我不記得在哪兒看來的，說是一些特定情形下可以renew５年。

看來是有誤，可能把對藥做點改動拿新的專利及 evergreening等混在一起了。


這個是Legal Zoom的說法：


http://info.legalzoom.com/renew-patent-23430.html

Drug Patent Renewal
Drug patents are among the rare patents occasionally renewed by Congress. To qualify for this renewal, a drug manufacturer must demonstrate that there was an extended wait for the drug to be approved for distribution and consumption. If this period interfered with the manufacturer's ability to profit off of the patent, and if the drug is viewed as a public good, the patent may be extended for a few years. Patent maintenance fees must still be paid during this time, and when this time period ends, the patent is permanently expired.

所有跟帖： 

• 可能你看到的是，若由於專利局的原因,申請審議延長等，專利法允許專利期限為二十年加上所 delayed 的時間，但這是在發給你專利 -二水成雨- ♂ (27 bytes) () 01/30/2015 postreply 18:38:29

• 有可能。多謝澄清。 -Lily168- ♀ (0 bytes) () 01/30/2015 postreply 18:43:50