Isavuconazole treatment for rare fungal diseases and for invasive aspergillosis in patients with renal impairment: Challenges and lessons of the VITAL trial.

Invasive fungal disease (IFD) confers a substantial risk for morbidity and mortality to immunocompromised patients. Invasive aspergillosis (IA) is the most common IFD caused by moulds but the prevalence of other rare mould diseases, such as mucormycosis, hyalohyphomycosis and phaeohyphomycosis, may be increasing. Treatments are available for IA, but evidence to support efficacy and safety of antifungal agents for rare IFDs, or for IFDs in special patient populations, is limited or lacking. The VITAL trial was conducted to assess the efficacy and safety of isavuconazole for the treatment of patients with IA and renal impairment, or with IFDs caused by rare moulds, yeasts or dimorphic fungi. These patients stand to benefit most from a new treatment option but are unlikely to be included in a randomised, controlled trial. In this article, we review the challenges faced in the design and conduct of the VITAL trial. We also review the findings of VITAL, which included evidence of the efficacy and safety of isavuconazole. Finally, we consider the importance of trials such as VITAL to inform therapeutic decision making for clinicians faced with the challenge of treating patients with rare IFDs and as one paradigm of how to determine efficacy and safety of new drugs for rare and resistant infections without a suitable comparator.

Safety and efficacy of daptomycin as first-line treatment for complicated skin and soft tissue infections in elderly patients: an open-label, multicentre, randomized phase IIIb trial.

BACKGROUND: Daptomycin has proven efficacy in patients with Gram-positive complicated skin and soft tissue infections (cSSTIs), including those caused by Staphylococcus aureus, regardless of methicillin susceptibility. OBJECTIVE: This study was undertaken to evaluate the efficacy and safety of daptomycin in elderly patients. STUDY DESIGN: This was an open-label, multicentre, randomized phase IIIb study conducted in hospitalized patients PATIENTS: Patients aged ≥65 years with a diagnosis of Gram-positive cSSTIs with or without bacteraemia were included. In addition, infections were required to be of sufficient severity to require inpatient hospitalization and treatment with parenteral antibiotics for at least 96 h. The main exclusion criterion was the presence of a non-complicated SSTI that could heal by itself or be cured by surgical removal of the site of infection. INTERVENTION: Patients were randomized (2:1) to intravenous daptomycin or pooled intravenous standard therapies (semi-synthetic penicillin or vancomycin, referred to as the 'comparator'). Duration of treatment was between 5 and 14 days for cSSTIs without bacteraemia and between 10 and 28 days for cSSTIs with bacteraemia. MAIN OUTCOME MEASURE: The primary objective was descriptive comparison of clinical success in clinically evaluable patients at test of cure, 7-14 days post treatment. Secondary objectives were microbiological outcome, duration of treatment and safety. RESULTS: In total, 120 patients were randomized (81 to daptomycin; 39 to the comparator) and 102 patients completed the study. Baseline characteristics were similar between the two groups. Common infections included cellulitis, ulcers and abscesses; six patients had bacteraemia [five documented (daptomycin, n = 3; comparator, n = 2); and one suspected (daptomycin, n = 1)]. Test-of-cure clinical success rates were numerically higher for daptomycin than for the comparator [89.0 % (65/73) vs. 83.3 % (25/30); odds ratio 1.65 (95 % confidence interval 0.49-5.54)]. For patients with S. aureus infections, cure rates were 89.7 % (35/39) versus 69.2 % (9/13), respectively; percentage points difference, 20.5 (95 % confidence interval -12.2 to 50.9)]. Rates of adverse events (AEs) and serious AEs were similar in both treatment arms; however, discontinuation rates for AEs/serious AEs were lower for daptomycin than for the comparator (3.8 % vs. 10.0 %). Three serious AEs were considered to be related to the study drug: one case each of pancytopenia (semi-synthetic penicillin), renal failure (vancomycin) and asymptomatic increase in creatine phosphokinase concentrations (daptomycin). CONCLUSION: In elderly patients, for whom data were previously limited, the efficacy and safety of daptomycin have been confirmed, including for infections caused by S. aureus, regardless of methicillin susceptibility.

Daptomycin use in patients with osteomyelitis: a preliminary report from the EU-CORE(SM) database.

BACKGROUND: Osteomyelitis is a complex and heterogeneous group of infections that require surgical and antimicrobial interventions. Because treatment failure or intolerance is common, new treatment options are needed. Daptomycin has broad Gram-positive activity, penetrates bone effectively and has bactericidal activity within biofilms. This is the first report on clinical outcomes in patients with osteomyelitis from the multicentre, retrospective, non-interventional European Cubicin(®) Outcomes Registry and Experience (EU-CORE(SM)), a large database on real-world daptomycin use. PATIENTS AND METHODS: In total, 220 patients were treated for osteomyelitis; the population was predominantly elderly, with predisposing baseline conditions such as diabetes and chronic renal/cardiac diseases. RESULTS: Most patients (76%) received prior antibiotic treatment, and first-line treatment failure was the most frequent reason to start daptomycin. Common sites of infection were the knee (22%) or hip (21%), and the most frequently isolated pathogens were Staphylococcus aureus (33%) and coagulase-negative staphylococci (32%). Overall, 52% of patients had surgery, 55% received concomitant antibiotics and 29% received a proportion of daptomycin therapy as outpatients. Clinical success was achieved in 75% of patients. Among patients with prosthetic device-related osteomyelitis, there was a trend towards higher success rates if the device was removed. Daptomycin was generally well tolerated. CONCLUSIONS: This analysis suggests that daptomycin is an effective and well-tolerated treatment option for osteomyelitis and highlights the importance of optimal surgical intervention and appropriate microbiological diagnosis for clinical outcomes.

Daptomycin for the treatment of infective endocarditis: results from a European registry.

OBJECTIVES: Infective endocarditis (IE) is a complex infection associated with high mortality. Daptomycin, a cyclic lipopeptide antibiotic highly active against Gram-positive bacteria, has recently been incorporated into IE treatment guidelines. This retrospective analysis provides insights into the use of daptomycin in IE in the European Cubicin(®) Outcomes Registry Experience (EU-CORE(SM)) between 2006 and 2010. PATIENTS AND METHODS: Three hundred and seventy-eight (10%) of 3621 enrolled patients received daptomycin for treatment of IE. Two hundred and fifty-nine (69%) had left-sided IE (LIE) and 182 patients (48%) underwent concomitant surgery. RESULTS: Staphylococcus aureus was the most frequently identified pathogen (n=92; methicillin susceptible, n=50) and daptomycin was used empirically in 134 patients. Among cases of second-line therapy (n=312), the most common reason for switching to daptomycin was failure of the previous regimen (including glycopeptides and penicillins). Daptomycin was administered at 6 mg/kg in 224 patients and at ≥ 8 mg/kg in 72 patients. Clinical success rates were 80% overall, 91% for right-sided IE (RIE) and 76% for LIE, with similar rates seen for infections caused by methicillin-susceptible S. aureus (84%) and methicillin-resistant S. aureus (81%). The clinical success rate in patients treated with ≥ 8 mg/kg daptomycin was 90% [n=72 (RIE, 91%; LIE, 89%)]. No new safety signals were observed. CONCLUSIONS: In patients with IE registered in EU-CORE, daptomycin was most frequently used as second-line treatment after treatment failure. The majority of patients had LIE and most commonly received daptomycin for the treatment of staphylococcal infections. Clinical success was high in this difficult-to-treat population. The role of doses ≥ 8 mg/kg per day in the empirical treatment of IE deserves further investigation.

Results of a double-blind, randomized trial of ceftobiprole treatment of complicated skin and skin structure infections caused by gram-positive bacteria.

Ceftobiprole is the first broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) to be assessed in late-stage clinical trials. As a pivotal step in the clinical development of ceftobiprole, a multicenter, global, randomized, double-blind trial was conducted to compare the efficacy of ceftobiprole to that of vancomycin in patients with complicated skin and skin structure infections (cSSSIs) caused by gram-positive bacteria. The primary objective was to assess noninferiority on the basis of the cure rates 7 to 14 days after the completion of therapy in patients administered ceftobiprole 500 mg every 12 h or vancomycin 1 g every 12 h. Of 784 patients randomized, 282 receiving ceftobiprole and 277 receiving vancomycin were clinically evaluable. Of these patients, 93.3% treated with ceftobiprole and 93.5% treated with vancomycin were cured (95% confidence interval of difference, -4.4%, 3.9%). The cure rates for patients with MRSA infections were 91.8% (56/61) with ceftobiprole treatment and 90.0% (54/60) with vancomycin treatment (95% confidence interval of difference, -8.4%, 12.1%). At least one adverse event (AE) was reported by 52% of the ceftobiprole-treated patients and 51% of the vancomycin-treated patients. The most common AEs reported by the ceftobiprole-treated patients were nausea (14%) and taste disturbance (8%). Discontinuation of the study drug because of treatment-emergent AEs occurred in 4% (n = 17) of the ceftobiprole-treated patients and 6% (n = 22) of the vancomycin-treated patients. The results of this trial support the use of ceftobiprole as an effective and well-tolerated treatment option for patients with cSSSIs caused by a spectrum of gram-positive bacteria.

Anti-MRSA beta-lactams in development, with a focus on ceftobiprole: the first anti-MRSA beta-lactam to demonstrate clinical efficacy.

Ceftobiprole is the first of the investigational beta-lactam antibiotics with in vitro activity against methicillin-resistant staphylococci to reach and complete Phase III therapeutic trials. Its antibacterial spectrum includes methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, penicillin-resistant streptococci and many Gram-negative pathogens. It has demonstrated in vivo activity against many experimental infections caused by these pathogens. Ceftobiprole has completed Phase III clinical trials for complicated skin and skin structure infections, is being studied in Phase III pneumonia trials and has demonstrated non-inferiority compared with vancomycin in a Phase III complicated skin and skin structure infections trial, resulting in > 90% clinical cures of infections caused by MRSA. Other anti-MRSA beta-lactams in therapeutic clinical trials include the carbapenem CS-023/RO-4908463 and the cephalosporin ceftaroline (PPI-0903). The future of all of these agents will depend on their clinical efficacy, safety and their ability to be accepted as beta-lactams for the reliable treatment of a broad spectrum of infections, including those caused by MRSA.

Comparative in vivo activity of BAL4815, the active component of the prodrug BAL8557, in a neutropenic murine model of disseminated Aspergillus flavus.

BACKGROUND: BAL8557 (WSA) is the water-soluble prodrug of the triazole BAL4815 with in vitro anti-Aspergillus activity. We compared the activity of oral BAL8557 with oral itraconazole, oral voriconazole and intravenous caspofungin in a temporarily neutropenic murine model of disseminated Aspergillus flavus. METHODS: Mice were immunosuppressed using cyclophosphamide, then infected. Mice were treated either 2 h pre-infection (PRE), or 4 or 24 h post-infection (4POST and 24POST, respectively). Treatment was for 10 days followed by 4 days of observation. Surviving mice were killed and liver, kidneys, lungs and brain cultured. BAL8557 groups included doses corresponding to approximately 30, 15, 6 and 3 mg/kg of the active BAL4815; comparators included itraconazole 25 and 10 mg/kg/dose, voriconazole (plus oral grapefruit) 25 and 10 mg/kg/day or caspofungin 1 mg/kg/day. In a simultaneous tissue burden study mice were treated for 3 days, kidneys removed and homogenized and burden measured by quantitative culture and quantitative PCR using fluorescence resonance energy transfer (FRET). RESULTS: Control mice had 83-100% mortality. Over 66% of BAL8557-treated mice survived after >6 mg/kg PRE or >15 mg/kg POST. In the PRE models BAL8557 (6 mg/kg) and caspofungin were 100% protective and itraconazole 67% protective, but voriconazole 10 mg/kg had 100% mortality (P = 0.0016). In the 4POST and 24POST models survival was >66% with BAL8557 30 and 15 mg/kg/dose and similar to voriconazole or itraconazole. In the 24POST groups, sterilization of all organs was achieved in 11/16 survivors treated with BAL8557. The quantitative PCR correlated with kidney fungal burden (r2 = 0.59). Earlier treatment reduced burdens. CONCLUSIONS: BAL8557 demonstrated impressive antifungal activity against A. flavus in this model, in both survival and tissue burden.

Single-ascending-dose pharmacokinetics and safety of the novel broad-spectrum antifungal triazole BAL4815 after intravenous infusions (50, 100, and 200 milligrams) and oral administrations (100, 200, and 400 milligrams) of its prodrug, BAL8557, in healthy volunteers.

BAL8557 is the water-soluble prodrug of a novel antifungal triazole, BAL4815. BAL4815 is active against a broad spectrum of major opportunistic and pathogenic fungi, including strains that are resistant to other azoles. Cohorts of healthy male subjects received single-ascending oral (p.o.) doses of BAL8557 that were equivalent to 100, 200, or 400 mg of BAL4815 or single-ascending, 1-h constant-rate intravenous (i.v.) infusions of BAL8557 which were equivalent to 50, 100, or 200 mg of BAL4815. In each cohort, six subjects were randomly assigned to receive active drug and two subjects were assigned to receive the placebo. All doses were well tolerated, and no severe or serious adverse events occurred. Maximum plasma concentrations of BAL4815 were observed 1.5 to 3 h after p.o. drug intake or at the end of the 1-h infusion. After both routes of administration, values for maximum drug concentration observed in plasma and area under the concentration-time curve increased slightly more than proportionally to the administered dose. Mean elimination half-lives were particularly long (56 to 77 h after p.o. administration and 76 to 104 h after i.v. administration). The volume of distribution was large (155 to 292 liters after p.o. administration and 304 to 494 liters after i.v. administration) and systemic clearance was low (1.9 to 2.8 liter/h after p.o. administration and 2.8 to 5.0 liter/h after i.v. administration). Urinary recovery of BAL4815 was less than 0.4% of the infused dose. Based on the exposure data, oral bioavailability of BAL4815 is assumed to be very high. The pharmacokinetics of BAL4815 are well suited to maintaining concentrations of BAL4815 for a long period of time in the body and to enabling an effective treatment of systemic mycoses.

Multiple-dose pharmacokinetics and safety of the new antifungal triazole BAL4815 after intravenous infusion and oral administration of its prodrug, BAL8557, in healthy volunteers.

BAL8557 is the water-soluble prodrug of BAL4815, a new broad-spectrum antifungal. Healthy male subjects were randomly assigned to four treatment cohorts to receive multiple oral doses or multiple 1-h constant-rate intravenous infusions of BAL8557. Loading doses of BAL8557 were equivalent to 100 mg (followed by once-daily maintenance doses of 50 mg) or 200 mg (followed by once-daily maintenance doses of 100 mg) of BAL4815. In each cohort, six subjects received active drug and two subjects received the placebo. Study duration was 21 days (oral) and 14 days (intravenous). All adverse events reported were mild or moderate, except one severe rhinitis event which was not related to trial medication. After both routes of administration, maximum drug concentration observed in plasma (C(max)) and area under the concentration-time curve (AUC) values of BAL4815 increased proportionally to the administered dose. AUC values reflected a fourfold to fivefold accumulation of active drug in plasma during once-daily dosing, which is in line with the long elimination half-life of BAL4815 determined after the last administration (mean, 84.5 to 117 h). At steady state, the volume of distribution was large and amounted to 308 to 542 liters. Systemic clearance reached only 2.4 to 4.1 liter/h. At the levels obtained in the present study, C(max) values of 2.56 and 2.55 microg/ml after oral and intravenous administrations, respectively, there was no indication of CYP3A4 induction or inhibition (as revealed by the urinary 6-beta-hydroxycortisol/cortisol test). Based on AUC values after oral and intravenous administration, an excellent oral bioavailability can be predicted for BAL4815. Once-daily oral dosing of 50- or 100-mg equivalents of BAL8557 were recently demonstrated to be efficacious in a phase 2 study conducted with patients with esophageal candidiasis. These doses (preceded by adequate loading dose[s]) will be further explored in the treatment of systemic mycoses.