Comparison of Culture With Antibiogram to Next-Generation Sequencing Using Bacterial Isolates and Formalin-Fixed, Paraffin-Embedded Gastric Biopsies.

BACKGROUND & AIMS: The decline in Helicobacter pylori cure rates emphasizes the need for readily available methods to determine antimicrobial susceptibility. Our aim was to compare targeted next-generation sequencing (NGS) and culture-based H pylori susceptibility testing using clinical isolates and paired formalin-fixed, paraffin-embedded (FFPE) gastric biopsies. METHODS: H pylori isolates and FFPE tissues were tested for susceptibility to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifabutin using agar dilution and NGS targeted to 23S rRNA, gyrA, 16S rRNA, pbp1, rpoB and rdxA. Agreement was quantified using κ statistics. RESULTS: Paired comparisons included 170 isolates and FFPE tissue for amoxicillin, clarithromycin, metronidazole, and rifabutin and 57 isolates and FFPE tissue for levofloxacin and tetracycline. Agreement between agar dilution and NGS from culture isolates was very good for clarithromycin (κ = 0.90012), good for levofloxacin (κ = 0.78161) and fair for metronidazole (κ = 0.55880), and amoxicillin (κ = 0.21400). Only 1 isolate was resistant to tetracycline (culture) and 1 to rifabutin (NGS). Comparison of NGS from tissue blocks and agar dilution from isolates from the same stomachs demonstrated good accuracy to predict resistance for clarithromycin (94.1%), amoxicillin (95.9%), metronidazole (77%), levofloxacin (87.7%), and tetracycline (98.2%). Lack of resistance precluded comparisons for tetracycline and rifabutin. CONCLUSIONS: Compared with agar dilution, NGS reliably determined resistance to clarithromycin, levofloxacin, rifabutin, and tetracycline from clinical isolates and formalin-fixed gastric tissue. Consistency was fair for metronidazole and amoxicillin. Culture-based testing can predict treatment outcomes with clarithromycin and levofloxacin. Studies are needed to compare the relative ability of both methods to predict treatment outcomes for other antibiotics.

Absence of QT prolongation after administration of a 24-mg bimodal-release ondansetron pill (RHB-102).

OBJECTIVES: Prospective data evaluating the effect of ondansetron on the corrected QT (QTc) interval is lacking in emergency department clinical use. As part of a randomized trial of a 24-mg bimodal-release ondansetron (RHB-102) pill, we tested the effect of RHB-102 compared to placebo on QTc change. METHODS: This was a planned safety outcome analysis within a multicenter, double-blind, placebo-controlled trial. The trial compared the effects of RHB-102 among patients ≥12 years who presented to 21 centers with symptoms of acute gastroenteritis. Patients with an initial baseline electrocardiogram as well as a follow-up electrocardiogram 4 h later were included in the analysis. The safety endpoint for this analysis was the change from baseline in QTc interval at 4 h, the median time at which ondansetron serum level peaks. RESULTS: A total of 147 patients were included with a mean baseline QTc in the RHB-102 and placebo arms of 410 and 406 ms, respectively. There was no difference in the change in QTc at 4 h post-study drug administration between the RHB-102 (+4, 95% CI 1-8 ms) and placebo group (+5, 95% CI 1-9 ms). In the RHB-102 arm, 6.6% of patients had a QTc change >30 ms and in the placebo arm 3.6% (p = 0.48). No patient in either arm had a QTc change >60 ms after study drug administration. CONCLUSION: In patients with normal baseline QTc, 24-mg bimodal-release ondansetron did not prolong the QTc in comparison to placebo.

Rifabutin-Based Triple Therapy (RHB-105) for Helicobacter pylori Eradication: A Double-Blind, Randomized, Controlled Trial.

BACKGROUND: Although consensus supports eradication of Helicobacter pylori infections, antimicrobial resistance has substantially reduced eradication rates with most current therapies. OBJECTIVE: To assess the effectiveness of a novel rifabutin-based therapy (RHB-105) for H pylori eradication. DESIGN: Phase 3, double-blind trial (ERADICATE Hp2). (ClinicalTrials.gov: NCT03198507). SETTING: 55 clinical research sites in the United States. PARTICIPANTS: 455 treatment-naive adults with epigastric discomfort and confirmed H pylori infection. INTERVENTION: RHB-105 (amoxicillin, 3 g; omeprazole, 120 mg; and rifabutin, 150 mg) versus active comparator (amoxicillin, 3 g, and omeprazole, 120 mg), given as 4 capsules every 8 hours for 14 days. MEASUREMENTS: Between-group difference for H pylori eradication rate, demonstrated by 13C urea breath test 4 weeks after treatment, analyzed by using the χ2 test. RESULTS: In the intention-to-treat population, the eradication rate was higher with RHB-105 than with the active comparator (228 vs. 227 patients, respectively; 83.8% [95% CI, 78.4% to 88.0%] vs. 57.7% [95% CI, 51.2% to 64.0%]; P < 0.001). Eradication rates were unaffected by resistance to clarithromycin or metronidazole. No rifabutin resistance was detected. The most commonly reported adverse events (incidence ≥5%) were diarrhea (10.1% with RHB-105 vs. 7.9% with active comparator), headache (7.5% vs. 7.0%), and nausea (4.8% vs. 5.3%). LIMITATION: Persons of Asian descent were excluded because of their higher prevalence of poor cytochrome P450 2C19 metabolizers. CONCLUSION: These findings suggest potential for RHB-105 as first-line empirical H pylori therapy, addressing an unmet need in the current environment of increasing antibiotic resistance. PRIMARY FUNDING SOURCE: RedHill Biopharma Ltd.

Bimodal Release Ondansetron Improves Stool Consistency and Symptomatology in Diarrhea-Predominant Irritable Bowel Syndrome: A Randomized, Double-Blind, Trial.

INTRODUCTION: Previous, small studies have suggested that ondansetron has beneficial effects in diarrhea-predominant irritable bowel syndrome (IBS-D). This randomized, double-blind study evaluated the efficacy and safety of daily 12 mg RHB-102, an investigational bimodal release ondansetron tablet, in IBS-D. METHODS: Men and women with IBS-D by the Rome III criteria, Bristol Stool Scale ≥6 on 2 or more days weekly, and average daily worst pain intensity ≥3/10 were randomized 60:40 to RHB-102 or placebo once daily for 8 weeks. The primary end point was overall stool consistency response for at least 4 of 8 weeks. Secondary end points included overall worst abdominal pain and overall composite response, defined as response on both abdominal pain and stool consistency end points. RESULTS: Overall stool consistency response rates were 56.0% and 35.3% (RHB-102 vs placebo, P = 0.036) and similar among male and female patients. Overall pain response (50.7% vs 39.2%) and composite response rates (40.0% vs 25.5%) favored RHB-102, although these differences were not statistically significant. Stool consistency response rates were enhanced in patients with baseline C-reactive protein above the median (2.09 mg/L), 59.5%, vs 23.1% (P = 0.009). Overall rates of adverse events were similar, with a higher rate of constipation in RHB-102 patients (13.3% vs 3.9%) that resolved rapidly on withholding treatment. DISCUSSION: RHB-102 was effective and safe in the treatment of men and women with IBS-D. Baseline C-reactive protein seemed to be predictive of response.

Randomized, Double-Blind, Placebo-Controlled Study of Anti-Mycobacterial Therapy (RHB-104) in Active Crohn's Disease.

This study, conducted between 4 October 2013, and 30 November 2018, tested the hypothesis that triple antimicrobial therapy, targeting Mycobacterium avium subspecies paratuberculosis (MAP), long considered a putative cause, would favorably affect Crohn's disease. A double-blind multicenter study of adults with active Crohn's disease, (i.e., Crohn's Disease Activity Index [CDAI] 220-450 plus C-reactive protein ≥ 1.0 mg/dL, fecal calprotectin (FCP) >162.9 µg/g stool, or recent endoscopic or radiographic confirmation of active disease) receiving concomitant standard-of-care Crohn's disease treatment (Clinicaltrials.gov: NCT01951326) were stratified by anti-tumor necrosis factor use and randomized (1:1) to anti-MAP RHB-104 (clarithromycin 95 mg, rifabutin 45 mg, and clofazimine 10 mg per capsule) (n = 166), resulting in clarithromycin 950 mg/day, rifabutin 450 mg/day, and clofazimine 100 mg/day, or placebo (n = 165) for up to 52 weeks. A greater proportion of RHB-104 versus placebo-treated patients met the primary endpoint-remission (i.e., CDAI < 150)-at week 26 (36.7% [61/166] vs. 22.4% [37/165], respectively; 95% CI for difference: 4.6, 24.0, p = 0.0048; chi-square test). Clinical response (reduction of CDAI by ≥100 points from baseline) at week 26 (first secondary endpoint) was also higher among the patients treated with RHB-104 (73/166 [44.0%]) compared with placebo (50/165 [30.3%]; 95% CI for difference: 3.4, 24.0, p = 0.0116), and it remained higher at week 52 among the patients treated with RHB-104 (59/166 [35.5%] vs. (35/165 [21.2%] for placebo; 95% CI for difference: 4.7, 23.9, p = 0.0042). A statistically significantly greater decline in FCP (another prospective efficacy endpoint) was also observed in RHB-104-treated patients, compared with placebo, at weeks 12, 26, and 52. The rates of serious adverse events were similar between groups (RHB-104: 18.7%; placebo: 18.8%). No patient died during the study. Antimicrobial therapy directed against MAP resulted in significantly greater improvement in clinical and laboratory (FCP) measures of active Crohn's disease.

Nanofiltered C1 inhibitor concentrate for treatment of hereditary angioedema.

BACKGROUND: Hereditary angioedema due to C1 inhibitor deficiency is characterized by recurrent acute attacks of swelling that can be painful and sometimes life-threatening. METHODS: We conducted two randomized trials to evaluate nanofiltered C1 inhibitor concentrate in the management of hereditary angioedema. The first study compared nanofiltered C1 inhibitor concentrate with placebo for treatment of an acute attack of angioedema. A total of 68 subjects (35 in the C1 inhibitor group and 33 in the placebo group) were given one or two intravenous injections of the study drug (1000 units each). The primary end point was the time to the onset of unequivocal relief. The second study was a crossover trial involving 22 subjects with hereditary angioedema that compared prophylactic twice-weekly injections of nanofiltered C1 inhibitor concentrate (1000 units) with placebo during two 12-week periods. The primary end point was the number of attacks of angioedema per period, with each subject acting as his or her own control. RESULTS: In the first study, the median time to the onset of unequivocal relief from an attack was 2 hours in the subjects treated with C1 inhibitor concentrate but longer than 4 hours in those given placebo (P=0.02). In the second study, the number of attacks per 12-week period was 6.26 with C1 inhibitor concentrate given as prophylaxis, as compared with 12.73 with placebo (P<0.001); the subjects who received the C1 inhibitor concentrate also had significant reductions in both the severity and the duration of attacks, in the need for open-label rescue therapy, and in the total number of days with swelling. CONCLUSIONS: In subjects with hereditary angioedema, nanofiltered C1 inhibitor concentrate shortened the duration of acute attacks. When used for prophylaxis, nanofiltered C1 inhibitor concentrate reduced the frequency of acute attacks. (Funded by Lev Pharmaceuticals; ClinicalTrials.gov numbers, NCT00289211, NCT01005888, NCT00438815, and NCT00462709.)

Nanofiltered C1-esterase inhibitor for the acute management and prevention of hereditary angioedema attacks due to C1-inhibitor deficiency in children.

OBJECTIVES: To evaluate the use of Cinryze (nanofiltered C1-esterase inhibitor [C1 INH-nf]) for the acute management and prevention of hereditary angioedema attacks in the subgroup of children and adolescents who participated in 2 placebo-controlled and 2 open-label extension studies. STUDY DESIGN: In the acute-attack treatment studies, the efficacy of 1000 U of C1 INH-nf (with an additional 1000 U given 1 hour later if needed) was assessed based on the time to the start of symptomatic relief and the proportion of patients experiencing relief within 4 hours of therapy. In the prophylaxis studies, C1 INH-nf 1000 U was given twice weekly, and efficacy was based on the frequency of attacks. RESULTS: Across 4 studies, 46 children received a total of 2237 C1 INH-nf infusions. The median time to the start of unequivocal relief in the acute-attack treatment study (n = 12) was 30 minutes with C1 INH-nf, compared with 2 hours for placebo. In the open-label extension (n = 22), clinical relief began within 4 hours of therapy in 89% of attacks. In the prophylaxis study (n = 4), the number of attacks was reduced by approximately 2-fold with C1 INH-nf compared with placebo. In the prophylaxis open-label extension (n = 23), the median monthly attack rate decreased from 3.0 before treatment to 0.39 with C1 INH-nf use. CONCLUSION: In children, C1 INH-nf was well tolerated, provided relief from symptoms of hereditary angioedema attacks, and reduced the rate of attacks.

Nanofiltered C1 esterase inhibitor (human) for hereditary angioedema attacks in pregnant women.

Data are limited on hereditary angioedema (HAE) in pregnant women and the safety and efficacy of therapies for treatment and prevention of HAE attacks during pregnancy. Prospective studies are unlikely given the rarity of HAE and ethical considerations regarding enrollment of pregnant female subjects in clinical trials. A retrospective analysis of clinical trial and compassionate-use data was conducted to identify subjects who received nanofiltered C1 esterase inhibitor (C1 INH-nf; human) during pregnancy. This study evaluates the efficacy and safety of human C1 INH-nf for treatment and prevention of HAE attacks in pregnant women. Data from pregnant subjects enrolled in either open-label extensions of two randomized, double-blind, placebo-controlled trials of C1 INH-nf or in a compassionate-use program were retrospectively analyzed for efficacy (e.g., total attacks, attack frequency during prophylaxis, and monthly attack rates) and safety (e.g., pregnancy outcomes and adverse events). C1 INH-nf was administered as acute treatment, preprocedural prophylaxis, or routine prophylaxis. C1 INH-nf prophylaxis substantially reduced monthly attack rates. Of 16 subjects, 13 delivered 14 healthy neonates (1 set of twins). Two adverse fetal outcomes were reported; neither was considered by the principal investigator to be related to C1 INH-nf. One subject's pregnancy outcome was unknown. This analysis shows a favorable risk-benefit profile for C1 INH-nf for managing HAE during pregnancy. NCT Identifier: NCT00438815; NCT00462709.

Nanofiltered C1 esterase inhibitor (human) for the treatment of acute attacks of hereditary angioedema: an open-label trial.

BACKGROUND: Hereditary angioedema (HAE) is a rare disease caused by C1INH gene mutations, which leads to a deficiency or dysfunction of C1 inhibitor (C1 INH), resulting in recurrent episodes of severe and potentially life-threatening edema. OBJECTIVE: To evaluate the efficacy and safety of repeat use of nanofiltered C1 esterase inhibitor (human) (C1 INH-nf) for the short-term treatment of HAE attacks. METHODS: In this open-label study, patients received C1 INH-nf, 1,000 U intravenously, for the treatment of HAE attacks. Efficacy end points included the proportion of attacks with unequivocal relief of the defining symptom within 1 and 4 hours after receiving study drug and time to beginning of relief of the defining symptom. Safety was monitored through adverse event reporting, vital signs measurements, and laboratory testing. RESULTS: A total of 113 patients were enrolled in the study from September 21, 2006, through March 31, 2009, and received 885 doses of C1 INH-nf. A total of 609 HAE attacks were treated with C1 INH-nf, and the numbers of attacks achieving unequivocal relief of the defining symptom within 1 and 4 hours after the start of the first dose were 412 (68%) and 529 (87%), respectively. Of 101 patients treated for an attack during the study period, 80 achieved unequivocal relief of their first attack within 4 hours after study medication (response rate, 79%); median time to the beginning of unequivocal relief was 0.75 hour. C1 INH-nf was safe and well tolerated. CONCLUSIONS: This open-label study demonstrates the efficacy and safety of C1 INH-nf for short-term treatment of HAE attacks. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00438815.

Preprocedural administration of nanofiltered C1 esterase inhibitor to prevent hereditary angioedema attacks.

Patients with hereditary angioedema (HAE) may have attacks triggered by dental, medical, or surgical procedures. This analysis evaluated the efficacy and safety of preprocedural administration of nanofiltered C1 esterase inhibitor (C1 INH-nf; human) for the prevention of HAE attacks during and after dental, medical, or surgical procedures. Data were reviewed retrospectively from two acute treatment trials in which at least 1000 U of C1 INH-nf was administered i.v. within 24 hours before an emergency or noncosmetic medical, surgical, or dental procedure. Dosing data, HAE attacks reported within 72 hours, and adverse events (AEs) reported within 7 days after a preprocedural dose of C1 INH-nf were analyzed to assess efficacy and safety. Forty-one unique subjects (8 children and 33 adults) received C1 INH-nf for 91 procedures (40 in children and 51 in adults). The majority of procedures (56%) involved dental work and 44% involved a variety of surgical or medical procedures. A single 1000-U dose of C1 INH-nf was administered for 96% of procedures. An HAE attack did not occur within 72 hours after C1 INH-nf dosing for 98% (89/91) of procedures. Two HAE attacks were reported after the procedure, and both were treated with C1 INH-nf and achieved relief. None of the reported AEs were judged to be related to C1 INH-nf or were associated with an HAE attack. This analysis supports the efficacy and safety of preprocedural administration of C1 INH-nf for the prevention of HAE attacks.

Rifabutin-Containing Triple Therapy (RHB-105) for Eradication of Helicobacter pylori: Randomized ERADICATE Hp Trial.

Due to increasing resistance to commonly used antibiotics, the World Health Organization and Food and Drug Administration have advocated the development of new therapeutic regimens for Helicobacter pylori (H. pylori). This phase three, double-blind study (ERADICATE Hp) randomized (2:1) treatment-naïve adults with H. pylori infection and dyspepsia to RHB-105 (an all-in-one combination of omeprazole 40 mg, amoxicillin 1000 mg, and rifabutin 50 mg) or an identically-appearing placebo, both administered every 8 h for 14 days. The H. pylori eradication rate with RHB-105, using a modified intent-to-treat (mITT) population of subjects who received ≥1 dose of study drug and had test-of-eradication performed 28-35 days post-completion of therapy, was compared (one-sample Z-test) to a literature-derived comparator rate of 70% and success rate with physician-selected standard-of-care given to placebo failures. The mITT H. pylori eradication rate (95% CI) with RHB-105 of 89.4% (82.0-96.8%) was greater than both the literature-derived comparator rate (P < 0.001) and the standard-of-care rate of 63.0% (44.8-81.1%) (P = 0.006). Adverse events with an incidence ≥5% for RHB-105 were diarrhea (12.7%), headache (11.9%), chromaturia (9.3%), abdominal tenderness (6.8%), and dizziness (5.1%). No leukopenia was noted. RHB-105 (Talicia®) proved to be a safe and effective empiric therapy for H. pylori eradication.

Bimodal Release Ondansetron for Acute Gastroenteritis Among Adolescents and Adults: A Randomized Clinical Trial.

Importance: Vomiting resulting from acute gastroenteritis is commonly treated with intravenous antiemetics in acute care settings. If oral treatment were beneficial, patients might not need intravenous administered hydration or medication. Furthermore, a long-acting treatment could provide sustained relief from nausea and vomiting. Objective: To determine whether an experimental long-acting bimodal release ondansetron tablet decreases gastroenteritis-related vomiting and eliminates the need for intravenous therapy for 24 hours after administration. Design, Setting, and Participants: This placebo-controlled, double-blind, randomized clinical trial included patients from 19 emergency departments and 2 urgent care centers in the United States from December 8, 2014, to February 17, 2017. Patients 12 years and older with at least 2 vomiting episodes from presumed gastroenteritis in the previous 4 hours and symptoms with less than 36 hours' duration were randomized using a 3:2 active to placebo ratio. Analyses were performed on an intent-to-treat basis and conducted from June 1, 2017, to November 1, 2017. Intervention: Bimodal release ondansetron tablet containing 6 mg of immediate release ondansetron and 18 mg of a 24-hour release matrix for a total of 24 mg of ondansetron. Main Outcomes and Measures: Treatment success was defined as no further vomiting, no need for rescue medication, and no intravenous hydration for 24 hours after bimodal release ondansetron administration. Results: Analysis included 321 patients (mean [SD] age, 29.0 [11.1] years; 195 [60.7%] women), with 192 patients in the bimodal release ondansetron group and 129 patients in the placebo group. Treatment successes were observed in 126 patients in the bimodal release ondansetron group (65.6%) compared with 70 patients in the placebo group (54.3%), with an 11.4% (95% CI, 0.3%-22.4%) absolute probability difference. The proportion of treatment success was 21% higher among patients who received bimodal release ondansetron compared with those who received a placebo (relative risk, 1.21; 95% CI, 1.00-1.46; P = .04). In an analysis including only patients with a discharge diagnosis of acute gastroenteritis and no major protocol violations, there were 123 treatment successes (69.5%) in the bimodal release ondansetron group compared with 67 treatment successes (54.9%) in the placebo group (relative risk, 1.27; 95% CI, 1.05-1.53; P = .01). Adverse effects were infrequent and similar to the known safety profile of ondansetron. Conclusions and Relevance: This randomized clinical trial found that a long-acting bimodal release oral ondansetron tablet was an effective antiemetic among adolescents and adults with moderate to severe vomiting from acute gastroenteritis. The drug benefits extended to 24 hours after administration. Bimodal release ondansetron may decrease the need for intravenous access and emergency department care to manage acute gastroenteritis. Trial Registration: ClinicalTrials.gov identifier: NCT02246439.

Nanofiltered C1 esterase inhibitor for treatment of laryngeal attacks in patients with hereditary angioedema.

BACKGROUND: Laryngeal edema is a life-threatening manifestation of hereditary angioedema (HAE), an autosomal-dominant disorder caused by quantitative or functional C1 esterase inhibitor (C1 INH) deficiency. The preparation of nanofiltered C1 INH (C1 INH-nf) used in this study is indicated for routine prophylaxis against angioedema attacks in the United States and for treatment, preprocedure prevention, and routine prevention of HAE in Europe. The objective of this analysis was to evaluate the effectiveness and tolerability of C1 INH-nf when used for the treatment of laryngeal attacks. METHODS: A post hoc analysis of an open-label treatment study evaluated the effectiveness of C1 INH-nf in the treatment of laryngeal attacks in patients with HAE. Outcomes included unequivocal or clinical relief rates and time from treatment to onset of relief. Data were compiled from this and three other studies for post hoc dosing and tolerability analyses. In all studies, C1 INH-nf at 1000 U was administered i.v., with a second 1000-U dose given after 60 minutes if indicated. RESULTS: In the open-label treatment study, 60 (50/84) and 77% (65/84) of attacks achieved unequivocal relief within 1 and 4 hours, respectively, after treatment. Time to unequivocal relief was shorter with prompt treatment. When C1 INH-nf was administered within 4 hours of symptom onset, clinical relief was achieved in 94% (45/48) of attacks within 4 hours after treatment. Of 265 attacks from the four studies, 62% received two 1000-U doses of C1 INH-nf. No serious adverse events occurring within 7 days after treatment were attributed to study drug, and only one patient required intubation after receiving C1 INH-nf (14.5 hours after symptom onset). CONCLUSION: This analysis supports that C1 INH-nf is an effective and well-tolerated therapy for laryngeal angioedema attacks.

Safety and efficacy of prophylactic nanofiltered C1-inhibitor in hereditary angioedema.

OBJECTIVE: Nanofiltered C1-inhibitor (C1INH-nf) is approved for prophylactic treatment of hereditary angioedema. This study assessed the efficacy and safety of C1INH-nf as prophylactic therapy in a large cohort of patients with hereditary angioedema. METHODS: An open-label multicenter extension study was performed involving 146 subjects with hereditary angioedema who were treated with C1INH-nf for up to 2.6 years in centers throughout the United States. Subjects were to be treated with C1INH-nf 1000 units every 3 to 7 days. The primary efficacy variable was the number of attacks of angioedema experienced. RESULTS: Subjects experienced a 93.7% reduction in attacks while taking prophylactic C1INH-nf (0.19 attacks per month; interquartile range, 0.00-0.64) compared with the historical rate of attacks. Some 87.7% reported an attack frequency of 1 or less attack per month during prophylactic C1INH-nf and 34.9% had no attacks during the study. Some 7.5% of subjects experienced relatively frequent attacks despite twice-weekly C1INH-nf. Although twice-weekly dosing was highly effective in most subjects, once-weekly dosing provided adequate control in a subgroup of subjects. No clinical characteristics predicted the response to prophylactic C1INH-nf, including historical attack frequency. C1INH-nf was well tolerated. CONCLUSION: Prophylactic C1INH-nf is highly effective and safe, and provides durable prophylaxis in the majority of patients with hereditary angioedema. The recommended dose of C1INH-nf 1000 units twice weekly is supported by this open-label study. Individual patients may benefit from further dose adjustment on the basis of response to therapy and individual treatment goals.

When is prophylaxis for hereditary angioedema necessary?

OBJECTIVE: To determine when newer agents, such as C1 esterase inhibitor protein (C1-INH), should be considered as prophylaxis to decrease hereditary angioedema (HAE) attacks as an alternative to androgens, which have significant adverse events. DATA SOURCES: A literature review (PubMed, Google, and Ovid), guideline review, expert panel meeting, and group discussion were performed to decide when prophylaxis is indicated. STUDY SELECTION: Articles addressing HAE therapy published in the peer-reviewed literature were selected. RESULTS: The retrieved studies demonstrate that C1-INH is effective and that the half-life makes it attractive for prophylactic use. The short half-lives of ecallantide, icatibant, and recombinant human C1-INH limit their use as prophylactic agents. Patients with severe anxiety, more than 1 attack per month, rapid progression of attacks, limited access to health care, more than 10 days lost from work or school per year, previous laryngeal swelling, more than 3 emergency department visits per year, more than 1 hospitalization per year, previous intubation, previous intensive care unit care, significant compromise in quality of life, or narcotic dependency should be considered for androgen or C1-INH prophylaxis therapy. CONCLUSION: Patients with HAE with frequent attacks, severe attacks, past laryngeal attacks, excessive loss of work or school, significant anxiety, and poor quality of life should be considered for C1-INH prophylaxis, especially those who fail, are intolerant of, have adverse reactions to, or are not candidates for androgen therapy.