Long-term Efficacy, Safety, and Durability of Cabotegravir and Rilpivirine as 2-Drug Oral Maintenance Therapy After 6 Years of Study

Background

In the LATTE study, daily oral cabotegravir + rilpivirine demonstrated higher rates of efficacy than efavirenz + 2 nucleoside reverse-transcriptase inhibitors (NRTIs) through Week 96 in antiretroviral therapy (ART)-naive adults with human immunodeficiency virus (HIV)-1. We present the results from 6 years of continued treatment with oral cabotegravir + rilpivirine.

Methods

LATTE was a phase IIb, randomized, multicenter, partially blinded, dose-ranging study in ART-naive adults with HIV-1. After a 24-week induction phase with cabotegravir + 2 NRTIs, participants with HIV-1 ribonucleic acid (RNA) <50 copies/mL were randomized to receive cabotegravir (10, 30, or 60 mg) + rilpivirine (25 mg) in the maintenance phase through Week 96 and switched to cabotegravir 30 mg + rilpivirine 25 mg in the open-label phase through Week 312.

Results

Of 160 participants who entered the maintenance phase, 111 completed the study at Week 312. At Week 312, 105 (66%) participants maintained HIV-1 RNA <50 copies/mL, 15 (9%) had HIV-1 RNA ≥50 copies/mL, and 40 (25%) had no virologic data. Eight participants met protocol-defined virologic failure criteria through Week 312, 2 of whom met protocol-defined virologic failure criteria after Week 144. Six participants developed treatment-emergent resistance to 1 or both agents during the study, 3 of whom developed integrase inhibitor resistance substitutions. Two participants (1%) reported drug-related serious adverse events. Few adverse events led to withdrawal during the open-label phase (n = 5, 3%).

Conclusions

Oral cabotegravir + rilpivirine demonstrated efficacy in the majority of participants and an acceptable safety profile through 6 years of treatment, demonstrating its durability as maintenance therapy for HIV-1.

A Randomized Trial of Bictegravir or Dolutegravir with Emtricitabine and Tenofovir Alafenamide (F/TAF) Followed by Open Label Switch to Bictegravir/F/TAF Fixed Dose Combination

Background

Integrase strand transfer inhibitors (INSTIs) are widely recommended for initial HIV-1 treatment. Bictegravir (BIC, B) is a novel, once-daily INSTI with potent antiviral activity being developed in coformulation with emtricitabine and tenofovir alafenamide (F/TAF).

Methods

In this Phase 2 study, treatment naïve, HIV-infected adults were randomized 2:1 to receive blinded treatment with BIC or dolutegravir (DTG) coadministered with open label F/TAF (200/25 mg). After all participants completed 48 weeks, they were unblinded and switched to a single fixed-dose combination tablet of B/F/TAF 50/200/25 mg. The proportion of participants with HIV-1 RNA <50 copies/mL (c/mL) was assessed at Week (W) 24 and W48 of the blinded phase and 12 weeks after switching to open label B/F/TAF (W72).

Results

Of 98 participants enrolled in the blinded treatment phase, 65 were randomized to BIC+F/TAF and 33 to DTG+F/TAF. Most were male, had asymptomatic HIV infection, with median HIV-1 RNA 4.4–4.5 log₁₀ c/mL. The proportion of subjects with HIV-1 RNA <50 c/mL at W24 was 97% for the BIC arm and 94% for the DTG arm, and at W48 was 97% and 91%, respectively (Table). All 92 participants who completed the blinded phase were switched to B/F/TAF at W60. At W72 or 12 weeks after switching to open-label B/F/TAF, 99% (91/92) maintained HIV-1 RNA <50 c/mL (98% prior BIC arm [N = 62]; 100% prior DTG arm [N = 30]) and one individual withdrew prior to the analysis. No viral resistance was detected in participants treated with BIC. No participants discontinued open label B/F/TAF due to an adverse event, there were no treatment-related serious adverse events and no deaths. One individual on BIC previously discontinued due to an adverse event of urticaria following the W24 visit.

Conclusion

All participants switched from DTG+F/TAF to open-label B/F/TAF maintained virologic suppression, with none discontinuing due to adverse events. During 72 weeks of follow-up, no treatment-emergent resistance to any components was detected in participants taking B/F/TAF. B/F/TAF demonstrated durable virologic suppression in naïve patients through W72 and was safe and effective after switching from DTG + F/TAF, further study in treatment naïve and experienced populations is warranted.

Disclosures

P. E. Sax, Gilead: Consultant and Investigator, Consulting fee, Research grant and Research support; BMS: Consultant and Investigator, Consulting fee, Research grant and Research support; GlaxoSmithKline/ViiV: Consultant and Investigator, Consulting fee, Research grant and Research support; AbbVie: Consultant, Consulting fee; Janssen: Consultant, Consulting fee; Merck: Consultant, Consulting fee; E. Dejesus, Gilead Sciences: Consultant, Investigator and Speaker’s Bureau, Consulting fee and Speaker honorarium; Janssen: Consultant, Investigator and Speaker’s Bureau, Consulting fee and Speaker honorarium; G. Crofoot, Gilead: Investigator and Scientific Advisor, Advisory honorarium and Research grant; ViiV: Investigator and Scientific Advisor, Advisory honorarium, Research grant and Research support; D. Ward, Gilead: Investigator, Research support; P. Benson, Gilead Sciences: Investigator, Shareholder and Speaker’s Bureau, Research support and Speaker honorarium; ViiV Healthcare: Investigator, Research support; L. Wei, Gilead: Employee and Shareholder, Salary; K. White, Gilead Sciences, Inc.: Employee and Shareholder, Salary; S. Collins, Gilead: Employee and Shareholder, Salary; H. Martin, Gilead Sciences: Employee, Salary; A. Cheng, Gilead: Employee and Shareholder, Salary; E. Quirk, Gilead: Employee and Shareholder, Salary

Long-term treatment with raltegravir or efavirenz combined with tenofovir/emtricitabine for treatment-naive human immunodeficiency virus-1-infected patients: 156-week results from STARTMRK

BACKGROUND

We compared 3 years of antiretroviral therapy with raltegravir or efavirenz as part of a combination regimen in the ongoing STARTMRK study of treatment-naive patients infected with human immunodeficiency virus (HIV).

METHODS

Eligible patients with HIV-1 RNA (vRNA) levels >5000 copies/mL and without baseline resistance to efavirenz, tenofovir, or emtricitabine were randomized in a double-blind, noninferiority study to receive raltegravir or efavirenz, each combined with tenofovir/emtricitabine. Outcomes included viral suppression, adverse events, and changes from baseline metabolic parameters. Dual energy X-ray absorptiometry scans were obtained on a convenience sample of patients at prespecified time points to assess changes in body fat composition.

RESULTS

At week 156 counting noncompleters as failures, 212 (75.4%) of 281 versus 192 (68.1%) of 282 had vRNA levels <50 copies/mL in the raltegravir and efavirenz groups, respectively [Δ (95% CI) = 7.3% (-0.2, 14.7), noninferiority P < .001]. Mean changes from baseline CD4 count were 332 and 295 cells/mm³ in the raltegravir and efavirenz arms, respectively [Δ (95% CI) = 37 (4, 69)]. Consistent virologic and immunologic efficacy was maintained across prespecified demographic and baseline prognostic subgroups for both treatment groups. Fewer drug-related clinical adverse events (49% vs 80%; P < .001) occurred in raltegravir than efavirenz recipients, with discontinuations due to adverse events in 5% and 7%, respectively. Elevations in fasting lipid levels (including LDL- and HDL-cholesterol) were consistently lower in the raltegravir than efavirenz group (P < .005). Fat gain was 19% in 25 raltegravir recipients and 31% in 32 efavirenz recipients at week 156.

CONCLUSIONS

When combined with tenofovir/emtricitabine in treatment-naive patients, raltegravir produced durable viral suppression and immune restoration that was at least equivalent to efavirenz through 156 weeks of therapy. Both regimens were well tolerated, but raltegravir was associated with fewer drug-related clinical adverse events and smaller elevations in lipid levels. Clinical Trials Registration. NCT00369941.

Non-nucleoside reverse transcriptase inhibitor (NNRTI) cross-resistance: implications for preclinical evaluation of novel NNRTIs and clinical genotypic resistance testing

OBJECTIVES

The introduction of two new non-nucleoside reverse transcriptase inhibitors (NNRTIs) in the past 5 years and the identification of novel NNRTI-associated mutations have made it necessary to reassess the extent of phenotypic NNRTI cross-resistance.

METHODS

We analysed a dataset containing 1975, 1967, 519 and 187 genotype-phenotype correlations for nevirapine, efavirenz, etravirine and rilpivirine, respectively. We used linear regression to estimate the effects of RT mutations on susceptibility to each of these NNRTIs.

RESULTS

Sixteen mutations at 10 positions were significantly associated with the greatest contribution to reduced phenotypic susceptibility (≥10-fold) to one or more NNRTIs, including: 14 mutations at six positions for nevirapine (K101P, K103N/S, V106A/M, Y181C/I/V, Y188C/L and G190A/E/Q/S); 10 mutations at six positions for efavirenz (L100I, K101P, K103N, V106M, Y188C/L and G190A/E/Q/S); 5 mutations at four positions for etravirine (K101P, Y181I/V, G190E and F227C); and 6 mutations at five positions for rilpivirine (L100I, K101P, Y181I/V, G190E and F227C). G190E, a mutation that causes high-level nevirapine and efavirenz resistance, also markedly reduced susceptibility to etravirine and rilpivirine. K101H, E138G, V179F and M230L mutations, associated with reduced susceptibility to etravirine and rilpivirine, were also associated with reduced susceptibility to nevirapine and/or efavirenz.

CONCLUSIONS

The identification of novel cross-resistance patterns among approved NNRTIs illustrates the need for a systematic approach for testing novel NNRTIs against clinical virus isolates with major NNRTI-resistance mutations and for testing older NNRTIs against virus isolates with mutations identified during the evaluation of a novel NNRTI.

Sofosbuvir (GS-7977) plus peginterferon/ribavirin in treatment-naïve patients with HCV genotype 1: a randomized, 28-day, dose-ranging trial

BACKGROUND & AIMS

Sofosbuvir (formerly GS-7977) is a pyrimidine nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B polymerase. We assessed the safety, tolerability, antiviral activity, and pharmacokinetics of sofosbuvir plus pegylated-interferon (PegIFN)/ribavirin (RBV) in a 28-day, dose-ranging trial in treatment-naïve patients infected with genotype 1 HCV.

METHODS

In this double-blind study, 64 patients were randomized (1:1:1:1) to receive one of three once-daily doses of oral sofosbuvir (100, 200, or 400mg) or placebo plus PegIFN/RBV for 28 days, after which all patients continued to receive PegIFN/RBV alone for a further 44 weeks.

RESULTS

Patients in the sofosbuvir/PegIFN/RBV groups experienced mean reductions in HCV RNA >5 log₁₀ IU/ml (-5.3 for 100 mg, -5.1 for 200 mg and -5.3 for 400 mg) vs. -2.8 log₁₀ IU/ml for placebo/PegIFN/RBV after 28 days. Rapid virologic response (RVR) rates were markedly higher after sofosbuvir treatment (88-94%) than placebo (21%), as were rates of sustained virologic response (SVR) at post-treatment Week 24 (56%, 83%, and 80% for sofosbuvir 100, 200, and 400 mg, respectively, vs. 43% for placebo). The number of patients experiencing virologic breakthrough and post-treatment relapse was higher in the sofosbuvir 100 mg group than sofosbuvir 200 and 400 mg groups. Sofosbuvir was well tolerated; the most frequent adverse events were fatigue and nausea.

CONCLUSIONS

These results support further studies with sofosbuvir at 200 mg and 400 mg to determine the optimal dose and treatment duration of sofosbuvir in HCV genotype 1.

Sofosbuvir in combination with peginterferon alfa-2a and ribavirin for non-cirrhotic, treatment-naive patients with genotypes 1, 2, and 3 hepatitis C infection: a randomised, double-blind, phase 2 trial

BACKGROUND

Protease inhibitors have improved treatment of infection with hepatitis C virus (HCV), but dosing, a low barrier to resistance, drug interactions, and side-effects restrict their use. We assessed the safety and efficacy of sofosbuvir, a uridine nucleotide analogue, in treatment-naive patients with genotype 1-3 HCV infection.

METHODS

In this two-cohort, phase 2 trial, we recruited treatment-naive patients with HCV genotypes 1-3 from 22 centres in the USA. All patients were recruited between Aug 16, 2010, and Dec 13, 2010, and were eligible for inclusion if they were aged 18-70 years, had an HCV RNA concentration of 50,000 IU/mL or greater, and had no cirrhosis. We randomly allocated all eligible patients with HCV genotype 1 (cohort A) to receive sofosbuvir 200 mg, sofosbuvir 400 mg, or placebo (2:2:1) for 12 weeks in combination with peginterferon (180 μg per week) and ribavirin (1000-1200 mg daily), after which they continued peginterferon and ribavirin for an additional 12 weeks or 36 weeks (depending on viral response). Randomisation was done by use of a computer-generated randomisation sequence and patients and investigators were masked to treatment allocation until week 12. Patients with genotypes 2 or 3 (cohort B) received open-label sofosbuvir 400 mg plus peginterferon and ribavirin for 12 weeks. Our primary outcomes were safety and tolerability. Secondary efficacy analyses were by intention to treat and endpoints included sustained virological response, defined as undetectable HCV RNA at post-treatment weeks 12 and 24. This study is registered with ClinicalTrials.gov, number NCT01188772.

FINDINGS

In cohort A, 122 patients were assigned 200 mg sofosbuvir (48 patients), 400 mg sofosbuvir (48), or placebo (26). We enrolled 25 patients into cohort B. The most common adverse events--fatigue, headache, nausea, and chills--were consistent with those associated with peginterferon and ribavirin. Eight patients discontinued treatment due to adverse events, two (4%) receiving sofosbuvir 200 mg, three (6%) receiving sofosbuvir 400 mg, and three (12%) receiving placebo. In cohort A, HCV RNA was undetectable at post-treatment week 12 in 43 (90%; 95% CI 77-97) of 48 patients in the 200 mg sofosbuvir group; 43 (91%; 80-98) of 47 patients in the 400 mg sofosbuvir group, and 15 (58%; 37-77) of 26 patients in the placebo group. In cohort B, 23 (92%) of 25 patients had undetectable HCV RNA at post-treatment week 12.

INTERPRETATION

Our findings lend support to the further assessment, in phase 2 and 3 trials, of sofosbuvir 400 mg plus peginterferon and ribavirin for 12 weeks in treatment-naive patients with HCV genotype-1.

FUNDING

Gilead Sciences.

IDX184 in combination with pegylated interferon-α2a and ribavirin for 2 weeks in treatment-naive patients with chronic hepatitis C

BACKGROUND

IDX184 is a liver-targeted nucleotide prodrug that selectively inhibits HCV NS5B polymerase.

METHODS

This randomized, double-blind, placebo-controlled, ascending-dose study investigated the antiviral activity, safety and pharmacokinetics of IDX184 plus pegylated interferon-α2a and ribavirin (P/R) in treatment-naive patients with genotype-1 HCV. A total of 81 patients with baseline HCV RNA≥5 log10 IU/ml, alanine aminotransferase ≤3× upper limit of normal and compensated liver disease were dosed. Sequential cohorts of 20 patients, randomized 16:4 (active:placebo), received IDX184 for 14 days at rising daily doses of 50, 100, 150 or 200 mg in combination with P/R for 14 days.

RESULTS

At the end of triple dosing, HCV RNA changes from baseline (mean ±sd log10) and proportion of patients achieving undetectable viral load (<15 IU/ml) based on the efficacy-evaluable population were -2.7 ±1.3 (13%), -4.0 ±1.7 (50%), -4.2 ±1.9 (50%), -4.1 ±1.2 (40%), -4.3 ±1.5 (29%) and -3.7 ±1.2 (25%) for the 50 mg once daily, 50 mg twice daily, 100 mg once daily, 150 mg once daily, 100 mg twice daily and 200 mg once daily IDX184 doses, respectively. P/R alone resulted in a reduction of -1.5 ±1.3 log10 with only 6% of patients with undetectable viral load. Patients with genotypes-1a or -1b responded similarly. No viral breakthrough or resistance associated with IDX184 was observed. Anti-HCV activity of IDX184 correlated with plasma exposure of its nucleoside metabolite 2'-methylguanosine. Most adverse events were mild or moderate in severity and were consistent with those associated with P/R. The most common adverse events were fatigue and headache.

CONCLUSIONS

IDX184 in combination with P/R for 14 days was well tolerated and demonstrated greater antiviral activity with more patients achieving undetectable viral load than P/R.

A randomised comparison of safety and efficacy of nevirapine vs. atazanavir/ritonavir combined with tenofovir/emtricitabine in treatment-naïve patients

BACKGROUND

We report data from NEWART, a randomised phase 4 clinical trial comparing virologic efficacy and safety of nevirapine (NVP) vs. ritonavir-boosted atazanavir (ATV/r) on a background of tenofovir/emtricitabine (TDF/FTC) in HIV-1-infected treatment-naïve patients. This study enrolled patients according to CD4-based initiation criteria for NVP (<250 cells/mm(3) for women and <400 cells/mm(3) for men), to reduce the likelihood of symptomatic hepatic events. NEWART was designed to support and confirm results from ARTEN, an international trial with similar design and study endpoints.

METHODS

A total of 152 patients were randomised 1 : 1 to open-label NVP 200 mg twice daily or ATV/r (300/100 mg) once daily, plus once daily TDF/FTC (300/200 mg). All participants met CD4(+) guidelines at entry. The primary endpoint for non-inferiority was virologic response prior to and at week 48 (confirmed HIV plasma viral load <50 copies/ml, without rebound or change in ARVs). Safety data, including plasma lipids, were recorded throughout the study.

RESULTS

The primary endpoint was achieved in 46/75 (61.3%) and 50/77 (64.9%) of patients taking NVP and ATV/r, respectively. Frequency of adverse events (AEs) was similar between arms, with 88.0% of NVP-treated patients and 94.8% of ATV/r-treated patients experiencing at least one AE. Nine patients (12%) in each arm experienced an AE that led to discontinuation. At week 48, a significantly greater increase was seen in mean plasma HDL cholesterol (HDL-C) in the NVP arm (9.6 mg/dl) vs. the ATV/r arm (3.5 mg/dl); p = 0.016. Also, total cholesterol (TC):HDL-C ratio on-treatment was -0.38 and -0.02 for the NVP and ATV/r arms, respectively (p = 0.038).

CONCLUSIONS

Efficacy results were consistent with the ARTEN study demonstrating that NVP was non-inferior to ATV/r when taken in combination with TDF/FTC. Rates of AEs were similar between the two arms, whereas HDL-C increased and TC:HDL-C decreased significantly more in patients taking NVP than ATV/r.

Randomized comparison of metabolic and renal effects of saquinavir/r or atazanavir/r plus tenofovir/emtricitabine in treatment-naïve HIV-1-infected patients

OBJECTIVES

The aim of the study was to compare the effects on lipids, body composition and renal function of once-daily ritonavir-boosted saquinavir (SQV/r) or atazanavir (ATV/r) in combination with tenofovir/emtricitabine (TDF/FTC) over 48 weeks.

METHODS

An investigator-initiated, randomized, open-label, multinational trial comparing SQV/r 2000/100 mg and ATV/r 300/100 mg once daily, both in combination with TDF/FTC, in 123 treatment-naïve HIV-1-infected adults was carried out. The primary endpoint was to demonstrate noninferiority of SQV/r compared with ATV/r with respect to the change in fasting cholesterol after 24 weeks. Secondary outcome measures were changes in metabolic abnormalities, body composition, renal function, and virological and immunological efficacy over 48 weeks. Patients who had used at least one dose of trial drug were included in the analysis.

RESULTS

Data for 118 patients were analysed (57 patients on SQV/r and 61 on ATV/r). At week 24, changes in lipids were modest, without increases in triglycerides, including a significant rise in high-density lipoprotein (HDL) cholesterol and a nonsignificant decrease in the total:HDL cholesterol ratio in both arms with no significant difference between arms. Lipid changes at week 48 were similar to the changes observed up to week 24, with no significant change in the homeostasis model assessment (HOMA) index. Adipose tissue increased regardless of the regimen, particularly in the peripheral compartment and to a lesser extent in the central abdominal compartment, with an increase in adipose tissue reaching statistical significance in the ATV/r arm. A slight decline in the estimated glomerular filtration rate (eGFR) was observed in both arms during the first 24 weeks, with no progression thereafter. The immunological and virological responses were similar over the 48 weeks.

CONCLUSIONS

Combined with TDF/FTC, both SQV/r 2000/100 mg and ATV/r 300/100 mg had comparable modest effects on lipids, had little effect on glucose metabolism, conserved adipose tissue, and similarly reduced eGFR. The virological efficacy was similar.

Similar efficacy of raltegravir when used with or without a protease inhibitor in treatment-experienced patients

BACKGROUND

Patients with multiclass-resistant HIV-1 have limited treatment options. Raltegravir, an inhibitor of integrase, has shown excellent efficacy when used with protease inhibitors (Pis) in patients with drug-resistant HIV-1. Limited data are available however about the outcomes when using raltegravir without Pis in this population.

METHODS

Medical records of subjects who received raltegravir as part of the Merck EAP study 0518 were reviewed and abstracted at participating sites. Eligibility criteria included HIV positivity, age ≥ 16 years, limited or no treatment options due to resistance or intolerance to multiple antiretroviral regimens, detectable viremia on current treatment regimen, and documented resistance to at least one drug in each antiretroviral class (PI, NNRTI, and nucleoside analogue). Demographic, clinical, and laboratory data were collected locally using a standardized collection form. Genotypic susceptibility scores (GSS) were determined from the most recent genotypic resistance test available prior to the initiation of raltegravir. The main objective was to compare virologic results in patients who received raltegravir with a PI versus those who received raltegravir without a PI.

RESULTS

Four hundred forty-two subjects were evaluated from the respective sites in the EAP trial, of whom 340 were evaluable. The baseline mean HIV RNA was 4.6 log copies/ mL, and the mean CD4 cell count was 159 cells/μL. The median number of total and new antiretroviral agents in the background regimen was 4 and 2, respectively. Among the 254 patients who received a PI, the most common PI used was darunavir (89%). Etravirine was commonly used in both groups: 39% of the PI group and 67% of the non-PI group. At week 12, 67% of PI patients and 64% of non-PI patients achieved HIV RNA <75 copies/mL and 85% and 86%, respectively, achieved HIV RNA <400 copies/mL GSS, which was similar in both groups at baseline, predicted achieving an HIV RNA of <400 and 75 copies/mL at week 12 (P < .05).

CONCLUSIONS

In treatment-experienced patients, the combination of raltegravir with a regimen not containing a PI (used with etravirine in two-thirds of patients) had similar virologic activity when compared to more standard regimens using raltegravir with a PI. The main determinant of efficacy was the number of active drugs as measured by GSS. These data expand the potential utility of raltegravir in patients with multidrug-resistant HIV.

A pilot study of abacavir/lamivudine and raltegravir in antiretroviral-naïve HIV-1-infected patients: 48-week results of the SHIELD trial

PURPOSE

to evaluate raltegravir plus abacavir/lamivudine in antiretroviral-naïve, HIV-1-infected patients.

METHODS

SHIELD is an ongoing 96-week pilot study of abacavir/lamivudine 600 mg/300 mg once daily with raltegravir 400 mg twice daily among HLA-B*5701-negative adults with screening viral load (VL) > 1,000 copies/mL. HBsAg+ patients were excluded, as were patients with key mutation(s) to any study drug. Virologic failure (VF) was defined as either VL > 400 copies/mL at week 24 or confirmed virologic rebound.

RESULTS

thirty-five patients enrolled (mean age 38.7 years). Most were white males, but 26% self-identified as Hispanic/Latino. At baseline, 34% had VL ≥ 100,000 copies/mL (median, 4.8 log10 copies/mL) and 20% had CD4 cell counts <200 cells/mm3 (median, 301). One patient discontinued due to adverse events (AEs); one patient experienced VF. At week 48, 91% (32/35) had VL <50 and <400 copies/mL by missing/discontinuation equals failure analysis. Median CD4 cell count change from baseline was +247 cells/mm3. Five patients (14%) had treatment-related grade 2-4 AEs; no treatment-related serious AEs were reported. Over 48 weeks, median fasting lipids increased for total (+17%), LDL (+9%), and HDL (+6%) cholesterol but remained stable for triglycerides (-1%) and total:HDL cholesterol ratio (0%).

CONCLUSIONS

in this pilot study, abacavir/lamivudine plus raltegravir was effective and generally well-tolerated over 48 weeks with modest changes in fasting lipids.

Efficacy and Safety of Abacavir/Lamivudine/Zidovudine Plus Tenofovir in HBV/HIV-1 Coinfected Adults: 48-Week Data

In HBV/HIV-coinfected patients, the risk of end-stage liver disease and death is increased. This open-label, prospective, pilot study evaluated abacavir/lamivudine/zidovudine twice daily plus tenofovir once daily in HBV/HIV-coinfected antiretroviral-naïve subjects. Nine adults (8 males) enrolled, with baseline mean HIV-1 RNA = 4.5 log₁₀ copies/mL, HBV DNA = 9.0 log₁₀ copies/mL, and median CD4 count =158 cells/mm³. No subject had baseline ALT >5x ULN.

Six subjects completed the study: 1 withdrew due to non-treatment-related toxoplasmosis and 2 were lost-to-follow-up. At week 48, 100% (6/6) of remaining subjects had ≥2 log₁₀ decrease in HBV DNA, and 100% (6/6) and 83% (5/6) had HIV-1 RNA <400 and <50 copies/mL, respectively. Median change from baseline in CD4 count was 157 cells/mm³. One subject experienced treatment-related grade 3 leukopenia. These results demonstrate that abacavir/lamivudine/zidovudine and tenofovir were well tolerated with sustained HIV-1 and HBV antiviral activity through 48 weeks in HBV/HIV-coinfected, antiretroviral-naïve subjects.

Raltegravir versus Efavirenz regimens in treatment-naive HIV-1-infected patients: 96-week efficacy, durability, subgroup, safety, and metabolic analyses

BACKGROUND

We analyzed the 96-week results in the overall population and in prespecified subgroups from the ongoing STARTMRK study of treatment-naive HIV-infected patients.

METHODS

Eligible patients with HIV-1 RNA (vRNA) levels >5000 copies per milliliter and without baseline resistance to efavirenz, tenofovir, or emtricitabine were randomized in a double-blind noninferiority study to receive raltegravir or efavirenz, each combined with tenofovir/emtricitabine.

RESULTS

At week 96 counting noncompleters as failures, 81% versus 79% achieved vRNA levels <50 copies per milliliter in the raltegravir and efavirenz groups, respectively [Delta (95% confidence interval) = 2% (-4 to 9), noninferiority P < 0.001]. Mean change in baseline CD4 count was 240 and 225 cells per cubic millimeter in the raltegravir and efavirenz groups, respectively [Delta (95% confidence interval) = 15 (-13 to 42)]. Treatment effects were consistent across prespecified baseline demographic and prognostic subgroups. Fewer drug-related clinical adverse events (47% versus 78%; P < 0.001) occurred in raltegravir than efavirenz recipients. Both regimens had modest effects on serum lipids and glucose levels and on body fat composition.

CONCLUSIONS

When combined with tenofovir/emtricitabine in treatment-naive patients, raltegravir exhibited durable antiretroviral activity that was noninferior to the efficacy of efavirenz through 96 weeks of therapy. Subgroup analyses were generally consistent with the overall findings. Both regimens were well tolerated.

Switch to a raltegravir-based regimen versus continuation of a lopinavir-ritonavir-based regimen in stable HIV-infected patients with suppressed viraemia (SWITCHMRK 1 and 2): two multicentre, double-blind, randomised controlled trials

BACKGROUND

To reduce lipid abnormalities and other side-effects associated with antiretroviral regimens containing lopinavir-ritonavir, patients might want to switch one or more components of their regimen. We compared substitution of raltegravir for lopinavir-ritonavir with continuation of lopinavir-ritonavir in HIV-infected patients with stable viral suppression on lopinavir-ritonavir-based combination therapy.

METHODS

The SWITCHMRK 1 and 2 studies were multicentre, double-blind, double-dummy, phase 3, randomised controlled trials. HIV-infected patients aged 18 years or older were eligible if they had documented viral RNA (vRNA) concentration below the limit of assay quantification for at least 3 months while on a lopinavir-ritonavir-based regimen. 707 eligible patients were randomly allocated by interactive voice response system in a 1:1 ratio to switch from lopinavir-ritonavir to raltegravir (400 mg twice daily; n=353) or to remain on lopinavir-ritonavir (two 200 mg/50 mg tablets twice daily; n=354), while continuing background therapy consisting of at least two nucleoside or nucleotide reverse transcriptase inhibitors. Primary endpoints were the mean percentage change in serum lipid concentrations from baseline to week 12; the proportion of patients with vRNA concentration less than 50 copies per mL at week 24 (with all treated patients who did not complete the study counted as failures) with a prespecified non-inferiority margin of -12% for each study; and the frequency of adverse events up to 24 weeks. Analyses were done according to protocol. These trials are registered with ClinicalTrials.gov, numbers NCT00443703 and NCT00443729.

FINDINGS

702 patients received at least one dose of study drug and were included in the efficacy and safety analyses for the combined trials (raltegravir, n=350; lopinavir-ritonavir, n=352). Percentage changes in lipid concentrations from baseline to week 12 were significantly greater (p<0.0001) in the raltegravir group than in the lopinavir-ritonavir group in each study, yielding combined results for total cholesterol -12.6%vs 1.0%, non-HDL cholesterol -15.0%vs 2.6%, and triglycerides -42.2%vs 6.2%. At week 24, 293 (84.4%, 95% CI 80.2-88.1) of 347 patients in the raltegravir group had vRNA concentration less than 50 copies per mL compared with 319 (90.6%, 87.1-93.5) of 352 patients in the lopinavir-ritonavir group (treatment difference -6.2%, -11.2 to -1.3). Clinical and laboratory adverse events occurred at similar frequencies in the treatment groups. There were no serious drug-related adverse events or deaths. The only drug-related clinical adverse event of moderate to severe intensity reported in 1% or more of either treatment group was diarrhoea, which occurred in ten patients in the lopinavir-ritonavir group (3%) and no patients in the raltegravir group. The studies were terminated at week 24 because of lower than expected virological efficacy in the raltegravir group compared with the lopinavir-ritonavir group.

INTERPRETATION

Although switching to raltegravir was associated with greater reductions in serum lipid concentrations than was continuation of lopinavir-ritonavir, efficacy results did not establish non-inferiority of raltegravir to lopinavir-ritonavir.

FUNDING

Merck.

Modulation of K65R selection by zidovudine inclusion: analysis of HIV resistance selection in subjects with virologic failure receiving once-daily abacavir/lamivudine/zidovudine and tenofovir DF (study COL40263)

COL40263 was a pilot 48-week, open-label, multicenter study evaluating the efficacy and safety of once-daily coformulated abacavir/lamivudine/zidovudine plus tenofovir in ART-naive, HIV-infected subjects. We examined the patterns of resistance that were selected on-therapy through 48 weeks in subjects with virologic nonresponse (VF). A total of 123 antiretroviral-naive HIV-1-infected subjects with plasma HIV-1 RNA > or = 30,000copies/ml were enrolled. For subjects with confirmed VF (HIV-1 RNA > or = 400 copies/ml at week 24 or later), HIV population genotypic and phenotypic analysis was performed. Of the 123 enrolled subjects, 14 (11%) had confirmed plasma HIV-1 RNA > or = 400 copies/ml through week 48. Of these subjects, 3/14 had evidence of drug resistance at baseline: 2/14 had HIV with K103N, Y188F/H/L/Y, and/or T215A and 1/14 had reduced zidovudine susceptibility. At the last time point analyzed, 4/14 subjects had wild-type HIV, while 10/14 subjects had HIV with either thymidine analogue mutations (TAMS) alone (3/10), TAMS + M184V (4/10), M184V only (1/10), or K65R/K (2/10). Matched phenotype was obtained for 13/14 subjects and 8/13 (62%) subjects had reduced susceptibility to one or more study drugs: 2/13 tenofovir, 3/13 abacavir, 4/13 zidovudine, and 7/13 lamivudine. The resistance pattern in COL40263 subjects with VF differs significantly from that reported for tenofovir-containing triple-nucleoside regimens. TAMs were detected in the majority (7/10) of samples from subjects with VF who selected any resistance mutation. These data suggest that TAMs selection is a preferred resistance route of this combination, with zidovudine modulating the resistance pathway against selection for K65R.

Safety, pharmacokinetics, and antiviral activity of HGS004, a novel fully human IgG4 monoclonal antibody against CCR5, in HIV-1-infected patients

BACKGROUND

HGS004 is a fully human immunoglobulin (Ig) G4 monoclonal antibody against CC chemokine receptor 5 (CCR5) with robust in vitro activity against a diverse panel of CCR5-tropic human immunodeficiency virus type 1 (HIV-1) isolates.

METHODS

A single-blind, randomized, placebo-controlled study was conducted in patients infected with CCR5-tropic HIV-1 to evaluate the safety, pharmacokinetics, and antiviral activity of HGS004. Sixty-three subjects were randomized into 5 dose cohorts (0.4, 2, 8, 20, and 40 mg/kg) and received a single intravenous dose of HGS004 or placebo.

RESULTS

HGS004 was well tolerated, and no dose-limiting toxicities were observed. Pharmacokinetics were nonlinear across the 0.4-40-mg/kg dose range, with dose-proportional increases in maximum concentration, although the area under the curve increased more than proportionally to dose. High levels of receptor occupancy were observed for up to 28 days in the higher-dose cohorts. Plasma HIV-1 RNA reductions of >1 log(10) at day 14 were observed in 14 (54%) of 26 subjects in the 8-, 20-, and 40-mg/kg cohorts. In the 40-mg/kg cohort, 4 of 10 subjects had a >1 log(10) HIV-1 RNA reduction at day 28. Drug concentrations relative to isolate sensitivity (the ratio of the concentration at day 14 to IC(90)) predicted antiviral response on day 14.

CONCLUSIONS

HGS004 is safe and well tolerated and demonstrates meaningful antiviral activity when administered to patients infected with CCR5-tropic HIV-1.

Concomitant Use of an Active Boosted Protease Inhibitor with Enfuvirtide in Treatment-Experienced, HIV-Infected Individuals: Recent Data and Consensus Recommendations

Recent data from clinical trials investigating the efficacy of enfuvirtide, a fusion inhibitor, in treatment-experienced patients have revealed that the addition of enfuvirtide (ENF) to an active boosted protease inhibitor regimen doubles the rate of virological response. At week 48 of the TORO studies, 55% of patients previously naive to and receiving lopinavir/ritonavir (LPV/r) with ENF achieved a viral load of <400 copies/mL compared with 24% of patients treated with LPV/r alone. At week 24 of the RESIST studies, 70% of previously ENF-naive patients who took both ENF and tipranavir/ritonavir (TPV/r) achieved a >or=1 log10 reduction in viral load compared with 37% of such patients treated with TPV/r alone. Similarly, concomitant use of TMC114/ritonavir (TMC114/r) with ENF, compared with TMC114/r alone, increased the number of patients with <50 copies/mL from 46% to 64% in a combined 24-week analysis from the POWER trials. Data from these trials suggest that combining one agent from a new class with a new agent from a previously exposed class offers a greater chance of achieving full virological control than either type of agent alone. Undetectable viraemia should be the primary objective for treatment-experienced patients requiring a switch in therapy, and the present data support the combination of an active boosted protease inhibitor with an agent from a new class (e.g., ENF) for triple-class-experienced patients.

Abacavir and lamivudine fixed-dose combination tablet once daily compared with abacavir and lamivudine twice daily in HIV-infected patients over 48 weeks (ESS30008, SEAL)

BACKGROUND

Abacavir (ABC) and lamivudine (3TC) administered twice daily were compared with an ABC + 3TC fixed-dose combination (Epzicom, Kivexa; EPZ) administered once daily, both in combination with a protease inhibitor (PI) or nonnucleoside reverse transcriptase inhibitor (NNRTI).

METHODS

Two hundred sixty HIV-infected subjects with more than 6 months of ABC and 3TC administered twice daily plus a PI or NNRTI with an HIV-1 RNA level less than 400 copies/mL for more than 3 months and a CD4 count greater than 50 cells/mm were randomized 1:1 to ABC + 3TC administered twice daily or EPZ administered once daily.

RESULTS

At baseline, median time on ABC and 3TC administered twice daily was 22 months, and median CD4 count and HIV-1 RNA level were 554 cells/mm and <50 copies/mL, respectively. EPZ administered once daily was established as not inferior to ABC + 3TC administered twice daily based on the proportion of nonvirologic failures (confirmed HIV-1 RNA level > or =1265 copies/mL; 90% confidence interval: -3.4 to 6.4; (intent to treat [ITT]: missing [M] = failure [F]). Proportions with an HIV-1 RNA level <50 copies/mL were 81% of those taking EPZ once daily and 82% of those taking ABC + 3TC twice daily at week 48 (ITT: M = F). Virologic failure was rare (2 patients taking the once-daily regimen, 4 patients taking the twice-daily regimen). There was a low incidence of grade 2 through 4 adverse events (AEs) and no drug-related serious AEs or hypersensitivity reactions.

CONCLUSIONS

EPZ administered once daily was established as not inferior to ABC + 3TC administered twice daily in a regimen containing an NNRTI or a PI over 48 weeks. A dual-nucleoside backbone of ABC and 3TC administered once or twice daily is effective, durable, and well tolerated.

Basic fibroblast growth factor induces a transformed phenotype in normal human melanocytes

Basic fibroblast growth factor (bFGF or FGF-2) is produced by nearly all melanomas in vitro and in vivo but not by normal melanocytes, which require exogenous bFGF for growth. In this study, we transduced normal human melanocytes to overexpress two forms of bFGF: (bFGF-Long and bFGF-Short) using replication-deficient adenovirus 5 vectors. bFGF-Long induced the 17.8, 22.5, 23.1 and 24.2 kDa forms of bFGF, whereas bFGF-Short induced only the 17.8 kDa mature form. Growth of cultured melanocytes transduced with either vector was similar to that of nevus and melanoma cells and was independent of exogenous bFGF and of insulin/insulin-like growth factor 1, and cyclic AMP enhancers, requiring only phorbol ester as an exogenous mitogen. Like primary melanoma cells, transduced normal melanocytes grew anchorage independently in soft agar. When injected into the dermis of human skin grafted to mice, bFGF-transduced melanocytes proliferated for at least 20 days, whereas cells from control cultures showed poor survival and no proliferation. These results demonstrate that bFGF upregulation is a critical component in melanoma progression.