Strategies for Extending the Life of Patents

To maximize patent term, seek patent protection for new formulations, new methods of use, and potential combination products.
Mar 01, 2005
Volume 18, Issue 3

Pharmaceutical companies today are faced with increased costs for drug discovery and development and aggressive competition from generic drug companies. As research costs skyrocket, generic drug companies sit poised and ready to compete as soon as a patent expires. Maximizing patent term for successful products is an effective strategy for fending off generic competition and extending product lifecycle. This article will explore strategies for keeping a product under the patent umbrella.

RISING COSTS OF DRUG DEVELOPMENT The costs associated with discovering a compound, turning that discovery into a suitable drug candidate, and getting that candidate to market have risen dramatically. Some estimates indicate that the cost for developing and marketing a single pharmaceutical product has risen from $54 million in the 1970s to greater than $800 million by 2000.1

Figure 1. U.S. Patent Application Process.9
Patent protection and the market exclusivity that comes with it help to ensure a return on investment. A patent holder has the right to exclude others from making, using, and selling the patented invention for a defined period (Figure 1). Therefore, patented drugs are temporarily safe from the competition of generics, often resulting in substantial revenues. For example, US sales for Prilosec in 2000 were over $4 billion,2 and worldwide sales of on-patent Lipitor and Prevacid totaled over $9.2 billion and $2.5 billion, respectively, in 2003.3,4

Table 1. Blockbuster Drugs Facing Patent Expiration10, 11, 12
Over the next few years, a remarkable number of patented "blockbuster" drugs will lose their protection (Table 1). When Eli Lilly's patents for Prozac (fluoxetine) expired in 2001, the concomitant multi-million dollar losses in revenue demonstrated the devastating impact of patent expiration. Table 2 shows three examples of revenue losses following patent expiration.

Table 2. Revenue Losses Following Patent Expiration and Generic Drug Entry13-16
Pharmaceutical companies can employ a number of strategies to maximize patent protection on important compounds, thereby maximizing the commercial lifecycle. During the research and development phase of drug discovery, a company will typically obtain patent protection for the general compound and likely a method of using the compound in the treatment or prevention of a particular disease or condition. Often, additional patents can be obtained to effectively extend patent term and market exclusivity.

Table 3. Strategies for Extending Drug Commercial Lifecycle
Once a compound or pharmaceutical composition has been patented, that patent becomes a prior art reference that must be considered when seeking additional patent protection around the compound or pharmaceutical. As a result, the new patent protection generally encompasses narrow improvements or new uses for the pharmaceutical not disclosed or suggested in the original patent. Strategies for maximizing patent term are summarized in Table 3.

NEW FORMULATIONS One means for extending patent protection for a commercially successful drug is to obtain additional patents covering new formulations of the known compound. Developing and patenting new formulations that promote patient compliance through reduced dosing or ease of use, or that exhibit improved therapeutic outcomes or more-favorable side-effect profiles, is particularly advantageous for defending against generics and protecting market share. Moreover, new formulations, as long as sufficiently similar to the original approved drug, have the additional advantage of a shorter FDA approval route.

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