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# Complete Response Letter for 4-Dose Heplisav-B
- URL: https://www.fdaweb.com/complete-response-letter-for-4-dose-heplisav-b/
- Published: 2024-05-14T12:00:00.000Z
- Updated: 2026-09-14T14:30:50.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5156971

FDA has issued a complete response letter to Dynavax Technologies for its sBLA for a four-dose Heplisav-B vaccine (hepatitis B vaccine \[recombinant\] adjuvanted) regimen for adults on dialysis. A company [statement](https://www.prnewswire.com/news-releases/dynavax-provides-regulatory-update-on-sbla-for-four-dose-heplisav-b-regimen-for-adults-on-hemodialysis-in-the-us-302144529.html?ref=fdaweb.com) says FDA said the application did not provide sufficient data to support the full evaluation of the effectiveness or safety of the four-dose regimen.

The letter says data from the Phase 1 HBV-24 trial were insufficient due to the destruction of data source documents by a third-party clinical trial site operator for about half the subjects enrolled in the trial, Dynavax says. In addition, it says, the total number of subjects in the single-arm study was deemed to be insufficient to evaluate the safety of the four-dose regimen.

The company says it plans to request a meeting with FDA to evaluate the options for providing additional data to support the four-dose regimen for the dialysis population.

Heplisav-B is currently indicated to prevent infection caused by all known subtypes of hepatitis B virus in adults aged 18 and older.