By Doug Macron
The University of Utah last week filed an amended version of its lawsuit against Alnylam Pharmaceuticals and the other groups in control of the so-called Tuschl-II patent family, providing a few additional details on the work of the university researcher who allegedly conceived of the RNAi discoveries on which the intellectual property is based.
According to the new court filing, the researcher, Brenda Bass, “conceived of all of the issued claims of Tuschl-II patents ...as well as still-pending Tuschl-II applications, well before any date asserted by the currently named inventors.”
Bass' idea for the patents at issue “was so well-defined in her mind that it could have been reduced to practice by someone with ordinary skill in the art without further research,” the amended complaint adds. “Moreover, she had a specific, particular solution to the problem at hand, not just general research goals.”
In contrast, the inventors listed on the IP were unaware of how siRNAs were produced from long dsRNA and did not understand their structure until Bass passed along that information, the university maintains.
The IP at the heart of the litigation is a portfolio of patents and applications named for co-inventor and Alnylam co-founder Thomas Tuschl. They essentially claim siRNAs, 21 to 23 nucleotides in length and with 2- to 3-nucleotide-long 3' overhangs, to target specific mRNA degradation in mammals. A related IP family, known as Tuschl-I, covers the same constructs, but without the overhangs.
Tuschl-I lists as inventors Tuschl, the Whitehead Institute for Biomedical Research's Phillip Zamore and Phillip Sharp, and the Massachusetts Institute of Technology's David Bartel, all of whom are Alnylam co-founders. Tuschl has since moved on to Rockefeller University, while Sharp now works at MIT and Zamore has a post at the University of Massachusetts Medical School.
Tuschl-II's inventors include Tuschl and Max Planck's Sayda Elbashir and Winfried Lendeckel. Elbashir currently works at Alnylam.
In March, the University of Utah sued Alnylam and the IP's other institutional assignees — the Max Planck Institute, Whitehead, MIT, and U Mass — for allegedly failing to name Bass as an inventor on any of the Tuschl-II patents despite her having been the first to make key discoveries contained within them (GSN 3/31/2011).
In the original suit, the university claims that Bass first discovered the C. elegans gene K12H4.8, which is now known to produce the Dicer enzyme required to cleave long double-stranded RNA into siRNA with 3' overhangs.
“She identified this gene well before the RNA interference phenomenon was demonstrated and discovered it has a dsRNA-binding motif, two RNase III domains, and a helicase domain,” the suit states. She was also the first to discern that the gene plays a role in dsRNA metabolism, findings that were published in 1994.
In 2000, Bass published her hypothesis that Dicer's RNase III domains were responsible for cleaving dsRNA into siRNAs with 3' overhangs, identifying the genes that encode Dicer in various organisms, and suggested that introducing siRNAs into cells would silence genes.
The university alleges in its lawsuit that the Tuschl-I inventors were unaware of how the siRNAs were produced, nor did they fully understand their structure, citing an e-mail between Tuschl and Zamore written in April 2000 in which Tuschl admitted “he and Zamore did not know … that Dicer cuts dsRNA into pieces ... 21 [to] 23 nucleotides long.”
“The Tuschl-I inventors simply did not know about the 3' overhangs when they filed [the first applications from that IP family], and only became aware of the 3' overhangs after … Bass conveyed her concept to them” at two scientific conferences in 2000, the University of Utah said in its suit.
Shortly thereafter, “Tuschl's lab submitted a paper … in which Elbashir stated that the most effective siRNAs are those that have 3' overhangs,” the suit states. Since then, a number of patent applications from Tuschl-I and -II have been submitted, both in the US and abroad, claiming the 3' overhang conception, none of which list Bass as an inventor.
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“There is no written description of the 3' overhangs” in the first Tuschl-I patent applications, the university stated in the amended complaint. “Tuschl himself, having extraordinary skill in the art, has admitted as much.
“No person having only ordinary skill in the art, upon reading the specification for the [first Tuschl-I application] would have been able to synthesize, enzymatically create, or isolate any dsRNA effective in mediating RNAi,” it added in the amended complaint. It was, in fact, “Bass' conception and collaborative conveyance to … Tuschl of Dicer's role and the 3' overhang [that] broke through the intellectual logjam” he described in his e-mail to Zamore.
The university said in its suit that while Bass should also rightfully be listed as an inventor on the Tuschl-I IP, no patents have issued on any of those applications, and US patent law only permits a correction of inventorship on patent applications when all named inventors agree to a change, which has not happened.
“The university is, for the time being, without a cause of action to redress the Tuschl-I erroneous inventorship until a Tuschl-I patent issues,” it said.
As such, the lawsuit is seeking that Bass be listed as either the sole or joint inventor on the issued Tuschl-II patents, as well as certain financial damages.
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