I saw the following press release from Amgen on friday evening:
Amgen Inc. (Nasdaq: AMGN) today announced that the U.S. Food and Drug Administration (FDA) has evaluated the content of the Company's Complete Response submission for Prolia(TM) (denosumab) in the treatment of postmenopausal osteoporosis and classified it as a Class 2 resubmission. With the Class 2 designation, the FDA set a corresponding Prescription Drug User Fee Act (PDUFA) action date of July 25, 2010.
The above paragraph wins a prize for one of the most unintelligible pieces of PR marketing communications I have read this year, since at first glance I was not sure what the message was i.e. whether this was good news, bad news or a piece of information that the company wanted to bury by intentionally distributing it late on a friday after the markets had shut. So what does the above paragraph mean ?
Last October, the FDA responded to Amgen's BLA submission and in a complete response letter requested additional safety data and further information on the design of the post-marketing surveillance program. Amgen responded to this in January this year.
Under the Prescription Drug User Fee Act (PDUFA) a submission of further information that addresses deficiencies in a BLA or NDA are classified into class 1 or class 2 resubmissions. According to the FDA, Class 1 are minor such as final printed labeling, safety updates, stability updates and other minor clarifying information. A Class 2 resubmission includes anything not in class 1 and any item that would require a presentation to an advisory committee.
The PDUFA requires the FDA to review and act on 90% of class 1 resubmitted applications within 2 months of receipt, and 90 months of Class 2 resubmitted applications within 6 months of receipt. Source: FDA
In the case of denosumab, the FDA action date of July 25, 2010 is simply 6 months from when the additional information was submitted, and is the date by which the FDA must make a decision in order to hit its performance target under PDUFA.
It remains to be seen what the FDA thinks about the safety data submitted. Denosumab is a key drug for Amgen, and any further delay in approval is likely to be taken negatively by investors given that every day of lost sales in a competitive osteoporosis market can be quantified as lost revenue.
So, the commercial significance of last friday's press release is that no approval is likely until the second half of 2010, an extended delay in the commercialization of Prolia, which is not good news for Amgen.