When the CEO of the chemical sciences startup transferred a pending U.S. patent application to our firm, he was quite proud when he told us the application contained over 200 claims.
When I suggested to a life sciences startup company that we cut our set of fifty draft claims down to twenty claims for filing with the USPTO, the head of the business said no. When I asked why, he told me investors want large numbers of patent claims.
At first glance, more claims in a patent application might seem like a good idea. But if you’re a venture capitalist trying to maximize your ROI, or a startup executive sweating your burn rate, more claims are not better.
Patent claims—the numbered items at the end of a published patent—are the basis for determining what the patent covers. Claims come in two types. Independent claims start off with a phrase like “A composition, comprising…” or “A method, comprising the steps of….” Dependent claims begin with a term such as “The composition of [a particular prior composition claim], wherein…” or “The method of [a particular prior method claim], further comprising the step of….” In other words, dependent claims are narrower than the independent claims on which they depend. If you liked set theory in your math classes, dependent claims are subsets of independent claims.
For the visual learners in the audience, here’s a schematic of a recommended number and type of claims in U.S. patent practice. The ovals are independent claims and the rectangles inside the ovals are dependent claims. Yes, dependent claims can be nested inside other dependent claims.
There is plenty of value in having several dependent claims inside the scope of each of your independent claims. If a patent examiner finds prior art inside the scope of one of your independent claims but outside the scope of a dependent claim, you can amend that independent claim to require the limitations of that dependent claim. After a patent is granted, having claims of various scope gives a patent owner more options when asserting infringement. Maybe the infringer can find prior art that the patent examiner missed, which knocks out your independent claim, but not your dependent claim that the infringer is practicing.
But there comes a point where more claims don’t add much value. Consider this schematic:
As you can see, most of those extra dependent claims cover only tiny slivers of the independent claim. Tiny slivers are easy to design around. In litigation, if you have to assert a claim covering the peptide with the amino acid sequence INFRINGED because the opponent found prior art with the sequence INFRINGE, your case is on shaky ground.
Still, even if a large number of claims doesn’t add value, does it harm anything to leave them in?
Yes, it does. We’ll get to that in part II.