Retrospective Analysis of the Safety and Efficacy of Fecal Microbiota, Live-jslm (REBYOTATM) Administered Under Enforcement Discretion to Patients With Clostridioides difficile Infection

Organoid-Based Assessment of Metal-Organic Framework (MOF) Nanomedicines for Ex Vivo Cancer Therapy

Nanomaterials have been extensively exploited in tumor treatment, leading to numerous innovative strategies for cancer therapy. While nanomedicines present immense potential, their application in cancer therapy is characterized by significant complexity and unpredictability, especially regarding biocompatibility and anticancer efficiency. These considerations underscore the essential need for the development of ex vivo research models, which provide invaluable insights and understanding into the biosafety and efficacy of nanomedicines in oncology. Fortunately, the emergence of organoid technology offers a novel approach to the preclinical evaluation of the anticancer efficacy of nanomedicines in vitro. Hence, in this study, we constructed intestine and hepatocyte organoid models (Intestine-orgs and Hep-orgs) for assessing intestinal and hepatic toxicity at the microtissue level. We utilized three typical metal-organic frameworks (MOFs), ZIF-8, ZIF-67, and MIL-125, as nanomedicines to further detect their interactions with organoids. Subsequently, the MIL-125 with biocompatibility loaded methotrexate (MTX), forming the nanomedicine (MIL-125-PEG-MTX), indicated a high loading efficiency (82%) and a well-release capability in an acid microenvironment. More importantly, the anticancer effect of the nanomedicine was investigated using an in vitro patient-derived organoids (PDOs) model, achieving inhibition rates of 48% and 78% for PDO-1 and PDO-2, respectively, demonstrating that PDOs could predict clinical response and facilitate prospective therapeutic selection. These achievements presented great potential for organoid-based ex vivo models for nano theragnostic evaluation in biosafety and function.

Review article: The epidemiology and management of Clostridioides difficile infection-A clinical update

BACKGROUND

Clostridioides difficile is the most common cause of healthcare-associated infection, and severe cases can result in significant complications. While anti-microbial therapy is central to infection management, adjunctive therapies may be utilised as preventative strategies.

AIM

This article aims to review updates in the epidemiology, diagnosis, and management, including treatment and prevention, of C. difficile infections.

METHODS

A narrative review was performed to evaluate the current literature between 1986 and 2023.

RESULTS

The incidence of C. difficile infection remains significantly high in both hospital and community settings, though with an overall decline in recent years and similar surveillance estimates globally. Vancomycin and fidaxomicin remain the first line antibiotics for treatment of non-severe C. difficile infection, though due to lower recurrence rates, infectious disease society guidelines now favour use of fidaxomicin. Faecal microbiota transplantation should still be considered to prevent recurrent C. difficile infection. However, in the past year the field has had a significant advancement with the approval of the first two live biotherapeutic products-faecal microbiota spores-live brpk, an oral capsule preparation, and faecal microbiota live-jslm-both indicated for the prevention of recurrent C. difficile infection, with additional therapies on the horizon.

CONCLUSION

Although the prevalence of C. difficile infection remains high, there have been significant advances in the development of novel therapeutics and preventative measures following changes in recent practice guidelines, and will continue to evolve in the future.

Update on microbiota-derived therapies for recurrent Clostridioides difficile infections

BACKGROUND

Faecal microbiota transplantation (FMT) is the standard treatment for patients with multiple recurrent Clostridioides difficile infection (rCDI). Recently, new commercially developed human microbiota-derived medicinal products have been evaluated and Food and Drug Administration-approved with considerable differences in terms of composition, administration, and targeted populations.

OBJECTIVES

To review available data on the different microbiota-derived treatments at the stage of advanced clinical evaluation and research in rCDI in comparison with FMT.

SOURCES

Phase II or III trials evaluating a microbiota-derived medicinal product to prevent rCDI.

CONTENT

Two commercial microbiota-derived medicinal products are approved by the Food and Drug Administration: Rebyota (RBX2660 Ferring Pharmaceuticals, marketed in the United States) and VOWST (SER-109 -Seres Therapeutics, marketed in the United States), whereas VE303 (Vedanta Biosciences Inc) will be studied in phase III trial. RBX2660 and SER-109 are based on the processing of stools from healthy donors, whereas VE303 consists of a defined bacterial consortium originating from human stools and produced from clonal cell banks. All have proven efficacy to prevent rCDI compared with placebo in patients considered at high risk of recurrence. However, the heterogeneity of the inclusion criteria, and the time between each episode and CDI diagnostics makes direct comparison between trials difficult. The differences regarding the risk of recurrence between the treatment and placebo arms were lower than previously described for FMT (FMT: Δ = 50.5%; RBX2660-phase III: Δ = 13.1%; SER-109-phase III: Δ = 28%; high-dose VE303-phase-II: Δ = 31.7%). All treatments presented a good overall safety profile with mainly mild gastrointestinal symptoms.

IMPLICATIONS

Stool-derived products and bacterial consortia need to be clearly distinguished in terms of product characterization and their associated risks with specific long-term post-marketing evaluation similar to registries used for FMT. Their place in the therapeutic strategy for patients with rCDI requires further studies to determine the most appropriate patient population and administration route to prevent rCDI.

Retrospective subgroup analysis of fecal microbiota, live-jslm (REBYOTA®) administered by colonoscopy under enforcement discretion for the prevention of recurrent Clostridioides difficile infection

Background

Fecal microbiota, live-jslm (RBL; REBYOTA®), is the first Food and Drug Administration (FDA)-approved, single-dose, rectally administered, microbiota-based live biotherapeutic product for preventing Clostridioides difficile infection (CDI) recurrence. Alternative routes of administration are of clinical interest.

Objectives

Evaluate the safety and efficacy of RBL administration via colonoscopy.

Design

Retrospective analysis of electronic medical records of participants administered RBL via colonoscopy under FDA enforcement discretion.

Methods

The number of participants with treatment and/or procedure-emergent adverse events (TEAEs) was evaluated. Treatment success and sustained clinical response, defined as the absence of CDI recurrence within 8 weeks and 6 months, respectively, were evaluated.

Results

TEAEs were experienced by 75% (6/8) of participants; most were mild to moderate in severity, and none due to RBL or its administration. Most participants had treatment success (80%; 8/10); 75% (6/8) had sustained clinical response.

Conclusion

Real-world safety and efficacy of RBL administered via colonoscopy were consistent with clinical trials of rectally administered RBL.

Graphical abstract

Bring it on again: antimicrobial stewardship in transplant infectious diseases: updates and new challenges

Advancement in solid organ transplantation and hematopoietic stem cell transplant continues to improve the health outcomes of patients and widens the number of eligible patients who can benefit from the medical progress. Preserving the effectiveness of antimicrobials remains crucial, as otherwise transplant surgeries would be unsafe due to surgical site infections, and the risk of sepsis with neutropenia would preclude stem cell transplant. In this review, we provide updates on three previously discussed stewardship challenges: febrile neutropenia, Clostridioides difficile infection, and asymptomatic bacteriuria. We also offer insight into four new stewardship challenges: the applicability of the "shorter is better" paradigm shift to antimicrobial duration; antibiotic allergy delabeling and desensitization; colonization with multidrug-resistant gram-negative organisms; and management of cytomegalovirus infections. Specifically, data are accumulating for "shorter is better" and antibiotic allergy delabeling in transplant patients, following successes in the general population. Unique to transplant patients are the impact of multidrug-resistant organism colonization on clinical decision-making of antibiotic prophylaxis in transplant procedure and the need for antiviral stewardship in cytomegalovirus. We highlighted the expansion of antimicrobial stewardship interventions as potential solutions for these challenges, as well as gaps in knowledge and opportunities for further research.

Bile acids impact the microbiota, host, and C. difficile dynamics providing insight into mechanisms of efficacy of FMTs and microbiota-focused therapeutics

Clostridioides difficile is a major nosocomial pathogen, causing significant morbidity and mortality worldwide. Antibiotic usage, a major risk factor for Clostridioides difficile infection (CDI), disrupts the gut microbiota, allowing C. difficile to proliferate and cause infection, and can often lead to recurrent CDI (rCDI). Fecal microbiota transplantation (FMT) and live biotherapeutic products (LBPs) have emerged as effective treatments for rCDI and aim to restore colonization resistance provided by a healthy gut microbiota. However, much is still unknown about the mechanisms mediating their success. Bile acids, extensively modified by gut microbes, affect C. difficile's germination, growth, and toxin production while also shaping the gut microbiota and influencing host immune responses. Additionally, microbial interactions, such as nutrient competition and cross-feeding, contribute to colonization resistance against C. difficile and may contribute to the success of microbiota-focused therapeutics. Bile acids as well as other microbial mediated interactions could have implications for other diseases being treated with microbiota-focused therapeutics. This review focuses on the intricate interplay between bile acid modifications, microbial ecology, and host responses with a focus on C. difficile, hoping to shed light on how to move forward with the development of new microbiota mediated therapeutic strategies to combat rCDI and other intestinal diseases.

Review Article: Safety of Live Biotherapeutic Products Used for the Prevention of Clostridioides difficile Infection Recurrence

Live biotherapeutic products (LBPs) represent a new class of therapeutics indicated to prevent the recurrence of Clostridioides difficile infection (CDI) in adults. However, microbiota-based therapies have been used in CDI management before the Food and Drug Administration (FDA) designated this new drug class. The regulation of these microbiome-based therapies has varied, and several safety concerns have arisen over time. Requirements established by the FDA regarding the development of LBPs minimizes many of these prior concerns, and phase III trials have proven the safety and efficacy of 2 stool donor-derived LBPs: fecal microbiota, live-jslm (Rebyota™; formerly RBX2660) and fecal microbiota spores, live-brpk (Vowst™; formerly SER-109). Mild gastrointestinal side effects are common, but no severe drug-related adverse events have been reported with their use to date. A third LBP entering phase III clinical trials, VE303, follows a novel approach by sourcing bacterial strains from clonal cell banks and has demonstrated a similarly favorable safety profile.

Therapeutics for Clostridioides difficile infection: molecules and microbes

INTRODUCTION

Clostridioides difficile infection (CDI) is a major healthcare problem in the developed world, and effective management of recurrent infection remains one of the biggest challenges. Several advances have occurred in the management of CDI, and in the last 15 years, multiple new agents have been tested. Since 2011, four new products have been approved by the US FDA for treatment of CDI or prevention of recurrent CDI.

AREAS COVERED

This review focuses on therapeutics of CDI and includes sections on primary prevention, management of active infection, and prevention of recurrent CDI. Specifically, data are included on fecal microbiota transplantation and live biotherapeutics. A comprehensive search of several databases including Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from inception to 1 May 2023 was conducted.

EXPERT OPINION

Metronidazole is no longer advised for management of outpatient CDI. The preferred medication of choice for a first episode is oral vancomycin or fidaxomicin. For those patients who recur after the first episode, vancomycin taper pulse or fidaxomicin can be used. Intravenous bezlotoxumab, a monoclonal antibody, is available to prevent recurrences. There are now two FDA-approved microbiome-based therapies or live biotherapeutics for prevention of recurrent CDI, for any recurrent CDI and not necessarily multiply recurrent C difficile. Fecal microbiota transplantation remains available in limited settings for recurrent CDI.