Bezlotoxumab

ZINPLAVA (bezlotoxumab) is a human monoclonal antibody that binds to C. difficile toxin B and neutralizes its effects [see Microbiology (12.4) ] .

• ZINPLAVA™ is indicated to reduce recurrence of Clostridioides difficile infection (CDI) in adults and pediatric patients 1 year of age and older who are receiving antibacterial drug treatment for CDI and are at a high risk for CDI recurrence. ZINPLAVA is a human monoclonal antibody that binds to Clostridioides difficile toxin B, indicated to reduce recurrence of Clostridioides difficile infection (CDI) in adults and pediatric patients 1 year of age and older who are receiving antibacterial drug treatment for CDI and are at a high risk for CDI recurrence.

• None.contraindicated

Administer ZINPLAVA during antibacterial drug treatment for CDI. ( 2.1 ) The recommended dose is a single dose of 10 mg/kg administered as an intravenous infusion over 60 minutes. ( 2.2 ) Dilute prior to intravenous infusion. Administer via a low-protein binding 0.2 micron to 5 micron in-line or add-on filter. See Full Prescribing Information for dilution and administration instructions. ( 2.3 ) 2.1 Important Administration Instructions Administer ZINPLAVA during antibacterial drug treatment for CDI. 2.2 Dosing Recommendations in Adults and Pediatric Patients 1 year of age and older The recommended dose of ZINPLAVA is a single dose of 10 mg/kg administered as an intravenous infusion over 60 minutes. The safety and efficacy of repeat administration of ZINPLAVA in patients with CDI have not been studied. 2.3 Preparation and Administration Preparation of Diluted Solution ZINPLAVA must be diluted prior to intravenous infusion. Prepare the diluted solution immediately after removal of the vial(s) from refrigerated storage, or the vial(s) may be stored at room temperature protected from light for up to 24 hours prior to preparation of the diluted solution. Inspect vial contents for discoloration and particulate matter prior to dilution. ZINPLAVA is a clear to moderately opalescent, colorless to pale yellow solution. Do not use the vial if the solution is discolored or contains visible particles. Do not shake the vial.

Heart Failure : Was reported more commonly in ZINPLAVA-treated patients with a history of congestive heart failure (CHF) in Trial 1 and Trial 2. In patients with a history of CHF, ZINPLAVA should be reserved for use when the benefit outweighs the risk. ( 5.1 ) 5.1 Heart Failure Heart failure was reported more commonly in Trial 1 and Trial 2 in ZINPLAVA-treated patients compared to placebo-treated patients. These adverse reactions occurred primarily in patients with underlying congestive heart failure (CHF). In patients with a history of CHF, 12.7% (15/118) of ZINPLAVA-treated patients and 4.8% (5/104) of placebo-treated patients had the serious adverse reaction of heart failure during the 12-week study period [see Adverse Reactions (6.1) ] . Additionally, in patients with a history of CHF, there were more deaths in ZINPLAVA-treated patients, 19.5% (23/118) than in placebo-treated patients, 12.5% (13/104) during the 12-week study period. The causes of death varied and included cardiac failure, infections, and respiratory failure. In patients with a history of CHF, ZINPLAVA should be reserved for use when the benefit outweighs the risk.

Adult Patients : The most common adverse reactions (reported in ≥4% of adult patients) included nausea, pyrexia, and headache. ( 6.1 ) Pediatric Patients : The most common adverse reactions (reported in >10% of pediatric patients) were pyrexia and headache ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Clinical Trials Experience in Adults The safety of ZINPLAVA was evaluated in two placebo-controlled Phase 3 trials (Trial 1 n=390 and Trial 2 n=396). Patients received a single 10 mg/kg intravenous infusion of ZINPLAVA and concomitant standard of care (SoC) antibacterial drugs (metronidazole, vancomycin or fidaxomicin) for CDI. Adverse reactions reported within the first 4 weeks after ZINPLAVA was administered are described for the pooled Phase 3 trial population of 786 patients. The median age of patients receiving ZINPLAVA was 65 years (range 18 to 100), 50% were age 65 years or older, 56% were female, and 83% were white. Serious Adverse Reactions in Adults Serious adverse reactions occurring within 12 weeks following infusion were reported in 29% of ZINPLAVA-treated patients and 33% of placebo-treated patients.

8.1 Pregnancy Risk Summary Adequate and well controlled studies with ZINPLAVA have not been conducted in pregnant women. No animal reproductive and developmental studies have been conducted with bezlotoxumab. The background risk of major birth defects and miscarriage for the indicated population is unknown; however, the background risk in the U.S. general population of major birth defects is 2-4% and of miscarriage is 15-20% of clinically recognized pregnancies. 8.2 Lactation Risk Summary There is no information regarding the presence of bezlotoxumab in human milk, the effects on the breast-fed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for ZINPLAVA and any potential adverse effects on the breastfed child from ZINPLAVA or from the underlying maternal condition. 8.4 Pediatric Use The safety and effectiveness of ZINPLAVA to reduce recurrence of CDI have been established in pediatric patients 1 year of age and older. Use of ZINPLAVA in pediatric patients 1 year of age and older is supported by evidence from adequate and well-controlled trials in adults with additional pharmacokinetic and safety data in pediatric patients aged 1 year and older.

Metabolism

The pharmacokinetics of bezlotoxumab were studied in 1515 adult CDI patients in two Phase 3 trials (Trial 1 and Trial 2). Based on a population PK analysis, the geometric mean (%CV) clearance of bezlotoxumab was 0.317 L/day (41%), with a mean volume of distribution of 7.33 L (16%), and elimination half-life (t½) of approximately 19 days (28%).

There is no clinical experience with overdosage of ZINPLAVA. In case of overdose, patients should be closely monitored for signs or symptoms of adverse reactions, and appropriate symptomatic treatment should be instituted.

• Oct 21, 2016BLABLA761046Merck Sharp Dohme

The 10 most recently updated of 15 ClinicalTrials.gov registrations naming Bezlotoxumab as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Bezlotoxumab Yielded Outcomes by Addressing Personalized Needs in Clostridioides Difficile Infection
  Completed · Phase 2 · Interventional · 44 enrolled · Hellenic Institute for the Study of Sepsis
  NCT05304715updated 2026-03-04
• ICON-2: FMT and Bezlotoxumab Compared to FMT and Placebo for Patients With IBD and CDI
  Completed · Phase 2 · Interventional · 61 enrolled · Brigham and Women's Hospital
  NCT03829475updated 2025-12-09
• Prevention of Recurrent Clostridium Difficile Infection (CDI) in Patients With Inflammatory Bowel Disease (IBD).
  Terminated · Phase 4 · Interventional · 19 enrolled · David Binion, MD
  NCT04626947updated 2025-06-05
• Rescue FMT with Bezlotoxumab for Recurrent C. Difficile Infection
  Completed · Observational · 24 enrolled · Alexander Khoruts
  NCT06669936updated 2024-11-01
• Addressing Personalized Needs in Clostridioides Difficile Infection
  Completed · Interventional · 153 enrolled · Hellenic Institute for the Study of Sepsis
  NCT04725123updated 2023-12-12
• Bezlotoxumab (MK-6072) Versus Placebo in Children With Clostridium Difficile Infection (CDI) (MK-6072-001)
  Completed · Phase 3 · Interventional · 148 enrolled · Merck Sharp & Dohme LLC
  NCT03182907updated 2023-07-27
• Bezlotoxumab - in "Real Life" - During the First Episode of Clostridium Difficile Infection in Patients With High Risk of Recurrence.
  Completed · Observational · 869 enrolled · Fundacion SEIMC-GESIDA
  NCT04075422updated 2023-06-26
• Comparing the Effectiveness of IV Bezlotoxumab Versus Placebo in Decreasing Morbidity and Mortality in Patients With Fulminant C. Diff Requiring Surgery.
  Terminated · Phase 4 · Interventional · 5 enrolled · Michael E Villarreal, MD
  NCT03756454updated 2023-05-12
• Bezlotoxumab Versus FMT for Multiple Recurrent CDI
  Withdrawn · Phase 4 · Interventional · 0 enrolled · Leiden University Medical Center
  NCT05077085updated 2023-03-28
• Real-world Evaluation of Bezlotoxumab for the Management of Clostridioides Difficile Infection
  Completed · Observational · 180 enrolled · University of Illinois at Chicago
  NCT04317963updated 2023-02-28

Frequently asked questions

How does Bezlotoxumab work?

ZINPLAVA (bezlotoxumab) is a human monoclonal antibody that binds to C. difficile toxin B and neutralizes its effects [see Microbiology (12.4) ] .

What is Bezlotoxumab used for?

According to FDA labeling, Bezlotoxumab carries indications including: ZINPLAVA™ is indicated to reduce recurrence of Clostridioides difficile infection (CDI) in adults and pediatric patients 1 year of age and older who are receiving antibacterial drug treatment for CDI and are at a high risk for CDI recurrence. ZINPLAVA is a human monoclonal antibody that binds to Clostridioides difficile toxin B, indicated to reduce recurrence of Clostridioides difficile infection (CDI) in adults and pediatric patients 1 year of age and older who are receiving antibacterial drug treatment for CDI and are at a high risk for CDI recurrence.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Bezlotoxumab?

Bezlotoxumab is classified as Antibacterial monoclonal antibodies, Bacterial Toxin Neutralization, Binding Activity.

What are the brand names for Bezlotoxumab?

Bezlotoxumab is marketed under brand names including Zinplava.

What are the contraindications for Bezlotoxumab?

Bezlotoxumab labeling lists contraindications including: None.. Always consult the full prescribing information and a clinician.