Silence Strongly Disagrees with Alnylam’s Version of Tuschl I Hearing

On February 29, there was a hearing on the Tuschl I patent in Europe (EP 1309726; co-owners: UMass, MIT, Max-Planck, the Whitehead; licensees: Alnylam and Merck). Once with the potential to be a relatively broad patent covering the sweet-spot of most RNAi triggers (dsRNA lengths between 21-23nt/bp), the importance of this patent has been greatly watered down due to interpretations by the patent offices, and to some degree even by one of the licensees of the patent (Alnylam) during the Tuschl litigation, that the importance of this patent is largely limited to a mix of RNAi triggers produced in fly tissue lysates. Nevertheless, ambiguities in the wording of the Tuschl I claims gave rise to the concern that a legally aggressive company such as Alnylam would sue based on the tenuous interpretation that some of the claims would be relevant to mainstream therapeutic use in humans (note: precedence shows that Alnylam has filed lawsuits on much less substance).

To remove these ambiguities, Silence Therapeutics, along with Aventis and BASF, opposed and thereby sought to invalidate, or at least clarify T-I to their benefit. This attempt was the subject of the Oral Hearing.

The Hearing documents have not posted yet to the EPO site, so I will only comment on what has transpired from the two main antagonists: Alnylam and Silence.

On March 1, Alnylam (and patent holder UMass) proudly announced: ‘The requested claims of the ‘726 patent were upheld without any modification.’, and go on to strongly suggest that this is a strong, if not blocking patent for RNAi therapeutic development and commercialization: ‘The Tuschl I ‘726 patent consists of 14 claims broadly covering RNAi methods, including methods of reducing the expression of a gene, with double-stranded RNAs between 21 and 23 nucleotides in length of mammalian or viral origin.’

By contrast, Silence Therapeutics just issued a press release basically expressing that Alnylam’s representations of the T-I Oral Hearings are, to put it mildly, inaccurate. Titled ‘Silence and Other Opponents of Tuschl I Patent Succeed in Limiting Scope and Ambiguity in the Patent’, the PR further states that ‘the claims as originally granted were modified [emphasis mine] during the hearing…’

Clearly, between ‘modified’ and ‘unmodified’ there is little room for reconciliation, and if there were (‘as originally granted’), then it would be in meaningless semantics.

Personally, when the Hearing docs come out, I will look out for what was particularly said about independent claim 10 which states:

‘10. A method of producing knockdown cells, comprising introducing into cells in which a gene is to be knocked down isolated double-stranded RNA of from 21 to 23 nucleotides in length and corresponding to a sequence of the gene, that targets the mRNA corresponding to the gene and maintaining the resulting cells under conditions under which RNAi occurs, resulting in degradation of the mRNA of the gene, thereby producing knockdown cells.’

In the context of the patent prosecution and patent description, it seems pretty clear that this was also a ‘fly lysate claim’, but read in isolation, it is not obvious. Note also that even if not reflected in the wording of a patent, what is said during patent prosecution would matter in an infringement suit.

To be continued…here