There are three general outcomes from submitting a new drug to the FDA for approval. First – approval, for which everyone hopes. Second non-approval, which is the obvious bad scenario. Third are approvable letters, issued by the FDA when they are signaling an intent to approve a drug, but there are contingencies that must first be satisfied by the company.
There has been a recent current of thought, as noted here in the past, that the category of approvable letters has grown in recent months in order for the agency to have issued an "action" by time the PDUFA date has come merely because they are unable to keep up with solid decisions of yes or no by the action date. While I don’t subscribe to that outlook, I thought it would be a good idea to start tracking notices of approvable letters here and keeping a running list.
To that end, this past week Shire received an approvable letter for the attention deficit treatment NRP-104, with the agency saying that the company needed to work on details including labeling information, scheduling and the drug’s trade name.
It should be noted that the contents of an approvable letter are proprietary and the FDA will not reveal the contents. The contingencies noted by the FDA can be very easy to accomplish (as in Shire’s case) or more onerous, such as requiring new clinical trials. Whether or not a company discloses the contents of such a letter is entirely up to it, though for reporting purposes the development may be material to the company and therefore the receptions of the approvable letter must be disclosed. That is up to legal counsel. But the contents themselves are the purview of the company. In this case, the contents were stated because they the contingencies laid out by the agency were so minimal, and approval would appear easily accomplished. That is reflected by the fact that Shire’s shares rose dramatically as a result of the announcement – not always the outcome of an approvable letter.
In the interests of studying the issue related to whether or not approvable letters are on the increase, I thought it a good idea to start tracking them. Therefore, whenever an approvable letter comes to my attention, I will mention it in the weekly round up. I am also creating a link to a running list of approvable letters that will be in the left column of Eye on FDA.