Hedy Teppler

Raltegravir with optimized background therapy for resistant HIV-1 infection.

BACKGROUND Raltegravir (MK-0518) is an inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase active against HIV-1 susceptible or resistant to older antiretroviral drugs. METHODS We conducted two identical trials in different geographic regions to evaluate the safety and efficacy of raltegravir, as compared with placebo, in combination with optimized background therapy, in patients infected with HIV-1 that has triple-class drug resistance in whom antiretroviral therapy had failed. Patients were randomly assigned to raltegravir or placebo in a 2:1 ratio. RESULTS In the combined studies, 699 of 703 randomized patients (462 and 237 in the raltegravir and placebo groups, respectively) received the study drug. Seventeen of the 699 patients (2.4%) discontinued the study before week 16. Discontinuation was related to the study treatment in 13 of these 17 patients: 7 of the 462 raltegravir recipients (1.5%) and 6 of the 237 placebo recipients (2.5%). The results of the two studies were consistent. At week 16, counting noncompletion as treatment failure, 355 of 458 raltegravir recipients (77.5%) had HIV-1 RNA levels below 400 copies per milliliter, as compared with 99 of 236 placebo recipients (41.9%, P<0.001). Suppression of HIV-1 RNA to a level below 50 copies per milliliter was achieved at week 16 in 61.8% of the raltegravir recipients, as compared with 34.7% of placebo recipients, and at week 48 in 62.1% as compared with 32.9% (P<0.001 for both comparisons). Without adjustment for the length of follow-up, cancers were detected in 3.5% of raltegravir recipients and in 1.7% of placebo recipients. The overall frequencies of drug-related adverse events were similar in the raltegravir and placebo groups. CONCLUSIONS In HIV-infected patients with limited treatment options, raltegravir plus optimized background therapy provided better viral suppression than optimized background therapy alone for at least 48 weeks. (ClinicalTrials.gov numbers, NCT00293267 and NCT00293254.)

Subgroup and Resistance Analyses of Raltegravir for Resistant HIV-1 Infection

BACKGROUND We evaluated the efficacy of raltegravir and the development of viral resistance in two identical trials involving patients who were infected with human immunodeficiency virus type 1 (HIV-1) with triple-class drug resistance and in whom antiretroviral therapy had failed. METHODS We conducted subgroup analyses of the data from week 48 in both studies according to baseline prognostic factors. Genotyping of the integrase gene was performed in raltegravir recipients who had virologic failure. RESULTS Virologic responses to raltegravir were consistently superior to responses to placebo, regardless of the baseline values of HIV-1 RNA level; CD4 cell count; genotypic or phenotypic sensitivity score; use or nonuse of darunavir, enfuvirtide, or both in optimized background therapy; or demographic characteristics. Among patients in the two studies combined who were using both enfuvirtide and darunavir for the first time, HIV-1 RNA levels of less than 50 copies per milliliter were achieved in 89% of raltegravir recipients and 68% of placebo recipients. HIV-1 RNA levels of less than 50 copies per milliliter were achieved in 69% and 80% of the raltegravir recipients and in 47% and 57% of the placebo recipients using either darunavir or enfuvirtide for the first time, respectively. At 48 weeks, 105 of the 462 raltegravir recipients (23%) had virologic failure. Genotyping was performed in 94 raltegravir recipients with virologic failure. Integrase mutations known to be associated with phenotypic resistance to raltegravir arose during treatment in 64 patients (68%). Forty-eight of these 64 patients (75%) had two or more resistance-associated mutations. CONCLUSIONS When combined with an optimized background regimen in both studies, a consistently favorable treatment effect of raltegravir over placebo was shown in clinically relevant subgroups of patients, including those with baseline characteristics that typically predict a poor response to antiretroviral therapy: a high HIV-1 RNA level, low CD4 cell count, and low genotypic or phenotypic sensitivity score. (ClinicalTrials.gov numbers, NCT00293267 and NCT00293254.)

Rapid and durable antiretroviral effect of the HIV-1 Integrase inhibitor raltegravir as part of combination therapy in treatment-naive patients with HIV-1 infection: results of a 48-week controlled study.

Background:Raltegravir is an HIV-1 integrase strand-transfer inhibitor with potent in vitro activity. This study explored the antiretroviral activity and safety of raltegravir in treatment-naive patients with plasma HIV-1 RNA levels ≥5000 copies/mL and CD4+ T-cell counts ≥100 cells/mm3. Methods:Multicenter, double-blind, randomized, controlled study of raltegravir at doses of 100, 200, 400, and 600 mg twice daily versus efavirenz at a dose of 600 mg/d, all in combination with tenofovir at a dose of 300 mg/d and lamivudine at a dose of 300 mg/d (clinicaltrials.gov identifier: NCT00100048). Results:In the 198 patients treated (160 on raltegravir and 38 on efavirenz), the mean HIV-1 RNA level ranged from 4.6 to 4.8 log10 copies/mL at baseline. At weeks 2, 4, and 8, the proportion of patients achieving an HIV-1 RNA level <50 copies/mL was greater in each of the raltegravir treatment groups than in the efavirenz group. By week 24, all treatment groups appeared similar, with plasma HIV-1 RNA levels <400 copies/mL in 85% to 98% of patients and <50 copies/mL in 85% to 95% of patients. These reductions were maintained through week 48 in 85% to 98% of patients and in 83% to 88% of patients, respectively. Five (3%) patients on raltegravir and 1 (3%) on efavirenz experienced virologic failure before week 48. Drug-related clinical adverse events were less common with raltegravir than with efavirenz. After 24 and 48 weeks of treatment, raltegravir did not result in increased serum levels of total cholesterol, low-density lipoprotein cholesterol, or triglycerides. Conclusions:Raltegravir at all doses studied was generally well tolerated in combination with tenofovir and lamivudine. Raltegravir exhibited potent and durable antiretroviral activity similar to that of efavirenz at 24 and 48 weeks but achieved HIV-1 RNA levels below detection at a more rapid rate.

Antiretroviral activity, pharmacokinetics, and tolerability of MK-0518, a novel inhibitor of HIV-1 integrase, dosed as monotherapy for 10 days in treatment-naive HIV-1-infected individuals

Background:MK-0518 is a novel HIV-1 integrase strand transfer inhibitor with potent in vitro activity against HIV-1 (95% inhibitory concentration [IC95] = 33 nM in 50% human serum) and good bioavailability in uninfected subjects. This study explored the antiretroviral activity and safety of MK-0518 versus placebo for 10 days as monotherapy in antiretroviral therapy-naive HIV-1-infected patients with plasma HIV-1 RNA levels of at least 5000 copies/mL and CD4+ T-cell counts of at least 100 cells/mm3. Methods:This was a multicenter, double-blind, randomized, placebo-controlled 2-part study, with the first part using MK-0518 in 1 of 4 doses (100, 200, 400, and 600 mg) versus placebo (randomized 1:1:1:1:1) given twice daily for 10 days of monotherapy. Patients were monitored for safety, pharmacokinetic parameters, and antiretroviral effect. Results:Thirty-five patients were enrolled (6-8 patients per treatment group) and completed 10 days of therapy; the mean baseline log10 HIV RNA level ranged from 4.5 to 5.0 copies/mL in each group. On day 10, the mean decrease from baseline in the log10 HIV RNA level was −0.2 copies/mL for the placebo group and −1.9, −2.0, −1.7 and −2.2 log10 copies/mL for the MK-0518 100-, 200-, 400-, and 600-mg treatment groups, respectively. All dose groups had superior antiretroviral activity compared with placebo (P < 0.001 for comparison of each dose with placebo). At least 50% of patients in each MK-0518 dose group achieved an HIV RNA level <400 copies/mL by day 10. Mean trough MK-0518 concentrations at each dose exceeded the IC95 of 33 nM. Study therapy was generally well tolerated. The most common adverse experiences were headache and dizziness; these were similar between active and control groups. There were no discontinuations because of adverse experiences and no serious adverse experiences. Conclusions:MK-0518 showed potent antiretroviral activity as short-term monotherapy and was generally well tolerated at all doses. Based on these results, part 2 of the study, a dose-ranging 48-week trial of MK-0518 versus efavirenz in a combination regimen, has been initiated.

Antiretroviral therapy with the integrase inhibitor raltegravir alters decay kinetics of HIV, significantly reducing the second phase

Objective:Raltegravir (MK-0518) belongs to the new class of HIV integrase inhibitors. To date, there have been no reports investigating the potential for differential effects on viral dynamics with integrase inhibitors relative to current antiretroviral drugs. Methods:Patients in this phase II study (P004) were antiretroviral treatment naive. Part 1 of this study compared monotherapy with raltegravir (100 mg, 200 mg, 400 mg, or 600 mg twice daily) with placebo over 10 days. In part 2, patients were enrolled for 48 weeks of combination therapy, with randomization to one of the four dosages of raltegravir or to efavirenz, in addition to tenofovir and lamivudine. Mathematical models were used to investigate processes underlying viral dynamics. Results:From day 15 through to day 57, individuals in the raltegravir arm were significantly more likely to have HIV RNA < 50 copies/ml (P ≤ 0.047). Plasma viral loads were 70% lower at initiation of second-phase decay for individuals taking raltegravir than for those taking efavirenz (P < 0.0001). This challenges the current hypothesis that second-phase virus originates from infected long-lived cells, as an integrase inhibitor should not impact on viral production from this cell population. Mathematical modeling supported two hypotheses as consistent with these observations: (i) that second-phase virus arises from cells newly infected by long-lived infected cells and (2) that it arises from activation of latently infected cells with full-length unintegrated HIV DNA. Conclusions:These observations challenge the current understanding of HIV-1 turnover and compartmentalization. They also indicate the promise of this new integrase inhibitor raltegravir.

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 [Δ (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 [Δ (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.

Ertapenem Versus Piperacillin/Tazobactam in the Treatment of Complicated Intraabdominal Infections: Results of a Double-Blind, Randomized Comparative Phase III Trial

ObjectiveTo examine the clinical efficacy and safety of ertapenem, a novel &bgr;-lactam agent with wide activity against common pathogens encountered in intraabdominal infection. Summary Background DataErtapenem has a pharmacokinetic profile and antimicrobial spectrum that support the potential for use as a once-a-day agent for the treatment of common mixed aerobic and anaerobic infections. MethodsThis prospective, randomized, controlled, and double-blind trial was conducted to compare the safety and efficacy of ertapenem with piperacillin/tazobactam as therapy following adequate surgical management of complicated intraabdominal infections. ResultsSix hundred thirty-three patients were included in the modified intent-to-treat population, with 396 meeting all criteria for the evaluable population. Patients with a wide range of infections were enrolled; perforated or abscessed appendicitis was most common (approximately 60% in microbiologically evaluable population). A prospective, expert panel review was conducted to assess the adequacy of surgical source control in patients who were failures as a component of evaluability. For the modified intent-to-treat groups, 245 of 311 patients treated with ertapenem (79.3%) were cured, as were 232 of 304 (76.2) treated with piperacillin/tazobactam. One hundred seventy-six of 203 microbiologically evaluable patients treated with ertapenem (86.7%) were cured, as were 157 of the 193 (81.2%) treated with piperacillin/tazobactam. ConclusionsIn this study, the efficacy of ertapenem 1 g once a day was equivalent to piperacillin/tazobactam 3.375 g every 6 hours in the treatment of a range of intraabdominal infections. Ertapenem was generally well tolerated and had a similar safety and tolerability profile to piperacillin/tazobactam. A formal process for review of adequacy of source control was found to be of benefit. The results of this trial suggest that ertapenem may be a useful option that could eliminate the need for combination and/or multidosed antibiotic regimens for the empiric treatment of intraabdominal infections.

Long-Term Efficacy and Safety of Raltegravir Combined with Optimized Background Therapy in Treatment-Experienced Patients with Drug-Resistant HIV Infection: Week 96 Results of the BENCHMRK 1 and 2 Phase III Trials

BENCHMRK-1 and -2 are ongoing double-blind phase III studies of raltegravir in patients experiencing failure of antiretroviral therapy with triple-class drug-resistant human immunodeficiency virus infection. At week 96 (combined data), raltegravir (400 mg twice daily) plus optimized background therapy was generally well tolerated, with superior and durable antiretroviral and immunological efficacy, compared with optimized background therapy alone.

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.

Ritonavir-boosted lopinavir plus nucleoside or nucleotide reverse transcriptase inhibitors versus ritonavir-boosted lopinavir plus raltegravir for treatment of HIV-1 infection in adults with virological failure of a standard first-line ART regimen (SECOND-LINE): a randomised, open-label, non-inferiority study.

Methods We did this 96-week, phase 3b/4, randomised, open-label non-inferiority trial at 37 sites worldwide. Adults with HIV-1 who had confi rmed virological failure (plasma viral load >500 copies per mL) after 24 weeks or more of fi rst-line treatment were randomly assigned (1:1) to receive ritonavir-boosted lopinavir plus two or three NtRTIs (control group) or ritonavir-boosted lopinavir plus raltegravir (raltegravir group). The randomisation sequence was computer generated with block randomisation (block size four). Neither participants nor investigators were masked to allocation. The primary endpoint was the proportion of participants with plasma viral load less than 200 copies per mL at 48 weeks in the modifi ed intention-to-treat population, with a non-inferiority margin of 12%. This study is registered with ClinicalTrials.gov, number NCT00931463.BACKGROUND Uncertainty exists about the best treatment for people with HIV-1 who have virological failure with first-line combination antiretroviral therapy of a non-nucleoside analogue (NNRTI) plus two nucleoside or nucleotide analogue reverse transcriptase inhibitors (NtRTI). We compared a second-line regimen combining two new classes of drug with a WHO-recommended regimen. METHODS We did this 96-week, phase 3b/4, randomised, open-label non-inferiority trial at 37 sites worldwide. Adults with HIV-1 who had confirmed virological failure (plasma viral load >500 copies per mL) after 24 weeks or more of first-line treatment were randomly assigned (1:1) to receive ritonavir-boosted lopinavir plus two or three NtRTIs (control group) or ritonavir-boosted lopinavir plus raltegravir (raltegravir group). The randomisation sequence was computer generated with block randomisation (block size four). Neither participants nor investigators were masked to allocation. The primary endpoint was the proportion of participants with plasma viral load less than 200 copies per mL at 48 weeks in the modified intention-to-treat population, with a non-inferiority margin of 12%. This study is registered with ClinicalTrials.gov, number NCT00931463. FINDINGS We enrolled 558 patients, of whom 541 (271 in the control group, 270 in the raltegravir group) were included in the primary analysis. At 48 weeks, 219 (81%) patients in the control group compared with 223 (83%) in the raltegravir group met the primary endpoint (difference 1·8%, 95% CI -4·7 to 8·3), fulfilling the criterion for non-inferiority. 993 adverse events occurred in 271 participants in the control group versus 895 in 270 participants in the raltegravir group, the most common being gastrointestinal. INTERPRETATION The raltegravir regimen was no less efficacious than the standard of care and was safe and well tolerated. This simple NtRTI-free treatment strategy might extend the successful public health approach to management of HIV by providing simple, easy to administer, effective, safe, and tolerable second-line combination antiretroviral therapy. FUNDING University of New South Wales, Merck, AbbVie, the Foundation for AIDS Research.