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Merck’s Patent Loss to Gilead May Have Big Impact on Drugmakers

Oct. 31, 2019, 6:23 PM

Merck & Co.’s failed patent infringement case against Gilead Sciences Inc. has important implications for the pharmaceutical and biotech industries, according to lawyers watching the case.

The precedential Oct. 30 ruling by the U.S. Court of Appeals for the Federal Circuit suggests those patents must be written more narrowly, and it potentially exposes existing patents to new challenges from competitors in the field, said Charles Duan, a patent lawyer and director of technology and innovation for the R Street think tank in Washington, D.C.

“It opens up a new line of attack on existing drug patents,” Duan said.

At issue was a patent for a compound that Merck’s Idenix unit contends is the basis for all major treatments for hepatitis C, including Gilead’s Sovaldi product.

In a 2-1 decision, the Federal Circuit denied Idenix’s bid to restore a record $2.5 billion jury verdict against Gilead, ruling that the patent failed to provide a narrow enough written description to prove the company possessed the full scope of the intellectual property it was claiming. The Federal Circuit affirmed a lower court’s decision to negate the verdict after finding the patent invalid.

Description Too Broad

According to the Federal Circuit, the Idenix patent for its own Zepatier product sought to cover countless variations on the compound it had developed—which was ultimately too broad of a description.

Idenix provided “at least many, many thousands” of potential compounds and “each of these compounds would need to be screened in order to know whether or not they are effective” against the hepatitis C virus, Chief Judge Sharon Prost wrote for the majority.

“Companies who are on the cutting edge—certainly in drug and biologic discovery—when they claim their compound they have to be careful to not over-claim beyond what they invented,” said Chad Landmon, chair of Axinn’s intellectual property group. “It’s a tricky issue because sometimes minor differences have a big impact.”

The case is the latest example in which the Federal Circuit has invalidated a compound patent for “doing what many pharmaceutical patents often attempt to do—namely, isolate a handful of working example compounds, and then try to corner the market on the thousands or millions of potential permutations,” said Zachary Silbersher, a New York-based partner with Kroub, Silbersher & Kolmykov.

A recent Federal Circuit decision in Enzo Life Sciences Inc. v. Roche Molecular Systems Inc. also signals that the court is seeking a new level of specificity in descriptions of inventions in drug patents.

“Notably, Gilead’s compound did not resemble any of the working examples in Idenix’s patent,” Silbersher said.

Vague Description

The court also found that Idenix failed to meet a legal requirement—known as enablement—that the patent must include a description that is sufficient to enable an expert in the field to make the invention in question.

“The purpose of the enablement and written description requirements is to ensure that the public is not burdened with over-broad patents when the inventor has actually revealed only a few examples of use,” Duan said.

“I’d anticipate seeing many more written description and enablement challenges,” he added.

Another potential ripple effect is that the decision could open up new research avenues for competitor drug products.

“Now, a drugmaker might conduct research on alternate forms of an existing drug with less fear” that a broadly written patent will sweep up those alternate formulations, Duan said.

The ruling drew on the 2013 decision in Wyeth & Cordis Corp. v. Abbott Labs, which also dealt with the issue of enablement.

In Wyeth, the Federal Circuit affirmed a grant of summary judgment and held the patent in question was invalid for lack of enablement because, again, it would have required “undue experimentation” for an expert in the field to make or use the invention.

“In light of this decision and the Wyeth decision and others, patentees will have to be careful they aren’t grasping too much beyond what they have invented and described as their invention in their patent specification,” said Lauren Fornarotto, principal in McKool Smith’s New York City office.

In a dissent, Judge Pauline Newman said she would have upheld the validity of the paten. The majority’s analysis “provides a new path of uncertainty and unreliability of the patent grant,” she wrote.

Merck’s next step is to ask the panel to reconsider the decision or seek review by a full panel of active judges on the court. The last resort would be to petition the U.S. Supreme Court for review.

The case is: Idenix Pharm. LLC v. Gilead Scis. Inc., Fed. Cir., 2018-1691, 10/30/19

To contact the reporter on this story: Valerie Bauman in Washington at

To contact the editors responsible for this story: Fawn Johnson at; Randy Kubetin at

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