for people ages 1-17 (full criteria)
at San Francisco, California and other locations
study started
estimated completion
Principal Investigator
by Philip Rosenthal



The primary objectives of this study are to evaluate the pharmacokinetics (PK), safety, and tolerability of bezlotoxumab in children aged 1 to <18 years of age with a confirmed diagnosis of Clostridium difficile infection (CDI) who are receiving antibacterial drug treatment. The primary hypothesis is that the area under the concentration-time curve from 0 to infinity (AUC0-inf) of bezlotoxumab after treatment of pediatric participants with bezlotoxumab is similar when compared to the AUC0-inf of bezlotoxumab after treatment of adults with bezlotoxumab,

Official Title

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial to Evaluate the Safety, Tolerability, Pharmacokinetics, and Efficacy of a Single Infusion of Bezlotoxumab (MK-6072, Human Monoclonal Antibody to C. Difficile Toxin B) in Children Aged 1 to <18 Years Receiving Antibacterial Drug Treatment for C. Difficile Infection (MODIFY III)


Clostridium Difficile Infection Infections Communicable Diseases Clostridium Infections Enterocolitis, Pseudomembranous Bezlotoxumab


You can join if…

Open to people ages 1-17

  • At screening has suspected or confirmed CDI, and is receiving or is planning to receive a 10- to 21-day course of antibacterial drug treatment for CDI
  • At study infusion has a diagnosis of CDI confirmed by a diagnostic assay which detects the presence of C. difficile toxin in stool, and is still receiving antibacterial drug treatment for CDI.
  • Female is not pregnant, and not breastfeeding; but if of childbearing potential agrees to follow contraceptive guidance during the treatment period and for at least 12 weeks after the last dose of study treatment
  • Participant and/or parent or caregiver must be able to read, understand, and complete the daily diary

You CAN'T join if...

  • Has an uncontrolled chronic diarrheal illness
  • Has a known hypersensitivity to bezlotoxumab, its active substance and/or any of its excipients
  • At randomization, their planned course of antibacterial drug treatment for CDI is longer than 21 days
  • At screening has received any listed prohibited prior and concomitant treatments and procedures
  • Has previously participated in this study, has previously received bezlotoxumab, has received an experimental monoclonal antibody against C. difficile toxin B, or has received a vaccine directed against C. difficile or its toxins.
  • Has received an investigational study agent within the previous 30 days, or is currently participating in or scheduled to participate in any other clinical study with an investigational agent during the 12-week study period


  • UCSF Medical Center ( Site 0049) accepting new patients
    San Francisco California 94158 United States
  • Children's Hospital - Los Angeles ( Site 0021) accepting new patients
    Los Angeles California 90027 United States

Lead Scientist at UCSF


accepting new patients
Start Date
Completion Date
Merck Sharp & Dohme LLC
Phase 3 research study
Study Type
Last Updated