What You Need to Know About Keryx and Zerenex’s IP – A PropThink Expert Call

PropThink will host an expert interview on Thursday, April 11 (details below) to discuss the intellectual property (IP) position on Zerenex, Keryx Biopharmaceutical’s (KERX) late-stage phosphate binder. The call will feature Intellectual Property attorney and former associate solicitor for the U.S. Patent and Trademark Office (USPTO), Dr. Scott Chambers, and will include a question/answer session for participants. Dr. Chambers will offer his professional opinion regarding Patent Term Extension for Zerenex, and will develop insight into the overall strength of Zerenex’s existing patents.

For Keryx, a major debate on the strength of Zerenex’s IP estate has been ongoing since the company reported impressive Phase III results for the drug candidate in January. Skepticism on the length of patent protection for Zerenex, and the ability of the company to strike a commercial deal with a global drug company or get acquired, has caused the stock to shed 30% from its highs, shortly after the Phase III results were released. The clinical data were, in fact, so compelling that shares of KERX rose sharply when the company priced its equity capital raise in January, despite the added dilution, as investors saw the long-term opportunity for the drug to take significant share in the phosphate binder market while helping to reduce the costs of other expensive and potentially dangerous dialysis treatments. Additionally, the data support that Zerenex has potential to be approved further down the road for pre-dialysis use (Chronic Kidney Disease), a blockbuster opportunity on top of the end-stage renal disease (dialysis) indication initially sought. As a result, a better understanding of the company’s patent position on Zerenex may help investors make good decisions on whether or not to Buy, Sell, or Hold KERX.

Zerenex is a phosphate binder that most anticipate will receive approval for the treatment of hyperphsophatemia in end-stage renal disease (ESRD) patients on dialysis. Game-changing clinical trial results (summarized here) and the company’s SPA (Special Protocol Assessment) with the FDA back the expectation that the drug will, in fact, receive U.S. and international approvals next year. What’s most impressive about Zerenex, however, is the drug’s ability to spare IV iron usage and the use of expensive erythropoietin stimulating agents (ESA’s) like Amgen’s (AMGN) Epogen (and at one point, Affymax’s (AFFY) Omontys).

With the clinical, regulatory, and commercial aspects of the KERX story significantly de-risked, the focus has turned to Zerenex’s intellectual property position and exclusivity potential in the U.S. (no dispute that the drug will have long IP life in both the EU and Japan). The major questions remain: 1) Will Zerenex receive a patent-term extension (PTE) for the ‘706 patent from the U.S. Patent and Trade Office (USPTO)? 2) Are ferric citrate (Zerenex) and ferric ammonium citrate (Ferriseltz) considered related salts and does it even matter with regard to a potential PTE? 3) Will older ferric citrate formulations (allowed as dietary supplements by the FDA before the 1962 Kefauver Harris Amendment, or “Drug Efficacy Amendment”) stand in the way of a term extension for Zerenex? and 4) Are the company’s other Zerenex patents (dissolution and surface area patents) and new patent applications (given the unanticipated Phase III trial results) sufficient to protect the drug beyond the ‘706 patent in the U.S.? (You can read more on these points in our previous report.)

Thus, we believe that clarity on these issues — the strength of Zerenex’s existing and potential patents and the potential to receive Patent Term Extension — will provide both valuable and actionable insight to investors, as strong IP for Zerenex means that KERX has a high probability of entering into a partnership or being acquired in the coming quarters.

With this in mind, PropThink.com has engaged Intellectual Property attorney and former associate solicitor for the U.S. Patent and Trademark Office (USPTO), Dr. Scott Chambers, to evaluate Zerenex’s existing patent estate. We will be hosting a conference call with Dr. Chambers to discuss Zerenex’s potential to receive patent term extension, and the overall strength of the drug’s IP estate. The call will take place on Thursday, April 11 at 11:00AM EDT, will feature a discussion with Dr. Chambers, and will also include a Question and Answer session for participants. The call is open to members of PropThink’s Premium Subscription service, and interested parties can find details and sign up for a free 30-day trial membership by clicking here, or by emailing editor@propthink.com.

Dr. Chambers currently serves as chair of the Intellectual Property Department for the offices of Patton Boggs’, a leading international law firm located in Washington D.C. with a focus on Public Policy and Business Law. Dr. Chambers formerly served as an associate solicitor for the USPTO, where he defended the Office’s patentability determinations and statutory interpretation before the U.S. Court of Appeals for the Federal Circuit and District Court. In his tenure at the USPTO, Dr. Chambers played a role in determining Patent Term Extension for various drug products. He has also drafted Examination Guidelines for the Examining Corps of the USPTO and congressional testimony for the agency regarding biotechnology and patents. Dr. Chambers has served as a frequent speaker on behalf of the USPTO and is a member of the Editorial Board of the Biotechnology Law Report, an advisory Board member for the Patent Trademark and Copyright Journal, and IP Law 360.

Considering his extensive background and involvement in key Patent Term decisions, Dr. Chambers’ opinion carries weight. We believe that this call will offer valuable insight for biotech investors, specifically those interested in Keryx Biopharmaceuticals and the future of Zerenex. Again, details can be found here, along with a sign-up page for interested parties.

In connection with KERX, PropThink has taken a long position.