Kim M. Strohmaier

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.)

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.

A Multicenter, Double-Blind Trial of a High-Dose Caspofungin Treatment Regimen versus a Standard Caspofungin Treatment Regimen for Adult Patients with Invasive Candidiasis

BACKGROUND The standard caspofungin treatment regimen (50 mg/day after a 70-mg dose on day 1) is effective and well tolerated for the treatment of invasive candidiasis, but experience with higher doses of caspofungin is limited. We evaluated the safety and efficacy of caspofungin at 3 times the standard dosing regimen. METHODS Patients with proven invasive candidiasis were randomized to receive a standard or high-dose (150 mg/day) caspofungin treatment regimen. Safety was assessed in all patients as treated. Efficacy was assessed as a secondary objective in a full-analysis-set population. A favorable overall response was defined as symptom resolution and microbiological clearance at the end of caspofungin therapy. RESULTS A total of 204 patients were included in the safety analysis (104 received the standard regimen, and 100 received the high-dose regimen), and 197 were included in the efficacy analysis (102 and 95 in the standard and high-dose treatment groups, respectively). Patient demographic characteristics, neutropenia status (6.7% and 8.0% had neutropenia, respectively), and Acute Physiology and Chronic Health Evaluation II scores (mean, 16.5 and 17, respectively) were similar between treatment groups. Significant drug-related adverse events occurred in 1.9% of patients receiving the standard regimen and 3.0% of patients receiving the high-dose regimen (difference, 1.1%; 95% confidence interval, -4.1% to 6.8%). The most-common drug-related adverse events in the standard and high-dose treatment groups were phlebitis (3.8% and 2.0%, respectively), increased alkaline phosphatase level (6.9% and 2.0%, respectively), and increased aspartate transaminase level (4.0% and 2.0%, respectively). Overall, 71.6% of patients who received the standard regimen and 77.9% of patients who received the high-dose regimen had favorable overall responses (difference, 6.3%; 95% confidence interval, -5.9% to 18.4%; not statistically significant). Mortality at 8 weeks after therapy was similar between groups. CONCLUSIONS Both caspofungin dosing regimens were effective and well tolerated in patients with invasive candidiasis. No safety concerns were found for caspofungin at a dosage of 150 mg/day.

A Randomized, Double-Blind, Multicenter Study of Caspofungin Versus Liposomal Amphotericin B for Empiric Antifungal Therapy in Pediatric Patients With Persistent Fever and Neutropenia

Background: Persistently febrile neutropenic children at risk for invasive fungal infections receive empiric antifungal therapy as a standard of care. However, little is known about the role of echinocandins and liposomal amphotericin B (L-AmB) for empiric antifungal therapy in pediatric patients. Methods: Patients between the ages of 2 to 17 years with persistent fever and neutropenia were randomly assigned to receive caspofungin (70 mg/m2 loading dose on day 1, then 50 mg/m2 daily [maximum 70 mg/d]) or l-AmB (3 mg/kg daily) in a 2:1 ratio. Evaluation of safety was the primary objective of the study. Efficacy was also evaluated, with a successful outcome defined as fulfilling all components of a prespecified 5-part composite endpoint. Suspected invasive fungal infections were evaluated by an independent, treatment-blinded adjudication committee. Results: Eighty-two patients received study therapy (caspofungin 56, l-AmB 26), and 81 were evaluated for efficacy (caspofungin 56; l-AmB 25). Outcomes for safety and efficacy endpoints were similar for both study arms. Adverse drug-related event rates [95% confidence interval] were similar between the caspofungin and l-AmB groups (clinical 48.2% [34.7–62.0] versus 46.2% [26.6–66.6]; laboratory 10.7% [4.0–21.9] versus 19.2% [6.6–39.4]). Serious drug-related adverse events occurred in 1 (1.8%) of caspofungin-treated patients and 3 (11.5%) of l-AmB-treated patients. Overall success rates [95% CI] were 46.4% [33.4–59.5] for caspofungin and 32.0% [13.7–50.3] for l-AmB. Conclusions: Caspofungin and l-AmB were comparable in tolerability, safety, and efficacy as empiric antifungal therapy for persistently febrile neutropenic pediatric patients.

Sustained antiretroviral effect of raltegravir after 96 weeks of combination therapy in treatment-naive patients with HIV-1 infection.

Objectives:The purpose of this study was to evaluate the safety and efficacy of raltegravir vs efavirenz-based antiretroviral therapy after 96 weeks in treatment-naive patients with HIV-1 infection. Methods:Multicenter, double-blind, randomized study of raltegravir (100, 200, 400, or 600 mg twice a day) vs efavirenz (600 mg every day), both with tenofovir/lamivudine (TDF/3TC), for 48 weeks, after which raltegravir arms were combined and all dosed at 400 mg twice a day. Eligible patients had HIV-1 RNA ≥5000 copies per milliliter and CD4+ T cells ≥100 cells per microliter. Results:One hundred ninety-eight patients were randomized and treated; 160 received raltegravir and 38 received efavirenz. At week 96, 84% of patients in both groups achieved HIV-1 RNA <400 copies per milliliter; 83% in the raltegravir group and 84% in the efavirenz group achieved <50 copies per milliliter (noncompleter = failure). Both groups showed similar increases in CD4+ T cells (221 vs 232 cells/uL, respectively). An additional 2 patients (1 in each group) met the protocol definition of virologic failure between weeks 48 and 96; no known resistance mutations were observed in the raltegravir recipient; the efavirenz recipient had nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor resistance mutations. Investigator reported drug-related clinical adverse events (AEs) were less frequent with raltegravir (51%) than efavirenz (74%). Drug-related AEs occurring in >10% of patients in either group were nausea in both groups and dizziness and headache in the efavirenz group. Laboratory AEs remained infrequent. Raltegravir had no adverse effect on total or low-density lipoprotein cholesterol or on triglycerides. Neuropsychiatric AEs remained less frequent with raltegravir (34%) than efavirenz (58%). There were no drug-related serious AEs in patients receiving raltegravir. Conclusions:In antiretroviral therapy-naive patients, raltegravir with TDF/3TC had potent antiretroviral activity, which was similar to efavirenz/TDF/3TC and was sustained to week 96. Raltegravir was generally well tolerated; drug-related AEs were less frequent in patients treated with raltegravir compared with efavirenz.

A Prospective, Multicenter Study of Caspofungin for the Treatment of Documented Candida or Aspergillus Infections in Pediatric Patients

OBJECTIVE. We evaluated the safety, tolerability, and efficacy of caspofungin in pediatric patients with invasive aspergillosis, invasive candidiasis, or esophageal candidiasis. METHODS. This was a multicenter, prospective, open-label study in children 3 months to 17 years of age with proven or probable invasive aspergillosis, proven invasive candidiasis, or proven esophageal candidiasis. All of the patients received caspofungin 70 mg/m2 on day 1, followed by 50 mg/m2 per day (maximum: 70 mg/day), as primary or salvage monotherapy. Favorable response was defined as complete resolution of clinical findings and microbiologic (or radiographic/endoscopic) eradication (complete response) or significant improvement in these parameters (partial response). Efficacy was assessed at the end of caspofungin therapy in patients with a confirmed diagnosis who received ≥1 dose of caspofungin. The primary safety evaluation was the proportion of patients with clinical or laboratory drug-related adverse events. RESULTS. Of the 49 patients enrolled, 3 were <2 years of age, 30 were 2 to 11 years of age, and 16 were 12 to 17 years of age. Forty-eight patients had confirmed disease: invasive aspergillosis (10), invasive candidiasis (37), and esophageal candidiasis (1). Eight of 10 patients with invasive aspergillosis had pulmonary involvement; 34 of 37 patients with invasive candidiasis had candidemia. Caspofungin was given for 2 to 87 days. Success at end of therapy was achieved in 5 of 10 patients with invasive aspergillosis, 30 of 37 with invasive candidiasis, and 1 of 1 with esophageal candidiasis. One patient (invasive candidiasis) relapsed during the 28-day follow-up period. Drug-related clinical or laboratory adverse events occurred in 27% and 35% of patients, respectively. There were no serious drug-related adverse events or discontinuations of caspofungin because of toxicity. CONCLUSIONS. Caspofungin was generally well tolerated in pediatric patients aged 6 months through 17 years. Efficacy outcomes in patients with invasive aspergillosis or invasive candidiasis were consistent with previous adult studies in these indications.

Pharmacokinetics and Safety of Caspofungin in Neonates and Infants Less than 3 Months of Age

ABSTRACT Candida infections represent a major threat in neonatal intensive care units. This is the first prospective study to obtain caspofungin plasma levels and safety data for neonates and very young infants. Patients of <3 months of age receiving intravenous amphotericin B for documented or highly suspected candidiasis were enrolled in a single-dose (n = 6) or subsequent multiple-dose (n = 12) panel; all received caspofungin at 25 mg/m2 once daily as a 1-hour infusion. Caspofungin plasma levels were measured by high-performance liquid chromatography and compared to historical data from adults. Patient chronological ages ranged from 1 to 11 weeks, and weights ranged from 0.68 to 3.8 kg. Gestational ages ranged from 24 to 41 weeks. Geometric mean (GM) peak (C1 h) and trough (C24 h) caspofungin levels were 8.2 and 1.8 μg/ml, respectively, on day 1, and 11.1 and 2.4 μg/ml, respectively, on day 4. GM ratios for C1 h and C24 h for neonates/infants relative to adults receiving caspofungin at 50 mg/day were 1.07 and 1.36, respectively, on day 1, and 1.18 and 1.21, respectively, on day 4. Clinical and laboratory adverse events occurred in 17 (94%) and 8 (44%) patients, respectively. Five patients (28%) had serious adverse events, none of which were considered drug related. Caspofungin at 25 mg/m2 once daily was well tolerated in this group of neonates/infants of <3 months of age and appears to provide relatively similar plasma exposure to that obtained in adults receiving 50 mg/day. However, the small number of patients studied precludes any definitive recommendations about caspofungin dosing for this group comprising a broad range of ages and weights.

Efficacy and safety of raltegravir for treatment of HIV for 5 years in the BENCHMRK studies: final results of two randomised, placebo-controlled trials

BACKGROUND Two randomised, placebo-controlled trials-BENCHMRK-1 and BENCHMRK-2-investigated the efficacy and safety of raltegravir, an HIV-1 integrase strand-transfer inhibitor. We report final results of BENCHMRK-1 and BENCHMRK-2 combined at 3 years (the end of the double-blind phase) and 5 years (the end of the study). METHODS Integrase-inhibitor-naive patients with HIV resistant to three classes of drug and who were failing antiretroviral therapy were enrolled. Patients were randomly assigned (2:1) to raltegravir 400 mg twice daily or placebo, both with optimised background treatment. Patients and investigators were masked to treatment allocation until week 156, after which all patients were offered open-label raltegravir until week 240. The primary endpoint was previously assessed at 16 weeks. We assessed long-term efficacy with endpoints of the proportion of patients with an HIV viral load of less than 50 copies per mL and less than 400 copies per mL, and mean change in CD4 cell count, at weeks 156 and 240. FINDINGS 1012 patients were screened for inclusion. 462 were treated with raltegravir and 237 with placebo. At week 156, 51% in the raltegravir group versus 22% in the placebo group (non-completer classed as failure) had viral loads of less than 50 copies per mL, and 54% versus 23% had viral loads of less than 400 copies per mL. Mean CD4 cell count increase (analysed by an observed failure approach) was 164 cells per μL versus 63 cells per μL. After week 156, 251 patients (54%) from the raltegravir group and 47 (20%) from the placebo group entered the open-label raltergravir phase; 221 (47%) versus 44 (19%) completed the entire study. At week 240, viral load was less than 50 copies per mL in 193 (42%) of all patients initially assigned to raltegravir and less than 400 copies per mL in 210 (45%); mean CD4 cell count increased by 183 cells per μL. Virological failure occurred in 166 raltegravir recipients (36%) during the double-blind phase and in 17 of all patients (6%) during the open-label phase. The most common drug-related adverse events at 5 years in both groups were nausea, headache, and diarrhoea, and occurred in similar proportions in each group. Laboratory test results were similar in both treatment groups and showed little change after year 2. INTERPRETATION Raltegravir has a favourable long-term efficacy and safety profile in integrase-inhibitor-naive patients with triple-class resistant HIV in whom antiretroviral therapy is failing. Raltegravir is an alternative for treatment-experienced patients, particularly those with few treatment options. FUNDING Merck Sharp & Dohme.

Pharmacokinetics and Safety of Caspofungin in Older Infants and Toddlers

ABSTRACT Although information about the efficacy and safety experience with caspofungin at 50 mg/m2 daily is available for children and adolescents, the dosing regimen in infants and toddlers 3 to 24 months of age has yet to be established. We studied the pharmacokinetics and safety of caspofungin at 50 mg/m2 once daily in nine patients 10 to 22 months (median, 13 months) of age with fever and neutropenia who received caspofungin once daily for 2 to 21 (mean, 9.3) days. Plasma caspofungin concentrations were measured by high-performance liquid chromatography assay on days 1 and 4. On day 4, the area under the curve from 0 to 24 h (AUC0-24) was 130.3 μg-h/ml, the peak concentration (C1) was 17.2 μg/ml, and the trough concentration (C24) was 1.6 μg/ml. The day 4 geometric mean ratios (GMRs) and 90% confidence interval (CI) for these parameters in infants/toddlers relative to adults were 1.26 (1.06, 1.50), 1.83 (1.57, 2.14), and 0.81 (0.64, 1.04), respectively. Relative to children (2 to 11 years of age), the day 4 GMRs (and 90% CI) were 1.13 (0.89, 1.44), 1.10 (0.85, 1.42), and 1.12 (0.72, 1.76), respectively. The harmonic mean elimination phase t1/2 in infants/toddlers (8.8 h) was reduced ∼33% relative to adults (13.0 h) but was similar to that in children (8.2 h). Clinical adverse events occurred in seven patients (78%); none were considered drug related. Laboratory adverse events occurred in five patients (56%) and were considered drug related in three (33%). There were no infusion-related events or discontinuations due to toxicity. Caspofungin at 50 mg/m2 daily was well tolerated in infants and toddlers; the AUC and caspofungin C24 were generally comparable to those in adults receiving caspofungin at 50 mg daily.