Merck & Co.'s BLA for Gardasil, the investigational cervical cancer vaccine, has been accepted and granted priority review by the FDA. A priority designation is intended for products that address unmet medical needs. Under the Prescription Drug User Fee Act (PDUFA), for BLAs filed in 2005, the FDA's goal is to review and act on BLAs designated as priority review within six months of receipt. The FDA has informed Merck that the review goal date is June 8, 2006.

Merck has also submitted applications for Gardasil to additional regulatory agencies including those in the EU and Australia, Mexico, Brazil, Argentina, Taiwan and Singapore. Gardasil is designed to protect against four types of human papillomavirus (HPV): types 16 and 18, which account for an estimated 70% of cervical cancer cases and HPV types 6 and 11, which account for an estimated 90% of genital wart cases.

In 1995, Merck entered into a license agreement and collaboration with CSL Ltd. relating to technology used in Gardasil and is also the subject of other third-party licensing agreements.