The safe harbor provision prevents the citation of the earlier filed, restricted application against a later filed divisional application filed in response to the restriction requirement for purposes of ODP and vice versa.
Patents give a time-limited monopoly for patentees to exclude others from practicing the claimed invention. The judicially created doctrine of obviousness-type double patenting prevents patentees from an unjustified extension of patent term on a later expiring patent directed to an obvious variant of the invention claimed the earlier expiring patent. Typically, a terminal disclaimer is filed during prosecution to obviate obviousness-type double patenting, disclaiming the remaining patent term of the later expiring patent such that the two patents expire at the same time. Obviousness-type double patenting (ODP) has been at the forefront for those involved in the patent process, from patent practitioners to stakeholders, based on recent case law developments, in particular, In re Cellect, 81 F.4th 1216 (Fed. Cir. 2023), regarding the ability of a terminal disclaimer to cut off earned Patent Term Adjustment (PTA) awarded for administrative delays during prosecution versus any extended term granted under Patent Term Extension (PTE) awarded for delays experienced during the regulatory approval process. (See our previous Alert.)
One strategy to avoid raising issues of ODP is to utilize the safe harbor provision under 35 U.S.C. § 121 following issuance of a restriction requirement, identifying multiple distinct inventions. The safe harbor provision prevents the citation of the earlier filed, restricted application against a later filed divisional application filed in response to the restriction requirement for purposes of ODP and vice versa.
A recent case, Acadia Pharmaceuticals, Inc. v. Aurobindo Pharma Ltd., No. 22-cv-1387-GBW, 2023 WL 8622111 (D. Del. Dec. 13, 2023), provides insight as to the interpretation of the safe harbor provision against citation of a reference for ODP purposes when the challenged patent is the earlier issued patent.
Facts and Case History
Acadia Pharmaceuticals Inc. is the owner of numerous patents directed to the Parkinson’s drug pimavanserin, marketed as Nuplazid ®. Acadia asserted numerous patents in response to numerous defendants’ filings of abbreviated new drug applications. Acadia ultimately dismissed its pending claims against all defendants except for MSN Laboratories PVT. Ltd. and MSN Pharmaceuticals Inc. The only patent remaining at issue is U.S. Patent No. 7.601,740 (’740 patent), namely the validity of claim 26, directed to a tartrate salt of pimavanserin. MSN moved for summary judgment on the grounds that the ’740 patent is invalid under ODP in view of U.S. Patent No. 9,566,271 (’271 patent) whose lineage can be traced to the ’740 patent. Acadia sought a cross-motion for summary judgment of no invalidity.
The ’740 patent issued on October 13, 2009 from U.S. Patent Application No. 10/759,561 (’561 application), filed January 15, 2004, and was granted 980 days of PTA. Following FDA review and approval, the ’740 patent received 1,310 days of PTE based on the delay encountered during the regulatory review and approval process. The ’271 patent issued on February 14, 2017 from U.S. Patent Application No. 11/416,527 (’527 application) and did not receive any PTA. The ’527 application was filed as a continuation of the ’561 application following issuance of a restriction requirement in the ’561 application. Acadia canceled the pending claims of the ’527 application and replaced them with the nonelected claims of the ’561 application. Acadia also changed the designation of the ’527 application from a continuation to a divisional ahead of the eventual February 14, 2017 issuance. Terminal disclaimers were filed in neither the challenged ’740 patent nor the reference ’271 patent. Claim 26 of the challenged ’740 patent is directed to a tartrate salt of pimavanserin and claim 5 of the reference ’271 patent is directed to treatment of hallucinations by administering the tartrate salt of pimavanserin.
Discussion
The main issue is whether the ’271 patent is available as a reference for ODP purposes. To resolve this issue, the parties disputed the interpretation of the safe harbor provision, which is reproduced below for convenience:
If two or more independent and distinct inventions are claimed in one application, the Director may require the application to be restricted to one of the inventions. If the other invention is made the subject of a divisional application which complies with the requirements of section 120 it shall be entitled to the benefit of the filing date of the original application. A patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement, shall not be used as a reference either in the Patent and Trademark Office or in the courts against a divisional application or against the original application or any patent issued on either of them, if the divisional application is filed before the issuance of the patent on the other application. The validity of a patent shall not be questioned for failure of the Director to require the application to be restricted to one invention.
35 U.S.C. § 121.
In particular, the parties disagreed on the application of the requirement that the divisional patent be filed “before the issuance of the patent on the other application” and “as a result” of a restriction requirement when the challenged patent is the original patent versus the patent issuing from the subsequent divisional application.
Acadia advanced an interpretation of the statute contending that there are two types of reference applications: the original application and the application filed following a restriction requirement―and that the “filed before the issuance” requirement only applies to a challenged divisional application, not the original application.
In contrast, MSN argued that the second sentence of the statute defines a divisional application as containing the “other invention” and, as such, is an application filed “as a result” of a restriction requirement, permitting the “divisional application” to be the reference patent only if it is filed as a result of a restriction requirement “before the issuance of the patent on the other application.” MSN also relied on In re Janssen Biotech, Inc., 880 F.3d 1315 (Fed. Cir. 2018), in which a later-filed child patent can invalidate an earlier filed parent via ODP.
The court acknowledged a lack of clear Federal Circuit precedent in resolving the issue, being directed to situations where the challenged patent is the one issuing from the divisional application, which would favor Acadia’s interpretation. See, e.g., Amgen Inc. v. F. Hoffman-La Roche Ltd., 580 F.3d 1340, 1353 (Fed. Cir. 2009) (discussing sheltering of divisional or original application or a patent issuing on any of them from attack if the divisional is filed prior to issuance of the patent in the original application). The court further noted that the Janssen ruling relied on by MSN contains language that the requirement that the divisional application be filed “before the issuance of the patent” requirement applies to the challenged patent, not a reference patent. See Janssen, 880 F.3d at 1323.
Accordingly, the court agreed with Acadia, holding that the statute describes what could be a reference patent, namely the “patent issuing on an application with respect to which a requirement for restriction under this section has been made, or on an application filed as a result of such a requirement,” and the inability to use these documents as a reference against “the original application or any patent issued on either of them” if the divisional application is filed pre-issuance. The court further relied on the intent of Congress in its decision, finding that enacting the safe harbor provision serves to preserve the rights of the inventor and to not harm the inventor or the inventor’s rights following issuance of a restriction requirement. Thus, the requirement that the divisional application be “filed before the issuance of the patent” is inapplicable when the challenged patent issued from the original application.
Next, the court determined whether the reference patent was filed “as a result” of a restriction requirement such that 35 U.S.C. § 121 would provide safe harbor to the ’740 patent. The ’527 application from which the ’271 patent issued was amended from a continuation to a divisional during prosecution. The court relied on Boehringer Ingelheim Int’l GmbH v. Barr Labys., 592 F.3d 1340, 1353-54 (Fed. Cir. 2010), in which related applications that are in consonance with the restriction requirement regardless of how the applications are filed, such as being originally designated as a continuation before amendment as a divisional, can meet the “filed as a result of requirement” for safe harbor protection.
MSN argued that the continuation in the present case was filed before issuance of the restriction requirement and amendment to divisional. The court did not find these arguments persuasive, indicating that these arguments ignore the clear language of the holding in Boehringer Ingelheim, in which how the applications are originally filed and subsequently amended in view of the restriction requirement for safe harbor protection does not matter.
Because the ’527 application was amended to a divisional application in view of the issued restriction requirement in the ’561 application from which the challenged ’740 patent issued, the ’271 patent issuing from the ’527 application was filed within the meaning of the safe harbor provision and the ’740 patent is protected from the ’271 patent being used as an ODP reference.
In the alternative, the court also held that the ’271 patent did not qualify as a reference for ODP because the challenged ’740 patent is the earlier filed patent and the application of ODP would be inverted. Rather than prevent unjustified extension of patent term, an earlier patent term that would be valid but for the later filed reference patent would ultimately be cut short. Claims in challenged patents should be entitled to its full term, including grants of PTA. See In re Cellect, 81 F.4th at 1230.
Because the ’740 is protected under the safe harbor provision from ODP and, in the alternative, the ’271 patent did not qualify as a reference for ODP, the Court granted Acadia’s cross-motion for summary judgment of no invalidity.
Conclusion and Practice Points
This case presented the unusual situation of a later filed and later issued patent being used to try to invalidate the patent issuing from the original application under ODP. Acadia’s successful defense of the ’740 patent against MSN’s ODP invalidity challenge and the Court’s clarification of the interpretation of the safe harbor provision of 35 U.S.C. § 121 demonstrates the viability of a prosecution strategy that relies on the use of divisional applications and the safe harbor provision to ensure that each granted patent within a patent family can be entitled to its full term including any granted PTA.
The In re Cellect decision made it clear that based on the differences in the respective granting statutes, the application of a terminal disclaimer to obviate ODP can cut off any earned PTA awarded to the diligent applicant but not PTE granted following delays in obtaining regulatory approval. Thus, preservation of PTA for patentees is of great interest and importance in the fallout of the Cellect decision and practitioners may have to adopt new strategies for maximizing patent term in view of the ability of a terminal disclaimer to cut off earned PTA.
One proposed strategy for maximizing patent term via preservation of any earned PTA is the presentation of claims directed to multiple, distinct inventions at the initial filing and utilization of subsequent divisional applications following the inevitable issuance of a restriction requirement based on such claims. Because the safe harbor provision prevents citation of the original application against the divisional application as an ODP reference, there should be no issue of ODP in prosecution of the divisional and no need for a terminal disclaimer that would cut off any earned PTA. Acadia presents just one example of this strategy in action, albeit in a more unusual context regarding the use of the later filed and later issuing patent as the ODP reference, in which the safe harbor provision was successfully used to defend against a challenge of ODP, thus preserving 980 days of earned PTA in addition to 1,315 days of PTE following regulatory approval.
For More Information
If you have any questions about this Alert, please contact Thomas J. Kowalski, Deborah L. Lu, Ph.D., Brandon A. Chan, Ph.D., any of the attorneys in our Intellectual Property Practice Group or the attorney in the firm with whom you are regularly on contact.
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