Analysis: PTO Should Deny Abbott’s Patent Extension for Rapid-Exchange Technology

Doug Portnow, Annie M. Rogaskiand 1 more

October 1, 2008

19 Min Read
Analysis: PTO Should Deny Abbott’s Patent Extension for Rapid-Exchange Technology

At the beginning of July 2008, Abbott Cardiovascular Systems Inc. (ACS), a division of Abbott (Abbott Park, IL), received FDA premarket approval to commercialize its long-anticipated Xience V everolimus-eluting coronary stent system.1 The Xience system is a combination product having four basic components: a cobalt-chromium alloy stent; a delivery catheter; a nonerodible polymer used as the substrate for an embedded drug; and everolimus, an antirestenosis drug.2

Portnow: An important patent.

Shortly after receiving FDA approval, ACS filed an application with the U.S. Patent and Trademark Office (PTO) requesting that the term of U.S. Patent 5,451,233 (the ‘233 patent) be extended under provisions of the Hatch-Waxman Act. The ‘233 patent has been important in the field of interventional cardiology, with disclosure and claims relating to the use of rapid-exchange catheter technology in angioplasty procedures. If ACS's application for patent term extension is granted, it would extend the monopoly of the '233 patent almost three years—until May 24, 2011—which would enable ACS to continue preventing other medical device manufacturers from using the technology during this time. Earlier this month, the PTO granted Abbott a one-year interim extension for its patent while the application undergoes review.

The ‘233 Patent and Rapid-Exchange Technology

The '233 patent is entitled “Angioplasty Apparatus Facilitating Rapid Exchanges,” and is owned by Paul G. Yock, MD, who licensed the patent exclusively to ACS. The '233 patent was filed on March 9, 1994; issued on September 19, 1995; and was set to expire on October 29, 2008.

The ‘233 patent discloses an angioplasty catheter that may be rapidly loaded over and unloaded from a guidewire during an angioplasty procedure (see sidebar, “Guidewire Innovation, from OTW to ‘233”). The innovation described in the ‘233 patent allows a much shorter guidewire to be used during interventional procedures. Because a single physician can manipulate both the catheter and the guidewire, this configuration is termed rapid exchange. This seemingly simple concept has revolutionized interventional cardiology and is now used in 70–80% of all angioplasty procedures performed in the United States . More recently, the technology has also been adopted for use in stent-delivery procedures.

The ‘233 patent discloses the use of rapid-exchange technology in the context of an angioplasty procedure. At least some of the patent's claims may be broad enough to cover other uses, such as the delivery of bare-metal and drug-eluting stents. However, it is important to note that the ‘233 patent does not actually disclose or claim any use other than angioplasty. In fact, the term stent never appears in the patent, nor is drug use suggested. Thus, it does not appear that the inventor contemplated use of rapid-exchange technology for anything other than an angioplasty procedure.

Whether the ‘233 patent ‘claims' the use of a rapid-exchange catheter for delivery of a drug-eluting stent is a key factor in determining whether or not the patent term extension should be granted (see sidebar, “Rationale for Patent Term Extensions”).

ACS's Patent Term Extension Application

ACS' patent term extension request is currently under review by the PTO with cooperation from FDA (see sidebar, “Obtaining Patent Term Extensions”). Because the ‘233 patent was set to expire on October 29, and because the PTO did not expect to make a final determination by that date, an interim extension of one year has already been granted to the ‘233 patent.

It is difficult to predict whether the PTO will grant ACS's request for patent term extension. On its face, ACS's request appears to comply with the procedural requirements outlined in the Hatch-Waxman Act. Furthermore, in a letter from the PTO to FDA dated July 30, 2008, the patent office requested FDA's assistance in determining the regulatory period and the letter concluded by stating that “our review of the application to date indicates that the subject patent would be eligible for extension of the patent term under 35 USC sect. 156.”3

As described below, however, closer examination of this application in view of the Hatch-Waxman Act suggests that the ACS application for a patent term extension should be denied.

Not the First Permitted Use. One of the key provisions for obtaining a patent term extension under the Hatch-Waxman Act is that the regulatory approval must be for “the first permitted commercial marketing or use of the product,” and the application for patent term extension must be submitted within 60 days of obtaining the regulatory approval.4,5 ACS's application for patent term extension was predicated on the recent premarket approval (PMA) of the Xience stent system, which is a combination product consisting of a medical device and a drug component. The device consists of ACS's Multilink Vision coronary stent system or the Multilink Mini Vision coronary stent system coated with a formulation containing everolimus, an antirestenosis drug, embedded in a nonerodible polymer. The delivery catheter comes in either rapid-exchange or over-the-wire configurations. Both Multilink Vision and Multilink Mini Vision systems were preexisting, approved PMA products marketed by ACS prior to approval of the Xience system, and everolimus was also an approved immunosuppressant drug sold by Novartis prior to approval of the Xience system. Thus, the Xience stent system is essentially a drug-device combination of existing, already approved components. Only the drug-polymer portion of this combination product is new—not the stent system that contains the rapid-exchange technology disclosed in the ‘233 patent.

Rogaski: PTO action unpredictable.

If the regulatory approval of Xience was based solely on the device components of the system—that is, the Multilink Vision or Multilink Mini Vision stent delivery system—then clearly these products do not represent the first commercial marketing or use of the product. The Multilink Vision system received FDA approval on July 16, 2003, and the Multilink Mini Vision system received FDA approval on September 10, 2004.6,7 Additionally, any application for a patent term extension based on these products would not have been made within the 60- day window.

If the regulatory approval was based on either the drug component or the system as a whole, then case law helps to demonstrate that ACS's application should be denied. While there are no cases dealing with the exact facts of the present case, existing case law and administrative rules established for drug products support denial of ACS's application.

An FDA frequently asked questions (FAQ) Web page related to drug rules addresses the question of what combination products are eligible for patent extension. It states that:

In combination products, at least one of the active ingredients (including any salt or ester of that active ingredient) of the product must have not been previously approved by the FDA to be eligible for patent extension, based on the approval of the combination product, and then only the patent covering the newly approved component or the combination of components may be extended.8

Because the Xience system includes a previously approved stent, a previously approved rapid-exchange delivery catheter, and a previously approved drug, the combination should not qualify for a term extension. Furthermore, since the ‘233 patent only discloses angioplasty catheters utilizing rapid-exchange technology, it does not cover the approved combination of components, and is therefore ineligible for a patent term extension based on approval of the Xience stent system.

FDA's FAQ guidance is consistent with precedents established by the PTO in other patent term extension applications. In the case In re Alcon Laboratories Inc., for example, a patent term extension was denied even though there was recent approval of a combination drug product.9 In Alcon, the product upon which the extension was sought was a combination drug product (Tobradex) containing tobramycin (A) and dexamethasone (B). Both A and B were previously approved by the FDA, but the combination product (A+B) was not. FDA found approval of the combination product did not warrant a patent term extension. It reasoned that either A, B, or the combination could be a product under Hatch-Waxman, but to be eligible for a patent term extension, the product must also be recited in at least one claim of the patent for which an extension was sought.

This legal interpretation has been followed by the Court of Appeals for the Federal Circuit, which has jurisdiction over patent-related appeals from federal courts.10 In Alcon, only A was claimed by the patent; neither B nor A+B was recited in the claims of the patent. As such, only A could provide eligibility for an extension; but because it had been previously approved by FDA, an extension was denied.

The Alcon decision supports the conclusion that ACS's request for a patent term extension should be similarly denied. Here, the product under Hatch-Waxman could be the device components (A), the drug component (B), or the combination (A+B). But the device components (including the rapid-exchange catheter covered by the ‘233 patent), were previously approved by FDA, and thus do not represent the first permitted commercial marketing or use of the product. Furthermore, because neither the drug component (B) nor the combination (A+B) is claimed by the ‘233 patent, neither makes the ‘233 patent eligible for an extension. Since none of A, B, or A+B provide eligibility for a patent term extension for the ‘233 patent, ACS's application appears to be ineligible for a term extension.

No Time Lost to Regulatory Processes. Even assuming that the Xience stent is an appropriate product on which to base a patent term extension, granting an extension to the ‘233 patent would be contrary to the policy behind the Hatch-Waxman Act, which was originally designed to compensate patent holders for the time lost during regulatory approval of their product. ACS has enjoyed the full benefit of the ‘233 patent, which originally issued in 1995. ACS and its predecessors (i.e., Advanced Cardiovascular Systems and Guidant) have already reaped the benefit of the full ‘233 patent term, so the policies behind Hatch-Waxman do not support an extension of this patent's term.

The ‘233 patent is directed to balloon catheters having rapid-exchange configurations. In addition to the particular medical devices identified in ACS's combination product, which were approved years ago, many other similar stents and balloon catheters have been previously approved by FDA. Rapid-exchange angioplasty catheters have been commercialized by Abbott or its predecessor companies since at least 1990—years before the ‘233 patent even issued. For example, Advanced Cardiovascular Systems received premarket approval for the ACS RX Alpha coronary dilatation catheter on April 20, 1990.11 Advanced Cardiovascular Systems also received numerous other PMA approvals for other rapid-exchange angioplasty catheters after submitting PMA supplements for changes in design, components, or specifications. Abbott Cardiovascular Systems has enjoyed the benefits of the ‘233 patent throughout its entire, unextended term. It lost no portion of its patent term while awaiting FDA approval for any of these products. In fact, ACS's predecessor company, Advanced Cardiovascular Systems, successfully asserted the '233 patent against Medtronic in 2001, obtaining millions of dollars in damages and an injunction.12

Additionally, rapid-exchange balloon catheters have also been used in stent delivery systems for a number of years. Abbott and its predecessor companies have a long history of commercializing rapid-exchange stent delivery systems, including the Multilink Duet, Tristar, Ultra, Tetra, Penta, Pixel, and Zeta coronary stent systems.

Thus, the purposes behind the patent term restoration act would not be advanced by extension of the term of the ‘233 patent. Instead, an extension under these circumstances would unfairly provide ACS a benefit far beyond the policy behind the Hatch-Waxman Act – and contrary to the natural term established under patent law. Therefore, a further extension of the patent, particularly when a component of the approved device covered by this patent was long ago approved, would frustrate the purposes of the Hatch-Waxman Act.

PTO Leaning toward a Bad Precedent. If the extension request is granted, this could establish a precedent that could be used as a new strategy for patent holders to extend the life of their patents. By combining an old existing product with a new feature that requires regulatory approval, a patent holder could potentially extend the life of a patent that was originally intended to cover only the old, existing product. The risk in doing so is, of course, having to deal with the expense and uncertainty of obtaining regulatory approval. While this strategy might work, it would clearly take advantage of loopholes in the Hatch-Waxman Act, and would constitute an abuse of the system that might require legislative action to correct.

Thus, while case law and policy suggest that ACS's application for patent term extension should be denied, the PTO appears to leaning in favor of approving the extension. As previously mentioned, initial correspondence from the PTO has already indicated that “review of the application to date indicates that the subject patent would be eligible for extension of the patent term.” 3 This sentiment appears again in the order granting ACS an interim patent extension of one year. The order states:

The initial USPTO review of the application to date indicates that the subject patent is eligible for extension of the patent term under 35 USC sect. 156. A final determination of the length of the extension of the patent term and issuance of a patent term extension certificate cannot be made until a final determination of the length of the regulatory period is made. Because the original term of the patent would expire before a certificate of patent term extension can be issued, an interim extension of the patent term is appropriate.”13

Thus, it appears as if the PTO will grant ACS's request for a patent term extension, contrary to established precedent. This is expected, especially since the PTO appears to interpret the requirements of Hatch-Waxman broadly. In recent correspondence from the PTO to Congress, the PTO explained its position regarding patent term extensions involving medical devices as follows.

The USPTO construes the claims of a patent to determine whether at least one claim encompasses the approved product. The USPTO interprets a claim as encompassing the approved product if it encompasses either the medical device as a whole, or any component part of the medical device. Based on a strict statutory interpretation of section 156, one may conclude that a patent claiming a component part of a medical device would not be eligible for extension because the patent does not claim the product, where product means the complete medical device. The USPTO does not believe that this was the intent of Hatch-Waxman and liberally construes the statutory provision requiring that a patent claim a product.14

It appears then, that the PTO broadly interprets the requirements of the Hatch-Waxman Act. Competitors may be forced to challenge any extension granted by the PTO in a court action under the Administrative Procedure Act.

Effect of Extending Patent Term on Industry

The ‘233 patent has been successful in preventing competitors from incorporating rapid-exchange technology into their interventional cardiology products. Advanced Cardiovascular Systems, a predecessor of ACS, asserted the ‘233 patent against Medtronic and, since 2000, Medtronic has been enjoined from selling rapid-exchange catheters in the United States. The injunction against Medtronic was set to expire October 29, 2008, when the ‘233 patent would also expire. Any patent extension granted could also extend the injunction against Medtronic.

Barrish: Medtronic on the move.

But on October 21, Medtronic received a favorable decision from the federal court for the Northern District of California, which ordered an end to the injunction on October 29, regardless of the interim extension already granted to ACS. The court held that preventing Medtronic from accessing the rapid-exchange technology for its FDA-approved Endeavor drug-eluting stent system and Driver bare-metal stent system would prevent physicians from obtaining a state-of-the-art medical device and thus be detrimental to the public. Furthermore, ACS could still seek monetary damages from Medtronic for infringing the ‘233 patent.

Medtronic estimates that providing its stents with rapid-exchange technology is worth about two market share points—a significant figure in the $2 billion drug-eluting stent business.15 Medtronic has already issued several press releases indicating the imminent launch of these products.

With the injunction against Medtronic lifted, Medtronic will be able to sell rapid-exchange catheters and will no longer be the last major domestic manufacturer not selling such products. However, if Medtronic does sell these products, ACS can still sue Medtronic for patent infringement. And as expected, ACS did not waste any time in taking legal action against Medtronic. On October 29, ACS filed a complaint in federal court asking for a declaratory judgment and injunction against Medtronic's imminent sale of rapid-exchange. If the suit is successful, Medtronic will remain the only major domestic manufacturer without access to rapid-exchange technology. Other major catheter manufacturers, such as Boston Scientific and Johnson & Johnson, have licenses to the rapid-exchange technology, and would therefore be relatively unaffected by any grant of patent term extension. But it would certainly be to their advantage to keep Medtronic out of the market.

For other, smaller medtech companies, extending the ‘233 patent could be devastating. Some companies have planned the introduction of their new products around the expiration date of the ‘233 patent, and an extension would force them to delay selling product domestically. Other companies might have to redesign products to avoid infringing the ‘233 patent.

Thus it is clear that extending the ‘233 patent could have significant impact on cardiovascular device manufacturers. However, estimating impact is also difficult, especially because this raises another issue of law that is very gray—particularly for medical devices.

The Hatch-Waxman Act specifically states that “the rights derived from any patent the term of which is extended . . . shall during the period during which the term of the patent is extended . . . be limited to any use approved for the product.”16 Thus, if the ‘233 patent is extended, is patent protection limited only to drug eluting stents delivered by rapid-exchange catheters?

Case law is very limited in interpreting this aspect of the statute, but seems to support the notion of some limitations to patent coverage after an extension. In one drug case, for example, the court stated that “the restoration period of the patent does not extend to all products protected by the patent but only to the product on which the extension was based.”17 In another drug case, the court stated that “the ‘rights derived' provision of sect. 156(b) specifically limits the extension to ‘any use approved for the product,' which means that other, (e.g., nonpharmaceutical) uses, are not subject to the extension.”18 Unfortunately, it will take interpretation by the courts to fully understand this aspect of the Hatch-Waxman Act, especially as it relates to medical devices.


U.S. Patent 5,451,233 has been a huge success for Abbott Cardiovascular Systems and its predecessor companies. This patent claims rapid-exchange technology that has become widely adopted in the interventional cardiology field because of its ease of use and operator-friendly nature. The patent in question has been in force for more than 13 years and ACS has fully reaped the benefit of protection provided by the patent. Now, ACS is seeking to extend the term of the patent by nearly three years, based on recent FDA approval of its Xience drug-eluting stent system.

The U.S. Patent and Trademark Office has already granted ACS a one-year interim extension on the patent, and appears to be headed toward granting the requested extension. While the laws for medical devices are somewhat unclear, existing case law and statutory interpretation of the Hatch-Waxman Act suggest that extending the patent term would be improper. Furthermore, granting an extension would militate against the public policy behind enactment of the patent term extension laws, especially since ACS has already enjoyed the full benefit of protection provided by the patent.

It remains to be seen how the patent office will adjudicate this decision, but it's certain that many observers are actively watching and awaiting a final decision. Granting the extension could result in preventing companies such as Medtronic and other smaller manufacturers from incorporating the rapid-exchange technology into their products, although the scope of patent coverage after a term extension is unclear. Moreover, if the patent term extension is granted, it could set a precedent that other patent holders could use as a strategy to unfairly extend their patent terms. Medical device engineers, patent attorneys, and corporate executives anxiously await a final answer.


1. FDA Premarket Approval (PMA) P070015.

2. Xience V Everolimus-Eluting Coronary Stent System, Instructions for Use, sect. 1.0.

3. Letter from Mary C. Till, legal adviser, Office of Patent Legal Administration, Office of the Deputy Commissioner for Patent Examination Policy, U.S. Patent and Trademark Office, to Beverly Friedman, Office of Regulatory Policy, FDA (July 30, 2008).

4. 35 USC sect. 156(a)(5)(A) (2006).

5. 35 USC sect. 156(d)(1) (2006).

6. PMA P020047.

7. PMA P020047, supp. S003.

8. “Frequently Asked Questions on the Patent Term Restoration Program,” in FDA Center for Drug Evaluation and Research, Small Business Assistance [online] (Rockville, MD: Center for Drug Evaluation and Research, FDA, 2008 [cited August 4, 2008]); available from Internet:

9. In re Alcon Laboratories Inc., 13 U.S.P.Q.2d (BNA) 1115 (Commr. Pat. 1989).

10. Hoechst-Roussel Pharmaceuticals Inc. v. Lehman, 109 F.3d 756 (Fed. Cir. 1997).

11. PMA P810046, supp. S067.

12. Advanced Cardiovascular Systems Inc. v. Medtronic Inc., 265 F.3d 1294 (Fed. Cir. 2001).

13. Order Granting Interim Extension to U.S. Patent 5,451,233 (October 10, 2004).

14. Letter from Jefferson D. Taylor, director, Office of Governmental Affairs, U.S. Patent and Trademark Office, to Congressman Howard L. Berman, chairman, Subcommittee on Courts, the Internet, and Intellectual Property, Committee on the Judiciary, House of Representatives (February 8, 2008).

15. M Barris, “Abbott Gets Extension on Its Stent Patent,” Wall Street Journal (October 20, 2008).

16. 35 USC sect. 156(b)(1) (2006).

17. Merck & Co. Inc. v. David A. Kessler, 80 F.3d 1547, 1543 (Fed. Cir. 1996).

18. Pfizer Inc. v. Dr. Reddy's Laboratories Ltd., 359 F.3d 1364, 1361 (Fed. Cir. 2004).

Mark D. Barrish is practice group leader of the mechanical and medical device practice group, Annie M. Rogaski is a partner specializing in intellectual property and complex business litigation, and Doug Portnow is an associate in the mechanical and medical device practice group, at the law firm of Townsend and Townsend and Crew LLP (Palo Alto, CA).

© 2008 Canon Communications LLC

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