Monday, 20 October 2014

US Biotech Claim Drafting

These points are from a CIPA seminar given by Linda Huber on 17 October 2014.

1. The following formats are relevant to biotech cases: methods of medical treatment, therapeutic compositions and diagnostic methods. Method of treatment claims usually refer treating a defined condition, i.e. ‘A method of treating disease X comprising administering compound Y’. However this is not always the case, for example: ‘A method of eliciting an immune response comprising administering immunogen ABC’. Swiss style medical use claims are not allowed.

2. Diagnostic claims are often in the format ‘A method of diagnosing disease X comprising analysing a sample for the presence of Y’. However there can be issues of matter eligibility for this claim as discussed below.

3. In the US ‘inherency’ can be a problematic issue for the novelty of method of treatment claims. A method of treatment claim is anticipated if the prior art inherently discloses the treatment due to a ‘natural result flowing from’ the disclosure. So for example if the prior art discloses drug X to treat high blood pressure in a patient, and if the drug also inhibits hair loss during the treatment, then it would be seen as ‘inherently’ disclosing this (though it does not explicitly do so), destroying the novelty of use of the drug to treat hair loss. One solution to this is to limit the claim to a class of patients that do not appear in the claim, and often this can be done by defining the patient to be ‘in need thereof’. Clearly another way would be to limit using a feature not disclosed in the prior art, such as routes of administration, etc.

4. Written description and enablement can be problematic if a method of treatment claims refers to ‘A method of preventing disease X…’. There is an assumption in US practice that no disease is 100% preventable.  One can argue against such objections if there is data to show that 100% prevention is achieved. However amending the claim to refer to ‘A method of reducing the likelihood of disease X…’ can often overcome the objection. Alternatively the term ‘prevention’ can be defined in the specification as not requiring 100% prevention. Written description and enablement objections are often raised against gene therapy claims, especially where the specification does not show actual treatment. Amendment of the claim to instead refer simply to expressing the protein may overcome such objections, i.e. A method of expressing protein Y in a subject in need of treatment for disease X, comprising administering to the subject an expression vector encoding gene Z.

5. Post -AIA ‘best mode’ is still mentioned in the relevant statute, 35 USC § 112(a), but it is no longer a ground for challenging the validity of a patent. However failure to provide the best mode could still render a patent unenforceable as a matter of equity and so best mode should still be disclosed. It was noted that the specification does not need to point out what which embodiment is the best mode.

6. Two recent Supreme Court cases, Mayo v Prometheus and Association for Molecular Pathology v Myriad Genetics, have had a huge impact on biotech patents. Mayo concerned a claim to a method for optimising therapeutic efficacy of a condition by assessing the in vivo level of a particular metabolite to determine the amount of drug to administer. The Supreme Court held the method to relate to a ‘law of nature’ and therefore to be ineligible matter. In addition the ‘application’ of a law of nature is also unpatentable if it merely relies on elements already known in the art. The ‘take home’ message from Mayo is that the invention must not too broadly pre-empt the use of the law, and should include an inventive concept which is significant and separate from the natural law.

Myriad decided that genomic DNA was not patentable since it was part of nature, and separating a gene from the surrounding genetic material (so it is ‘isolated’) does not make it an invention. However cDNA is patentable because it does not occur in nature and its sequence is created in the lab. Part of the logic of the decision is based on the fact that the ‘information’ in genomic DNA is unchanged by isolating it, and therefore it would seem that the logic would not apply to other molecules. However, as discussed below, new USPTO guidelines have applied the Myriad principle of ‘naturally occurring molecules being unpatentable’ to all molecules. It was noted that the Supreme Court’s decision Alice v CLS Bank had little impact on biotech cases.

7. The USPTO issued new guidelines in March of this year in view of Mayo and Myriad. They give examples of what is patent eligible and seem to have broadened the principles set out in Mayo and Myriad. They are also quite unclear as to what is patent eligible. The guidelines provide a 3 part test for patentability which determines whether the invention provides something ‘significantly different’ from a judicial exception (abstract ideas, laws of nature or natural principles, natural phenomena and natural products). The guidelines list ‘factors that weigh toward eligibility’, such as:

- the claim providing meaningful limits on scope so that others can use the judicial exception,

- the claim reciting a particular machine or transformation of an article which integrates the judicial exception into a particular application, or

- the claim recites one or more elements which are more than well-understood, conventional or routine.

8. From the examples given in the guidelines it is clear that the level of ‘generality’ of an invention is important in determining its eligibility. Simply identifying mutant gene sequences in an individual by comparing to wild-type or treating a condition by exposure to sunlight are ineligible. However diagnosis using a specific defined antibody and flow cytometry is given as an example of a patent eligible invention.

9. The guidelines are clearly going to be problematic for diagnostic claims which are normally based on measuring the level of a natural product or characteristic. One possible solution is to refer to specific reagents, such as a novel antibody, in the claim. Alternatively one could introduce a treatment step into the claim. However the recent Supreme Court decision Limelight v Akamai made it more difficult to find infringement where split infringement occurs, and so it could be difficult to enforce claims which had diagnostic and treatment steps as they are likely to be performed by different parties. One way to avoid having these two distinct steps in the claims is to refer to have a first step which refers to ‘obtaining the results of a diagnostic analysis’, rather than performing a diagnosis. Other solutions include having a ‘system’ claim referring to the components of the diagnostic assay, claiming the relevant protein-antibody complex which is formed during diagnosis or writing the claim as a ‘method of selecting a treatment for disease X…’. Narrowing the scope of the claim should be helpful in overcoming eligibility issues.

10. For product claims, it will be important to find ways in which the product is structurally different from nature. Referring to ‘synthetic’ or ‘recombinant’ DNA may work or requiring that the natural sequence is linked to another ‘heterologous’ sequence may also succeed. For cells and organism the feature of being ‘transgenic’ may also be enough to distinguish them from nature.

11. It is not clear how the guidelines will impact method of treatment claims. Some Examiners are taking the view that administering a naturally occurring polypeptide is ineligible matter. Clearly it would be wise to have fallbacks in the specification that could be used to limit the claims, for example specific administration schedules and routes of administration.

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