Sigma-Aldrich and Oxford BioMedica this week asked a US District Court to rule definitively that Open Biosystems infringes a Sigma-Aldrich-controlled patent, a legal move that could preclude a trial and end in victory for the co-plaintiffs.
The request, which was made as part of an ongoing legal battle between the companies, came after a high-profile RNAi researcher testified that certain Open Biosystems products infringe the patent in question.
The researcher’s finding, together with statements appearing in certain Open Biosystems product literature, could support a judgment of “literal infringement,” Sigma-Aldrich and Oxford BioMedica state in their court filing.
According to Sigma-Aldrich and Oxford BioMedica, Duke University researcher Bryan Cullen examined the results of experimental analyses conducted on those Open Biosystems products at issue in the suit and found that they contain the same properties as the patented inventions.
Such a judgment would mean that the court has determined there are no factual issues that remain to be tried in the case and that a ruling on the patent-infringement complaint could be made without a trial.
According to Sigma-Aldrich and Oxford BioMedica, Duke University researcher Bryan Cullen examined the results of experimental analyses conducted on the Open Biosystems products at the heart of the case, as well as reviewed relevant product literature, and found that they contain the same properties as the patented inventions.
The dispute began in mid-2006 when Sigma-Aldrich and Oxford BioMedica sued Open Biosystems for allegedly infringing two US patents owned by Oxford BioMedica and exclusively licensed by Sigma-Aldrich (see RNAi News, 6/15/2006).
The technology covered by the patents — Nos. 6,924,123 and 7,056,699 — comprises a lentiviral long terminal repeat-deleted vector “capable of transducing non-dividing and/or slowly dividing cells,” and involves “retroviral vectors based on the lentivirus family of viruses," including HIV-1, according to Sigma-Aldrich.
In their lawsuit, Sigma-Aldrich and Oxford BioMedica contend that numerous Open Biosystems products, including its RNAi Consortium shRNA lentiviral library and its shRNAmir libraries, infringe this IP.
The co-plaintiffs last year won what may prove to be a key battle in the case when the court accepted their definition of construction claims within the ‘699 patent.
In a memorandum supporting their motion for an infringement ruling filed this week, Sigma-Aldrich and Oxford BioMedica noted that the court accepted their definition of a “lentiviral LTR-deleted vector” to mean “a replication-defective vector based on a lentivirus in which one or more LTR nucleotide sequences from the lentivirus, including at least one such nucleotide sequence that is involved in transcription, are not present; and lentiviral LTR nucleotide sequences necessary for reverse transcription and integration are present.”
Open Biosystems had asked the court to interpret the term as “a lentiviral vector in which a certain portion of the long terminal repeat (an identical sequence of nucleotides at either end of the vector), including the entirety of the section known as the R region, are removed and substituted with non-lentiviral or heterologous sequences,” according to the co-plaintiffs’ filing.
Sigma-Aldrich and Oxford BioMedica said in the filing that Open Biosystems’ position that it did not infringe the ‘699 patent is based on its interpretation of the term “lentiviral LTR-deleted vector.”
“I looked at our vectors and said in the LTRs, ‘Do I have a replaced region? No, I have wild-type LTRs.’ So it’s my conclusion that we did not infringe [the ‘699 and ‘123] patents.”
In the filing, the co-plaintiffs cited statements made by Open Biosystems’ Co-founder and CTO Troy Moore during a deposition in July that his company’s products do not infringe the ‘699 patent because an infringing product would require “the deletion and replacement of the R region.
“I looked at our vectors and said in the LTRs, ‘Do I have a replaced region? No, I have wild-type LTRs.’ So it’s my conclusion that we did not infringe [the ‘699 and ‘123] patents,” Moore had said.
According to Sigma-Aldrich and Oxford BioMedica, Moore’s argument is invalid since the court rejected Open Biosystems’ interpretation that an LTR-deleted vector “requires deletion and replacement of the R region.”
Aside from the issue of the R region deletion and replacement, Sigma-Aldrich and Oxford BioMedica argue in this week’s filing that Open Biosystems’ vectors are similar in a number of ways to the ones described in the ‘699 patent. These similarities include being replication defective; being based on the lentivirus HIV-1; lacking at least one of the LTR nucleotide sequences involved in transcription; containing the nucleotide sequences necessary for reverse transcription; and containing the nucleotide sequences necessary for integration.
Supporting their argument is testimony provided by Duke’s Cullen, who said in an expert declaration that a sequencing analysis of Open Biosystem’s vectors conducted by MWG Biotech, as well as a review of the patent and Open Biosystems’ product literature, revealed the vectors to have “all the limitations found in [key claims] of the ‘699 patent.”
“Sequencing of the Open [Biosystems] vectors … confirms that [they] are derived from the genome of HIV-1, a lentivirus,” Cullen testified. He added that the vectors “bear extensive deletions of the lentiviral coding sequences … [which preclude] expression of the lentivial gag, pol, and env genes.” Consequently, “all of the … vectors are replication defective.”
Cullen also noted that the sequencing analysis reveals that the deletions include “a lentiviral LTR sequence that is involved in transcription,” but that the vectors retain “LTR nucleotide sequences necessary for reverse transcription and integration. Therefore, each of the Open [Biosystems] vectors comprises a lentiviral LTR-deleted vector” and infringe the ‘699 patent, he added.
Open Biosystems’ “infringement is supported not only by MWG’s definitive sequence analysis, but also by [the company’s] own documents, including information found on its website and in its product literature,” Sigma-Aldrich and Oxford BioMedica argued in a memorandum supporting their motion for an infringement ruling. As such, a summary judgment of literal infringement is requested.
A Sigma-Aldrich spokesman said the company does not comment on pending litigation. Officials from Open Biosystems were not immediately available for comment.