On July 31 2012 Pamplona Commercial Court No 1 issued a judgment that upheld a revocation action filed by Teva and Cinfa and revoked two of Eli Lilly's European patents: EP584952 - ES2102602 (and Supplementary Protection Certificate 9900002) and EP1438957 - ES2283939. The judgment was served on the parties on September 4 2012.

EP584952 (the parent patent) and EP1438957 (the divisional patent) essentially claim the same invention: the use of raloxifene for the treatment of osteoporosis. These patents protect the main indication of blockbuster drugs Evista and Optruma, which are manufactured by Eli Lilly and commercialised with its consent.

Following the plaintiffs' arguments, the court revoked both patents due to lack of inventive step. Apart from the technical issues of the judgment, the decision is remarkable for two reasons.

First, the court upheld the plaintiffs' challenge against the impartiality and objectiveness of the two bone specialists whom Eli Lilly had appointed as experts. It stated that according to the means of evidence filed by Teva and Cinfa, a conflict of interest existed because the clinicians had developed another drug for Eli Lilly and had acted as consultants for the company. Moreover, the court emphasised that neither expert had mentioned these facts in his reports.

These circumstances did not lead the court to reject the experts' opinion outright; however, the court acknowledged that it had exercised due caution when considering it. The court had previously reached a similar conclusion in a judgment which was issued on July 5 2012. In that case, it upheld another revocation action by Teva, revoking Ortho McNeil Janssen's European Patent EP0566709 (for a combination of paracetamol and tramadol), and acknowledged that it had exercised due caution when considering the expert opinion of one of the specialists appointed by the patentee, since he was a member of a foundation organised by the patent licensee (which was also a party to the proceedings) and had received economic support for research.

Second, the court rejected two alleged technical prejudices at the priority date of the patents, which Eli Lilly maintained would support the inventive step of the claimed invention. The alleged technical prejudices were that:

  • raloxifene has low bioavailability, which would lead an expert to disregard the use of raloxifene to prepare a drug; and
  • if a compound does not produce oestrogenic effects in sexual tissue (which was true of raloxifene), it was thought that it would not produce them in bone tissue.

Following case law from the European Patent Office Boards of Appeal, the court explained that a 'technical prejudice' is an opinion or preconceived idea that is widely or universally held by experts in the field, whose existence must be demonstrated by reference to textbooks or encyclopaedias published before the priority date. This had not been demonstrated; moreover, the plaintiffs had filed certain articles that contradicted the alleged technical prejudices.

The court concluded that the use of raloxifene in the preparation of a drug for treating osteoporosis was obvious to a skilled person in light of a paper by Jordan et al, published in 1987. This paper disclosed the effects of two anti-oestrogens (raloxifene and tamoxifen) in ovariectomised rats, showing that they inhibited the loss of bone density without increasing the risk of uterine cancer.

Eli Lilly can still appeal. However, Teva and Cinfa's generic raloxifene drugs have already been on the Spanish market for several months. In July 2011 a preliminary injunction petition filed by Eli Lilly against Teva was dismissed and is pending appeal (for further details please see "Court dismisses preliminary injunction petition for alleged infringement of raloxifene patent").

For further information on this topic please contact Miguel Gil at Grau & Angulo by telephone (+34 93 202 34 56), fax (+34 93 240 53 83) or email (m.gil@gba-ip.com).

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