Integrated Safety and Efficacy Analyses of Phase 3 Trials of a Microbiome Therapeutic for Recurrent CDI.

Introduction: Recurrent Clostridioides difficile infection (rCDI) often occurs after standard-of-care antibiotics. VOWST oral spores (VOS, previously SER-109), an FDA-approved orally administered microbiome therapeutic, is indicated to prevent rCDI following antibiotics for rCDI.

Objective, Design, And Patients: To evaluate safety and efficacy of VOS from two phase 3 trials, (randomized, placebo-controlled [ECOSPOR III: NCT03183128] and open-label, single arm [ECOSPOR IV: NCT03183141]) of 349 adults with rCDI and prevalent comorbidities.

Prevalence of Comorbid Factors in Patients With Recurrent Clostridioides difficile Infection in ECOSPOR III, a Randomized Trial of an Oral Microbiota-Based Therapeutic.

Background: Although comorbidities are risk factors for recurrent Clostridioides difficile infection (rCDI), many clinical trials exclude patients with medical conditions such as malignancy or immunosuppression. In a phase 3, double-blind, placebo-controlled, randomized trial (ECOSPOR III), fecal microbiota spores, live (VOWST, Seres Therapeutics; hereafter "VOS," formerly SER-109), an oral microbiota therapeutic, significantly reduced the risk of rCDI at week 8. We evaluated the efficacy of VOS compared with placebo in patients with comorbidities and other risk factors for rCDI.

Safety and Tolerability of SER-109 as an Investigational Microbiome Therapeutic in Adults With Recurrent Clostridioides difficile Infection: A Phase 3, Open-Label, Single-Arm Trial.

Importance: A safe and effective treatment for recurrent Clostridioides difficile infection (CDI) is urgently needed. Antibiotics kill toxin-producing bacteria but do not repair the disrupted microbiome, which promotes spore germination and infection recurrence.

Objectives: To evaluate the safety and rate of CDI recurrence after administration of investigational microbiome therapeutic SER-109 through 24 weeks.

SER-109: An Oral Investigational Microbiome Therapeutic for Patients with Recurrent Infection (rCDI).

Clostridioides difficile infection (CDI) is classified as an urgent health threat by the Centers for Disease Control and Prevention (CDC), and affects nearly 500,000 Americans annually. Approximately 20−25% of patients with a primary infection experience a recurrence, and the risk of recurrence increases with subsequent episodes to greater than 40%. The leading risk factor for CDI is broad-spectrum antibiotics, which leads to a loss of microbial diversity and impaired colonization resistance.

SER-109, an Oral Microbiome Therapy for Recurrent Infection.

Background: Current therapies for recurrent infection do not address the disrupted microbiome, which supports spore germination into toxin-producing bacteria. SER-109 is an investigational microbiome therapeutic composed of purified Firmicutes spores for the treatment of recurrent infection.

Methods: We conducted a phase 3, double-blind, randomized, placebo-controlled trial in which patients who had had three or more episodes of infection (inclusive of the qualifying acute episode) received SER-109 or placebo (four capsules daily for 3 days) after standard-of-care antibiotic treatment.

Cadazolid for the treatment of Clostridium difficile infection: results of two double-blind, placebo-controlled, non-inferiority, randomised phase 3 trials.

Background: Cadazolid is a novel quinoxolidinone antibiotic developed for treating Clostridium difficile infection. We aimed to investigate the safety and efficacy of cadazolid compared with vancomycin in patients with C difficile infection.

Methods: IMPACT 1 and IMPACT 2 were identically designed, multicentre, double-blind, placebo-controlled, non-inferiority, randomised phase 3 trials.

Changes in Composition of the Gut Bacterial Microbiome after Fecal Microbiota Transplantation for Recurrent Infection in a Pediatric Heart Transplant Patient.

The microbiome is increasingly recognized as an important influence on human health and many of the comorbidities that affect patients after solid organ transplantation (SOT) have been shown to involve changes in gut bacterial populations. Thus, microbiome changes in an individual patient may have important health implications after SOT but this area remains understudied. We describe changes in the composition of the fecal microbiome from a pediatric heart transplant recipient before and >2.

Clearance of Vancomycin-Resistant Concomitant With Administration of a Microbiota-Based Drug Targeted at Recurrent Infection.

 Vancomycin-resistant (VRE) is a major healthcare-associated pathogen and a well known complication among transplant and immunocompromised patients. We report on stool VRE clearance in a post hoc analysis of the Phase 2 PUNCH CD study assessing a microbiota-based drug for recurrent infection (CDI).  A total of 34 patients enrolled in the PUNCH CD study received 1 or 2 doses of RBX2660 (microbiota suspension).

Fidaxomicin versus Vancomycin in the Treatment of Clostridium difficile Infection: Canadian Outcomes.

Background. This analysis examined the efficacy of fidaxomicin versus vancomycin in 406 Canadian patients with Clostridium difficile infection (CDI), based on data from 2 randomized, clinical trials. Methods.

Differences of the Fecal Microflora With Clostridium difficile Therapies.

Background: During treatment of Clostridium difficile infection (CDI), patterns of pathogen reduction in relationship to changes in components of the normal microbiota are hypothesized to be predictive of response to treatment and subsequent sustained cure.

Methods: At a single center, subjects enrolled into phase 2 and 3 C. difficile treatment clinical trials (2003-2008) provided fecal samples to assess killing of C.

Vancomycin, metronidazole, or tolevamer for Clostridium difficile infection: results from two multinational, randomized, controlled trials.

Background: Clostridium difficile infection (CDI) is a common complication of antibiotic therapy that is treated with antibiotics, contributing to ongoing disruption of the colonic microbiota and CDI recurrence. Two multinational trials were conducted to compare the efficacy of tolevamer, a nonantibiotic, toxin-binding polymer, with vancomycin and metronidazole.

Methods: Patients with CDI were randomly assigned in a 2:1:1 ratio to oral tolevamer 9 g (loading dose) followed by 3 g every 8 hours for 14 days, vancomycin 125 mg every 6 hours for 10 days, or metronidazole 375 mg every 6 hours for 10 days.

Renal impairment and clinical outcomes of Clostridium difficile infection in two randomized trials.

Background/aims: Patients with chronic kidney disease (CKD) have increased risk for Clostridium difficile infection (CDI) and for subsequent mortality. We determined the effect of CKD on response to treatment for CDI.

Methods: This is a post hoc analysis of two randomized controlled phase 3 trials that enrolled patients with CDI.

Effect of age on treatment outcomes in Clostridium difficile infection.

Objectives: To determine the effect of advancing age on the clinical outcomes of Clostridium difficile (CDI) treatment.

Design: Regression modeling of results from two double-blind randomized multicenter studies on the treatment of primary and first recurrent cases of CDI to examine for effects of age and study drug on outcomes of cure (resolution of diarrhea), recurrence within 4 weeks of completing successful therapy, and cure without recurrence.

Setting: Participants were randomized into studies in the United States, Canada, and Europe.

Fidaxomicin versus vancomycin for Clostridium difficile infection: meta-analysis of pivotal randomized controlled trials.

Two recently completed phase 3 trials (003 and 004) showed fidaxomicin to be noninferior to vancomycin for curing Clostridium difficile infection (CDI) and superior for reducing CDI recurrences. In both studies, adults with active CDI were randomized to receive blinded fidaxomicin 200 mg twice daily or vancomycin 125 mg 4 times a day for 10 days. Post hoc exploratory intent-to-treat (ITT) time-to-event analyses were undertaken on the combined study 003 and 004 data, using fixed-effects meta-analysis and Cox regression models.

Treatment of first recurrence of Clostridium difficile infection: fidaxomicin versus vancomycin.

Recurrence of Clostridium difficile infection (CDI) occurs in approximately 25% of successfully treated patients. Two phase 3 randomized, double-blind trials were conducted at 154 sites in the United States, Canada, and Europe to compare fidaxomicin vs vancomycin in treating CDI. Patients with CDI received fidaxomicin 200 mg twice daily or vancomycin 125 mg 4 times daily for 10 days.

Fidaxomicin preserves the intestinal microbiome during and after treatment of Clostridium difficile infection (CDI) and reduces both toxin reexpression and recurrence of CDI.

The microflora-sparing properties of fidaxomicin were examined during the conduct of a randomized clinical trial comparing vancomycin 125 mg 4 times per day versus fidaxomicin 200 mg twice per day for 10 days as treatment of Clostridium difficile infection (CDI). Fecal samples were obtained from 89 patients (45 received fidaxomicin, and 44 received vancomycin) at study entry and on days 4, 10, 14, 21, 28, and 38 for quantitative cultures for C. difficile and cytotoxin B fecal filtrate concentrations.

Fidaxomicin attains high fecal concentrations with minimal plasma concentrations following oral administration in patients with Clostridium difficile infection.

Fidaxomicin has recently been approved for the treatment of Clostridium difficile infection (CDI). As part of phase III studies, plasma and fecal samples were analyzed for concentrations of fidaxomicin and its metabolite, OP-1118. Plasma samples were collected before and after dose receipt on the first and last days of therapy, and fecal samples were collected on the last day of therapy.

Efficacy of fidaxomicin versus vancomycin as therapy for Clostridium difficile infection in individuals taking concomitant antibiotics for other concurrent infections.

Background: Treatment guidelines recommend stopping all implicated antibiotics at the onset of Clostridium difficile infection (CDI), but many individuals have persistent or new infections necessitating the use of concomitant antibiotics (CAs). We used data from 2 phase 3 trials to study effects of CAs on response to fidaxomicin or vancomycin.

Methods: Subjects with CDI were treated for 10 days with fidaxomicin 200 mg every 12 hours or vancomycin 125 mg every 6 hours, assessed for resolution of symptoms, and followed up for an additional 4 weeks for evidence of recurrence.

Fidaxomicin versus vancomycin for Clostridium difficile infection.

Background: Clostridium difficile infection is a serious diarrheal illness associated with substantial morbidity and mortality. Patients generally have a response to oral vancomycin or metronidazole; however, the rate of recurrence is high. This phase 3 clinical trial compared the efficacy and safety of fidaxomicin with those of vancomycin in treating C.

OPT-80 eliminates Clostridium difficile and is sparing of bacteroides species during treatment of C. difficile infection.

During a 10-day treatment for Clostridium difficile infection, OPT-80 and vancomycin were comparably effective in reducing C. difficile counts. Bacteroides fragilis group counts appeared unaffected with increasing dosages of OPT-80, whereas vancomycin was markedly suppressive.