Inherent Anticipation and Inherent Obviousness?
By Andrew Williams --
Last week, in King Pharmaceuticals, Inc. v. Eon Labs, Inc., the Federal Circuit affirmed a grant of summary judgment of invalidity of U.S. Patent Nos. 6,407,128 (the "'128 patent") and 6,683,102 (the "'102 patent"), although not necessarily for the same reasons articulated by the U.S. District Court for the Eastern District of New York. King initiated the litigation after Eon filed an ANDA to market and sell a generic 800 mg metaxalone tablet for the treatment of "discomforts associated with acute, painful musculoskeletal conditions." Metaxalone was first discovered in the 1960s, and had been sold under the brand name Skelaxin since 1962 -- first by A.H. Robins Co., then by Elan Pharma, Inc ("Elan"), and finally by King. The '128 and '102 patents issued on June 18, 2002 and January 27, 2004, respectively, and claimed methods for increasing the bioavailability of metaxalone, and methods of using metaxalone in the treatment of musculoskeletal conditions. The inventors of these two patents discovered and claimed that the oral bioavailability of metaxalone increases when it is administered with food. The Federal Circuit determined, however, that all of the claims could be found inherently in the prior art.
Inherent Anticipation of Claims 1-3, 8-11, and 15-17 of the '128 Patent
Claim 1 of the '128 patent recites:
A method of increasing the oral bioavailability of metaxalone to a patient receiving metaxalone therapy comprising administering to the patient a therapeutically effective amount of metaxalone in a pharmaceutical composition with food.
The Federal Circuit agreed with the District Court that three references -- Fathie, Musculoskeletal Disorders and Their Management with a New Relaxant, Clinical Medicine 678 (April 1965) ("Fathie II"); Joseph A. Albanese, Nurses' Drug Reference 427 (2nd ed. 1982) ("Albanese"); and Anne C. Abrams, Clinical Drug Therapy 145 (1995) ("Abrams") -- each inherently anticipated this claim, because they each taught taking metaxalone with food. Specifically, Fathie II taught that nausea associated with metaxalone treatment can be alleviated if taken with food, Albanese taught that administration of metaxalone with meals can help reduce gastric upset, and Abrams instructed nurses to give metaxalone with "milk or food" to decrease gastrointestinal distress. Therefore, the only potential point of novelty was the preamble requiring the increase of oral bioavailability of the drug. Nevertheless, the District Court held that an increase in metaxalone bioavailability was an inherent property of taking metaxalone with food as taught by all three of these references.
King argued that the District Court erred because Eon did not provide any evidence that these references would necessarily result in the claimed invention, as required for a finding of inherent anticipation. King noted that the '128 patent specification provides precise conditions for food consumption that can accomplish the stated goal of the claim, while the prior art references only provide vague conditions. The Federal Circuit found this position untenable. Even though the specification provided examples with specific conditions, the disclosure did not indicate that these conditions were essential, and the Federal Circuit pointed out that the claim terms cannot be limited by specific conditions found within the specification. In other words, the patentees erred by broadly claiming "with food," and perhaps they would have been better served by narrowing the claim scope to specific conditions required to achieve the stated goal of increasing oral bioavailability. Of course, this is conditional on whether there were, in fact, specific conditions. Moreover, the Federal Circuit pointed out the general rule that discovering a new benefit of an old process cannot render the process patentable again. To inherently anticipate, the prior art need only meet the limitation to the extent the patented method does. And because the claimed methods require no more than taking metaxalone with food, the prior art references that teach the same thing inherently anticipate. The Federal Circuit also found that because claims 2-3, 8-11, and 15-17 had the same or similar preamble, they were also inherently anticipated.
Inherent Anticipation of Claims 4-6, 12-14, and 18-20 of the '128 Patent
The '128 patent also contained dependant claims that limit the time-frame in which the food must be ingested. These ranged from "30 minutes prior to 3 hours after consumption," to "substantially at the same time," to "immediately after the consumption of food up to 1 hour after." Even though none of the prior art references recited specific time requirements, King's own experts explained that "with food," as taught in the prior art, could mean "1 hour prior to up to about 2 hours after eating." Because every claim included at least part of this range, the Federal Circuit had no difficulty finding that claims 4-6, 12-14, and 18-20 of the '128 patent were also inherently anticipated.
Claim 21 of the '128 Patent is Patent Eligible, but Nonetheless is Inherently Anticipated
Claim 21 depended from claim 1 (shown above), but included the limitation "informing the patient that administration of a therapeutically effective amount of metaxalone in a pharmaceutical composition with food results in an increase in the maximal plasma concentration (Cmax) and extent of absorption (AUC(last)) of metaxalone compared to administration without food." The District Court invalidated this claim as patent ineligible pursuant to 35 U.S.C. § 101, because the act of informing was not transformative, as required by In re Bilski. The Federal Circuit disagreed, pointing out that the District Court focused on the "informing" limitation, and not the claim as a whole. Instead, the Court noted that Claim 21 as a whole is a method of treatment claim, and as such is always transformative, citing Prometheus Labs., Inc. v. Mayo Collaborative Serv., 581 F.3d 1336, 1346 (Fed. Cir. 2009).
Nevertheless, the Federal Circuit also found this claim invalid, not as patent ineligible, but as inherently anticipated. As claim 1 was already found anticipated, the only potential source of novelty was the "informing" limitation. The Court considered whether an inherently anticipated claim could be rendered novel by requiring that the patient be told about the existence of the inherent property. Answering its own question, the Federal Circuit analogized the case to "printed matter" cases, such as In re Gulack, 703 F.2d 1381, 1385 (Fed. Cir. 1983), which hold that if claimed printed matter is not functionally related to a claimed product, it cannot be used to distinguish the invention from the prior art. And because informing the patient about the benefits of a drug do not transform the process of taking the drug (even if it increased the likelihood that the patient will take the drug), claim 21 was inherently anticipated.
Claim 22 of the '128 Patent is Also Inherently Anticipated
Claim 22 also depends from claim 1, but includes the further limitation that the container have a printed label advising that administration with food results in an increase in the maximal plasma concentration (Cmax) and extent of absorption (AUC(last)) of metaxalone compared to administration without food. This, of course, brings the case squarely within the "printed matter" cases as described above. King tried to distinguish on the bases that this claim was a method claim, and the previous "printed matter" cases involved product claims. However, the Federal Circuit found this to be a distinction without a difference and invalidated the claims based on inherent anticipation.
The Claims of the '102 Patent Are Inherently Anticipated or Inherently Obvious?
Claim 1 of the '102 recited:
A method of using metaxalone in the treatment of musculoskeletal conditions comprising:
providing the patient with a therapeutically effective amount of metaxalone; and
informing the patient that the administration of metaxalone with food results in an increase in at least one of C(max) and AUC(last) of metaxalone compared to administration without food.
Again, the District Court invalidated this claim as patent ineligible, but the Federal Circuit affirmed on alternate grounds, specifically that the claim was inherently anticipated.
Of more interest, the District Court also found claim 5 invalid, but as inherently obvious. Claim 5 depends from claim 1, and limits metaxalone to a "unit dosage form." The District Court found this claim obvious over Albanese in view of 18 R.W. Dent Jr. and Dorthey K. Ervin, A Study of Metaxalone (Skelaxin) vs. Placebo in Acute Musculoskeletal Disorders: A Cooperative Study, Current Therapeutic Research (1975) ("Dent"). King's apparently only new challenge to this holding was that the District Court did not consider the secondary considerations of non-obviousness. Specifically, King alleged that the District Court failed to consider sales of Skelaxin from 1998 to 2003. However, the Federal Circuit noted that sales of the drug actually began to increase before the discovery that ingesting metaxalone with food increased bioavailability. Moreover, King apparently did not show any nexus between the alleged commercial success and the claimed invention. As such, the District Court correctly did not give much weight to commercial success.
The Federal Circuit affirmed the obviousness of this claim because it found that "it would be obvious to a person of ordinary skill in the art to combine Dent's teaching of taking a tablet dosage of metaxalone four times a day with Albanese's teaching of administrating metaxalone with food." However, no mention was made as to why one of skill in the art would have combined these references. If Albanese had explicitly anticipated the other claims of these two patents, than obviousness would have probably been clear. However, Albanese inherently anticipated the prior claims, because the newly claimed property was inherently present. In other words, it was not known prior to the determination by the patentees. The obviousness determination needs to take into account why one of skill in the art would have combined these two references, especially when the person of ordinary skill would have been unaware of this inherent property. It is possible that such a reason existed, for example, it is possible that the use of the unit dosage form would have caused increased nausea and/or gastrointestinal distress (thereby leading one to take it with food). However, no such reason was articulated in the Federal Circuit's opinion, and without articulating such a reason, it would appear that one of skill in the art would have only combined these references by mere happenstance. As obviousness determination requires more. The Court did point out that the person of ordinary skill is also a person of ordinary creativity, and not an automaton. Nevertheless, such a hypothetically person needs to have a reason to be creative, and the Federal Circuit did not even address this fact. As such, it is not clear that claim 5 of the '102 patent should have been invalidated.
Jurisdiction of Elan, the Prior Patent Holder
The Federal Circuit also addressed the issue whether the District Court had jurisdiction over Elan, because the lower court had entered the order against both King and Elan. Elan had previously owned the '128 patent, and the application that led to the '102 patent. However, before the filing of the present suit, Elan sold the patent and application to King, recording the assignment with the Patent and Trademark office. Nevertheless, Eon filed declaratory counterclaims against Elan. Elan even provided a letter to the District Court that stated that it waived any rights to pursue any damages or relief from Eon based on Elan's past ownership of the '128 patent. The District Court did not address whether it had jurisdiction over Elan. The Federal Circuit said was a mistake, and found that Eon had not met its burden of demonstrating that an actual case or controversy existed between it and Elan. The broad and unrestricted covenants not sue were determinative. Consequently, the Court vacated the order of invalidity as entered against Elan.
King Pharmaceuticals, Inc. v. Eon Labs, Inc. (Fed. Cir. 2010)
Panel: Circuit Judges Bryson, Gajarsa, and Prost
Opinion by Circuit Judge Gajarsa