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Expert Testimony Stricken Where Expert Did Not Show Non-Infringing Alternatives Were Available in the United States

In this patent infringement action, DUSA Pharmaceuticals, Inc. (“DUSA”) sought to strike the testimony of Biofrontera’s expert witness, Professor Harry Moseley, for his reliance on a non-infringing alternative, the Paterson lamp. DUSA asserted that the testimony should be stricken because the Paterson lamp had never been available in the United States.

The district court explained that the Paterson lamp was designed and built by the Paterson Institute in the United Kingdom in the early to mid-1990’s and that five articles describing the Paterson lamp were published in the United States, but there was no evidence that the lamp was ever sold, used, or exhibited in the United States. “Based on his personal involvement in the creation of the Paterson lamp, Professor Moseley testified to its composition and functionality. In particular, Professor Moseley identified the lamp’s desired treatment distance as 4 inches, a parameter not explicitly disclosed in the published references.”

DUSA challenges the testimony as impermissible (attempting to back-fill gaps in the Paterson lamp references) and as untimely. Biofrontera responded that Professor Mosleys’ testimony was admissible evidence of prior art and that the parties had agreed to modify the expert discovery schedule to give DUSAs expert witness, Dr. Zamenhof, an opportunity to submit a supplemental declaration.

The district court agreed with DUSA: “Professor Mosley’s testimony regarding the Paterson lamps preferred treatment distance should be excluded. To the extent that the Paterson lamp was known in the United States, it was known only through the disclosures in the five cited journal articles. Professor Moseley’s personal experience with the Paterson lamp was not public knowledge in the United States and cannot be used to establish features of the lamp not ‘known… by others in this country.'”

Professor Moseley also opined that there were numerous other lamps that qualify as “nonfringing alternatives” to DUSA’s patented BLU-U. See Mentor Graphics Corp. v. EVE-USA, Inc., 851 F.3d 1275, 1285 (Fed. Cir. 2017) (to prove entitlement to lost profits, DUSA must establish, inter alia, the “absence of non-infringing alternatives”). The district court also determined that Professor Moseley did not have a sufficient basis to conclude that the alternative lamps he identified were available noninfringing alternatives for purposes of a lost profits analysis.

As the district court explained, to constitute an “acceptable noninfringing alternative,” the substitute must be “available for purchase,” Zygo Corp. v. Wyko Corp., 79 F.3d 1563, 1571 (Fed. Cir. 1996), or at least that “the material and know-how for the alleged substitute were readily available at the time of infringement,” Micro Chem., Inc. v. Lextron, Inc., 318 F.3d 1119, 1123 (Fed. Cir. 2003).

Although Professor Moseley cited to two 2001 presentations as the source of his information, he admitted during his deposition that he did not “do anything to investigate whether the products [he] identified in [his] noninfringing alternatives analysis are available in the United States.” As a result, the district court excluded his opinion as to these substitute lamps constituting “acceptable noninfringing alternatives.”

DUSA Pharmaceuticals, Inc. v. Biofrontera Inc. et al, Case No. 1-18-cv-10568 (D. Mass. Octt. 9, 2020)


The authors of are patent trial lawyers at Jeffer Mangels Butler & Mitchell LLP. For more information about this case, contact Stan Gibson at 310.201.3548 or