Patents are a bit like vampires, they're not dead until at least two stakes have been driven into their hearts. Just when NeXstar Inc. thought The Liposome Co. Inc.'s Janoff patent covering liposome drying technology was dead and buried, it has come back to life - with potential consequences that won't be clear for some time.

The U.S. Patent and Trademark Office has said it will issue a certificate of re-examination on Patent No. 4,880,635, also known as the Janoff patent. The PTO said that it intends to allow the patent with claims that were amended during the re-examination. As amended, the claims will cover certain pharmaceutical preparations containing liposomes that retain a substantial portion of their internal contents upon dehydration and subsequent rehydration. UBS Securities analyst Marc Ostro, a founder of LIPO, said the claims include liposomes with sugars inside and