Barbara A. Chatfield

Comparative Efficacy and Safety of 4 Randomized Regimens to Treat Early Pseudomonas aeruginosa Infection in Children With Cystic Fibrosis

OBJECTIVE To investigate the efficacy and safety of 4 antipseudomonal treatments in children with cystic fibrosis with recently acquired Pseudomonas aeruginosa infection. DESIGN Randomized controlled trial. SETTING Multicenter trial in the United States. PARTICIPANTS Three hundred four children with cystic fibrosis aged 1 to 12 years within 6 months of P aeruginosa detection. INTERVENTIONS Participants were randomized to 1 of 4 antibiotic regimens for 18 months (six 12-week quarters) between December 2004 and June 2009. Participants randomized to cycled therapy received tobramycin inhalation solution (300 mg twice a day) for 28 days, with oral ciprofloxacin (15-20 mg/kg twice a day) or oral placebo for 14 days every quarter, while participants randomized to culture-based therapy received the same treatments only during quarters with positive P aeruginosa cultures. MAIN OUTCOME MEASURES The primary end points were time to pulmonary exacerbation requiring intravenous antibiotics and proportion of P aeruginosa -positive cultures. RESULTS The intention-to-treat analysis included 304 participants. There was no interaction between treatments. There were no statistically significant differences in exacerbation rates between cycled and culture-based groups (hazard ratio, 0.95; 95% confidence interval [CI], 0.54-1.66) or ciprofloxacin and placebo (hazard ratio, 1.45; 95% CI, 0.82-2.54). The odds ratios of P aeruginosa- positive culture comparing the cycled vs culture-based group were 0.78 (95% CI, 0.49-1.23) and 1.10 (95% CI, 0.71-1.71) comparing ciprofloxacin vs placebo. Adverse events were similar across groups. CONCLUSIONS No difference in the rate of exacerbation or prevalence of P aeruginosa positivity was detected between cycled and culture-based therapies. Adding ciprofloxacin produced no benefits. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00097773.

Diagnostic value of transbronchial, thoracoscopic, and open lung biopsy in immunocompetent children with chronic interstitial lung disease

OBJECTIVES To evaluate the diagnostic value of transbronchial biopsy (TBB), video-assisted thoracoscopy (VAT), and open lung biopsy (OLB) in immunocompetent children with chronic, diffuse infiltrates; to identify factors that may predict diagnosis in children requiring biopsy; to determine whether age, number of biopsies, or type of procedure are associated with diagnostic yield in children undergoing transthoracic biopsy; and to compare morbidity of VAT with that of OLB. STUDY DESIGN As part of a prospective, descriptive study to define the clinical spectrum of pediatric interstitial lung disease, 30 immunocompetent children required TBB, VAT, and/or OLB for diagnosis of diffuse infiltrates. We reviewed and analyzed the following clinical variables: age; preoperative diagnosis; type of procedure; number of lobes undergoing biopsies; durations of surgery, chest tube insertion, and hospitalization; tissue diagnosis; and complications. RESULTS Specific diagnoses were made in 50%, 60%, and 53% of patients undergoing TBB, VAT, and OLB, respectively. A variety of rare disorders was found, and tissue diagnosis confirmed the preoperative diagnosis in 25% of all procedures. For patients who underwent transthoracic biopsy, patient age of greater than 24 months was significantly associated with increased diagnostic yield, but the number of lobes biopsied and type of procedure were not. VAT was associated with shorter operating time, chest tube placement, and hospitalization when compared with OLB. The complications of VAT and OLB were comparable. CONCLUSION Lung biopsy is an important tool for the diagnosis of interstitial lung disease in immunocompetent children, but the diagnosis of many children, particularly those aged 2 years or younger, remains uncertain.

EUR-1008 pancreatic enzyme replacement is safe and effective in patients with cystic fibrosis and pancreatic insufficiency

BACKGROUND EUR-1008 (Zenpep [pancrelipase]) is a new, enteric-coated, porcine-derived pancreatic enzyme product (PEP) developed for the treatment of cystic fibrosis (CF) patients with malabsorption associated with exocrine pancreatic insufficiency (EPI). Unlike currently marketed PEPs, EUR-1008 contains the label-claimed lipase content. Safety and efficacy were assessed in younger (<7 years) and older (> or =7 years) CF patients with EPI. METHODS Two multicenter studies were conducted: a randomized, double-blind, placebo-controlled, crossover trial in patients > or =7 years of age (N=34) and a supplemental, open-label study in children <7 years of age (N=19). Use of any medications altering gastric pH/motility was prohibited during the studies. Outcome measures in the randomized trial included changes in the coefficient of fat absorption (CFA), coefficient of nitrogen absorption (CNA), and signs/symptoms of malabsorption for EUR-1008 vs. placebo. Outcome measures in the supplemental study included safety and response (defined as no steatorrhea and no overt signs/symptoms of malabsorption) to EUR-1008 vs. previous enzyme treatment. RESULTS In the randomized trial, EUR-1008 treatment compared to placebo resulted in a significantly higher mean CFA (88.3% vs. 62.8%, respectively) and CNA (87.2% vs. 65.7%, respectively) (both p<0.001) and reduced the incidence of malabsorption signs and symptoms in 32 evaluable patients. In the supplemental study, 11 of 19 patients met the criteria for responder with EUR-1008 at the end of the study vs. 10 of 19 patients at screening (previous PEP), and improvements in clinical symptoms were reported with EUR-1008 treatment. EUR-1008 was safe and well tolerated, and no serious drug-related AEs were reported in either study. CONCLUSIONS EUR-1008 was safe, well tolerated, and effective in CF patients of all ages with EPI-associated malabsorption in two clinical trials. Treatment led to clinically and statistically significant improvements in CFA and CNA in the randomized study, and control of malabsorption and clinical symptoms in both studies.

Long-term treatment with oral N-acetylcysteine: Affects lung function but not sputum inflammation in cystic fibrosis subjects. A phase II randomized placebo-controlled trial

PURPOSE To evaluate the effects of oral N-acetylcysteine (NAC), which replenishes systemic glutathione, on decreasing inflammation and improving lung function in CF airways. METHODS A multicenter, randomized, double-blind proof of concept study in which 70 CF subjects received NAC or placebo orally thrice daily for 24 weeks. ENDPOINTS primary, change in sputum human neutrophil elastase (HNE) activity; secondary, FEV(1) and other clinical lung function measures; and safety, the safety and tolerability of NAC and the potential of NAC to promote pulmonary hypertension in subjects with CF. RESULTS Lung function (FEV(1) and FEF(25-75%)) remained stable or increased slightly in the NAC group but decreased in the placebo group (p=0.02 and 0.02). Log(10) HNE activity remained equal between cohorts (difference 0.21, 95% CI -0.07 to 0.48, p=0.14). CONCLUSIONS NAC recipients maintained their lung function while placebo recipients declined (24 week FEV1 treatment effect=150 mL, p<0.02). However no effect on HNE activity and other selected biomarkers of neutrophilic inflammation were detected. Further studies on mechanism and clinical outcomes are warranted.

A survey of the utilization of anti-pseudomonal beta-lactam therapy in cystic fibrosis patients.

The purpose of this study was to characterize the utilization of anti‐pseudomonal beta‐lactam antibiotics in the treatment of acute pulmonary exacerbations (APE) among Cystic Fibrosis Foundation (CFF)‐accredited care centers. An anonymous national cross‐sectional survey of CFF‐accredited care centers was performed using an electronic survey tool (SurveyMonkey.com®). One hundred and twenty‐one of 261 centers completed the survey (46%) representing 56% (14,856/26,740) of patients in the CFF Patient Registry. One hundred and nineteen of 121 (98%) respondents reported using beta‐lactams for the treatment of APE. Intermittent dosing regimens constituted 155/167 (93%) reported regimens, while extended infusions were 12/167 (7%). Ceftazidime was the most commonly utilized beta‐lactam comprising 74/167 (44%) of all infusions (intermittent and extended) of which 70/74 (95%) were intermittent infusions. The majority of intermittent ceftazidime regimens (56/70; 80%) were at doses lower than CFF and European guidelines recommended doses. In conclusion, a great majority of respondents use intermittent anti‐pseudomonal beta‐lactam antibiotics, with over half of respondents utilizing lower than guidelines recommended doses. While this is of concern, it is not known if optimization of dosing strategies according to guidelines recommendations will result in clinical benefit. Pediatr. Pulmonol. 2011; 46:987–990.

International phase III trial of liprotamase efficacy and safety in pancreatic-insufficient cystic fibrosis patients

BACKGROUND Most cystic fibrosis (CF) patients have exocrine pancreatic insufficiency (EPI) and need supplementation with pancreatic enzyme replacement therapy (PERT). Liprotamase, a novel non-porcine PERT containing highly purified biotechnology-derived lipase, protease, and amylase, has successfully undergone initial efficacy and safety testing. METHODS In this international phase III parallel-group, randomized-withdrawal, double-blind placebo-controlled trial, CF patients with EPI 7 years and older, including nutritionally and functionally compromised individuals, underwent baseline testing for coefficients of fat and nitrogen absorption (CFA and CNA) and stool weight and frequency while off PERT. After an open-label treatment period with liprotamase, subjects were randomized 1:1 to one liprotamase or placebo capsule taken with 3 meals and 2 snacks per day. The dose was fixed and increases were not allowed. The same measurements were obtained again after treatment with double-blind study drug or placebo. RESULTS 138 subjects were randomized. The adjusted least squares mean (LSM) difference between the treatment and placebo groups for change in CFA was 15.1% (p=0.001) for the subgroup with baseline CFA <40%, 8.6% (p=0.006) for subjects with baseline CFA ≥40%, and 10.6% (p<0.001) for the overall intent-to-treat population. Similar results were seen for change in CNA. Stool weight was significantly decreased although not stool frequency. Liprotamase was well tolerated with no safety concerns identified. CONCLUSIONS In a CF patient population reflective of that encountered in clinical practice, this trial demonstrated that liprotamase at a fixed dose of one capsule per meal or snack (5 capsules per day) was well tolerated and significantly increased fat absorption as measured by improvement in CFA, significantly increased protein absorption as measured by improvement in CNA, and significantly decreased stool weight.

Clostridium difficile Infection and Proton Pump Inhibitor Use in Hospitalized Pediatric Cystic Fibrosis Patients

Children with cystic fibrosis (CF) often take proton pump inhibitors (PPIs), which helps improve efficacy of fat absorption with pancreatic enzyme replacement therapy. However, PPI use is known to be associated with Clostridium difficile-(C. diff-) associated diarrhea (CDAD). We retrospectively evaluated the incidence of C. diff infection from all pediatric hospital admissions over a 5-year period at a single tertiary childrens hospital. We found significantly more C. diff-positive stool tests in hospitalized patients with CF compared to patients with no diagnosis of CF. However, use of a PPI was not associated with an increased risk of CDAD in hospitalized CF patients. In summary, C. diff infection is more common in hospitalized pediatric CF patients although PPI use may not be a risk factor for CDAD development in this patient population.

High dose intermittent ticarcillin–clavulanate administration in pediatric cystic fibrosis patients

BACKGROUND The Intermountain Cystic Fibrosis Pediatric Center utilizes ticarcillin-clavulanate 400mg/kg/day divided every 6h, (maximum 24 g/day). This dosing strategy is higher than the Cystic Fibrosis Foundation (CFF) recommendations and the Food and Drug Administration (FDA) approved package labeling. The purpose is to determine the safety of this dosing regimen. METHODS A retrospective study of pediatric cystic fibrosis (CF) patients admitted from January 1, 2005 to December 31, 2009 who received the dosing regimen for at least 7 days. Baseline and follow-up laboratory parameters were recorded. Statistical analysis was performed. RESULTS 127 patients met inclusion criteria. The mean (+ or - SD) ticarcillin dose was 3.5 g (+ or - 2.16) every 6 h; while the mean (+ or - SD) total ticarcillin dose was 13.5 g (+ or - 6.5) per day. No significant differences occurred in liver function tests, white blood count, and platelet count from baseline. Serum creatinine showed a statistically significant decrease from baseline. CONCLUSIONS Higher than FDA approved doses of ticarcillin-clavulanate may be safely used in the treatment of exacerbations in pediatric cystic fibrosis patients.

Population Pharmacokinetic and Pharmacodynamic Modeling of High-Dose Intermittent Ticarcillin-Clavulanate Administration in Pediatric Cystic Fibrosis Patients

BACKGROUND The Intermountain Cystic Fibrosis Pediatric Center utilizes ticarcillin-clavulanate 400 mg/kg/d divided every 6 hours, (maximum 24 g/d). This dosing strategy is higher than the Food and Drug Administration (FDA)-approved package labeling. We evaluated the microbiologic efficacy of this dosing regimen. OBJECTIVES The primary study objective was to predict the pharmacokinetic (PK) and pharmacodynamic (PD) MIC breakpoints (the highest MIC with a probability of target attainment [PTA] of at least 90%) for the bacteriostatic and bactericidal targets of ticarcillin activity against Pseudomonas aeruginosa using the study dosing regimen. A secondary objective was to evaluate the tolerability profile of the higher ticarcillin-clavulanate dosing regimen in children with cystic fibrosis (CF). METHODS This was a population-based PK-PD modeling study of pediatric CF patients admitted from January 1, 2005 to December 31, 2009 who received the dosing regimen for at least 7 days. Population PK and PD models were used to estimate PK and PD parameters for 127 clinically evaluable patients. A 10,000-patient Monte Carlo simulation was performed to estimate the target time in which free drug concentrations exceeded the MIC of the infecting organism. The 2 PK-PD targets of microbiologic efficacy included ≥30% for bacteriostasis and ≥50% for bactericidal effects of ticarcillin-clavulanate at higher than FDA-approved doses. RESULTS A total of 127 patients (age, 0-19 years) met inclusion criteria. Serum concentration levels were modeled in this patient population using published PK parameters with intermittent ticarcillin peak concentrations reaching 288 (93.4) mg/L. The model predicted the PTA of the MICs for P. aeruginosa with a near-maximal bactericidal PK-PD MIC breakpoint of 16 μg/mL and a bacteriostasis PK-PD MIC breakpoint of 32 μg/mL. CONCLUSIONS The results of our simulation suggest that in this select pediatric population, higher than FDA-approved doses of ticarcillin-clavulanate were effective in achieving bactericidal effects among pseudomonal isolates with MICs <16 μg/mL. Bacteriostatic and bactericidal effects were not frequently achieved among P. aeruginosa isolates with MICs >32 μg/mL. Additional studies are warranted to determine the clinical effectiveness of this dosing regimen.

Cystic Fibrosis and Celiac Disease: Both Can Occur Together

Cystic fibrosis (CF) is associated with malnutrition resulting from exocrine pancreatic insufficiency, bacterial overgrowth, and intestinal dysmotility as a consequence of hyperviscous intestinal contents. Celiac disease (CD) is an autoimmune disease associated with gluten exposure leading to such symptoms as malnutrition, abdominal pain, and diarrhea. CD is common in many countries, including the United States, and it should be considered in any patient that presents with malnutrition, abdominal pain, or diarrhea. Other autoimmune diseases, including type 1 diabetes mellitus, autoimmune thyroiditis, and autoimmune hepatitis can be associated with CD. Various serum antibody tests are available to diagnose CD, although the gold standard of CD diagnosis is esophagogastroduodenoscopy with multiple duodenal biopsies. Treatment of CD includes lifelong removal of dietary gluten, which leads to resolution of malnutrition symptoms and reduces the risk of developing other autoimmune diseases and small bowel lymphoma. The prevalence of CD in CF patients is higher than in the general population, and any CF patient showing continuing signs and symptoms of malabsorption should be screened for CD.