D. Del. (2012)
Fitzpatrick Secures Another Victory For Genzyme In Patent Suit Over Genzyme's Kidney Disease Drug Hectorol®.
On June 11, 2012, Chief Judge Gregory M. Sleet of the District of Delaware issued a decision in favor of Fitzpatrick’s client, Genzyme Corporation, upholding the validity of Genzyme’s United States Patent No. 5,602,116 and finding that defendants Anchen, Roxane and Sandoz would infringe the ‘116 patent. The ‘116 patent claims a method of using the vitamin D analog doxercalciferol to treat secondary hyperparathyroidism in patients on dialysis. Genzyme markets doxercalciferol for such use under the trade name Hectorol®. Defendants sought FDA approval to market generic versions of Hectorol®, and in this consolidated suit alleged that they would not induce infringement of the ‘116 patent by marketing their generic versions, and that the ‘116 patent was inoperable or obvious.
Judge Sleet’s opinion issued following a five-day bench trial in November, 2011. In the opinion, Judge Sleet first noted that the claimed method of the ‘116 patent, properly construed, requires the use of doxercalciferol to lower and maintain parathyroid hormone levels (PTH) with a lower incidence of hypercalcemia than would result from the use of the prior art treatments calcitriol and alfacalcidol to achieve the same level of PTH suppression. Judge Sleet then found that defendants would induce infringement of such a method, based on the expert testimony and clinical evidence presented by Genzyme showing that while calcitriol and alfacalcidol are not able to lower and maintain lowered PTH levels without concomitant hypercalcemia, doxercalciferol is. In view of that evidence, Judge Sleet rejected defendants’ counterarguments that improvements in treatment methodologies and not doxercalciferol itself were responsible for the lower incidence of hypercalcemia observed with that drug, and that doxercalciferol does not result in a lower incidence of hypercalcemia than the prior art treatments. Specifically, Judge Sleet found that defendants’ clinical evidence failed to show that doxercalciferol does not result in a lower incidence of hypercalcemia than the prior art treatments at the same level of PTH suppression.
Turning to inoperability, Judge Sleet observed that defendants’ inoperability argument was based upon largely the same evidence as defendants’ noninfringement argument: namely clinical evidence purporting to show that doxercalciferol does not result in a lower incidence of hypercalcemia than the prior art treatments. Judge Sleet concluded that such evidence was insufficient to prove inoperability of the claimed method of the ‘116 patent by clear and convincing evidence.
Last, turning to obviousness, Judge Sleet found that the claimed method of the ‘116 patent was entitled to a priority date of August 2, 1988, and that, as of that date, the prior art asserted by defendants would not have made it obvious to select doxercalciferol from among the other then-available vitamin D analogs.
The Fitzpatrick team was led by partners Scott Reed, Donald Curry, Christopher Loh and Robert Baechtold, and included associates Daniel Minion, John Kirkland, Fiona Darkin, Christina Schwarz and Susanne Flanders.