Sue L. Robinson: Noerr-Pennington Immunity Applies to Suits Brought on “Weak” Patents

Infringement actions often provoke a raft of counterclaims that assert non-patent theories, including business-competition torts. When a party pursues these unfair competition claims, however, the plaintiff retains some doctrinal immunity from suit. And, according to District of Delaware Judge Sue L. Robinson, this immunity extends to a party that relies on a “weak” but untested patent
In a recent post-trial decision, the Court assessed a defendant’s unfair competition counterclaims in light of the so-called Noerr-Pennington doctrine, a judicially created immunity that bars application of the antitrust laws to those who petition the government for redress. The patentee, a generic manufacturer, had acquired a patent of questionable validity on the subject drug as a hedge against other competitors in the generic market. After initiating the underlying litigation, defendant responded with unfair competition, tortious interference, and antitrust counterclaims.

Analyzing the patentee’s claims of immunity from suit, the Court criticized the business motives that led to the acquisition of the weak patent:

“The inference to be drawn from this chronology is that, instead of directing its efforts to launching a generic, [patentee] obtained and relied upon an admittedly ‘weak’ patent for protection from other generic competition.”

Noting that even a questionable patent “enjoys a presumption of validity,” however, the Court held that the infringement litigation could not be characterized as a sham suit. The Court highlighted the fact that no tribunal had invalidated the patent:

“The validity of the ‘183 patent has not be adjudicated by any court (or the USPTO on reexamination). This court has no occasion to judge the merits of [defendant’s] invalidity arguments, and declines to issue a finding that [the patentee] ‘should have known’ of its patent’s invalidity absent such findings.”

The lesson? Until an objective basis exists for invalidity – i.e., a court or agency ruling – the infringement plaintiff will enjoy Noerr-Pennington immunity.

Braintree Labs. Inc. v. Schwarz Pharma Inc., C.A. No. 03-477-SLR (D. Del. July 31, 2008) (Robinson, J.).

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