The Life Cycle of a Drug: Effexor XR

Pfizer's wholly-owned Wyeth subsidiary owned the original compound patent for venlafaxine hydrochloride (Effexor XR). This patent expired in 2008, but the company had filed a series of patents as explained in my post, Proprietary Drug Patents. with the aim of extending their patent monopoly to 2017. In 2002, Teva was the first generic manufacturer to file an abbreviated new drug application for the equivalence of their extended-release venlafaxine hydrochloride to the brand name product. In 2005, Wyeth entered into a pay-for-delay agreement with Teva to delay marketing of their generic until 2010. Among other things, Wyeth agreed to delay marketing an authorized generic until Teva's marketing exclusivity period for its generic ended. As is typical, this settled all the litigation between Wyeth and Teva. Wyeth also agreed to resolve any later litigation about the unenforceability or noninfringement of its follow-up series of drug development patents.

The above description is typical in the US. What is atypical is that a complaint in federal court alleging fraud by Wyeth and Teva has since been filed. Thanks to Don't trade out lives away for posting on this subject with links to the complaint and Reuters' announcement of the suit. The Incidental Economist's Kevin Outterson also has a post with links to the Federal Trade Commission's report on the consumer cost of pay-for-delay deals and an academic paper on the subject. Pfizer and Wyeth emphasize that they have engaged in a typical process that is lawful in the US. Perhaps the process is about to change?

Compulsory Licensing of Proprietary Drugs

Compulsory licensing is the process by which a country such as India grants a license to produce a patented proprietary drug without the consent of the patent holder. A provision of Indian patent law is that a compulsory license may be granted three years after a patent has been granted. The first case involves Natco Pharma, an Indian generic drug manufacturer, and Pfizer, the patent holder for maraviroc. As far as I can tell from searching the Internet, this case is still at the stage in which Natco requests a voluntary license from Pfizer. There was supposed to be a response from Pfizer by May 2011, and a negative response is expected. If someone has factual information on the status of this case, please share it.

Since this first case, it is now a matter of public record that Natco has applied for a compulsory license for Bayer's sorafenib. If you like you can skip to PDF p. 16, item 7 of the application.

Today's post is a continuation of my post Proprietary Drug Patents.

Proprietary Drug Patents

Drug life cycle management involves the US patent system, since sales of brand name drugs are mostly increased by patent extension strategies. These strategies work because the number of items related to a proprietary medicine that are considered novel and therefore eligible for patent monopoly protection increased from five in the 1980s to 18 in the 1990s. After the initial patent grant, the patent holder immediately starts work on these items, resulting in a series of overlapping 20 year intellectual property monopolies that delay the market entry of lower-priced generic versions of the brand name drug. People who see this as an abuse of the patent system's intent view it as one of the legal and business strategies that are included under the title evergreening. The pharmaceutical industry has strong objections to even the use of this term, and you can read them in the PDF version of GlaxoSmithKline's policy position paper of August 2011. Judge for yourself, I will only add a link to a couple of case studies that present more common scenarios than the case study presented by GSK.

Patent law is an international affair of numerous agreements, but the patent systems of other countries nevertheless illustrate alternatives to the US system. India is a country with a strong generic drug industry noted for sale of inexpensive medications to poorer nations because their patent law is designed to prevent patenting minor changes in medications or patent extensions. Novartis has been battling the Indian system and is about to go to trial again in the Indian Supreme Court because a patent for a new salt form of its cancer drug Gleevec has been denied because of patent office and court rulings that the new form of the drug is not any more effective than the old form. This is an entirely different standard than those applied in the US. The Indian court system has already ruled that this standard does not conflict with The Agreement on Trade Related Aspects of Intellectual Property Rights.

The Life Cycle of a Drug: Pediatric Exclusivity

The Life Cycle of a Drug: Pediatric Exclusivity - Update

The Life Cycle of a Drug: New Indication

Off-Label Drug Use: The Good, The Bad, and the Inexcusably Ugly

The Life Cycle of a Drug: New Formulation