Please ensure Javascript is enabled for purposes of website accessibility

Inherency and solving double-patentingDecember 21, 2005

In a recent case, the Federal Circuit explored how obviousness double patenting can be overcome and the concept of inherent anticipation. The patents at issue in Perricone v. Medicis Pharmaceutical Corp. relate to methods of treating or preventing sunburns using topical creams composed of an ascorbyl fatty acid ester. One of the two patents asserted by Dr. Perricone deals with sunburn prevention (application of the compound to skin in general), the other to treatment (application of the compound to sunburned skin). The district court found the asserted claims invalid based on a combination of double patenting and inherent anticipation.Double patenting occurs when two patents claim either the same invention or inventions that are obvious in view of one another. Because the patent statutes state that only one patent may be granted for a single invention, a later claim to exactly the same invention is always invalid. In this case, however, the issue was ‘obviousness’ double patenting. Ordinarily, this can be avoided by filing a terminal disclaimer with regard to the second patent claiming the obvious variation of the first, making the later patent expiring at the same time as the earlier patent. Here, Dr. Perricone had not filed such a disclaimer, so the Federal Circuit upheld the district court’s determination that the claims of Dr. Perricone’s second patent were invalid. However, the court did state that the claims could be salvaged, at least in the future, by filing a terminal disclaimer. The court did not, however, discuss whether such a disclaimer could retroactively restore the validity of the claims.The court also agreed with the district court that a prior patent inherently anticipated several of the asserted claims, but reversed the district court on others. A reference can inherently anticipate a patent if it necessarily function in accordance with or includes the claimed invention. A prior patent discussed the use of the compounds described in the patents to skin, but some of Dr. Perricone’s claims were addressed to application to skin sunburn. Because of this distinction, the Federal Circuit found that the prior art did not inherently anticipate the claims to applying the compound to sunburn, but did anticipate those to application to skin. Judge Bryson dissented, arguing that the prior art, by describing application to skin in general, inherently disclosed application to sunburned skin.For the complete decision, log on to

← Return to News & Events

Stay in Touch

Receive the latest news and updates from us and our attorneys.

Sign Up