An Issued Life Science MPF^[1] U.S. Patent Claim: Ex parte Gleave

PTAB Decision:  Ex parte Gleave, Appeal 2012-004973 (P.T.A.B. Jan. 22, 2014)

Background:  In a preliminary amendment, Gleave presented independent claims 25 and claim 33, introducing “means for” (with emphasis added):

25. (new) A pharmaceutical composition comprising a therapeutic agent effective to reduce the amount of active hsp27 in cancerous cells exposed to the therapeutic agent, and a pharmaceutically acceptable carrier, wherein the therapeutic agent is an antisense oligonucleotide having a sequence complementary to SEQ. ID NO. 91, wherein the oligonucleotide comprises at least ten bases complementary to bases 744-764 of SEQ. ID NO. 91, and wherein the antisense oligonucleotide is 12 to 35 nucleotides in length.

 33. (new) A pharmaceutical composition comprising a

(a) means for reducing the amount of active hsp27 in cancerous cells by sequence specific interaction with Seq. ID No. 91 and

(b) a pharmaceutically acceptable carrier.^[2]

The preliminary amendment also presented claims 34 and 35, depending directly or indirectly from claim 33.

In presenting the new claims, Applicants made clear an intent to invoke §112(f):

The PTO rejected claims 33-35 as not entitled to the effective date of two provisional applications, but rather only entitled to the actual filing date of the preliminary amendment. With respect to MPF claim 33, the examiner stated:

Applicants responded, targeting the examiner’s erroneous failure to construe the claims as MPF and noted the instructions doing so set out in MPEP §2181.

The PTO issued a final rejection, repeating its earlier position. Responding after final, Applicants persevered and again urged that the examiner failed to correctly construe a claim in MPF format pointing out the following:

The failure to properly treat the MPF claim compromised, according to Applicants, the anticipation rejection also. To anticipate a means-plus-function limitation, the applied prior art reference would have to disclose a sequence that performed the claimed function and was identical to or the equivalent of a structure disclosed in the application. The Examiner did not make either of these showings.

The USPTO issued an Advisory Action, ruling that the reply did not place the application in condition for allowance. Applicants engaged in a pre-brief appeal conference. The rejection was withdrawn in view of Applicant’s brief in its pre-brief conference request.

After prosecution was reopened, Applicants received yet another non-final rejection. In addition to making the same priority application analysis, the USPTO made a written description rejection, a prior art rejection, and a new indefiniteness rejection under §112(b).

In response, Applicants amended only claim 33 to delete “by sequence specific interaction with Seq. ID No. 91” as follows:

Claim 33. (currently amended) A pharmaceutical composition comprising a

(a) means for reducing the amount of active hsp27 in cancerous cells [by sequence specific interaction with Seq. ID No. 91] and

(b) a pharmaceutically acceptable carrier.

Applicants argued that were §112(f) applied properly, the rejections would be overcome.

The USPTO responded with yet another non-final rejection based solely on 102 and 103.

Applicants filed a Notice of Appeal, continuing to argue the examiner was not properly analyzing claim 33’s scope under §112(f). In addition, Applicant added a policy argument in its Appeal Brief:

Issues:  Did the Examiner properly interpret the means plus-function language in the claim?  And, does the cited prior art teach a structure disclosed in the Specification as having the recited claimed function?

Outcome:  Relying on Donaldson and other precedent, and citing MPEP 2181, the PTAB reversed the Examiner’s rejection:

And further that the examiner had not presented any evidence of equivalence in function in the disclosure of the asserted prior art reference. The anticipation and obviousness rejections were also reversed.

With the successful appeal, the claim issued and was entitled to 903 days of patent term adjustment. U.S. Pat. No. 8722872 issued May 13, 2014 and will expire March 24, 2026 (Oct 2, 2023 + 903 days PTA).

Prosecution Takeaway:  For patent drafters practicing in the U.S. life sciences, the MPF claim format may provide more accuracy and clarity than purely structural characterization and may end up providing broader scope. This alternative claim format is worth considering. Note also the guidance provided by the USPTO training materials claims 5 and 6 at https://www.uspto.gov/patent/laws-and-regulations/examination-policy/examination-guidance-and-training-materials. 

For those drafting claims related to a regulated industry, narrow claims are not necessarily bad; they can provide satisfactory claim scope. And if broader claims are desired, carefully draft the specification to encompass all embodiments intended to be covered by the language.

Taking care to carefully link the “means for” in the claim to the specification will help avoid prior art and avoid written description and enablement issues. This may mean added difficulty for third parties challenging patentability at the PTAB or validity in district court.

Since MPF claims are construed to include statutory equivalents to what is linked in the specification, the analysis of equivalents of an MPF claim is one of literal infringement by structure, material, or acts that perform the same function, rather than the far less certain doctrine of equivalents. The potential uncertainty of the scope of literal statutory equivalents also creates obstacles to third-party design-arounds.

There are challenges to consider though. Narrowness and linking to the specification may not provide satisfactory protection in specific circumstances. Defining statutory equivalents is not a very clear area of the law, and the USPTO treatment of an MPF claim may be inconsistent or even, in life sciences, reluctant to the point of necessitating appeals.