What’s in a priority date?  You might look on the face of a patent and see a filing date.  It might also have a list of priority documents such as an earlier filed PCT or provisional application.  So, is it that simple?  In a word – No.

There are a number of factors that go into determining the applicable priority date, some more on the administrative technicality side of things and others quite substantive.

One key factor to consider is that priority is determined claim by claim.  It is possible for claims in a patent to have different priority dates depending on when the material supporting the claim became part of the application.  The patent office doesn’t usually make a determination at this granular level.  But there are occasions where it comes up, particularly in litigation, post-grant challenges and interference proceedings.

A recent example is the Otonomy v. Auris case that played out at the Federal Circuit.  The two parties were duking it out over who was entitled to a claim to a method for treating an inner ear disease with an antibiotic. Who had the earlier priority date?  Auris had a 2005 filing and Otonomy had filed its patent application in 2013.  On the face of it, you’d think with the span of 8 years between the two, this was a no-brainer.  But not so fast!

At issue were claims to a controlled release composition with the antibiotic fluoroquinolone and a thermosetting polymer, where the antibiotic was suspended in the administered composition.

Turns out that the application Auris had filed in 2005 didn’t explicitly describe this composition.  Instead, it had an example where a different drug, ketamine, was stirred and dissolved into a composition and separately elsewhere in the application described fluoroquinolone as an antibiotic ingredient. Scientifically, Auris’s position fell down because dissolved is not the same as suspended.  Moreover, even though elsewhere the application described other ways of making a composition that included suspensions, nothing suggested to use the suspension composition with fluoroquinolone.   “Too much picking and choosing” noted the reviewing court.

The heart of adequate written description is whether the application reasonably conveys that the inventor had possession of the claimed subject matter as of the filing date. See Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc).  In other words, here, did the inventor envision a composition with the suspended fluoroquinolone when the application was originally filed in 2005?  It appears not.  The application was focused on ketamine (which is not an antibiotic), and included the fluoroquinolone only as a adjunct ingredient.

If not from the filed application, what was the basis of the claim to fluoroquinolone? The claim was added in a 2014 amendment.  And the added material as of 2014 formed the foundation of the Federal Circuit’s ruling that the Auris patent claim  was only entitled to a priority date of 2014 (not 2005).  Suddenly the 8 year lead Auris had over Otonomy based on the dates listed on the face of the patent vanished – and it was Otonomy who came out the winner with a 2013 priority date.


Is the focus of your application too narrow?

Sometimes, in starting a research project you have one embodiment in mind- like a particular chemical compound or a method with a set number and order of steps.  Nothing wrong with that.  But as you are placing your idea in a context for patent protection start looking at it like ripples radiating out from a pebble dropped in a pond.

What is in the next concentric circle?  Perhaps the compound belongs to a subfamily or there are logical variations to side groups.  Are there related therapeutic indications or uses?  For methods, can steps be done in sub-combinations, in other orders, or are some steps substitutable with others?

Are your descriptions too general and laundry-list like?

It’s possible to suffer from the opposite of too much focus by trying to capture everything. It is not unusual to see a patent application that lists every cancer under the sun as a potential target for a new compound or a list of what seems like every drug on the market that could be used in combination with a new proposed therapeutic.  The danger in this approach is that in many circumstances, there is no data to support casting such a broad net.  As a result, the issued claims that come from the application are limited to a small subset of the list.  However, the list in the patent specification becomes published prior art and can come back to haunt you when you later generate data on additional targets and combinations.

This is a balancing act.  Back to the ripples in a pond.  As you first go out from the initial concentric circles, the ripples are at first strong; the farther away you are from the center, the weaker the ripples become.  On the patent side, the strong ripples are variations on a theme, compounds in related subgroups, disease indications with commonalities in mechanisms and targets.  Consider saving the weaker outer ripples for future applications and use more broad terminology initially to capture the basic landscape.

What single and combo modes do you envision?

This relates to the cherry-picking aspect that came up in the Otonomy case.  Now, on one side of the coin – you can list out every variation and combination – but the size of your application could incur drafting fees, filing costs and translation charges that could take over your budget.  On the flip side, if the application in theory has it all in there but it is not at all clear what is envisioned to be combined and what is intended to be used on its own, then it is unlikely to provide the necessary written description to secure a priority date for the many potential embodiments.  Including guidance as to what is envisioned can go a long way to reaching a happy middle ground.

There’s no perfect solution.  But some forethought can go a long way to help establish and preserve your priority date.


The content of this blog is for informational purposes only and does not offer legal advice. Circumstances are fact-specific and you should consult an attorney for legal advice concerning your individual issues.