Whether the 406 Patent is Prior Art
As an alternative to its position that risedronate was not obvious, P&G argues that the 406 patent should not be considered prior art with respect to the 122 patent because risedronate was first synthesized by P&G before the 406 patent was filed. At trial, Dr. Benedict, one of the inventors named in the 122 patent, testified that he synthesized risedronate in May 1985. P&G submitted a portion of Dr. Benedicts laboratory notebook which contains a May 3, 1985 entry detailing the structure of risedronate and the procedure for its synthesis, but this entry was unwitnessed and was not corroborated by any other evidence.
It is well established that when a party seeks to prove conception via the oral testimony of a putative inventor, the party must proffer evidence corroborating that testimony. Shu-Hui Chen v. Bouchard, 347 F.3d 1299, 1309 (Fed. Cir. 2003). The inventor must provide independent corroborating evidence in addition to his own statements and documents. Hahn v. Wong, 892 F.2d 1028, 1032 (Fed. Cir. 1989). Because P&G did not provide adequate corroborating evidence of an earlier invention date for risedronate, the district court correctly concluded that the 406 patent qualifies as prior art for purposes of this inquiry.
Obviousness-Type Double Patenting
In addition to its obviousness defense, Teva also asserted that the 122 patent was invalid for double patenting. The double patenting doctrine is designed to prevent a patent owner from extending his exclusive rights to an invention through claims in a later-filed patent that are not patentably distinct from claims in the earlier filed patent. Geneva Pharm., Inc. v. GlaxoSmithKline PLC, 349 F.3d 1373, 1378 (Fed. Cir. 2003.) In general, the obviousness analysis applies to double patenting, except for three distinctions. First, statutory obviousness compares claimed subject matter to the prior art, while non-statutory double patenting compares claims in an earlier patent to claims in a later patent or application. Id. at 1377 n.1. Second, double patenting does not require inquiry into a motivation to modify the prior art. Id. Finally, double patenting does not require inquiry into objective criteria suggesting non-obviousness. Id.
Having concluded that risedronate was not obvious under 35 U.S.C. § 103, we similarly conclude that the 122 patent is not invalid for obviousness-type double patenting. Additionally, we agree with the district court that the claims of the 122 patent are distinct from the claims of the 406 patent. Comparing the claims of the 122 patent to those of the 406 patent, we note that, while claims 4 and 16 of the 122 patent explicitly claim the risedronate compound, the 406 patent claims an intermittent dosing regimen for the treatment of osteoporosis and claims no new compounds. Accordingly, Teva failed to present clear and convincing evidence of overlap between the claims of the two patents to invalidate the 122 patent based on obviousness-type double patenting.
For the foregoing reasons, we affirm.