Safety and pharmacokinetics of extended use of palivizumab in Saudi Arabian infants and children.

BACKGROUND: The peak season of respiratory syncytial virus (RSV) infections in warmer climates may extend beyond the typical five-month RSV season of temperate regions. Additional monthly doses of palivizumab may be necessary in warmer regions to protect children at high risk for serious infection by the RSV. METHODS: In a Phase II, single-arm, single-center, non-comparative, open-label, prospective study conducted in Saudi Arabia, children at high risk for RSV infection received up to seven monthly injections of palivizumab (15 mg/kg) during the 2000-2001 RSV season. Key enrollment criteria were no previous exposure to palivizumab and gestational age ≤35 weeks, ≤6 months of age at enrollment, or chronic lung disease and ≤24 months of age at enrollment. We wished to assess the safety, immunogenicity, and pharmacokinetics of palivizumab as an extended seven-dose regimen. RESULTS: Of 18 enrolled patients, 17 patients received seven palivizumab injections. Seven adverse events (AEs) occurred in five patients. Bronchiolitis was the most commonly reported AE. Six serious AEs occurred in four patients. No AEs were considered related to palivizumab. Trough levels of palivizumab in serum were >40 µg/mL in most patients after the first injection and in 16/18 and 14/17 patients after the fourth and sixth injections, respectively. Except for one patient at one visit, the anti-palivizumab titer was <1:10 at all visits. CONCLUSION: These data suggest that an extended palivizumab regimen of up to seven monthly doses during the RSV season exhibited an acceptable safety profile in children at high risk for RSV infection in Saudi Arabia.

Palivizumab use in Japanese infants and children with immunocompromised conditions.

A total of 27/28 (96%) immunocompromised Japanese children received ≥ 4 doses of palivizumab. No respiratory syncytial virus-associated hospitalizations occurred. Mean palivizumab trough concentrations were 59.0 and 91.8 µg/mL 30 days after the 1st and 4th doses, respectively. Of 28 subjects, 27 (96%) experienced ≥ 1 adverse event and 7 (25%) experienced ≥ 1 serious adverse event, none of which was considered related to palivizumab.

Three monthly doses of palivizumab are not adequate for 5-month protection: a population pharmacokinetic analysis.

Recent guidelines in British Columbia, Canada have suggested that the use of a maximum of 3 monthly doses of palivizumab 15 mg/kg intramuscularly for RSV immunoprophylaxis of high risk infants born prior to the RSV season is adequate to provide protection against severe RSV disease for a 5-month RSV season. Efficacy was established, however, with 2 large, randomized controlled clinical studies using 5 monthly doses of immunoprophylaxis. To evaluate the differences in expected palivizumab exposures between the 2 dosing regimens (3 vs 5 monthly doses across a 5-month period), we used a population pharmacokinetic (PK) model that was developed using palivizumab PK data collected from 22 clinical studies with a total of 1800 subjects. This model adequately described observed palivizumab concentrations from the different pediatric studies and was subsequently used to simulate expected palivizumab serum concentrations for 3 monthly doses compared with 5 monthly doses in children younger than 24 months with chronic lung disease of prematurity and infants younger than 6 months postnatal age who were born at ≤ 35 weeks gestational age. Results from the population PK model indicated lower serum concentrations of palivizumab during the fourth and fifth months, after an abbreviated 3-monthly-dose regimen when compared with the mean trough concentrations seen with the 5-monthly-dose regimen studied in the pivotal clinical trials in premature infants. Specifically, during the fourth and fifth months, 52% and 85%, respectively, would have levels below the lowest concentration (fifth percentile) in those receiving the 5-monthly-dose regimen. Simulations using this model did not support a 3-monthly-dose regimen to protect against severe RSV disease during the typical 5-month season.

A prospective, open-label, non-comparative study of palivizumab prophylaxis in children at high risk of serious respiratory syncytial virus disease in the Russian Federation.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections (LRTIs) in children globally. Predisposing conditions for the development of serious RSV disease include preterm infants and those with cardiopulmonary illness, including congenital heart disease (CHD) and bronchopulmonary dysplasia (BPD). No vaccine is currently approved for the prevention of RSV infection. It is recommended that children at high risk be prophylactically administered palivizumab, a monoclonal antibody that has been shown in a number of clinical studies to reduce hospitalization rates due to serious RSV infection. The objective of the current study was to determine the safety and effectiveness of palivizumab in preventing serious RSV disease in high-risk children in the Russian Federation. Children at high risk of serious RSV disease (ie, born at ≤ 35 wk gestational age and ≤ 6 mo of age, and/or aged ≤ 24 mo with BPD or hemodynamically significant CHD) were enrolled. Subjects were to receive 3 to 5 monthly injections of palivizumab 15 mg/kg (depending on the month of the initial injection) over the RSV season. The primary endpoint was RSV-related hospitalizations. Adverse events (AEs) were reported through 100 days following the final injection. RESULTS: One hundred subjects received ≥ 1 injection of palivizumab; 94 completed their dosing schedule. There were no RSV hospitalizations or deaths. Six of 7 subjects hospitalized for respiratory/cardiac conditions had an RSV test, which was negative in all cases. Three non-serious AEs (acute intermittent rhinitis and rhinitis, 1 subject; atopic dermatitis, 1 subject) were considered possibly related to palivizumab. All other AEs were mild or moderate and considered not related/probably not related to palivizumab. CONCLUSION: Palivizumab was generally well tolerated and effectively prevented serious RSV infection in a mixed population of high-risk children in the Russian Federation. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01006629.

Comparison of risk factors between preterm and term infants hospitalized for severe respiratory syncytial virus in the Russian Federation.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in infants. Preterm birth, in addition to several demographic and environmental factors, increases the risk for development of severe RSV infection. The purpose of this study was to describe differences in risk factors and protective factors between preterm birth (up to 35 weeks' gestational age) and term infants hospitalized for RSV lower respiratory tract infection in the Russian Federation during the 2008-2009 RSV season. METHODS: Infants up to two years of age hospitalized for a lower respiratory tract infection in Moscow, St Petersburg, and Tomsk were tested for RSV. Patient data, including risk factors and protective factors for RSV, were captured at admission. Differences in these factors were compared between preterm and term patients. RESULTS: A total of 519 infants hospitalized for lower respiratory tract infection were included in the study. Of these, 197 infants (182 term and 15 preterm) tested positive for RSV. Of all hospitalizations, 51.7% (15/29) of preterm infants versus 37.1% (182/490) of term infants had confirmed RSV (P = 0.118). Among the RSV-positive patients, preterm infants were more likely to have a lower weight at admission (P = 0.050), be of multiple gestation (P < 0.001), have more siblings (P = 0.013), and have more siblings under the age of eight years (P < 0.007) compared with term patients. The preterm infants were less likely to be breastfed (P < 0.001) and more likely to have older mothers (P = 0.050). CONCLUSION: Compared with term infants, RSV was a more prevalent cause of hospitalization for lower respiratory tract infection in preterm infants. Of infants hospitalized for RSV, preterm infants were more likely to have additional risk factors for severe RSV. These findings suggest that preterm infants may be exposed to a combination of more strongly interrelated risk factors for severe RSV than term infants.

Molecular characterization of Staphylococcus aureus isolates from a 2005 clinical trial of uncomplicated skin and skin structure infections.

A clinical trial of uncomplicated skin and skin structure infections (39 locations in 19 states) observed that community-associated or community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) represented 23% of all pathogens at baseline culture and 53% of 190 S. aureus isolates. CO-MRSA strains typically were Panton-Valentine leukocidin (PVL) positive (95%), contained staphylococcal cassette chromosome mec type IVa (99%), were USA300 or USA400 clones (92%), and exhibited minimal coresistances (macrolides and/or fluoroquinolones). Clinical results remained identical (89% cures) regardless of the antimicrobial used or CO-MRSA molecular patterns, PVL production, or antimicrobial susceptibility profiles.

Role for 5-day, once-daily extended-release clarithromycin in acute bacterial exacerbation of chronic bronchitis.

BACKGROUND: Clarithromycin is commonly dosed for 7 or more days in patients with acute bacterial exacerbation of chronic bronchitis (ABECB). Studies with other antibiotics have shown equivalent efficacy, reduced/similar frequency of adverse events, improved adherence and patient satisfaction, and lower treatment costs with a shorter treatment course. PATIENTS AND METHODS: The study population was derived from two multicenter, randomized, double-blind (North America)/single-blind (France) comparative trials in which outpatients at least 35 years old with a presumptive diagnosis of obstructive ABECB were randomized to receive clarithromycin extended-release (ER) 1000 mg once daily for 5 days or a comparator agent--clarithromycin immediate-release (IR) 500 mg twice daily for 7 days (in North America) or telithromycin 800 mg once daily for 5 days (in France). RESULTS: A total of 818 patients were randomized (411 to clarithromycin ER and 407 to a comparator agent). The clinical cure rate in clinically evaluable patients at the follow-up visit was 90% each for the clarithromycin ER group (318/353) and the comparator group (318/355). The patient bacteriological cure rate and the overall target pathogen eradication rate in clinically and bacteriologically evaluable patients were each 92% for the clarithromycin ER group (155/168 and 189/205, respectively) and 93% for the comparator group (147/158 and 183/197, respectively) at the follow-up visit. The study drugs were generally well tolerated, with < 2% of patients discontinuing their treatment prematurely due to a drug-related adverse event. The incidence of drug-related adverse events was 18% (73/411) in the clarithromycin ER group and 24% (97/407) in the comparator group. Clarithromycin ER-treated patients reported statistically significantly fewer episodes of abdominal pain than did patients treated with a comparator agent (0.2% vs. 1.7%, respectively; p = 0.037). This combined analysis is limited by differing blinding methods, comparator agents, and their duration of administration. Furthermore, many patients were excluded from the clinically and bacteriologically evaluable group due to lack of a pretreatment target pathogen. CONCLUSION: A once daily, 5-day clarithromycin ER regimen appears to be a suitable choice for treating patients with ABECB.

Efficacy, tolerability, and parent reported outcomes for cefdinir vs. high-dose amoxicillin/clavulanate oral suspension for acute otitis media in young children.

OBJECTIVES: To compare efficacy, tolerability, and parental satisfaction of cefdinir and high-dose amoxicillin/clavulanate oral suspensions given to young children with non-refractory acute otitis media (AOM) based on clinical endpoints and outcomes measures. RESEARCH DESIGN AND METHODS: This was an investigator-blinded, multicenter study in which 318 children 6 months through 6 years of age with a clinical diagnosis of AOM were randomized to receive 10 days of either cefdinir (14 mg/kg divided BID) or high-dose amoxicillin/clavulanate (90/6.4 mg/kg divided BID). MAIN OUTCOME MEASURES: Investigators evaluated clinical response at an end-of-therapy (EOT) office visit conducted on day 12-15. Outcomes of satisfaction, tolerability, and adherence were also assessed at that visit using an Otitis Parent Questionnaire. RESULTS: The treatment groups were similar at baseline with respect to patient demographics. At the EOT visit, for cefdinir and amoxicillin/clavulanate, respectively, intent-to-treat (ITT) clinical cure rates were 82% (129/158) and 85% (134/158) (p = 0.547; 95% confidence interval [CI] -11.7 to 5.4) and per-protocol cure rates were 82% (123/150) and 90% (129/143) (p = 0.045; 95% CI -16.4 to 0.0). This difference was driven primarily by reduced cefdinir response in patients with recurrent AOM (p = 0.010) and those younger than 24 months (p = 0.039). Comparing cefdinir with amoxicillin/clavulanate, parents more often reported significantly better ease of use (89% vs. 57%; p < 0.0001), better taste (85% vs. 39%; p < 0.0001), and better adherence (at least 95% of doses) (82% vs. 61%; p < 0.0001). Diarrhea/loose stools were more common in the amoxicillin/clavulanate group than in the cefdinir group (28% vs. 18%, respectively; p = 0.0341). One patient in the cefdinir group and eight patients in the amoxicillin/clavulanate group withdrew from the study prematurely due to at least one adverse event (p = 0.0364). Study limitations included assessment of clinical recurrence by telephone call rather than office visit, exclusion of children with refractory AOM, and no assessment of middle ear microbiology. CONCLUSIONS: Among young children with non-refractory AOM, cefdinir was as efficacious as high-dose amoxicillin/clavulanate in the ITT group, but somewhat less effective in per-protocol analysis. From the parental perspective, cefdinir was easier to administer, had a better taste, caused less diarrhea, and resulted in higher treatment adherence than high-dose amoxicillin clavulanate.

Cefdinir vs. cephalexin for mild to moderate uncomplicated skin and skin structure infections in adolescents and adults.

OBJECTIVES: To compare the efficacy and safety of cefdinir to that of cephalexin in adolescents and adults with mild to moderate uncomplicated skin and skin structure infections (USSSI). RESEARCH DESIGN AND METHODS: This was an investigator-blinded, multicenter study in which patients at least 13 years of age with USSSI were randomized to receive 10 days of cefdinir 300 mg twice daily (BID) or cephalexin 250 mg four times daily (QID). Patients were evaluated at baseline, by telephone on Days 3-5, and during office visits on Days 12-14 (end-of-therapy [EOT] visit) and Days 17-24 (test-of-cure [TOC] visit). MAIN OUTCOME MEASURES: Clinical response was evaluated at the TOC visit. Patient reported outcomes, including a usefulness questionnaire, were also assessed. RESULTS: Three hundred and ninety-one patients were treated. The treatment groups were well matched with regard to demographic characteristics and types of infection. Abscess(es) (26%), wound infection (24%), and cellulitis (21%) were the most common infections. At the TOC visit, the clinical cure rate for both treatment groups was 89% (151/170 for cefdinir and 154/174 for cephalexin) in clinically evaluable patients (95% CI for difference in cure rates [-6.7 to 7.3]). In the intent-to-treat analysis, cure rates were 83% for cefdinir vs. 82% for cephalexin. Clinical cure rates for infections caused by methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus were 93% (37/40) and 92% (35/38) for cefdinir vs. 91% (29/32) and 90% (37/41) for cephalexin (p > 0.999 comparing treatment groups for MSSA; p > 0.999 for MRSA). The usefulness questionnaire demonstrated that cefdinir was more highly rated in the mean composite score (87.4 vs. 83.6, p = 0.04), with the difference primarily due to the respondents' preference for the convenience of taking the study medication (mean score 93.5 vs. 74.1 for cephalexin, p < 0.001). The study had the following limitations: the requirement for culture at baseline likely skewed the enrollment of patients towards those with abscesses; the results of culture in patients with USSSIs are often nonspecific; in some patients entering the study with a diagnosis of cellulitis, the cellulitis was associated with an abscess; and, incision and drainage (I&D), spontaneous drainage, and needle aspiration are likely to have contributed to clinical response for purulent infections, and in particular MRSA-associated infections. Both study drugs were well tolerated. The most common treatment-related adverse events were diarrhea (10% cefdinir, 4% cephalexin, p = 0.017), nausea (3% and 6%, respectively, p = 0.203), and vaginal mycosis (3% and 6% of females, respectively, p = 0.500). CONCLUSIONS: This study demonstrated that empiric coverage of USSSIs with cephalosporin therapy remains an appropriate clinical strategy. MRSA infections responded well in both arms of the study, suggesting that the choice of a cephalosporin did not adversely affect patient outcome. However, cephalosporins do not have accepted, clinically relevant in vitro activity against MRSA. Hence, the clinical response rates seen in this study against MRSA infections must be interpreted with caution. Cefdinir was more highly rated than cephalexin in a composite usefulness assessment.

A prospective, randomized trial examining the efficacy and safety of clarithromycin in combination with ethambutol, rifabutin, or both for the treatment of disseminated Mycobacterium avium complex disease in persons with acquired immunodeficiency syndrome.

This multicenter, randomized, open-label phase 3 clinical trial compared the safety and efficacy of 3 clarithromycin-containing combination regimens for the treatment of disseminated Mycobacterium avium complex (MAC) disease in persons with acquired immunodeficiency syndrome. A total of 160 eligible patients with bacteremic MAC disease were randomized to receive clarithromycin with either ethambutol (C+E), rifabutin (C+R), or both (C+E+R) for 48 weeks. After 12 weeks of treatment, the proportion of subjects with a complete microbiologic response was not statistically significantly different among treatment arms: the proportion was 40% in the C+E group, 42% in the C+R group, and 51% in the C+E+R group (P=.454). The proportion of patients with complete or partial responses who experienced a relapse while receiving C+R (24%) was significantly higher than that of patients receiving C+E+R (6%; P=.027) and marginally higher than that of patients receiving C+E (7%; P=.057). Subjects in the C+E+R group had improved survival, compared with the C+E group (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.23-0.83) and the C+R group (HR, 0.49; 95% CI, 0.26-0.92).

A controlled, double-blind, multicenter study comparing clarithromycin extended-release tablets and levofloxacin tablets in the treatment of community-acquired pneumonia.

BACKGROUND: Macrolides and fluoroquinolones are frequently used for the empiric treatment of community-acquired pneumonia (CAP). OBJECTIVE: The aim of the study was to compare the safety profile and efficacy of clarithromycin extended-release (ER) tablets with those of levofloxacin tablets for the treatment of CAP in ambulatory adult patients. METHODS: In a Phase III, double-blind, randomized, parallel-group, multicenter study, ambulatory adult patients (> or = 18 years) with signs and symptoms of CAP received a 7-day course of treatment with either clarithromycin ER (two 500-mg tablets once daily) or levofloxacin (two 250-mg tablets once daily). A diagnosis of CAP was confirmed by radiography of the chest and physical examination, and sputum samples were analyzed to identify etiologic pathogen(s). Tolerability was assessed through subjective reports of adverse events and through changes in physical findings, concomitant medications, and laboratory values. RESULTS: There were no statistically significant differences between treatment groups in terms of sex, age, race, or body weight. The mean age was 50 years (range, 18-91 years). Of 299 patients randomized and treated, 252 were clinically evaluable (128 clarithromycin ER, 124 levofloxacin). The 95% CI for the difference between cure rates demonstrated equivalence of the 2 treatments. Among clinically evaluable patients at the test-of-cure visit, clinical cure rates were 88% (113/128) and 86% (107/124), and radiographic success rates were 95% (117/123) and 88% (104/118) for clarithromycin ER and levofloxacin, respectively. Both treatment regimens were effective in resolving and improving clinical signs and symptoms of CAP. Among clinically and bacteriologically evaluable pa- tients, bacteriologic cure rates were 86% (80/93) and 88% (85/97) for clarithromycin ER and levofloxacin, respectively. No statistically significant differences were observed between the 2 treatment groups in the overall incidence of adverse events. CONCLUSIONS: Clarithromycin ER demonstrated equivalent efficacy and tolerability to the fluoroquinolone levofloxacin in a group of ambulatory adult patients with CAP. Clarithromycin ER also appeared to be safe in the population studied.

A prospective, double-blind, multicenter study comparing clarithromycin extended-release with trovafloxacin in patients with community-acquired pneumonia.

BACKGROUND: Treatment guidelines for community-acquired pneumonia (CAP) generally include use of a macrolide, a fluoroquinolone, or doxycycline, although there is some debate concerning the use of a fluoroquinolone. OBJECTIVE: The efficacy and tolerability of a new once-daily, extended-release (ER) formulation of clarithromycin were compared with those of a fluoroquinolone, trovafloxacin, in the treatment of patients with CAP. METHODS: This was a prospective, multicenter, double-blind, double-dummy, parallel-group trial in which outpatients were randomized to receive 7 days of once-daily treatment with either clarithromycin ER (two 500-mg tablets) or trovafloxacin (200 mg). Eligible patients were > or = 18 years old with signs and symptoms of pneumonia, radiologic evidence of an acute infiltrate, and mild to moderate infection, as classified by the investigator. RESULTS: One hundred seventy-six patients were randomized to study treatment. They were primarily white (88%) and equally distributed between the sexes (52% female). Their mean (+/-SD) age was 47.5 +/- 16.2 years. Results were similar between treatment groups in rates of clinical cure, microbiologic cure, bacteriologic eradication, and radiologic success at the test-of-cure visit (14-21 days posttreatment) for both the per-protocol and intent-to-treat analyses. Among clinically evaluable patients, clinical cure rates for clarithromycin ER and trovafloxacin were 87% (74/85) and 95% (63/66), respectively, and radiologic success rates were 95% (80/84) and 95% (63/66), respectively. There were no statistically significant differences between groups. In clinically and microbiologically evaluable patients, overall bacteriologic eradication rates were 89% (85/95) for clarithromycin ER and 96% (64/67) for trovafloxacin, with no significant differences between groups. Both antibiotics demonstrated high eradication rates against target microorganisms. There were no clinically meaningful differences in the incidence of specific drug-related adverse events. The majority of drug-related adverse events (>90%) were considered mild or moderate and resolved without the need for additional treatment. CONCLUSIONS: Although the study was prematurely terminated, resulting in inadequate power to demonstrate equivalence, once-daily clarithromycin ER was effective and well tolerated in the treatment of ambulatory adult (age > or = 18 years) outpatients with CAP.