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# FDA Seeks More Data on Merck BLA for Bezlotoxumab
- URL: https://www.fdaweb.com/fda-seeks-more-data-on-merck-bla-for-bezlotoxumab/
- Published: 2016-07-22T12:00:00.000Z
- Updated: 2026-09-14T21:16:34.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5136261

FDA has asked Merck to submit new data and analyses from the clinical trials MODIFY I and MODIFY II that support a pending BLA for bezlotoxumab, an investigational agent for preventing *Clostridium difficile* (*C. difficile*) infection recurrence. The additional data and analyses will be considered a major amendment, resulting in a three-month user fee review extension. The new review goal date will be 10/23.

Merck had earlier said the pivotal [MODIFY I and MODIFY II clinical trials](http://cts.businesswire.com/ct/CT?id=smartlink&url=http%3A%2F%2Fwww.mercknewsroom.com%2Fnews-release%2Fresearch-and-development-news%2Fpivotal-phase-3-studies-bezlotoxumab-mercks-investigation&esheet=51267244&newsitemid=20160127005220&lan=en-US&anchor=MODIFY+I+and+MODIFY+II+clinical+trials&index=1&md5=76a96e77820e42d20a86d34763eb257c&ref=fdaweb.com) met their primary efficacy endpoint: the reduction in *C. difficile* recurrence through week 12 compared to placebo, when used in conjunction with standard of care antibiotics. Bezlotoxumab is an investigational antitoxin that is designed to neutralize *C. difficile* toxin B, a toxin that can damage the gut wall and cause inflammation, leading to *C. difficile*\-associated diarrhea, according to Merck.