Seqirus Successfully Opposes Translate Bio's Liposome Patent

Background Seqirus, Inc. opposed Translate Bio, Inc.’s patent application (AU2020202755) concerning the in vivo delivery of mRNA for augmenting proteins and enzymes in genetic diseases. The invention’s contribution lay in specific liposome-forming lipid combinations (and ratios) which encapsulate the mRNA to facilitate delivery into a cell. Whilst the specification exemplified liposomes with specific combinations and ratios of various lipids, the claims defined the combinations more broadly than what was exemplified. Seqirus opposed the application on several grounds, including novelty, inventive step, utility, clarity, sufficiency and support. The fate of the opposition ultimately turned on the questions of sufficiency (clear enough and complete enough disclosure) and support. Key Issues and Consideration Novelty and Inventive Step The novelty and inventive step debates were straightforward. Seqirus raised a series of prior art documents on the question of novelty. The Delegate, however, was not persuaded that any of this prior art provided a clear and unmistakable direction for the claimed liposome composition having the required combination of lipid components, encapsulating within its interior mRNA having the required structure, and a size of less than about 150 nm. The Delegate then considered inventive step based on the common general knowledge alone and taken together with a series of prior art documents. When considered in light of the common general knowledge alone, the Delegate stated that, at best, the evidence suggested that a person skilled in the art would have contemplated formulating mRNA with liposomes. However, it remained unanswered whether the liposome would have encapsulated or merely formed complexes with the mRNA, and what liposome formulation would have been used or what structural modifications may have been carried out on the mRNA. Ultimately, the Delegate found that, while each feature of the claims was individually known in the art, the combination of those features was not obvious. The Delegate also did not accept that a person skilled in the art faced with the problem of formulating mRNA for delivery, transfection and protein expression, and armed with any one of the prior art documents would arrive at the claimed invention as a matter of routine. Utility On the question of utility, both sides agreed that the specification showed that the scope of the claims included something that was capable of delivering mRNA to a cell and expressing the encoded protein in vivo. Seqirus argued that a therapeutic effect was also required (but not demonstrated). However, the Delegate, agreeing with Translate Bio, held that the ‘promise’ of the invention was delivery, transfection, and expression only, and that no therapeutic effect was required. Consequently, this ground of opposition failed. Sufficiency (clear enough and complete enough) This was the decisive issue (together with that of support). Australia’s law on sufficiency requires the specification to disclose the claimed invention in a manner that is clear enough and complete enough to enable a skilled person to perform the invention across the full width of the claims without undue burden or further invention. In the present case, the claims covered broad ranges of lipid ratios (e.g., 20–70% cationic lipid, 5%–90% non-cationic lipid (cholesterol and either DSPC or DOPE) and 1 %–15% PEG-modified lipids, but the specification only exemplified narrow ranges (e.g., 25–30% cationic lipid, ~40% cholesterol, 4% PEG-lipid). The question at hand, was whether Translate Bio’s contribution to the art extends to the general principle of encapsulating mRNA within the full breadth of the claimed liposomes and whether this has been sufficiently enabled. Experts on both sides agreed that small deviations in lipid content could collapse formulation stability of the essential liposome. In accepting the evidence presented, the Delegate concluded that each component in the liposome had structural and functional features, and that, if these components were not properly balanced, the successful formation of the liposome which was essential for delivery of the mRNA to the cell could be disrupted. Thus, the Delegate concluded that the specification did not provide a general principle for broader application beyond what was illustrated in the examples. As such the claims were said to be overly broad and not enabled across the full scope of the claims. Support For similar reasons, the broad monopoly claimed was not commensurate with the technical contribution. Translate Bio’s demonstrated contribution lay in identifying certain four-component lipid mixtures suitable for encapsulating and delivering mRNA, not a general principle covering all the broadly claimed ranges. Outcome The opposition succeeded on grounds of insufficiency and lack of support. All claims were found invalid in their current form. Translate Bio was given two months to propose amendments to overcome these deficiencies, but no amendments were proposed before the deadline. The application was formally refused on 12 May 2025, and costs were awarded to Seqirus. Implications Patent applicants should be careful to: