This was an impeachment action regarding patent 1,321,393 (’393 Patent) which claimed amlodipine besylate as a selection patent over an earlier patent for amlodipine.

Briefly, selection patents are valid if:

  1. the selected compounds, though encompassed by the genus, had not been actually made before;
  2. there is a substantial advantage to be had or disadvantage to be avoided by using the selected group;
  3. all of the selected members must have the advantage or avoid the disadvantage; and
  4. the special character is peculiar to the selected group, i.e. a large number of unselected members could not have the special character.

Amlodipine was a known compound and known to be useful in a salt form. Some specific salts were disclosed. There was nothing surprising in testing the besylate. In addressing obviousness, one must address the invention as claimed. The testing to select the besylate salt was routine. Applying the Apotex v. Sanofi-Synthelabo approach, the claimed invention was obvious.

It must be determined if the besylate salt of amlodipine has a “special advantage” in respect of a “quality of special character” unique to besylate.

The words “unexpectedly” and “unique” and “outstandingly suitable” are used in the ’393 Patent. However, adjectives and adverbs without solid foundation cannot create a “selection patent” where none in fact exists. It is unsupportable from the evidence to state that besylate is sufficiently superior to the other salts, for instance tosylate and mesylate so as to make it “unique” or “outstanding” or “particularly suitable.” If a category of “selection” patent exists, the besylate salt of amlodipine does not merit being a member of that category. The ’393 Patent was held invalid for this reason as well.

The promise of the patent as “unique” and “outstanding” was not fulfilled. The patent is invalid for lack of utility.

The evidence shows that the specification of the ’393 Patent does not disclose what the invention was as contemplated by the inventors. It io invalid for that reason.

Three statements were misleading and, sufficient intent to make such statements was made out in the evidence. The ’393 Patent was invalid for this reason as well.