Conversion of unresponsiveness to immune checkpoint inhibition by fecal microbiota transplantation in patients with metastatic melanoma: study protocol for a randomized phase Ib/IIa trial.

BACKGROUND: The gut microbiome plays an important role in immune modulation. Specifically, presence or absence of certain gut bacterial taxa has been associated with better antitumor immune responses. Furthermore, in trials using fecal microbiota transplantation (FMT) to treat melanoma patients unresponsive to immune checkpoint inhibitors (ICI), complete responses (CR), partial responses (PR), and durable stable disease (SD) have been observed. However, the underlying mechanism determining which patients will or will not respond and what the optimal FMT composition is, has not been fully elucidated, and a discrepancy in microbial taxa associated with clinical response has been observed between studies. Furthermore, it is unknown whether a change in the microbiome itself, irrespective of its origin, or FMT from ICI responding donors, is required for reversion of ICI-unresponsiveness. To address this, we will transfer microbiota of either ICI responder or nonresponder metastatic melanoma patients via FMT. METHODS: In this randomized, double-blinded phase Ib/IIa trial, 24 anti-PD1-refractory patients with advanced stage cutaneous melanoma will receive an FMT from either an ICI responding or nonresponding donor, while continuing anti-PD-1 treatment. Donors will be selected from patients with metastatic melanoma treated with anti-PD-1 therapy. Two patients with a good response (≥ 30% decrease according to RECIST 1.1 within the past 24 months) and two patients with progression (≥ 20% increase according to RECIST 1.1 within the past 3 months) will be selected as ICI responding or nonresponding donors, respectively. The primary endpoint is clinical benefit (SD, PR or CR) at 12 weeks, confirmed on a CT scan at 16 weeks. The secondary endpoint is safety, defined as the occurrence of grade ≥ 3 toxicity. Exploratory endpoints are progression-free survival and changes in the gut microbiome, metabolome, and immune cells. DISCUSSION: Transplanting fecal microbiota to restore the patients' perturbed microbiome has proven successful in several indications. However, less is known about the potential role of FMT to improve antitumor immune response. In this trial, we aim to investigate whether administration of FMT can reverse resistance to anti-PD-1 treatment in patients with advanced stage melanoma, and whether the ICI-responsiveness of the feces donor is associated with its effectiveness. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05251389 (registered 22-Feb-2022). Protocol V4.0 (08-02-2022).

Clinical Application and Potential of Fecal Microbiota Transplantation.

Fecal microbiota transplantation (FMT) is a well-established treatment for recurrent Clostridioides difficile infection. FMT has become a more readily available and useful new treatment option as a result of stool banks. The current state of knowledge indicates that dysbiosis of the gut microbiota is implicated in several disorders in addition to C. difficile infection. Randomized controlled studies have shown FMT to be somewhat effective in treating ulcerative colitis, irritable bowel syndrome, and hepatic encephalopathy. In addition, FMT has been beneficial in treating several other conditions, such as the eradication of multidrug-resistant organisms and graft-versus-host disease. We expect that FMT will soon be implemented as a treatment strategy for several new indications, although further studies are needed.

International consensus conference on stool banking for faecal microbiota transplantation in clinical practice.

Although faecal microbiota transplantation (FMT) has a well-established role in the treatment of recurrent Clostridioides difficile infection (CDI), its widespread dissemination is limited by several obstacles, including lack of dedicated centres, difficulties with donor recruitment and complexities related to regulation and safety monitoring. Given the considerable burden of CDI on global healthcare systems, FMT should be widely available to most centres.Stool banks may guarantee reliable, timely and equitable access to FMT for patients and a traceable workflow that ensures safety and quality of procedures. In this consensus project, FMT experts from Europe, North America and Australia gathered and released statements on the following issues related to the stool banking: general principles, objectives and organisation of the stool bank; selection and screening of donors; collection, preparation and storage of faeces; services and clients; registries, monitoring of outcomes and ethical issues; and the evolving role of FMT in clinical practice,Consensus on each statement was achieved through a Delphi process and then in a plenary face-to-face meeting. For each key issue, the best available evidence was assessed, with the aim of providing guidance for the development of stool banks in order to promote accessibility to FMT in clinical practice.

Nucleic Acid Amplification Test Quantitation as Predictor of Toxin Presence in Clostridium difficile Infection.

Multistep algorithmic testing in which a sensitive nucleic acid amplification test (NAAT) is followed by a specific toxin A and toxin B enzyme immunoassay (EIA) is among the most accurate methods for Clostridium difficile infection (CDI) diagnosis. The obvious shortcoming of this approach is that multiple tests must be performed to establish a CDI diagnosis, which may delay treatment. Therefore, we sought to determine whether a preliminary diagnosis could be made on the basis of the quantitative results of the first test in algorithmic testing, which provide a measure of organism burden. To do so, we retrospectively analyzed two large collections of samples (n = 2,669 and n = 1,718) that were submitted to the laboratories of two Dutch hospitals for CDI testing. Both hospitals apply a two-step testing algorithm in which a NAAT is followed by a toxin A/B EIA. Of all samples, 208 and 113 samples, respectively, tested positive by NAAT. Among these NAAT-positive samples, significantly lower mean quantification cycle (Cq ) values were found for patients whose stool eventually tested positive for toxin, compared with patients who tested negative for toxin (mean Cq values of 24.4 versus 30.4 and 26.8 versus 32.2; P < 0.001 for both cohorts). Receiver operating characteristic curve analysis was performed to investigate the ability of Cq values to predict toxin status and yielded areas under the curve of 0.826 and 0.854. Using the optimal Cq cutoff values, prediction of the eventual toxin A/B EIA results was accurate for 78.9% and 80.5% of samples, respectively. In conclusion, Cq values can serve as predictors of toxin status but, due to the suboptimal correlation between the two tests, additional toxin testing is still needed.

[Fecal microbiota transplantation, a novel therapy for recurrent Clostridium difficile infection]. / Fecale microbiota transplantatie: een nieuwe behandeling voor recidiverende Clostridium difficile-infectie.

Clostridium difficile infection is caused by a disturbance of the gut microbiota, often resulting from the use of antibiotics. Among a sub group of patients with this disorder, treatment with antibiotics is not effective. They develop a chronic, recurrent infection. Such patients can be treated with a fecal microbiota transplantation (FMT), or fecal transplantation. The crucial steps for safe application of fecal transplantation are central donor selection and screening. To optimise safety and to guarantee the availability of donor feces for fecal transplantation, the Nederlandse Donor Feces Bank (Dutch Donor Feces Bank) was established. At this facility, ready-to-use, screened donor feces can be ordered for patients with (recurrent) Clostridium difficile infections, who can then be treated at their own hospital.

Ten-Year Follow-Up of Patients Treated with Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection from a Randomized Controlled Trial and Review of the Literature.

Fecal microbiota transplantation (FMT) has become a well-established treatment for recurrent Clostridioides difficile infection (rCDI). While short-term outcomes and adverse events relating to FMT have been well documented, there still is a paucity of data with regard to long-term safety. In this report, we describe the long-term follow-up of the prospective cohort of the first randomized controlled trial of FMT for rCDI, and review the existing literature. A total of 34 patients were treated with FMT for rCDI. Seven patients were still alive after a follow-up of more than 10 years and three patients were lost to follow-up. None of the 34 patients had experienced a new-onset autoimmune, gastrointestinal, or malignant disorder during follow-up. We did not find any deterioration or amelioration of pre-existing medical conditions. Furthermore, no deaths directly attributable to FMT could be identified. These findings are in accordance with the data in available literature. In conclusion, no long-term adverse events or complications directly attributable to FMT were found in our prospective cohort. Review of the available literature does not point to long-term risks associated with FMT in this elderly population, provided that carefully screened fecal suspensions are being used. No firm conclusion on the long-term safety of FMT in younger patients could be drawn.

Fifty shades of graft: How to improve the efficacy of faecal microbiota transplantation for decolonization of antibiotic-resistant bacteria.

BACKGROUND: Spontaneous decolonization of antibiotic-resistant bacteria (ARB) takes time: approximately 25% after 30 days for carbapenem-producing Enterobacteriaceae or extended-spectrum beta-lactamase-producing Enterobacteriaceae. Faecal microbiota transplantation (FMT) has been proposed as a new strategy to promote decolonization in order to reduce the risk of superinfection due to these ARB. This paper discusses the literature on the use of FMT for this indication, and the improvement levers available to promote its efficacy. METHODS: Literature available to date concerning the use of FMT to eradicate ARB was reviewed, and the different factors that may have influenced the efficacy of decolonization were evaluated. RESULTS: Four axes that could have played major roles in the efficacy of FMT were identified: bowel preparation before FMT; donor; dose; and thermal conditioning of faeces. The positive or negative impact of each on the outcome of FMT is discussed. CONCLUSION: Although FMT is very efficient for the eradication of Clostridium difficile, the same 'recipe' cannot be used for the eradication of ARB. Working together with expert centres may help to improve the efficacy of FMT for this indication, and enable the reduction of in-hospital isolation precautions.

Spread of ESBL-producing Escherichia coli in nursing home residents in Ireland and the Netherlands may reflect infrastructural differences.

A prevalence study in two nursing homes (one each in the Netherlands and Ireland) found four (11%) Dutch and six (9%) Irish residents colonized with 11 extended-spectrum beta-lactamase-producing Escherichia coli, 10 of which contained CTX-M-15. Four Dutch isolates, from three residents of the same ward, belonged to E. coli O25:H4, sequence type (ST) 131 and were part of the same cluster type by whole-genome sequencing. Four Irish residents on three different wards were colonized with an identical E. coli O89:H9, ST131, complex type 1478. Cross-transmission between three Irish wards may reflect differences in nursing home infrastructure, specifically communal areas and multi-bedded resident rooms.

Update of treatment algorithms for Clostridium difficile infection.

BACKGROUND: Clostridium difficile is the leading cause of antibiotic-associated diarrhoea, both in healthcare facilities and in the community. The recurrence rate of C. difficile infection (CDI) remains high, up to 20%. Since the publication of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guidance document on CDI treatment in 2014, new therapeutic approaches have been developed and tested to achieve higher sustained clinical cure in CDI. AIM: To review novel treatments and approaches for CDI, except probiotics and vaccines. We focused on new antibiotics, antibiotic inactivators, monoclonal antibodies and gut microbiota modulating therapies. SOURCES: A literature review was performed for clinical trials published in PubMed, Embase or Cochrane Library between January 2013 and November 2017. CONTENT: We analysed 28 clinical trials and identified 14 novel agents. Completed phase 2 studies were found for cadazolid, LFF571, ridinilazole and nontoxigenic C. difficile strains. Four phase 3 active comparator studies comparing vancomycin with bezlotoxumab, surotomycin (n = 2) and rifaximin have been published. Seven clinical trials for treatment of multiple recurrent CDI with faecal microbiota transplantation were analysed, describing faecal microbiota transplantation by upper or lower gastrointestinal route (n = 5) or by capsules (n = 2). IMPLICATIONS: Metronidazole is mentioned in the ESCMID guideline as first-line therapy, but we propose that oral vancomycin will become the first choice when antibiotic treatment for CDI is necessary. Fidaxomicin is a good alternative, especially in patients at risk of relapse. Vancomycin combined with faecal microbiota transplantation remains the primary therapy for multiple recurrent CDI. We anticipate that new medication that protects the gut microbiota will be further developed and tested to prevent CDI during antibiotic therapy.

[Faecal microbiota transplantation: indications in perspective]. / Fecestransplantatie: wanneer wel en wanneer niet?

- As yet, with cure rates around 85%, recurrent Clostridium difficile infection is the only definite indication for faecal microbiota transplantation.- Faecal microbiota transplantation induces clinical remission and endoscopic improvements in 24-30% of patients with ulcerative colitis, compared to 5% (water) to 20% (autologous faeces) in placebo-treated patients. Current research focuses on the identification of 'super donors', and subgroups of patients in which faecal microbiota transplantation is effective.- In patients with metabolic syndrome, faecal microbiota transplantation may increase insulin sensitivity. Weight, body mass index, and energy metabolism are not affected by faecal microbiota transplantation in humans.- In addition to the aforementioned indications, faecal microbiota transplantation is an emerging treatment modality for patients with Crohn's disease, irritable bowel syndrome, graft-versus-host-disease, and carriage of multidrug-resistant micro-organisms. Randomized controlled trials, comparing faecal microbiota transplantation with placebo treatment, are required to determine the effectiveness of faecal microbiota transplantation in these patient groups.

How to: Establish and run a stool bank.

BACKGROUND: Since 2013, several stool banks have been developed following publications reporting on clinical success of 'faecal microbiota transplantation' (FMT) for recurrent Clostridium difficile infections (CDI). However, protocols for donor screening, faecal suspension preparation, and transfer of the faecal suspension differ between countries and institutions. Moreover, no European consensus exists regarding the legislative aspects of the faecal suspension product. Internationally standardized recommendations about the above mentioned aspects have not yet been established. OBJECTIVE: In 2015, the Netherlands Donor Feces Bank (NDFB) was founded with the primary aim of providing a standardized product for the treatment of patients with recurrent CDI in the Netherlands. Standard operation procedures for donor recruitment, donor selection, donor screening, and production, storage, and distribution of frozen faecal suspensions for FMT were formulated. RESULTS AND DISCUSSION: Our experience summarized in this review addresses current donor recruitment and screening, preparation of the faecal suspension, transfer of the faecal microbiota suspension, and the experiences and follow-up of the patients treated with donor faeces from the NDFB.

European Society of Clinical Microbiology and Infectious Diseases: update of the diagnostic guidance document for Clostridium difficile infection.

In 2009 the first European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guideline for diagnosing Clostridium difficile infection (CDI) was launched. Since then newer tests for diagnosing CDI have become available, especially nucleic acid amplification tests. The main objectives of this update of the guidance document are to summarize the currently available evidence concerning laboratory diagnosis of CDI and to formulate and revise recommendations to optimize CDI testing. This update is essential to improve the diagnosis of CDI and to improve uniformity in CDI diagnosis for surveillance purposes among Europe. An electronic search for literature concerning the laboratory diagnosis of CDI was performed. Studies evaluating a commercial laboratory test compared to a reference test were also included in a meta-analysis. The commercial tests that were evaluated included enzyme immunoassays (EIAs) detecting glutamate dehydrogenase, EIAs detecting toxins A and B and nucleic acid amplification tests. Recommendations were formulated by an executive committee, and the strength of recommendations and quality of evidence were graded using the Grades of Recommendation Assessment, Development and Evaluation (GRADE) system. No single commercial test can be used as a stand-alone test for diagnosing CDI as a result of inadequate positive predictive values at low CDI prevalence. Therefore, the use of a two-step algorithm is recommended. Samples without free toxin detected by toxins A and B EIA but with positive glutamate dehydrogenase EIA, nucleic acid amplification test or toxigenic culture results need clinical evaluation to discern CDI from asymptomatic carriage.