Last February I wrote about the 90-day review time for 510(k)s that often takes longer than 90 days. It turns out when Sponsors, are on the clock, 180 days really does mean 180 days.
When FDA sends a Sponsor back a request for Additional Information on a 510(k) the 90-day review clock is stopped. But another clock is started -- the 180 days that a Sponsor has to respond to FDA's comments. In the past, OIVD has been willing to be somewhat flexible on this timeline as long as the Sponsor is showing progress towards answer the questions posed by FDA. This has been incredibly helpful in a few instances where new studies need to be performed. It avoids the situation where a Sponsor needs to voluntarily withdraw the submission and file a new 510(k). Having to refile a submission creates a difficult discussion with investors and board members and can be embaressing to the company.
Based on conversations with OIVD personnel, FDA no longer expects to show this kind of flexibility. Rather, FDA will need to stick more closely to the requirements in FDA's guidance document.
Why the change? It is closely linked to User Fees and the various requirements within that legislation. The people I spoke to at FDA would, on a personal level, prefer to continue to be flexible. But I guess sometimes Rules are Rules -- even if 90 days isn't always 90 days.