Prozac lawsuit could have product lifecycle impact
have worrying implications for companies that use reformulation and
drug delivery as a way to extend the patented lifespan of their
drugs.
The EcoJ in Luxembourg has been tipped to side with Israeli generics company Teva Industries in a case seeking to overturn a patent on a liquid formulation of Eli Lilly's Prozac (fluoxetine), a widely used antidepressant, by Advocate General Francis Jacobs.
If this is the case - and advocate generals' opinions are upheld in about 80% of cases by the full court, according to a report in the Wall Street Journal - it would overturn an earlier ruling by the UK authorities that blocked attempts by Teva's UK subsidiary Approved Prescription Services to launch a generic version of fluoxetine in a liquid format.
The UK Medicines and Healthcare products Regulatory Agency (MHRA) ruled in 1999 that Lilly's liquid formulation of Prozac was still covered by formulation patents, despite the fact that the patent on fluoxetine had already expired. Teva appealed to the EcoJ, and if advocate Jacobs' assessment is correct, looks set to win its appeal when the case comes to fruition later this year or early in 2005.
The primary issue is thought to be that the liquid formulation is not sufficiently indistinct from the original dosage form, and so does not qualify as being novel. And the WSJ report suggests that this case could set a precedent in which companies fund it difficult to defend patents based on reformulation.
Martin Paltnoi, and independent patent consultant based in the UK, said that this kind of action is 'the tip of the iceberg'.
"A lot of patents filed by pharmaceutical companies in earlier years will not stand up to scrutiny, particularly as the generic industry is getting more aggressive in seeking out and challenging those that are weaker," he told In-Pharmatechnologist.com.
In this case, he suggested, the key will be the degree of difference in the liquid formulation, but he played down suggestions that the case could signal a weakening of the potential for using re-formulation and drug delivery to extend product lifespan.
"These cases must be considered on their individual merits, but what is clear is that there are a lot of patents - that rest on new formulations, crystal forms or combinations of drugs - that will fail when challenged," he said.
