Clinical and economic consequences of vancomycin and fidaxomicin for the treatment of Clostridium difficile infection in Canada

Efficacy of fidaxomicin versus vancomycin in the treatment of Clostridium difficile infection: A systematic meta-analysis

PURPOSE

To compare the efficacy, recurrence rate, adverse event rate and mortality of fidaxomicin compared with vancomycin in treating different types of Clostridium difficile infection (CDI).

METHODS

A systematic search was conducted on PubMed, Embase, Web of Science, Cochrane Library and clinical trial registration databases for research on fidaxomicin versus vancomycin in the treatment of CDI and the retrieval period extended from the establishment of the database to July 22, 2022. A total of 15 studies were included, including 8 RCTs and 7 retrospective cohort studies.

RESULTS

Results showed that there was no significant difference in the overall efficacy of the treatment between fidaxomicin and vancomycin, and results in the subgroups of CDI hypervirulent strains and recurrent CDI were obtained, but vancomycin was more effective than fidaxomicin in the treatment of severe CDI (RR = 0.94, 95% CI: 0.90-0.98, P < .01). Results showed that fidaxomicin is superior to vancomycin in terms of 40-day recurrence rate (RR = 0.52, 95% CI: 0.38-0.70, P < .01), 60-day recurrence rate (RR = 0.38, 95% CI: 0.21-0.69, P < .01) and 90-day recurrence rate (RR = 0.62, 95% CI: 0.50-0.77, P < .01). For the recurrence rate of the treatment in CDI hypervirulent strains, severe CDI and recurrent CDI, there was no significant difference between the 2 groups. In addition, there was no significant difference in the incidence of clinical adverse reactions, and same outcomes appeared in all-cause mortality at 40-day, severe CDI and recurrent CDI, but fidaxomicin was superior to vancomycin in all-cause mortality over 60-day (RR = 0.57, 95% CI: 0.34-0.96, P = .03).

CONCLUSION

There were no significant differences between fidaxomicin and vancomycin in the treatment of CDI in therapeutic effectiveness and adverse reactions, while fidaxomicin was superior to vancomycin in terms of recurrence rate and long-term mortality, and vancomycin is more effective in treating severe CDI.

Fidaxomicin to prevent recurrent Clostridioides difficile: what will it cost in the USA and Canada?

Importance

Recent changes in guidelines for managing Clostridioides difficile infections (CDI) have placed fidaxomicin as a first-line treatment.

Objective

To estimate the net cost of first-line fidaxomicin compared to vancomycin in the American and Canadian healthcare systems and to estimate the price points at which fidaxomicin would become cost saving for the prevention of recurrence.

Data sources and study selection

We identified randomized, placebo-controlled trials directly comparing fidaxomicin with vancomycin that reported on recurrence. Medication costs were obtained from the Veterans Affairs Federal Supply Schedule (US) and the Quebec drug formulary (Canada). The average cost of a CDI recurrence was established through a systematic review for each country.

Data extraction synthesis and outcome measures

For efficacy, data on CDI recurrence at day 40 were pooled using a restricted maximal likelihood random effects model. For the cost review, the mean cost across identified studies was adjusted to reflect May 2022 dollars. These were used to estimate the net cost per recurrence prevented with fidaxomicin and the price point below which fidaxomicin would be cost saving.

Results

The estimated mean system costs of a CDI recurrence were $15 147USD and $8806CAD, respectively. Preventing one recurrence by using first-line fidaxomicin over vancomycin would cost $38 222USD (95%CI $30 577-$57 332) and $13 760CAD (95%CI $11 008-$20 640), respectively. The probability that fidaxomicin was cost saving exceeded 95% if priced below $1140USD or $860CAD, respectively.

Conclusions and Relevance

An increased drug expenditure on fidaxomicin may not be offset through recurrence prevention unless the fidaxomicin price is negotiated.

The Risk of Clostridioides difficile Recurrence after Initial Treatment with Vancomycin or Fidaxomicin Utilizing Cerner Health Facts

(1) Background: Fidaxomicin has been shown to significantly reduce Clostridioides difficile infection (CDI) recurrences rates in randomized, controlled trials. However, national data from the Veterans Affairs has called the real-world applicability of these findings into question. Therefore, we conducted a retrospective cohort study of patients receiving fidaxomicin or vancomycin as initial therapy for an index case of CDI in the hospital to evaluate the relative rates CDI recurrence within 90 days of an index case. (2) Methods: We retrieved patients 18 years and older who were admitted between July 2011 through June 2018 and diagnosed and treated for CDI with vancomycin or fidaxomicin. The first occurrence of CDI with treatment was designated as the index case. Patients with CDI within 1 year prior to index case were excluded. From the remaining index cases (vancomycin = 14,785; fidaxomicin = 889) the primary outcome (a recurrence of CDI within 90 days of the index case) was determined. The CDI recurrence rates for fidaxomicin and vancomyicn were evaluated using a Cox Proportional Hazards model on a propensity score matched cohort. (3) Results: A statistically significantly lower risk of CDI recurrence was observed with fidaxomicin use in the matched cohort (889 patients per treatment) using a Cox Proportional Hazards model (HR 0.67, 95% CI 0.50–0.90). (4) Conclusions: Fidaxomicin was independently associated with a decreased CDI recurrence, as defined by readmission for CDI within 90 days.

Economic burden and cost-effectiveness of therapies for Clostridiodes difficile infection: a narrative review

Clostridioides difficile is the most common cause of healthcare-associated diarrhea. Disease complications as well as recurrent infections contribute significantly to morbidity and mortality. Over the past decades, there has been a rapid increase in the incidence of C. difficile infection (CDI), with a rise in the number of community-acquired cases. CDI has a profound economic impact on both the healthcare system and patients, secondary to recurrences, hospitalization, prolonged length of stay, cost of treatment, and indirect societal costs. With emergence of newer treatment options, the standard of care is shifting from metronidazole and vancomycin towards fidaxomicin and fecal microbiota transplantation (FMT), which despite being more expensive, are more efficacious in preventing recurrences and hence overall are more beneficial forms of therapy per cost-effectiveness analyses. Data regarding preferred route of FMT, timing of FMT, and non-conventional therapies such as bezlotoxumab is scant. There is a need for further studies to elucidate the true attributable costs of CDI as well as continued cost-effectiveness research to reduce the economic burden associated with the disease and improve clinical practice.

Emerging drugs for the treatment of clostridium difficile

INTRODUCTION

Clostridium difficile or Clostridioides difficile (C. difficile) infection represents the most common cause of healthcare-associated infection. Over the last decades, the incidence and severity of C. difficile infection is rapidly increasing, with a significant impact on morbidity and mortality, and burden on health care system. Orally administered vancomycin and fidaxomicin are the therapeutic options of choice for initial C. difficile infection and fecal microbiota transplant for the recurrence infection. Furthermore, in recent years several new antibiotics with narrow-spectrum activity and low intestinal resorption have been developed, including surotomycin, cadazolid, and ridinilazol, and novel toxoid vaccines are expected to be efficacious in the prevention of C. difficile infection. Areas covered: Literature review was performed to select publications about current guidelines and phase-II/III trials on emerging drugs. These include novel antibiotics, monoclonal antibodies, vaccines, and fecal microbiota transplantation. Expert opinion: We have today a wide spectrum of promising therapeutic possibilities against infection. Pivotal future clinical trials may be crucial in developing effective strategies to optimize outcomes, mainly in high-risk population.

Fidaxomicin vs Vancomycin for the Treatment of a First Episode of Clostridium Difficile Infection: A Meta-analysis and Systematic Review

Clostridium difficile infection (CDI) continues to possess a significant disease burden in the United States (US) as well as all over the world. Given the increase in severity and recurrence rate, the decrease in cure rate, and the fact that the virulent ribotype 027 strain remains one of the most commonly identified strains in the US, the Infectious Diseases Society of America (IDSA) published a clinical practice guideline in February 2018 moving away from metronidazole as the first-line treatment for initial CDI and recommending either oral vancomycin or fidaxomicin. The aim of this study is to evaluate the clinical data available comparing the efficacy of primary treatment of CDI between those two antibiotics. We performed a PubMed, PubMed Central, and ScienceDirect database search without restriction to regions, publication types, or languages. A comprehensive literature search was performed from January 1, 1980 up to March 20, 2018. We used the following keywords in different combinations: Clostridium difficile, Clostridium difficile infection, CDI, C. diff, C. difficile, fidaxomicin, vancomycin, pseudomembranous colitis, and antibiotic-associated colitis. The search was limited to human studies. Data were independently extracted by two reviewers with disagreements resolved by a third author. We pooled an odds ratio (OR) on two primary outcomes: Clinical cure rate and rate of recurrence during the follow-up period. The computer search was also supplemented with manual searches by the authors of the retrieved review articles and primary studies. The search phrase “((Clostridium difficile) AND vancomycin) AND fidaxomicin” had the highest yield results. We identified four observational studies with a total of 2,303 patients with CDI that met our inclusion criteria. Compared with vancomycin, fidaxomicin use was associated with a significantly lower recurrence of CDI with a pooled OR of 0.47 (95% confidence interval (CI), 0.37 - 0.60, I2 = 0). On the other hand, there was no significant association of fidaxomicin use with CDI cure rate compared to vancomycin with a pooled OR of 1.22 (95% CI, 0.93 - 1.60, I2 = 0). In light of the recently updated clinical practice guidelines by the IDSA, our review suggests that fidaxomicin has a more sustained clinical response with a statistically significant lower recurrence rate. Although fidaxomicin appears to be the better drug with statistical significance, its cost-effectiveness continues to be an ongoing controversy. More randomized clinical trials are needed to shed light on this matter to assess if there is any clinical significance in fidaxomicin superiority.

Cost-Effectiveness of Competing Treatment Strategies for Clostridium difficile Infection: A Systematic Review

BACKGROUND Clostridium difficile infection (CDI) presents a substantial economic burden and is associated with significant morbidity. While multiple treatment strategies have been evaluated, a cost-effective management strategy remains unclear. OBJECTIVE We conducted a systematic review to assess cost-effectiveness analyses of CDI treatment and to summarize key issues for clinicians and policy makers to consider. METHODS We searched PubMed and 5 other databases from inception to August 2016. These searches were not limited by study design or language of publication. Two reviewers independently screened the literature, abstracted data, and assessed methodological quality using the Drummond and Jefferson checklist. We extracted data on study characteristics, type of CDI, treatment characteristics, and model structure and inputs. RESULTS We included 14 studies, and 13 of these were from high-income countries. More than 90% of these studies were deemed moderate-to-high or high quality. Overall, 6 studies used a decision-tree model and 7 studies used a Markov model. Cost of therapy, time horizon, treatment cure rates, and recurrence rates were common influential factors in the study results. For initial CDI, fidaxomicin was a more cost-effective therapy than metronidazole or vancomycin in 2 of 3 studies. For severe initial CDI, 2 of 3 studies found fidaxomicin to be the most cost-effective therapy. For recurrent CDI, fidaxomicin was cost-effective in 3 of 5 studies, while fecal microbiota transplantation (FMT) by colonoscopy was consistently cost-effective in 4 of 4 studies. CONCLUSIONS The cost-effectiveness of fidaxomicin compared with other pharmacologic therapies was not definitive for either initial or recurrent CDI. Despite its high cost, FMT by colonoscopy may be a cost-effective therapy for recurrent CDI. A consensus on model design and assumptions are necessary for future comparison of CDI treatment. Infect Control Hosp Epidemiol 2018;39:412-424.

Economic burden and cost-effective management of Clostridium difficile infections

Clostridium difficile infection (CDI) is the most important cause of healthcare-associated infectious diarrhea in industrialized countries. We performed a literature review of the overall economic burden of initial and recurrent CDI as well as of the cost-effectiveness of the various treatment strategies applied in these settings. Even though analysis of health economic data is complicated by the limited comparability of results, our review identified several internationally consistent results. Authors from different countries have shown that recurrent CDI disproportionally contributes to the overall economic burden of CDI and therefore offers considerable saving potential. Subsequent cost-effectiveness analyses almost exclusively identified fidaxomicin as the preferred treatment option for initial CDI and fecal microbiota transplant (FMT) for recurrent CDI. Among the various FMT protocols, optimum results were obtained using early colonoscopy-based FMT.

Purine analogs targeting the guanine riboswitch as potential antibiotics against Clostridioides difficile

Riboswitches recently emerged as possible targets for the development of alternative antimicrobial approaches. Guanine-sensing riboswitches in the bacterial pathogen Clostridioides difficile (formerly known as Clostridium difficile) constitute potential targets based on their involvement in the regulation of basal metabolic control of purine compounds. In this study, we deciphered the structure-activity relationship of several guanine derivatives on the guanine riboswitch and determined their antimicrobial activity. We describe the synthesis of purine analogs modified in ring B as well as positions 2 and 6. Their biological activity was determined by measuring their affinity for the C. difficile guanine riboswitch and their inhibitory effect on bacterial growth, including a counter-screen to discriminate against riboswitch-independent antibacterial effects. Altogether, our results suggest that improvements in riboswitch binding affinity in vitro do not necessarily translate into improved antibacterial activity in bacteria, despite the fact that some structure-activity relationship was observed at least with respect to binding affinity.

Fidaxomicin versus Vancomycin as a First-Line Treatment for Clostridium difficile-Associated Diarrhea in Specific Patient Populations: A Pharmacoeconomic Evaluation

OBJECTIVES

The reduction in recurrent Clostridium difficile-associated diarrhea (CDAD) with fidaxomicin therapy may reduce hospital readmissions and lead to lower overall CDAD costs. However, studies assessing the cost-effectiveness of fidaxomicin as first-line therapy from the U.S. hospital perspective are lacking. This study evaluated the costs associated with utilizing fidaxomicin or vancomycin as a first-line therapy for CDAD in specific patient populations from a U.S. hospital perspective.

METHODS

A decision-analytic model was developed to estimate total costs (hospitalization and drug costs) associated with using fidaxomicin or vancomycin as first-line therapy for a first episode and up to two recurrences of CDAD in five patient populations: general population, elderly, patients receiving concomitant antibiotics, and patients with renal impairment or cancer.

RESULTS

The total cost of CDAD treatment using fidaxomicin first line in the general population was $14,442 per patient versus $14,179 per patient with vancomycin first line. In subgroup analyses, fidaxomicin use resulted in total hospital cost savings of $616 per patient in patients with cancer and $312 in patients with concomitant antibiotic use; vancomycin use was associated with total hospital cost savings of $243 per patient in the elderly and $371 in patients with renal impairment.

CONCLUSIONS

Fidaxomicin as first-line CDAD therapy is associated with similar total costs as compounded vancomycin oral solution in the general population. In elderly and renally impaired patients, slight increases in hospital cost were observed with fidaxomicin therapy, and in patients with cancer or concomitant antibiotic use, hospital cost savings were observed.

A Systematic Literature Review of Economic Evaluations of Antibiotic Treatments for Clostridium difficile Infection

BACKGROUND AND OBJECTIVE

Clostridium difficile infection (CDI) is associated with high management costs, particularly in recurrent cases. Fidaxomicin treatment results in lower recurrence rates than vancomycin and metronidazole, but has higher acquisition costs in Europe and the USA. This systematic literature review summarises economic evaluations (EEs) of fidaxomicin, vancomycin and metronidazole for treatment of CDI.

METHODS

Electronic databases (MEDLINE®, Embase, Cochrane Library) and conference proceedings (ISPOR, ECCMID, ICAAC and IDWeek) were searched for publications reporting EEs of fidaxomicin, vancomycin and/or metronidazole in the treatment of CDI. Reference bibliographies of identified manuscripts were also reviewed. Cost-effectiveness was evaluated according to the overall population of patients with CDI, as well as in subgroups with severe CDI or recurrent CDI, or those at higher risk of recurrence or mortality.

RESULTS

Overall, 27 relevant EEs, conducted from the perspective of 12 different countries, were identified. Fidaxomicin was cost-effective versus vancomycin and/or metronidazole in 14 of 24 EEs (58.3%), vancomycin was cost-effective versus fidaxomicin and/or metronidazole in five of 27 EEs (18.5%) and metronidazole was cost-effective versus fidaxomicin and/or vancomycin in two of 13 EEs (15.4%). Fidaxomicin was cost-effective versus vancomycin in most of the EEs evaluating specific patient subgroups. Key cost-effectiveness drivers were cure rate, recurrence rate, time horizon, drug costs and length and cost of hospitalisation.

CONCLUSIONS

In most EEs, fidaxomicin was demonstrated to be cost-effective versus metronidazole and vancomycin in patients with CDI. These results have relevance to clinical practice, given the high budgetary impact of managing CDI and increasing restrictions on healthcare budgets.

OTHER

This analysis was initiated and funded by Astellas Pharma Inc.

Cost-Effectiveness Analysis of Five Competing Strategies for the Management of Multiple Recurrent Community-Onset Clostridium difficile Infection in France

Background

Clostridium difficile infection (CDI) is characterized by high rates of recurrence, resulting in substantial health care costs. The aim of this study was to analyze the cost-effectiveness of treatments for the management of second recurrence of community-onset CDI in France.

Methods

We developed a decision-analytic simulation model to compare 5 treatments for the management of second recurrence of community-onset CDI: pulsed-tapered vancomycin, fidaxomicin, fecal microbiota transplantation (FMT) via colonoscopy, FMT via duodenal infusion, and FMT via enema. The model outcome was the incremental cost-effectiveness ratio (ICER), expressed as cost per quality-adjusted life year (QALY) among the 5 treatments. ICERs were interpreted using a willingness-to-pay threshold of €32,000/QALY. Uncertainty was evaluated through deterministic and probabilistic sensitivity analyses.

Results

Three strategies were on the efficiency frontier: pulsed-tapered vancomycin, FMT via enema, and FMT via colonoscopy, in order of increasing effectiveness. FMT via duodenal infusion and fidaxomicin were dominated (i.e. less effective and costlier) by FMT via colonoscopy and FMT via enema. FMT via enema compared with pulsed-tapered vancomycin had an ICER of €18,092/QALY. The ICER for FMT via colonoscopy versus FMT via enema was €73,653/QALY. Probabilistic sensitivity analysis with 10,000 Monte Carlo simulations showed that FMT via enema was the most cost-effective strategy in 58% of simulations and FMT via colonoscopy was favored in 19% at a willingness-to-pay threshold of €32,000/QALY.

Conclusions

FMT via enema is the most cost-effective initial strategy for the management of second recurrence of community-onset CDI at a willingness-to-pay threshold of €32,000/QALY.

A scoring system for prescribing fidaxomicin in Clostridium diffícile infection

Recurrences of Clostridium difficile infections lead to hospital readmissions and high costs, in addition to the suffering and frustration for the patients. Fidaxomicin has recently been introduced as a new antibiotic that has been shown to significantly reduce the recurrence of this infection. Despite this superiority, its high cost has led to very restrictive policies in its use, as such that many institutions only use it in patients with multiple recurrences. While waiting for new predictive clinical tools, we propose the development of scoring systems that allow the more high-risk patients to be treated earlier.

Economic burden of primary compared with recurrent Clostridium difficile infection in hospitalized patients: a prospective cohort study

BACKGROUND

Few studies have investigated the additional healthcare costs of recurrent C. difficile infection (CDI).

AIM

To quantify inpatient treatment costs for CDI and length of stay among hospitalized patients with primary CDI only, compared with CDI patients who experienced recurrent CDI.

METHODS

This was a prospective, observational cohort study of hospitalized adult patients with primary CDI followed for three months to assess for recurrent CDI episodes. Total and CDI-attributable hospital length of stay (LOS) and hospitalization costs were compared among patients who did or did not experience at least one recurrent CDI episode.

FINDINGS

In all, 540 hospitalized patients aged 62±17 years (42% males) with primary CDI were enrolled, of whom 95 patients (18%) experienced 101 recurrent CDI episodes. CDI-attributable median (interquartile range) LOS and costs (in US$) increased from 7 (4-13) days and $13,168 (7,525-24,456) for patients with primary CDI only versus 15 (8-25) days and $28,218 (15,050-47,030) for patients with recurrent CDI (P<0.0001, each). Total hospital median LOS and costs increased from 11 (6-22) days and $20,693 (11,287-41,386) for patients with primary CDI only versus 24 (11-48) days and $45,148 (20,693-82,772) for patients with recurrent CDI (P<0.0001, each). The median cost of pharmacological treatment while hospitalized was $60 (23-200) for patients with primary CDI only (N=445) and $140 (30-260) for patients with recurrent CDI (P=0.0013).

CONCLUSION

This study demonstrated that patients with CDI experience a significant healthcare economic burden attributed to CDI. Economic costs and healthcare burden increased significantly for patients with recurrent CDI.

Cost-Effectiveness Analysis of Six Strategies to Treat Recurrent Clostridium difficile Infection

Objective

To assess the cost-effectiveness of six treatment strategies for patients diagnosed with recurrent Clostridium difficile infection (CDI) in Canada: 1. oral metronidazole; 2. oral vancomycin; 3.oral fidaxomicin; 4. fecal transplantation by enema; 5. fecal transplantation by nasogastric tube; and 6. fecal transplantation by colonoscopy.

Perspective

Public insurer for all hospital and physician services.

Setting

Ontario, Canada.

Methods

A decision analytic model was used to model costs and lifetime health effects of each strategy for a typical patient experiencing up to three recurrences, over 18 weeks. Recurrence data and utilities were obtained from published sources. Cost data was obtained from published sources and hospitals in Toronto, Canada. The willingness-to-pay threshold was $50,000/QALY gained.

Results

Fecal transplantation by colonoscopy dominated all other strategies in the base case, as it was less costly and more effective than all alternatives. After accounting for uncertainty in all model parameters, there was an 87% probability that fecal transplantation by colonoscopy was the most beneficial strategy. If colonoscopy was not available, fecal transplantation by enema was cost-effective at $1,708 per QALY gained, compared to metronidazole. In addition, fecal transplantation by enema was the preferred strategy if the probability of recurrence following this strategy was below 8.7%. If fecal transplantation by any means was unavailable, fidaxomicin was cost-effective at an additional cost of $25,968 per QALY gained, compared to metronidazole.

Conclusion

Fecal transplantation by colonoscopy (or enema, if colonoscopy is unavailable) is cost-effective for treating recurrent CDI in Canada. Where fecal transplantation is not available, fidaxomicin is also cost-effective.

Fidaxomicin: A novel agent for the treatment of Clostridium difficile infection

Oral vancomycin and oral metronidazole have several limitations with regard to their use in the treatment of Clostridium difficile infections (CDIs); however, oral vancomycin has been considered the gold standard in clinical trials. In June 2012, fidaxomicin received Health Canada approval for the treatment of CDIs. Its chemistry, mechanisms of action and pharmacological properties are discussed, along with its potential role in CDI therapy.

BACKGROUND:

Due to the limitations of existing treatment options for Clostridium difficile infection (CDI), new therapies are needed.

OBJECTIVE:

To review the available data on fidaxomicin regarding chemistry, mechanisms of action and resistance, in vitro activity, pharmacokinetic and pharmacodynamic properties, efficacy and safety in clinical trials, and place in therapy.

METHODS:

A search of PubMed using the terms “fidaxomicin”, “OPT-80”, “PAR-101”, “OP-1118”, “difimicin”, “tiacumicin” and “lipiarmycin” was performed. All English-language articles from January 1983 to November 2014 were reviewed, as well as bibliographies of all articles.

RESULTS:

Fidaxomicin is the first macrocyclic lactone antibiotic with activity versus C difficile. It inhibits RNA polymerase, therefore, preventing transcription. Fidaxomicin (and its active metabolite OP-1118) is bactericidal against C difficile and exhibits a prolonged postantibiotic effect (approximately 10 h). Other than for C difficile, fidaxomicin demonstrated only moderate inhibitory activity against Gram-positive bacteria and was a poor inhibitor of normal colonic flora, including anaerobes and enteric Gram-negative bacilli. After oral administration (200 mg two times per day for 10 days), fidaxomicin achieved low serum concentration levels but high fecal concentration levels (mean approximately 1400 μg/g stool). Phase 3 clinical trials involving adults with CDI demonstrated that 200 mg fidaxomicin twice daily for 10 days was noninferior to 125 mg oral vancomycin four times daily for 10 days in regard to clinical response at the end of therapy. Fidaxomicin was, however, reported to be superior to oral vancomycin in reducing recurrent CDI and achieving a sustained clinical response (assessed at day 28) for patients infected with non-BI/NAP1/027 strains.

CONCLUSION:

Fidaxomicin was noninferior to oral vancomycin with regard to clinical response at the end of CDI therapy. Fidaxomicin has been demonstated to be as safe as oral vancomycin, but superior to vancomycin in achieving a sustained clinical response for CDI in patients infected with non-BI/NAP1/027 strains. Caution should be exercised in using fidaxomicin monotherapy for treatment of severe complicated CDI because limited data are available. Whether fidaxomicin is cost effective (due to its significantly higher acquisition cost versus oral vancomycin) depends on the acceptable willingness to pay threshold per quality-adjusted life year as a measure of assessing cost effectiveness.

Novel approaches to treating Clostridium difficile-associated colitis

Clostridium difficile is being recognized as a growing threat to many health-care systems. Epidemiology data shows that infection rates are soaring and the disease burden is increasing. Despite the efficacy of standard treatments, it is becoming evident that novel therapeutics will be required to tackle this disease. These new treatments aim to enhance the intestinal microbial barrier, activate the immune system and neutralize the toxins that mediate this disease. Many of these therapies are still in the beginning stages of investigation, however, in the next few years, more clinical data will become available to help implement many of these exciting new therapeutic approaches.

Therapies on the horizon for Clostridium difficile infections

INTRODUCTION

Clostridium difficile infections are a leading cause of healthcare facility outbreaks of gastrointestinal illness that may have serious complications and a high rate of recurrent disease. Despite the availability of standard antibiotic treatments, data from national surveillance programs indicate that the incidence of this disease continues to increase, placing a heavy burden on healthcare systems. New emerging strategies are being tested to replace or augment these standard antibiotics.

AREAS COVERED

Thirty-two current investigational agents focusing on different strategies for both prevention and treatment of C. difficile infections are reviewed. Data was gathered from a literature search of public databases for published trials from 1999-November 13, 2015 and from the author's compendium of knowledge. Agents reviewed included 13 antibiotics, two antibiotic inactivators, seven bacteria or yeasts acting to enhance the normal microbiome, seven immunizing agents and three toxin binders. Of the 32 investigational treatments reviewed, 8 (25%) showed significant efficacy in phase II or III clinical trials and are actively being developed as new therapies for C. difficile infections.

EXPERT OPINION

A number of potential treatments have floundered during their development process, while others have shown promising results. The strongest efficacy has been in the areas of newer antibiotics, probiotics, monoclonal antibodies and vaccines. By targeting the pathogenic pathway of C. difficile infections, multiple strategies for prevention and treatment have been developed.

Antimicrobial therapy of acute diarrhoea: a clinical review

Diarrhoea is one of the most commonly occurring diseases. This article presents a review of the current state of the treatment of acute infectious diarrhoea, as well as of the most important pathogens. The general principles of the therapy of diarrhoea are exemplified, followed by a description of the targeted antimicrobial therapy of the most important bacterial gastrointestinal infections, including salmonellosis, shigellosis and Campylobacter infections, as well as infections with pathogenic Escherichia coli strains, yersiniosis and cholera. Diarrhoea caused by toxigenic Clostridium difficile strains has increased in incidence and in severity. These infections will therefore be described in detail, including important new aspects of treatment. Symptomatic therapy is still the most important component of the treatment of infectious diarrhoea. However, empirical antibiotic therapy should be considered for severely ill patients with a high frequency of stools, fever, bloody diarrhoea, underlying immune deficiency, advanced age or significant comorbidities. Increasing resistance, in particular against fluoroquinolones, must be taken into consideration. Therapy with motility inhibitors is not recommended for Shiga toxin-producing Escherichia coli (STEC) infections, Clostridium difficile infections (CDI), and severe colitis. The macrocyclic antibiotic fidaxomicin can reduce the rate of recurrent disease in CDI. Furthermore, evidence for the benefits of faecal microbiota transplantation as a treatment option for multiple recurrences of CDI is increasing. In conclusion, the treatment of acute diarrhoea is still primarily supportive. General empirical antibiotic therapy for acute diarrhoea is not evidence-based.

Cost-effectiveness and pricing of antibacterial drugs

Growing resistance to antibacterial agents has increased the need for the development of new drugs to treat bacterial infections. Given increasing pressure on limited health budgets, it is important to study the cost-effectiveness of these drugs, as well as their safety and efficacy, to find out whether or not they provide value for money and should be reimbursed. In this article, we systematically reviewed 38 cost-effectiveness analyses of new antibacterial agents. Most studies showed the new antibacterial drugs were cost-effective compared to older generation drugs. Drug pricing is a complicated process, involving different stakeholders, and has a large influence on cost-effectiveness. Value-based pricing is a method to determine the price of a drug at which it can be cost-effective. It is currently unclear what the influence of value-based pricing will be on the prices of new antibacterial agents, but an important factor will be the definition of ‘value’, which as well as the impact of the drug on patient health might also include other factors such as wider social impact and the health impact of disease.

Clostridium difficile infection: guideline-based diagnosis and treatment

BACKGROUND

Clostridium difficile (C. difficile) is the pathogen that most commonly causes nosocomial and antibiotic-associated diarrheal disease. Optimized algorithms for diagnosis, treatment, and hygiene can help lower the incidence, morbidity, and mortality of C. difficile infection (CDI).

METHODS

This review is based on pertinent articles that were retrieved by a selective search in PubMed for recommendations on diagnosis and treatment(up to March 2014), with particular attention to the current epidemiological situation in Germany.

RESULTS

The incidence of CDI in Germany is 5 to 20 cases per 100,000 persons per year. In recent years, a steady increase in severe, reportable cases of CDI has been observed, and the highly virulent epidemic strain Ribotype 027 has spread across nearly the entire country. For therapeutic and hygiene management, it is important that the diagnosis be made as early as possible with a sensitive screening test, followed by a confirmatory test for the toxigenic infection. Special disinfection measures are needed because of the formation of spores. The treatment of CDI is evidence-based; depending on the severity of the infection, it is treated orally with metronidazole, or else with vancomycin or fidaxomicin. Fulminant infections and recurrences call for specifically adapted treatment modalities. Treatment with fecal bacteria (stool transplantation) is performed in gastroenterological centers that have experience with this form of treatment after multiple failures of drug treatment for recurrent infection. For critically ill patients, treatment is administered by an interdisciplinary team and consists of early surgical intervention in combination with drug treatment. A therapeutic algorithm developed on the basis of current guidelines and recommendations enables risk-adapted, individualized treatment.

CONCLUSION

The growing clinical and epidemiological significance of CDI compels a robust implementation of multimodal diagnostic, therapeutic, and hygienic standards. In the years to come, anti-toxin antibodies, toxoid vaccines, and focused bacterial therapy will be developed as new treatment strategies for CDI.

Predictive values of models of Clostridium difficile infection

In vivo and in vitro models are widely used to simulate Clostridium difficile infection (CDI). They have made considerable contributions in the study of C difficile pathogenesis, antibiotic predisposition to CDI, and population dynamics as well as the evaluation of new antimicrobial and immunologic therapeutics. Although CDI models have greatly increased understanding of this complicated pathogen, all have limitations in reproducing human disease, notably their inability to generate a truly reflective immune response. This review summarizes the most commonly used models of CDI and discusses their pros and cons and their predictive values in terms of clinical outcomes.

Investigational new treatments for Clostridium difficile infection

Significant progress has been made by industry and academia in the past two years to address the medical threats posed by Clostridium difficile infection. These developments provide an excellent example of how patient need has driven a surge of innovation in drug discovery. Indeed, only two drugs were approved for the infection in the past 30 years but there are 13 treatment candidates in clinical trials today. What makes the latter number even more remarkable is the diversity in the strategies represented (antibiotics, microbiota supplements, vaccines, antibiotic quenchers and passive immunization). In this review, we provide a snapshot of the current stage of these breakthroughs and argue that there is still room for further innovation in treating C. difficile infection.