Entitlement to claim priority - get it right from the start

In order to claim priority from an earlier application, the rights in that earlier application must belong to the entity making the priority claim, at the time of filing the later application.  Since the rights in an invention often belong initially to individual inventors, each of those inventors' rights must have passed to the applicant before the later application is filed.  An "obligation to assign", for example in a contract of employment, is not sufficient to effect the transfer of rights in the invention: an actual assignment must have taken place.

Recent developments in the case law on both sides of the Atlantic have brought into sharper focus the importance of ensuring that ownership of priority applications and, in particular, ownership of the right to claim priority from those applications, is clearly established.  In a 2009 decision of the High Court in England (Edwards Lifesciences AG v Cook Biotech Inc, EWHC1304 (Pat)), the Judge concluded that Cook was not entitled to claim priority from its initial US provisional application and that, due to prior art published between its priority and filing dates, Cook's patent was invalid.  The US provisional had been filed in the name of three inventors, only one of which was an employee of Cook.  Although the employee's share of the invention automatically transferred to Cook by virtue of the employment agreement, at the time of filing the PCT application the other two inventors had not assigned their shares to Cook.  Therefore, Cook was not a "successor in title" to all three inventors, as required by the Paris Convention for the right to claim priority to be available.  The Judge commented that such a defect was not rectifiable after the fact, for example by subsequent assignment of the various applications, patents and other rights to Cook.

This UK judgement is, as noted by the Judge, in line with earlier European Patent Office (EPO) Board of Appeal decisions T62/05 and J19/87.

Under US Federal Law, it has been determined that the question of whether or not ownership of an invention is transferred to an employer from an employee inventor is a Federal matter, dependent on the wording of the employment agreement.  An "obligation to assign" future inventions is unlikely to be sufficient proof that actual transfer of ownership has taken place.  Wording such as "do hereby assign" is more likely to be effective.  See, for example, DDB Technologies, LLC v MLB Advanced Media, LP (517 F.3d 1284, 1290 (2008)) and Stanford University v Roche (Fed Cir 2009, case 2008/1509-1510).

At the EPO, the Boards of Appeal have also indicated that an obligation to assign is not sufficient to show that an actual transfer has taken place (J12/00, relating to the refusal of an inventor to complete an assignment of a European application). Furthermore, in EPO Board of Appeal case T62/05, evidence was submitted of the intention of the priority applicant to transfer rights relating to the priority filing to the European patent applicant, although an assignment document was not completed until after the European application was filed.  Again the Board concluded that, since priority rights can be assigned independently of the corresponding application, this was not sufficient evidence that the priority rights had actually been transferred.  In this case, it was held that only a formal assignment document, mentioning the priority application by number and including reference to the transfer of priority rights, would have been sufficient proof.  The EPC requires that an assignment agreement is signed by all parties to the agreement, not just the assignors (Article 72 EPC).

Unless an employment agreement clearly states that all rights relating to an invention – including national and international patent applications relating to the invention and the right to claim priority from a priority application – are actually assigned to the employer, the EPC requirements are likely to apply.  Clauses in the agreement indicating an obligation to assign may not be sufficient to transfer the right of priority.  In addition, some comments by the EPO hint that a general agreement, which does not refer to specific priority applications, may not be sufficient to show that ownership of a priority application and the associated priority rights has been transferred.

Therefore, in cases where a priority application has been filed in the names of individual inventors, it would seem most prudent to arrange for an assignment document, signed by all parties to the agreement, to be completed before any later applications, for example a PCT application, are filed.

The assignment document should refer clearly to the number, date and country of filing of the priority application(s) and should make it clear that all subsequent related applications (in all countries), as well as the right to claim priority from the first application(s), are being assigned.  The document can be kept on file, to be available as evidence in the event that there is any dispute as to the entitlement to claim priority.  If completion of such an assignment is not possible in the timeframe, the later application should also be filed in the names of the inventors, with a subsequent assignment of the application and recordal of the applicant change.