Efficacy and safety of oral solithromycin versus oral moxifloxacin for treatment of community-acquired bacterial pneumonia: a global, double-blind, multicentre, randomised, active-controlled, non-inferiority trial (SOLITAIRE-ORAL).

BACKGROUND: Community-acquired bacterial pneumonia (CABP) is a leading cause of morbidity and mortality, and treatment recommendations, each with specific limitations, vary globally. We aimed to compare the efficacy and safety of solithromycin, a novel macrolide, with moxifloxacin for treatment of CABP. METHODS: We did this global, double-blind, double-dummy, randomised, active-controlled, non-inferiority trial at 114 centres in North America, Latin America, Europe, and South Africa. Patients (aged ≥18 years) with clinically and radiographically confirmed pneumonia of Pneumonia Outcomes Research Team (PORT) risk class II, III, or IV were randomly assigned (1:1), via an internet-based central block randomisation procedure (block size of four), to receive either oral solithromycin (800 mg on day 1, 400 mg on days 2-5, placebo on days 6-7) or oral moxifloxacin (400 mg on days 1-7). Randomisation was stratified by geographical region, PORT risk class (II vs III or IV), and medical history of asthma or chronic obstructive pulmonary disease. The study sponsor, investigators, staff, and patients were masked to group allocation. The primary outcome was early clinical response, defined as an improvement in at least two of four symptoms (cough, chest pain, sputum production, dyspnoea) with no worsening in any symptom at 72 h after the first dose of study drug, with a 10% non-inferiority margin. The primary analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT-01756339. FINDINGS: Between Jan 3, 2013, and Sept 24, 2014, we randomly assigned 860 patients to receive solithromycin (n=426) or moxifloxacin (n=434). Patients were followed up to days 28-35 after first dose. Solithromycin was non-inferior to moxifloxacin in achievement of early clinical response: 333 (78·2%) patients had an early clinical response in the solithromycin group versus 338 (77·9%) patients in the moxifloxacin group (difference 0·29, 95% CI -5·5 to 6·1). Both drugs had a similar safety profile. 43 (10%) of 155 treatment-emergent adverse events in the solithromycin group and 54 (13%) of 154 such events in the moxifloxacin group were deemed to be related to study drug. The most common adverse events, mostly of mild severity, were gastrointestinal disorders, including diarrhoea (18 [4%] patients in the solithromycin group vs 28 [6%] patients in the moxifloxacin group), nausea (15 [4%] vs 17 [4%] patients) and vomiting (ten [2%] patients in each group); and nervous system disorders, including headache (19 [4%] vs 11 [3%] patients) and dizziness (nine [2%] vs seven [2%] patients). INTERPRETATION: Oral solithromycin was non-inferior to oral moxifloxacin for treatment of patients with CABP, showing the potential to restore macrolide monotherapy for this indication. FUNDING: Cempra.

Randomized, double-blind, multicenter phase 2 study comparing the efficacy and safety of oral solithromycin (CEM-101) to those of oral levofloxacin in the treatment of patients with community-acquired bacterial pneumonia.

Solithromycin, a new macrolide, and the first fluoroketolide in clinical development, with activity against macrolide-resistant bacteria, was tested in 132 patients with moderate to moderately severe community-acquired bacterial pneumonia (CABP) in a multicenter, double-blind, randomized phase 2 study. Patients were enrolled and randomized (1:1) to either 800 mg solithromycin orally (PO) on day 1, followed by 400 mg PO daily on days 2 to 5, or 750 mg levofloxacin PO daily on days 1 to 5. Efficacy outcome rates of clinical success at the test-of-cure visit 4 to 11 days after the last dose of study drug were comparable in the intent-to-treat (ITT) (84.6% for solithromycin versus 86.6% for levofloxacin) and microbiological-intent-to-treat (micro-ITT) (77.8% for solithromycin versus 71.4% for levofloxacin) populations. Early response success rates at day 3, defined as improvement in at least two cardinal symptoms of pneumonia, were also comparable (72.3% for solithromycin versus 71.6% for levofloxacin). More patients treated with levofloxacin than with solithromycin experienced treatment-emergent adverse events (TEAEs) during the study (45.6% versus 29.7%). The majority of TEAEs were mild or moderate gastrointestinal symptoms and included nausea (1.6% for solithromycin; 10.3% for levofloxacin), diarrhea (7.8% for solithromycin; 5.9% for levofloxacin), and vomiting (0% for solithromycin; 4.4% for levofloxacin). Six patients, all of whom received levofloxacin, discontinued the study drug due to an adverse event. Solithromycin demonstrated comparable efficacy and favorable safety relative to levofloxacin. These findings support a phase 3 study of solithromycin for the treatment of CABP. (This study has been registered at ClinicalTrials.gov under registration no. NCT01168713.).

Population pharmacokinetics of fusidic acid: rationale for front-loaded dosing regimens due to autoinhibition of clearance.

The objectives of this analysis were to develop a population pharmacokinetic (PK) model to describe the absorption and disposition of fusidic acid after single and multiple doses and to determine the effect of food on the rate and extent of bioavailability. Plasma PK data from three phase 1 studies (n = 75; n = 14 with and without food) in which healthy subjects received sodium fusidate (500 to 2,200 mg) as single or multiple oral doses every 8 h (q8h) or q12h for up to 7 days were modeled using S-ADAPT (MCPEM algorithm). Accumulation of fusidic acid after multiple doses was more than that predicted based on single-dose data. The PK of fusidic acid was best described using a time-dependent mixed-order absorption process, two disposition compartments, and a turnover process to describe the autoinhibition of clearance. The mean total clearance (% coefficient of variation) was 1.28 liters/h (33%) and the maximum extent of autoinhibition was 71.0%, with a 50% inhibitory concentration (IC(50)) of 46.3 mg/liter (36%). Food decreased the extent of bioavailability by 18%. As a result of the autoinhibition of clearance, steady state can be achieved earlier with dosing regimens that contain higher doses (after 8 days for 750 mg q12h and 1 day for 1,500 mg q12h on day 1 followed by 600 mg q12h versus 3 weeks for 500 mg q12h). Given that large initial doses autoinhibit the clearance of fusidic acid, this characteristic provides a basis for the administration of front-loaded dosing regimens of sodium fusidate which would allow for effective concentrations to be achieved early in therapy.

Comparison of plasma, epithelial lining fluid, and alveolar macrophage concentrations of solithromycin (CEM-101) in healthy adult subjects.

The steady-state concentrations of solithromycin in plasma were compared with concomitant concentrations in epithelial lining fluid (ELF) and alveolar macrophages (AM) obtained from intrapulmonary samples during bronchoscopy and bronchoalveolar lavage (BAL) in 30 healthy adult subjects. Subjects received oral solithromycin at 400 mg once daily for five consecutive days. Bronchoscopy and BAL were carried out once in each subject at either 3, 6, 9, 12, or 24 h after the last administered dose of solithromycin. Drug concentrations in plasma, ELF, and AM were assayed by a high-performance liquid chromatography-tandem mass spectrometry method. Solithromycin was concentrated extensively in ELF (range of mean [± standard deviation] concentrations, 1.02 ± 0.83 to 7.58 ± 6.69 mg/liter) and AM (25.9 ± 20.3 to 101.7 ± 52.6 mg/liter) in comparison with simultaneous plasma concentrations (0.086 ± 0.070 to 0.730 ± 0.692 mg/liter). The values for the area under the concentration-time curve from 0 to 24 h (AUC(0-24) values) based on mean and median ELF concentrations were 80.3 and 63.2 mg · h/liter, respectively. The ratio of ELF to plasma concentrations based on the mean and median AUC(0-24) values were 10.3 and 10.0, respectively. The AUC(0-24) values based on mean and median concentrations in AM were 1,498 and 1,282 mg · h/L, respectively. The ratio of AM to plasma concentrations based on the mean and median AUC(0-24) values were 193 and 202, respectively. Once-daily oral dosing of solithromycin at 400 mg produced steady-state concentrations that were significantly (P < 0.05) higher in ELF (2.4 to 28.6 times) and AM (44 to 515 times) than simultaneous plasma concentrations throughout the 24-h period after 5 days of solithromycin administration.

Pharmacokinetics and safety of single, multiple, and loading doses of fusidic acid in healthy subjects.

A phase 1 trial of fusidic acid (CEM-102), an oral fusidane class antibiotic under development for treatment of gram-positive acute bacterial skin and skin structure infections, evaluating pharmacokinetics and safety is described. A randomized, double-blinded, placebo-controlled, dose escalation study was conducted in healthy adult subjects in the fasting state. Plasma exposure after multiple doses was higher than for single doses, indicating accumulation. Loading doses designed to optimize pharmacodynamic effects were well tolerated and achieved near-steady state concentrations of CEM-102 at 24 h. CEM-102 was safe and generally well tolerated at all single, multiple, and loading doses administered.

A randomized, double-blind phase 2 study comparing the efficacy and safety of an oral fusidic acid loading-dose regimen to oral linezolid for the treatment of acute bacterial skin and skin structure infections.

Fusidic acid (CEM-102), an orally bioavailable fusidane antibiotic with a unique mode of action, is under development for treatment of acute gram-positive bacterial skin and skin structure infections, including those caused by methicillin-susceptible and methicillin-resistant Staphylococcus aureus and streptococci. A phase 2, adaptive design, randomized, double-blind, multiple-center study of 198 adult patients with cellulitis or wound infections was conducted to evaluate an oral CEM-102 loading-dose regimen (1500 mg twice per day on day 1 followed by 600 mg twice per day) compared with oral linezolid (600 mg twice per day) administered for 10-14 days. The CEM-102 loading-dose regimen demonstrated efficacy, safety, and tolerability that was comparable to linezolid for the treatment of acute gram-positive bacterial skin and skin structure infections. Clinical Trials registration. NCT00948142.

Pharmacokinetics of solithromycin (CEM-101) after single or multiple oral doses and effects of food on single-dose bioavailability in healthy adult subjects.

The pharmacokinetics of orally administered solithromycin (CEM-101), a novel fluoroketolide, were evaluated in healthy subjects in three phase 1 studies. In two randomized, double-blinded, placebo-controlled studies, escalating single oral doses of solithromycin (50 to 1,600 mg) or seven oral daily doses (200 to 600 mg) of solithromycin were administered. A third study evaluated the effects of food on the bioavailability of single oral doses (400 mg) of solithromycin. Following single doses, the median time to peak concentration (Tmax) ranged from 1.5 h to 6 h. The mean maximum measured plasma concentration (Cmax) ranged from 0.0223 µg/ml to 19.647 µg/ml, and the area under the concentration-versus-time curve from time zero to time t (AUC0-t) ranged from 0.0402 µg·h/ml to 28.599 µg·h/ml. There was no effect of high-fat food on the oral bioavailability of solithromycin. In the multiple-dose study, after 7 days, the mean maximum measured plasma solithromycin concentration at steady-state (Cmax,ss) ranged from 0.248 to 1.50 µg/ml, and the area under the concentration-versus-time curve over the final dosing interval (AUCτ) ranged from 2.310 to 18.41 µg·h/ml. These values indicate a greater than proportional increase in exposure at 200 and 400 mg but a proportional exposure at 600 mg. Median Tmax values remained constant between day 1 and day 7. Moderate accumulation ratios of solithromycin were observed after 7 days of dosing. All dose regimens of solithromycin were well tolerated, and no discontinuations due to an adverse event occurred. The human pharmacokinetic profile and tolerability of solithromycin, combined with its in vitro potency and efficacy in animal models against a broad spectrum of pathogens, support further development of solithromycin.

A phase 2, open-label study of the safety and efficacy of intravenous anidulafungin as a treatment for azole-refractory mucosal candidiasis.

BACKGROUND: Azole-refractory mucosal candidiasis is a debilitating disease frequently seen in patients who are immunosuppressed as a result of HIV, malignancy, posttransplant immunosuppressive therapy, persistent neutropenia, steroid use, or diabetes. Anidulafungin has potent activity against a broad spectrum of Candida species, including strains resistant to azoles and amphotericin B. We performed an open-label, noncomparative study to examine efficacy and safety of anidulafungin in patients with azole-refractory oropharyngeal and esophageal candidiasis. METHODS: Patients enrolled met diagnostic criteria for azole-refractory mucosal candidiasis. They received intravenous anidulafungin 100 mg on day 1 followed by daily 50-mg doses on day 2 through day 14 or for a maximum of 21 days. Primary efficacy variables were clinical response (for oropharyngeal candidiasis) and endoscopic and clinical response (for esophageal candidiasis) at the end of therapy. RESULTS: Nineteen patients were enrolled; 89% had advanced HIV infection. Clinical success was observed in 95% of patients at end of therapy, and endoscopic success was observed in 92% of patients with esophageal candidiasis. At follow-up, clinical success was maintained in 47% of patients. The most common adverse event, experienced by 4 patients, was nausea and/or vomiting. CONCLUSIONS: Anidulafungin was well tolerated and efficacious in the treatment of patients with azole-refractory esophageal and oropharyngeal candidiasis.

Safety and pharmacokinetics of intravenous anidulafungin in children with neutropenia at high risk for invasive fungal infections.

Anidulafungin is an echinocandin with activity against Candida species and Aspergillus species. Adult dosages under study are 50 mg/day for esophageal candidiasis and 100 mg/day for invasive candidiasis and aspergillosis. Little is known, however, about the safety and pharmacokinetics of anidulafungin in children. A multicenter, ascending-dosage study of neutropenic pediatric patients was therefore conducted. Patients were divided into two age cohorts (2 to 11 years and 12 to 17 years) and were enrolled into sequential groups to receive 0.75 or 1.5 mg/kg of body weight/day. Blood samples were obtained following the first and fifth doses. Anidulafungin was assayed in plasma, and pharmacokinetic parameters were determined. Safety was assessed using National Cancer Institute (NCI) common toxicity criteria. Pharmacokinetic parameters were determined for 12 patients at each dosage (0.75 mg/kg/day or 1.5 mg/kg/day). Concentrations and drug exposures were similar for patients between age cohorts, and weight-adjusted clearance was consistent across age. No drug-related serious adverse events were observed. One patient had fever (NCI toxicity grade of 3), and one patient had facial erythema, which resolved with slowing the infusion rate. Anidulafungin in pediatric patients was well tolerated and can be dosed based on body weight. Pediatric patients receiving 0.75 mg/kg/day or 1.5 mg/kg/day have anidulafungin concentration profiles similar to those of adult patients receiving 50 or 100 mg/day, respectively.