Primary or Recurrent Clostridioides Difficile Infection Treatment With Capsules of Lyophilised Faecal Microbiota vs Fidaxomicin

This is a Phase III, multicenter, controlled and open label clinical trial in which patients who suffered an episode of Clostridioides difficile infection (either the first episode or subsequent recurrences) will be randomly assigned (1:1) to one of the following arms:

• Fidaxomicin
• MBK-01 (heterologous lyophilized fecal microbiota)

Objective: To assess the efficacy of FMT with capsules of lyophilized fecal microbiota (MBK-01), compared to the control (fidaxomicin) at 8 weeks after the start of the treatment. Also, assess the safety of MBK-01 and the quality of life of patients participating in the study.

Follow up: participants will return for clinic visits at 72 hours, week 3 and week 8 after the start of the treatment, and will receive follow-up phone calls at month 3 and month 6 after the start of the treatment. Stool samples will be collected from participants for further studies at time 0 and week 8 after the start of the treatment. Study Outcomes are detailed in the specific section of this website.

Rationale: The transferred microbiota restores the recipient's intestinal microbiota by reintroducing bacterial taxa that were absent or in low proportion in the recipient before the FMT. This supports the expansion of the recipient's own commensal microbiota and re-establishing a microbiota community with a high biodiversity.

Donors: All donors are screened to ensure they meet the strict requirements necessary to maintain the safety of the MBK-01.

Justification: The treatment of Clostridioides difficile infections (CDI) with antibiotics is usually effective for acute symptoms, but after the initial treatment, the probability of recurrence at 8 weeks ranges from 10-20 % of cases, and once a patient has a recurrence, the probability of further recurrences increases up to 40-65 %. In recent years, Fecal Microbiota Transfer (FMT) has emerged as the preferred non-pharmacological treatment to manage CDI with multiple recurrences and recent clinical trials have evaluated its potential efficacy and safety in the treatment of patients with primary CD infection. Although antibiotics are the recommended therapy for the first episode of CDI, treatment with oral vancomycin and/or metronidazole often results in significant treatment failure, with recurrences occurring in up to 30-40% of patients. Furthermore, antibiotic treatment does not correct deficiencies in the intestinal microbiota that facilitate CD infection and is associated with the risk of the emergence of antibiotic-resistant bacteria. Moreover, the treatment of recurrences is not adequately standardized. In recent years, although the most widely used alternatives have been fidaxomicin and bezlotoxumab, their efficacy in patients who already suffer from r-CDI is not proven. The administration of the FMT through oral capsules, although it is not standardized, has proven to be effective in the restoration of intestinal microbiota of patients with r-CDI. In addition, the use of lyophilized formulas facilitates the concentration of bacteria and further optimizes the donors' sample and reduces the amount of capsules that the patient has to ingest.

Inclusion criteria

• Patients of both genders, over 18 years.
• Patients that undergo an episode of CD infection (either the first episode or subsequent recurrences).
• Presence of an episode of diarrhea defined as ≥3 stools/24 hours, at the beginning of the episode.
• Confirmation of the presence of CD toxin A and/or B in faeces, by a direct toxin detection test or by the PCR technique for the detection of toxin/s producing genes, at the start of the episode that is going to be treated in the clinical trial (the toxin test must be positive within 7 days prior to the enrolment of the patient in the trial).

Exclusion criteria

• Previous faecal microbiota transfer.
• Transplanted patients, except those with a solid organ transplant of more than 2 years, with good organ function.
• Absolute neutrophil count <500 cells /μL at the time of the enrollment in the study.
• Pregnancy, breastfeeding, or pregnancy intentions over the course of the study.
• Active treatment with bile acid sequestrants (for instance: cholestyramine).
• Positive patients for the human immunodeficiency virus (HIV) except those with lymphocytes T CD4 count > 200 cells/μL and viral load less than 20 copies.
• Swallowing dysfunction or no oral motor coordination.
• Patient admitted in an intensive care unit or expected to be admitted in an intensive care unit due to serious illness.
• History of significant medical conditions that, in the opinion of the investigator, would not allow an adequate evaluation or follow-up of the patient.