia. Three patients discontinued TDF/FTC because their GFR decreased to <50 mL/min.

Conclusion

The all-QD regimens of FPV/r100 and ATV/r100, plus TDF/FTC, provided similar virologic, CD4+ response, and fasting total/LDL/HDL-cholesterol changes through 48 weeks. Fewer FPV/r100-treated patients experienced treatment-related grade 2–4 adverse events.

Recognizing and managing common toxicities in patients receiving antiretroviral therapy

Each of the 3 traditional classes of antiretroviral drugs (nucleoside/nucleotide reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors [PIs]) has characteristic sets of toxicities that are not found with the other drug classes. On the other hand, lipodystrophy, which was thought to be specific to PIs, is now known to be common to all 3 classes of drugs. An understanding of the drug-specific, class-specific, and general toxicities and side effects of antiretroviral drugs will help the clinician tailor treatment regimens to individual patients.

Evaluation of the impact of highly active antiretroviral therapy on immune recovery in antiretroviral naive patients

OBJECTIVES

To examine the extent of immune reconstitution in treatment-naive patients with CD4 T-cell counts <500 cells/microL following 48 weeks of highly active antiretroviral therapy (HAART).

METHODS

Thirteen antiretroviral naive patients were evaluated longitudinally for 48 weeks on HAART utilizing immune functional and lymphocyte phenotyping assays, including lymphocyte proliferation assay, flow cytometric evaluation of cell surface markers, and delayed type hypersensitivity skin tests. Virologic responses were monitored using commercially available viral load assays and gag/pol mRNA quantification using simultaneous immunophenotyping/UltraSensitive fluorescence in situ hybridization (ViroTect In Cell HIV-1 Detection Kit; Invirion, Frankfort, MI). Thymic function was evaluated for a subset of four patients using real-time polymerase chain reaction (PCR) for T-cell receptor excision circle (TREC) quantification and thymic scans using computerized axial tomography (CT) of the thymus.

RESULTS

HAART initiation resulted in a significant decline in plasma viremia and percentage of infected peripheral blood cells, and a rise in CD4 T cells from a baseline median of 207 cells/microL to a week-48 median of 617 cells/microL. The rise was predominately in CD4 memory cells. Naive T cells also increased in number, but at a slower rate. Activated (HLA-DR CD38) CD4 and CD8 T cells were elevated at baseline (24 and 62%, respectively) and declined by week 48 (17 and 36%, respectively) but did not reach normal levels. The number of Fas CD4 T cells increased from a baseline median of 169 to 381 cells/microL at week 48. Both soluble interleukin (IL)-2 and tumour necrosis factor (TNF) II receptors declined by week 48. HIV p24 lymphocyte proliferation assay responses were transiently detected in three patients. TREC values increased from a median 6400 copies/microg at baseline to a week-48 median value of 26 697 copies/microg.

CONCLUSION

Immune functional reconstitution was not achieved in these HAART naive patients.

Disparities and gaps in HIV research and care

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HIV-1-infected antiretroviral-treated patients with prolonged partial viral suppression: clinical, virologic, and immunologic course

The long-term feasibility of a drug conservation strategy that allows low-level viral replication is unknown. We performed a retrospective study of treated HIV-infected patients with stable detectable viral replication (<10000 copies/mL [low-level viremia]) and compared their clinical, virologic and immunologic courses with those of treated patients with undetectable viremia and viremia (>or=10000 copies/mL [high-level viremia]). Viral reverse transcriptase and protease genotype and HIV-specific CD4 T-cell responses were determined using patient-derived samples. Clinical and immunologic benefits were maintained in patients with partial virologic suppression (<or=10000 copies/mL). Although low-level viral replication under drug pressure led to the accumulation of resistance mutations in most subjects' viruses, most subjects retained susceptibility to drugs in >or=2 classes of antiretroviral medications. HIV-specific CD4+ T-cell immunity was detected in most subjects with low-level and undetectable viremia and may have a role in controlling viremia in the setting of partial suppression.

Optimizing care for African-American HIV-positive patients

The African-American community has been disproportionately affected HIV/AIDS, as noted by higher reported rates of HIV infection, higher proportion of AIDS cases, and more deaths caused by complications of AIDS than whites and other ethnic groups. In addition, epidemiologic trends suggest that African Americans with HIV infection are more often diagnosed later in the course of HIV disease than whites. Numerous reasons account for this disparity, including the lack of perception of risk and knowledge about HIV transmission as well as a delays in HIV testing and diagnosis in the African-American community. Understanding the important considerations in the management of HIV infection in the African-American patient may create awareness among health care professionals and broaden the knowledge of HIV-infected patients within the African-American community.

Role of Baseline pol Genotype in HIV-1 Fitness Evolution

Viral fitness can be modified upon development of antiretroviral drug resistance, usually by selection of compensatory mutations. In this study, we have used HIV-1 isolates from individuals receiving a protease inhibitor (PI)-based regimen to analyze the impact of basal genetic background on viral fitness evolution. Paired plasma samples and HIV-1 isolates were obtained from 10 PI-naive HIV-infected individuals enrolled in 2 different studies of combination antiretroviral therapy. Genomic regions from pol and env were sequenced. Viral fitness was measured using growth competition experiments followed by heteroduplex tracking analysis. Baseline genotypic analyses of pol showed that 9 of 10 viruses had a different degree of secondary mutations in the protease gene at codons associated with PI resistance (i.e., 10I, 36I, 63P, 71T, and 77I). After 48 weeks of PI-based therapy, a strong correlation was observed between protease genetic divergence and viral fitness difference (r = 0.78, P = 0.03), but not with reverse transcription or Env divergence, suggesting that genotypic changes in the protease gene were driving HIV-1 evolution in these patients. As expected, an inverse correlation was observed between the number of protease and reverse transcription primary mutations and viral fitness (r = -0.65, P < 0.0001). However, our results suggest that the preexistence of secondary mutations in protease genetic background may have implications in HIV-1 fitness evolution and virologic response to antiretroviral therapy.

Limited immune restoration after 3 years' suppression of HIV-1 replication in patients with moderately advanced disease

OBJECTIVE

To describe the magnitude of immune restoration after long-term control of HIV-1 replication. DESIGN Prospective study of immune restoration in patients starting highly active antiretroviral therapy (HAART).

METHODS

Patients with moderately advanced HIV-1 infection (CD4 cells between 100 x 10 and 300 x 10 /l) who enrolled in a trial of HAART and who had suppression of HIV-1 replication during 3 years of therapy were evaluated for phenotypic and functional indices of immune restoration.

RESULTS

Almost all immune restoration achieved occurred during the first year. The median CD4 lymphocyte count increased by 159 x 10 cells/l during the first year (P < 0.001); CD4 lymphocyte rises during the second and third years were not significant. Most decreases in activation antigen expression (CD38/HLA-DR) on CD4 and CD8 lymphocytes occurred during the first year, and after 3 years, patient lymphocytes were still abnormally activated. The proportion of CD4 lymphocytes expressing CD28 increased during the first and second years, but even after 3 years, CD28 expression on CD4 cells remained abnormally low. Lymphocyte proliferative responses to normalized during the first 12 weeks of HAART while responses to tetanus increased only after immunization and enhanced responses to HIV-1 p24 antigen were not observed.

CONCLUSIONS

Immune restoration was incomplete in patients who started HAART with moderately advanced HIV-1 disease and most changes occurred during the first year. These data suggest that this degree of suppression of HIV-1 replication alone will not suffice to restore immune competence. The clinical significance of incomplete reconstitution of CD4 lymphocyte number, phenotype, and proliferative function in HIV-1 infection remains to be determined.