What role does inherency have in an obviousness analysis?
WHDA Blogging Team | February 22, 2020
Persion Pharmaceuticals LLC v. Alvogen Malta Operations Ltd.
December 27, 2019
Before O’Malley, Reyna, and Chen (Opinion by Reyna).
Summary
The Federal Circuit affirmed the district court’s decision invalidating as obvious patents directed to method of using a hydrocodone-only formulation to treat pain in patients with hepatic impairment. Important to the obviousness determination was the concept of “inherency”. Specifically, the Federal Circuit agreed with the District Court that where the claimed method of would have been obvious from the prior art, claim limitations directed to the pharmacokinetic properties of the formulation would be inherent in the combination of the prior art.
Details
Hydrocodone is an opioid pain medication commonly prescribed to treat prolonged, severe pain. The bulk of metabolism of many opioids, including hydrocodone, occurs in the liver. People suffering from hepatic impairment (i.e., liver dysfunction) are at increased risk of opioid overdose, because their livers cannot clear the drugs from their bloodstreams as quickly and effectively as would be the case for people with healthy livers. As such, when prescribed to patients with impaired livers, dosages of opioids are often adjusted to prevent build-ups.
Persion Pharmaceuticals, LLC (“Persion”) commercializes a hydrocodone drug under the brand name Zohydro ER. The drug is an extended-released hydrocodone-only product—that is, it contains no other active ingredients. Clinical trials on Zohydro ER revealed, to its inventors’ surprise, that the concentration of hydrocodone in the bloodstream of subjects with mild and moderate hepatic impairment was not dramatically higher than in patients with unimpaired livers. The inventors of Zohydro ER filed U.S. patent applications that eventually issued as U.S. Patent Nos. 9,265,760 (“760 patent”) and 9,339,499 (“499 patent”).
The 760 and 499 patents were directed specifically to methods of treating pains in patients with mild or moderate hepatic impairment, and the claims emphasized the similar effects that the hydrocodone-only formulation had on patients with and without hepatic impairment.
The relevant claims of the two patents fell into two categories. The “non-adjustment” claims recited the lack of need to adjust the dosage for patients with mild or moderate hepatic impairment relative to patients without hepatic impairment. Meanwhile, the “pharmacokinetic” claims recited certain pharmacokinetic (PK) parameters that highlighted the similarity in the results of administering the claimed formulation to patients with and without hepatic impairment.
Claim 1 of the 760 patent is representative of the “non-adjustment” claims:
1. A method of treating pain in a patient having mild or moderate hepatic impairment, the method comprising:
administering to the patient having mild or moderate hepatic impairment a starting dose of an oral dosage unit having hydrocodone bitartrate as the only active ingredient, wherein the dosage unit comprises an extended release formulation of hydrocodone bitartrate, and wherein the starting dose is not adjusted relative to a patient without hepatic impairment.
Claim 12 of the 760 patent is representative of the “pharmacokinetic” claims:
12. A method of treating pain in a patient having mild or moderate hepatic impairment, the method comprising:
administering to the patient having mild or moderate hepatic impairment an oral dosage unit having hydrocodone bitartrate as the only active ingredient, wherein the dosage unit comprises an extended release formulation of hydrocodone bitartrate,
wherein the dosage unit provides a release profile of hydrocodone that:
(1) does not increase average hydrocodone AUC0-inf in subjects suffering from mild hepatic impairment relative to subjects not suffering from renal or hepatic impairment in an amount of more than 14%;
(2) does not increase average hydrocodone AUC0-inf in subjects suffering from moderate hepatic impairment relative to subjects not suffering from renal or hepatic impairment in an amount of more than 30%;
(3) does not increase average hydrocodone Cmax in subjects suffering from mild hepatic impairment relative to subjects not suffering from renal or hepatic impairment in an amount of more than 9%; and
(4) does not increase average hydrocodone Cmax in subjects suffering from moderate hepatic impairment relative to subjects not suffering from renal or hepatic impairment in an amount of more than 14%.
When Alvogen Malta Operations, Ltd. (“Alvogen”) filed an Abbreviated New Drug Application (ANDA) seeking to market a generic version of Zohydro ER, Persion sued Alvogen for infringing the 760 and 499 patents.
Naturally, Alvogen sought to invalidate those patents.
The prior art at issue were Devane (US2006/0240105), Jain (US2010/0010030), Vicodin label, and Lortab label.
Devane disclosed the same formulation as Zohydro ER, and disclosed an in vivo study in which the formulation was administered to treat post-operative pains in patients following their bunionectomy surgery. Devane did not disclose patients with mild or moderate hepatic impairment.
Jain disclosed a hepatic impairment PK study on Vicodin CR, a hydrocodone-acetaminophen combination formulation. Jain reported that the PK parameters (Cmax and AUC values) for hydrocodone in Vicodin CR were similar in normal and hepatically impaired subjects.
The Vicodin and Lortab labels disclosed the dosing instructions for those drugs. Vicodin contains hydrocodone and acetaminophen. Lortab contains hydrocodone and ibruprofen. The labels did not provide any precautions or dosing restrictions for individuals with mild or moderate hepatic impairment.
The district court found that the claims were obvious over the cited prior art.
As to the “non-adjustment” claims, the district court found that a person of ordinary skill in the art would have been motivated to administer Devane’s formulation to patients with mild or moderate hepatic impairment, because Jain taught that the hydrocodone exhibited similar PK parameters in normal and hepatically impaired patients, while the Vicodin and Lortab labels did not require different dosages for patients with mild or moderate hepatic impairment.
As to the “pharmacokinetic” claims, the district court found that the claimed PK values were “inherent in any obviousness combination that contains the Devane formulation”, because Devane disclosed what was essentially Zohydro ER, i.e., the claimed formulation, and the claimed values were “necessarily present” in Zohydro ER.
On appeal, the Federal Circuit honed in on Persion’s challenge of the district court’s “inherency” determination. Persion argued that Devane did not teach administering its formulation to hepatically impaired patients, so that “the natural result flowing from the operation as taught” in Devane could not be the claimed pharmacokinetic properties.
The Federal Circuit disagreed, distinguishing between the applications of “inherency” in the obviousness and anticipation contexts:
To the extent Persion contends that inherency can only satisfy a claim limitation when all other limitations are taught in a single reference, that position is contrary to our prior recognition that “inherency may supply a missing claim limitation in an obviousness analysis” where the limitation at issue is “the natural result of the combination of prior art elements.”
As the Federal Circuit noted, the longstanding rule is that “an obvious formulation cannot become nonobvious simply by administering it to a patient and claiming the resulting serum concentrations.”
Notably, there was no dispute that if administered under the same conditions, Devane’s formulation, which was identical to Zohydro ER, would necessarily exhibit the claimed PK values.
Related was Persion’s argument that the person skilled in the art would not have combined the cited prior art as the district court had. In particular, Persion argued that the district court should not have relied on the combination formulations disclosed in Jain and the Vicodin and Lortab labels.
Here also, the Federal Circuit disagreed. The Federal Circuit focused primarily on Jain’s teachings that its hydrocodone-acetaminophen combination formulation produced similar PK results for normal and hepatically impaired patients. That is, if Jain disclosed that its combination formulation was safe for patients with hepatic impairment, then it would be reasonable to expect the acetaminophen-free, hydrocodone-only formulation to be even safer. Further, considering Jain’s reported similarity in PK results for both hepatically impaired and unimpaired patients, it would have been obvious to the person skilled in the art to forgo dose adjustments when administering the same hydrocodone formulation to patients with hepatic impairment.
Where a claim defines some property of the claimed invention, it is not uncommon to find Examiners relying on inherency for those properties to complete their obviousness analyses. Reliance may be especially prevalent in chemical arts, as it has long been established that a chemical composition and its properties are inseparable. The Persion decision seems to reinforce the idea of inherency as a powerful argument that allows a missing limitation to be supplied based on some hypothetical combination of the prior art. That said, I suspect that the reach of the Persion decision will limited, as the fact that Persion’s claimed hydrocodone formulation already existed may have made it easier for the Federal Circuit to accept the finding of inherency.
Takeaway
- If the claim is directed to a new use of a known compound, then the claim should be more specific than a single, generic step of “applying the compound”. Consider defining the specific population or subpopulation that is helped by the compound, the specific conditions under which the compound is applied, and/or combination of the compound with other ingredients.
- If one can help it, avoid reciting intended results, which continue to be a complicated strategy. Not only could such a recitation force the issue of inherency, it could also raise the question of whether the recitation is even entitled to patentable weight, which is often a difficult argument to win with Examiners.
GENERAL KNOWLEDGE OF A SKILLED ARTISAN COULD BE USED TO SUPPLY A MISSING CLAIM LIMITATION FROM THE PRIOR ART WITH EXPERT EVIDENCE IN THE OBVIOUSNESS ANALYSIS
Sung-Hoon Kim | February 5, 2020
Koninklijke Philips N.V. v. Google LLC, Microsoft Corporation, Microsoft Mobile Inc.
January 30, 2020
Summary:
The Federal Circuit affirmed the PTAB’s final decision that claims of Philips’ ‘806 patent are unpatentable as obvious. The Federal Circuit held that the PTAB did not err in relying on general knowledge to supply a missing claim limitation in the IPR if the PTAB relied on expert evidence corroborated by a cited reference. The Federal Circuit also held that the PTAB did not have discretion to institute the IPR on the grounds not advanced in the petition.
Details:
The ‘806 Patent
Philips’ ‘806 patent is directed to solving a conventional problem where the user cannot play back the digital content until after the entire file has finished downloading. Also, the ‘806 patent states that streaming requires “two-way intelligence” and “a high level of integration between client and server software,” thereby excluding third parties from developing software and applications.
The ‘806 patent offers a solution that reduces delay by allowing the media player download the next portion of a media presentation concurrently with playback of the previous portion.
Representative claim 1 of the ‘806 patent:
1. A method of, at a client device, forming a media presentation from multiple related files, including a control information file, stored on one or more server computers within a computer network, the method comprising acts of:
downloading the control information file to the client device;
the client device parsing the control information file; and based on parsing of the control information file, the client device:
identifying multiple alternative flies corresponding to a given segment of the media presentation,
determining which files of the multiple alternative files to retrieve based on system restraints;
retrieving the determined file of the multiple alternative files to begin a media presentation,
wherein if the determined file is one of a plurality of files required for the media presentation, the method further comprises acts of:
concurrent with the media presentation, retrieving a next file; and
using content of the next file to continue the media presentation.
PTAB
Google filed a petition for IPR with two grounds of unpatentability. First, claims of the ‘806 patent are anticipated by SMIL 1.0 (Synchronized Multimedia Integration Language Specification 1.0). Second, claims of the ‘806 patent would have been obvious in view of SMIL 1.0 in view of the general knowledge of the skilled artisan regarding distributed multimedia presentation systems as of the priority date. Google cited Hua (2PSM: An Efficient Framework for Searching Video Information in a Limited-Bandwidth Environment, 7 Multimedia Systems 396 (1999)) and an expert declaration to argue that pipelining was a well-known design technique, and that a skilled artisan would have been motivated to use pipelining with SMIL.
The PTAB instituted review on three grounds (including two grounds raised by Google and additional ground). In other words, the PTAB exercised its discretion and instituted an IPR on the additional ground that claims would have been obvious over SMIL 1.0 and Hua based on the arguments and evidence presented in the petition.
In the final decision, the PTAB concluded that while Google had not demonstrated that claims were anticipated, Google had demonstrated that claims would have been obvious in view of SMIL 1.0 and that they would have been obvious in view of SMIL 1.0 in view of Hua as well.
CAFC
First, the CAFC held that the PTAB erred by instituting IPR reviews based on a combination of prior art references not presented in Google’s petition. Citing 35 U.S.C. § 314(b) (“[t]he Director shall determine whether to institute an inter partes review . . . pursuant to a petition”), the CAFC held that it is the petition, not the Board’s discretion, that defines the metes and bounds of an IPR.
Second, the CAFC held that while the prior references that can be considered in IPR are limited patents and printed publications only, it does not mean that the skilled artisan’s knowledge should be ignored in the obviousness inquiry. Distinguishing this case from Arendi (where the CAFC held that the PTAB erred in relying on common sense because such reliance was based merely upon conclusory statements and unspecific expert testimony), the CAFC held that the PTAB correctly relied on expert evidence corroborated by Hua in concluding that pipelining is within the general knowledge of a skilled artisan.
Third, with regard to Philips’ arguments that the PTAB’s combination fails because the basis for the combination rests on the patentee’s own disclosure, the CAFC held that the PTAB’s reliance on the specification was proper and that it is appropriate to rely on admissions in the specification for the obviousness inquiry. The CAFC held that the PTAB supported its findings with citations to an expert declaration and the Hua reference. Therefore, the CAFC found that the PTAB’s factual findings underlying its obviousness determination are supported by substantial evidence.
Accordingly, the CAFC affirmed the PTAB’s final decision that claims of the ‘806 patent are unpatentable as obvious.
Takeaway:
- In the obviousness analysis, the general knowledge of a skilled artisan could be used to supply a missing claim limitation from the prior art with expert evidence.
- Patentee’s own disclosure and admission in the specification could be used in the obviousness inquiry. Patent drafters should be careful about what to write in the specification including background session.
- Patent owners should check whether the PTAB instituted IPR on the grounds not advanced in the IPR petition because the PTAB does not discretion to institute IPR based on grounds not advanced in the petition.
Tags: anticipation > General Knowledge > inter partes review > obviousness > Petition > Skilled Artisan
A Claimed Range May be Anticipated and/or Obviousness When the Lower Limit of the Range of the Reference Abuts the Upper limit of the Disputed Claim Range
WHDA Blogging Team | January 31, 2020
Genentech, Inc., v. Hospira, Inc.
Prost, Newman and Chen. Opinion by Chen; Dissenting opinion by Newman.
Summary
At an inter partes review (IPR) proceeding, the Board held that a reference that discloses a range where the lower limit of said range abuts the upper limit of the disputed claim range was sufficient to render the disputed patent invalid for anticipation and obviousness. The Majority Opinion of the CAFC affirmed the holding of anticipation and obviousness. The Dissenting Opinion held that there was insufficient evidence to establish anticipation, the wrong reasoning was used to establish obviousness and the findings of Board and the Majority Opinion were based on hindsight.
Details
Background
Protein A affinity chromatography is a purification method, wherein “a composition comprising a mixture of the target antibody and undesired impurities often present in harvested cell culture fluid (HCCF) is placed into the chromatography column…. The target antibody binds to protein A, which is covalently bound to the chromatography column resin, while the impurities and rest of the composition pass through the column…. Next, the antibody of interest is removed from the chromatography column….” Id. at 3. A known problem of protein A affinity chromatography is leaching, wherein protein A detaches from the column and contaminates the purified antibody solution. Thus, further purification steps of the antibody solution retrieved from the column are necessary. Patent 7,807,799 (hereinafter “‘799”), owned by Genentech, addresses the known problem of protein A leaching, with regards to antibodies and other proteins that comprises a CH2/CH3 region. By reducing the temperature of the composition that is subjected to chromatography, leaching can be prevented and/or minimized to an acceptable level of impurity for commercial purposes. Claim 1, herein presented below, is the representative claim.
A method of purifying a protein which comprises CH2/CH3 region, comprising subjecting a composition comprising said protein to protein A affinity chromatography at a temperature in the range from about 10°C to about 18°C.
See Patent ‘799, Col. 35, Lines 44-47.
IPR
Hospira sought an inter partes review (IPR) of claims 1-3 and 5-11 of Patent ‘799. The Board instituted a trial of unpatentability and held that WO95/22389 (hereinafter “WO ‘389) anticipated and WO ‘389, both solely and in combination with secondary references, rendered obvious all of the challenged claims.
WO ‘389 discloses a method for purifying similar antibodies by a protein A affinity chromatography step and then a washing step, comprising washing with at least three column volumes of buffer. WO ‘389 discloses that “[a]ll steps are carried out at room temperature (18-25oC).” Id. at 6.
The Board held that WO ‘389 overlaps the claimed range of “about 10oC to about 18oC”, regardless of the claim construction of “about 18oC”. Further, the Board held that Genentech failed to establish the criticality of the claimed range to the operability of the claimed invention and thus did not overcome the prima facie case of anticipation. Also, the Board held that the claimed temperature range was in reference to the temperature of the composition both prior to and/or during chromatography. The Board held that the disclosed temperature range (18-25oC) of WO ‘389 applied to all components of the purification process and that the temperature of the HCCF composition both prior to and during chromatography were within said range.
Genentech appealed the Board’s holding of unpatentable due to anticipation and obviousness over WO ‘389. Of note, in the Appeal, Genentech did not challenge the Board’s holding that criticality of the claimed temperature range was not established.
CAFC
Anticipation
Genentech argued that the meaning of “all steps are carried out at room temperature (18-25oC)” is applicable only to the temperature of the laboratory and is not applicable to the temperature of the HCCF composition. Genentech asserted that 1) WO ‘389 discloses “steps” where the HCCF composition was cold or frozen, 2) Genentech’s expert and Hospira’s expert testified that typically HCCF coming from a bioreactor, are at a temperature of 37oC, 3) both experts testified WO ‘389 is silent regarding how long HCCF was held prior to chromatography and 4) Genentech’s expert testified that a skilled artisan in industrial processing would perform chromatography of the HCCF as soon as possible, i.e. without waiting for the HCCF to cool to room temperature, unless there were explicit instructions to do so. Id. at 8. Hospira argued that the explicit disclosure of “room temperature (18-25oC)” is with regards to the temperature of performing chromatography and all the components of said purification process, including the HCCF composition. Hospira noted that WO ‘389 disclosed specific temperatures for when the composition was not at room temperature. Further, Hospira’s expert testified that a skilled artisan would perform experiments at “ambient temperature with all materials equilibrated in order to obtain robust scientific data.” Id. at 9. The CAFC affirmed the Board and held that there was substantial evidence that the HCCF composition was within the claimed temperature of “about 10oC to about 18oC.” The CAFC agreed with the Board’s findings that 1) the statement “[a]ll steps are carried out at room temperature (18-25oC)” was a blanket statement and thus, specifying the temperature of HCCF during chromatography is redundant, 2) it disagreed with Genentech’s expert because said opinion was based upon large-scale industrially standards, and 3) it agreed with Hospira’s expert that a skilled artisan would not use HCCF at 37oC in a chromatography column and then report that all steps were performed at room temperature because the warm HCCF would raise the temperature of the entire system. Id. at 10. Lastly, the CAFC disagreed with Genentech’s argument that there was no anticipation because there was a missing limitation in WO ‘389 and agreed with the Board’s finding that WO ‘389 discloses a composition that is at the claimed temperature of “about 10oC to about 18oC” either prior to or during chromatography. (Nidec Motor Corp. v. Zhongshan Board Ocean Motor Co., cited by Genentech, holds that a reference missing a limitation cannot anticipate even if a skilled artisan would ‘at once envisage’ the missing limitation. 851 F.3d 1270, 1274–75 (Fed. Cir. 2017).” Id. at 10.)
Obviousness
The Board, citing the secondary references, determined that the temperature at which chromatography is performed is a result-effective variable and that when temperature is lowered, leaching is reduced. Thus, a skilled artisan would have been motivated to optimize temperature. Genentech argued that there was no reason or motivation to optimize the temperature because “the desire to reduce protein A leaching applies only to the large-scale, industrial purification of therapeutic antibodies for clinical applications…[and] that chilling HCCF for largescale, industrial processes would have been inconvenient, costly, and impractical.” Id. at 13. Hospira argued that a skilled artisan in non‑clinical applications would have been motivated to reduce leaching because leaching damages chromatography columns. The CAFC held that the Board was correct in holding that neither the ‘799 patent nor WO ‘389 are limited to large-scale industrial applications. The CAFC affirmed the Boards’ finding that temperature is a “result-effective variable” and that it would have been routine experimentation for a skilled artisan to optimize the temperature to reduce protein A leaching.
Dissent
Newman dissented and asserted that affirming the holding of invalidity for anticipation and obviousness was an error because none of the prior art shows or suggest the claimed method. Id. at 9. According to Newman, the determination by the Board and the CAFC is based on hindsight. Newman noted that the “retrospective simplicity of the solution apparently led the Board to find it obvious to them, despite the undisputed testimony that no reference suggests this solution to the contamination problem here encountered, as the experts for both sides acknowledged.” Id. at 3. Newman noted that the ‘799 patent disclosed in detail the complexities with regards to obtaining and purifying antibodies, the many factors to consider when performing chromatography, the problems associated with the leaching of protein A, and explained their discovery of the cause of said leaching and their solution to said problem. At the Board, Genentech argued the advantages of their claimed method, i.e. prevent leaching of protein A in protein A affinity chromatography, in contrast to the need to perform additional purification chromatography to remove protein A, as in WO ‘389. Both experts agreed that the reference to room temperature (18-25oC) was in reference to the ambient temperature and was not in reference to the chilled material in the column. “Nonetheless, the PTAB and now my colleagues hold that this ‘room temperature’ range anticipates the ‘799 patent’s chilled range of 10oC-18oC, ignoring the significantly different results in the recited ranges.” Id. at 6.
According to Newman, mere abutment of the 18oC is not anticipation. “Anticipation requires that the same invention, including all claim limitations, was previously described. Nidec Motor Corp. v. Zhongshan Broad Ocean Motor Co., 851 F.3d 1270, 1274– 75 (Fed. Cir. 2017). The “anticipating reference must describe the entirety of the claimed subject matter.” Id. at 7. Newman holds that the affirmation of anticipation fails to consider the “absence of identify of these ranges” (18-25oC vs. about 10oC-about 18oC), fails to consider “the different results at the lower range” and fails to consider “the significance of the purity of the eluted antibody.” Id. at 8 Regarding obviousness, Newman holds that there is no evidence that it was known or suggested that cooling the HCCF composition either prior to or during chromatography would minimize or prevent leaching of the protein A in the purified antibody solution. According to Newman, “the question is not whether it would have been easy to cool the material to the 10ºC–18ºC range; the question is whether it would have been obvious to do so. Contrary to the Board’s and the court’s view, this is not a matter of optimizing a known procedure to obtain a known result; for it was not known that cooling the material for chromatography would avoid contamination of the purified antibody with leached protein A.” Id. at 9. That is, even if it is possible to modify the temperature, Newman asserts that there is no reason or motivation to optimize the temperature to prevent leaching of protein A.
Takeaway
- If possible, establish the criticality of a claimed range. One is encouraged to rebut a prima facie case of anticipation or obviousness by establishing that the claimed range is critical to the operability of the claimed invention.
- If there is an overlap of a disputed claim range and the range disclosed in the prior art, but the results are different, this may be evidence of the criticality of the range.
One correct way of reciting a Markush group in the claim
WHDA Blogging Team | January 24, 2020
Amgen Inc. v. Amneal Pharmaceuticals LLC
January 7, 2020
Lourie (Opinion author), Newman, and Taranto
Summary
The Federal Circuit reversed the district court’s claim construction of the Markush groups as being closed to unrecited elements because the claim recites “comprising” as the transitional phrase and “at least one” in front of each of the Markush groups. Furthermore, the Federal Circuit affirmed the district court’s holding of noninfringement under the doctrine of equivalents by one of the Defendants’ products due to prosecution history estoppel.
Details
Amneal, Piramal, and Zydus each filed an Abbreviated New Drug Application (ANDA), seeking approval of a generic version of Sensipar®, a formulation of cinacalcet hydrochloride used to treat secondary hyperparathyroidism in adult patients with chronic kidney disease who are on dialysis and to treat hypercalcemia in patients with parathyroid cancer and primary and secondary hyperparathyroidism. Amgen holds the approved New Drug Application for Sensipar®, and sued them for infringing U.S. Patent No. 9,375,405 (the ‘405 patent).
The ‘405 patent is directed to a rapid dissolution formulation of cinacalcet. Claim 1 of the ‘405 patent is as follows:
A pharmaceutical composition comprising:
(a) from about 10% to about 40% by weight of cinacalcet HCl in an amount of from about 20 mg to about 100 mg;
(b) from about 45% to about 85% by weight of a diluent selected from the group consisting of microcrystalline cellulose, starch, dicalcium phosphate, lactose, sorbitol, mannitol, sucrose, methyl dextrins, and mixtures thereof,
(c) from about 1% to about 5% by weight of at least one binder selected from the group consisting of povidone, hydroxypropyl methylcellulose, hydroxypropyl cellulose, sodium carboxymethylcellulose, and mixtures thereof; and
(d) from about 1% to 10% by weight of at least one disintegrant selected from the group consisting of crospovid[o]ne, sodium starch glycolate, croscarmellose sodium, and mixtures thereof,
wherein the percentage by weight is relative to the total weight of the composition, and wherein the composition is for the treatment of at least one of hyperparathyroidism, hyperphosphonia, hypercalcemia, and elevated calcium phosphorus product.
The ‘405 patent issued from U.S. Patent Application 12/942,646 (the ‘646 application). The original ‘646 application contained only one claim, which recited a “pharmaceutical composition comprising an effective dosage amount of a calcium receptor-active compound and at least one pharmaceutically acceptable excipient, wherein” the composition achieved a specific dissolution profile. Later, Amgen filed a Preliminary Amendment, which cancelled claim 1 and added new claims 2-24. The newly filed claim 2, which ultimately issued as claim 1, is as follows:
A pharmaceutical composition comprising:
(a) from about 10% to about 40% by weight of cinacalcet HCl;
(b) from about 45% to about 85% by weight of a diluent selected from the group consisting of microcrystalline cellulose, starch, dicalcium phosphate, lactose, sorbitol, mannitol, sucrose, methyl dextrins, and mixtures thereof,
(c) from about 1% to about 5% by weight of at least one binder; and
(d) from about 1% to 10% by weight of at least one disintegrant,
wherein the percentage by weight is relative to the total weight of the composition.
The Examiner rejected the new claims. Then, Amgen filed an amendment of the independent claim 2, reciting “from about 10% to about 40% by weight of cinacalcet HCl in an amount of from about 20 mg to about 100mg.” Then, Amgen conducted a phone interview with the Examiner. During the interview, the Examiner proposed an Examiner’s Amendment of the independent claim 2, and Amgen accepted the Examiner’s Amendment. Specifically, the Examiner’s Amendment revised the binder and the disintegrant limitations into their current, Markush group format. Then, the claims are allowed. After the Notice of Allowance was issued, Amgen filed a number of RCE Requests with new IDS submission. In one of the RCE Requests, with regard to the previous Examiner’s Amendments, Amgen remarked that “[t]hese amendments have not been made in response to a prior art rejection but rather to place the claims in proper format and to better define the claimed subject matter, including equivalents.” The Examiner issued a Notice of Allowance after each RCE Request.
In the district court proceeding, one key issue is the construction of the binder and disintegrant Markush groups. The district court held that the Markush groups for the binder and disintegrant elements are closed to unrecited binders and disintegrants, relying on Multilayer Stretch Cling Film Holdings, Inc. v. Berry Plastics Corp., 831 F.3d 1350 (Fed. Cir. 2016). Furthermore, the district court held that Amneal does not infringe the ‘405 patent because Amneal uses Opadry Clear YS-1-7006 as the binder, a product that contains PEG 400 and PEG 8000 in addition to hydroxypropyl methylcellulose, which is a listed binder in claim 2. Furthermore, the district court held that Piramal does not infringe the ‘405 patent under the doctrine of equivalents because prosecution history estoppel barred Amgen’s argument that the cold-water soluble fraction of the preglatinized starch used by Piramal is equivalent to providone, a listed binder in claim 2.
On appeal, first, the Federal Circuit reversed the district court’s claim construction regarding the binder and disintegrant Markush groups. Specifically, contrary to the district court’s interpretation, because claim 1 uses “comprising” as the transitional phrase and “at least one” in front of each Markush group, the binder and disintegrant Markush groups do not preclude other binders and disintegrants in the claimed composition. Without more, such language is satisfied when an accused product contains a component that is from the Markush group and that meets the limitation’s other requirements such as concentration requirement for the component. Furthermore, the Federal Circuit held that Opadry used as a binder by Amneal contains HPMC, which is a listed binder in claim 1. Thus, irrespective of whether other components such as PEG are present, provided that Amneal’s formulation contains from about 1 to about 5% HPMC, the formulation literally infringes. Accordingly, the Federal Circuit vacates and remands those findings by the district court.
Next, the Federal Circuit held that Amgen’s doctrine of equivalents argument is barred by prosecution history estoppel. During the prosecution, Amgen accepted the Examiner’s Amendment that revised the claim’s disintegrant and binder limitations to be in Markush group format. Such an amendment narrows the scope of the claim, and Amgen failed to carry its burden to demonstrate that the Examiner’s Amendment was made for a reason unrelated to patentability. The Amgen’s statement in the later RCE Request was made over eight months after the Examiner’s Amendment was accepted, and accordingly does not provide any insight on the reasons for the Examiner’s Amendment. Furthermore, the tangential exception to prosecution history estoppel does not apply here because the use of pregelatinized starch as a binder is taught in the cited prior art. An amendment made to avoid prior art that contains the equivalent in question is not tangential.
Accordingly, the Federal Circuit vacated and remanded the district court’s judgment that Amneal does not infringe the ‘405 patent, and affirmed the district court’s judgment that Piramal does not infringe the ‘405 patent.
Take away
- The claims should recite “comprising” as the transitional phrase and “at least one” in front of the Markush groups to avoid being constructed to be closed to unrecited elements in the Markush groups.
- The original specification should contain a complete set of claims instead of one claim because later amendments may inevitably invoke prosecution history estoppel, which would bar most of the doctrine of equivalents arguments.
- The patent drafter should be mindful of an independent claim with an overly broad scope. Any later amendments during the patent prosecution may invoke prosecution history estoppel. Accordingly, the applicants have the risk of losing any protection afforded by patent infringement under the doctrine of equivalents.
