Efficacy of second-line dolutegravir plus 2 nucleoside reverse transcriptase inhibitors by baseline nucleoside reverse transcriptase inhibitor resistance and nucleoside reverse transcriptase inhibitor use in the DAWNING study

Background

In the DAWNING study, dolutegravir + 2 nucleoside reverse transcriptase inhibitors (NRTIs) demonstrated superior efficacy at Week 48 and a favourable safety profile compared with lopinavir/ritonavir + 2 NRTIs in adults with HIV-1 failing first-line therapy of a non-nucleoside reverse transcriptase inhibitor + 2 NRTIs.

Methods

Participants at 58 centres in 13 countries were randomised (1:1) to 52 weeks of open-label treatment with dolutegravir or lopinavir/ritonavir combined with 2 investigator-selected NRTIs, including at least one fully active NRTI based on screening resistance testing. The primary endpoint was the proportion of participants achieving HIV-1 RNA <50 copies/ml at Week 48 (Snapshot algorithm). Post-hoc efficacy analyses were performed based on baseline NRTI resistance profile and second-line NRTI use.

Results

Of 624 participants randomised and treated, 499 (80%) received <2 active NRTIs at Baseline. NRTI resistance was present in 561 participants (90%). Among participants receiving lamivudine or emtricitabine in the presence of M184V/I, 85% (187/220) of participants on dolutegravir versus 72% (152/210) on lopinavir/ritonavir had HIV-1 RNA <50 copies/ml at Week 48 (difference, 12.6%; 95% CI: 4.9–20.3%). High responses were also observed in the dolutegravir group, when zidovudine or tenofovir disoproxil fumarate were included in the background regimen in the presence of thymidine analogue mutations or K65R, respectively; however, participant numbers in these subgroups were small.

Conclusions

Response rates were high in participants receiving dolutegravir + 2 NRTIs as second-line treatment regardless of pre-existing resistance to one of the NRTIs, including in participants using lamivudine or emtricitabine in the presence of M184V/I.

Pharmacokinetics, Safety, and Tolerability of a Single Oral Dose of Abacavir/Dolutegravir/Lamivudine Combination Tablets in Healthy Japanese Study Participants

Pharmacokinetics, safety, and tolerability of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg were assessed in this phase 1, single‐arm, open‐label, single‐dose study in fasted healthy male (n = 4) and female (n = 8) participants of Japanese heritage. Participants received a single dose of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg after an 8‐hour fast, with safety assessments and blood samples for pharmacokinetic parameters collected through 72 hours after dosing. Geometric mean maximum plasma concentrations were 5.22 μg/mL (time to maximum concentration [t_max], 1.01 hours) for abacavir, 4.13 μg/mL (t_max, 3.50 hours) for dolutegravir, and 3.35 μg/mL (t_max, 2.98 hours) for lamivudine. Geometric mean area under the concentration‐time curve values were 18.20, 71.60, and 16.60 μg • h/mL for abacavir, dolutegravir, and lamivudine, respectively. No adverse events were reported, and no clinically significant findings were observed in laboratory values, physical examinations, or 12‐lead electrocardiographic parameters. Single‐tablet administration of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg was well tolerated in Japanese participants. Exposure to abacavir and lamivudine was comparable with that seen in previous studies. A modest increase in exposure to dolutegravir vs previous clinical studies was observed but is not expected to impact the clinical management of HIV‐1 or increase the risk for adverse events.

Abacavir Use and Risk for Myocardial Infarction and Cardiovascular Events: Pooled Analysis of Data From Clinical Trials

Background

Some observational studies and randomized controlled trials (RCTs) have suggested an association between abacavir (ABC) use and myocardial infarction (MI), whereas others have not.

Methods

This pooled analysis of 66 phase II–IV RCTs estimates exposure-adjusted incidence rates (IRs) and relative rates (RRs) of MI and cardiovascular events (CVEs) in participants receiving ABC- and non-ABC-containing combination antiretroviral therapy (cART). The primary analysis of MI included ABC-randomized trials with ≥48-week follow-up. Sensitivity analyses of MI and CVEs included non-ABC-randomized and <48-week follow-up trials.

Results

In 66 clinical trials, 13 119 adults (75% male, aged 18–85 years) were on ABC-containing cART and 7350 were not. Exposure-adjusted IR for MI was 1.5 per 1000 person-years (PY; 95% confidence interval [CI], 0.67–3.34) in the ABC-exposed group and 2.18 per 1000 PY (95% CI, 1.09–4.40) in the unexposed group. The IR for CVEs was 2.9 per 1000 PY (95% CI, 2.09–4.02) in the exposed group and 4.69 per 1000 PY (95% CI, 3.40–6.47) in the unexposed group with studies of ≥48 weeks of follow-up, with an RR of 0.62 (95% CI, 0.39–0.98). The inclusion of nonrandomized and shorter-duration trials did not significantly change the RR for MI or coronary artery disease.

Conclusions

This pooled analysis found comparable IRs for MI and CVEs among ABC-exposed and -unexposed participants, suggesting no increased risk for MI or CVEs following ABC exposure in a clinical trial population. Modifiable risk factors for MI and CVEs should be addressed when prescribing ART.

Dolutegravir/abacavir/lamivudine versus current ART in virally suppressed patients (STRIIVING): a 48-week, randomized, non-inferiority, open-label, Phase IIIb study

BACKGROUND

Simplified dosing regimens are important for patients who face challenges in adhering to HIV-1 therapy. We investigated the safety and virological efficacy of switching to once-daily abacavir/dolutegravir/lamivudine (ABC/DTG/3TC).

METHODS

The STRIIVING study was a randomized, open-label, Phase IIIb study in adults with HIV-1 RNA <50 copies/ml on antiretroviral therapy (ART) at enrolment (ClinicalTrials.gov identifier, NCT02105987). Subjects were randomly assigned to switch to ABC/DTG/3TC once daily for 48 weeks (early-switch group) or continue current ART for 24 weeks and then switch to ABC/DTG/3TC (late-switch group). The primary end point was the proportion of subjects with HIV-1 RNA <50 copies/ml at week 24.

RESULTS

Of 553 subjects enrolled, 275 were randomly assigned to switch immediately to ABC/DTG/3TC and 278 continued on current ART. At week 24, 85% and 88% of subjects who switched to ABC/DTG/3TC or remained on current ART, respectively, were virologically suppressed, indicating that ABC/DTG/3TC was non-inferior (difference in proportion, -3.4%; 95% CI -9.1, 2.4). At week 48, 83% and 92% were virologically suppressed in the early- and late-switch groups, respectively. Adverse events were reported more frequently with ABC/DTG/3TC (66%) than with current ART (47%) by week 24, and in the late-switch group, 60% of subjects reported adverse events post-switch. Pharmacokinetic data supported immediate switch. HIV Treatment Satisfaction Questionnaire scores improved in participants switching to ABC/DTG/3TC versus current ART.

CONCLUSIONS

Data demonstrating non-inferiority of switching to ABC/DTG/3TC versus continuing current ART support ABC/DTG/3TC as an option when considering switch regimens in HIV-1-infected adults with stable viral suppression.