On December 9 2016 Barcelona Commercial Court Number 4 dismissed the action filed by Bayer Pharma AG, Bayer Intellectual Property GmbH and Bayer Hispania SL (collectively, 'Bayer') against several generic drug companies, in which they alleged infringement of two patents claiming manufacturing processes for the active ingredient drospirenone.


Drospirenone is a contraceptive drug which, in combination with ethinyl estradiol, is commercialised by Bayer as Yasmin® and Yasminelle®.

The asserted patents were:

  • EP1149840 (EP'840), owned by Bayer Pharma; and
  • divisional patent EP2168974 (EP'974), owned by Bayer Intellectual Property.

Bayer Hispania is a non-exclusive licensee of the patents in Spain.

Both patents are in force until August 11 2017 and claim manufacturing processes for the active ingredient drospirenone:

  • EP'840 claims a process in which p-toluensulfonic acid is added to a particular starting compound (5-β-OH-DRSP) to obtain drospirenone; and
  • EP'974 claims a process in which the same starting compound in an isolated form is dehydrated to obtain drospirenone.

On July 3 2014 Bayer sued several generic drug companies for alleged infringement of EP'840 and EP'974.

During the first years of their commercialisation, generics contained drospirenone manufactured by way of two processes (Process 1 and Process 2). At present, they contain drospirenone manufactured by a third process, which has not been challenged.

In Processes 1 and 2, a mixture of 5-β-OH-DRSP and drospirenone was used as a starting material, to which p-toluensulfonic acid (Process 1) or pyridine and water (Process 2) were added to obtain drospirenone.

According to Bayer, Process 1 infringed EP'840, as the same starting compound (5-β-OH-DRSP) and the same reagent (p-toluensulfonic acid) were used. Process 1 was abandoned before EP'974 was granted.

Further, Bayer alleged that Process 2 also infringed EP'840, as – in its view – the use of pyridine was equivalent to the use of p-toluensulfonic acid (resulting in infringement under the doctrine of equivalents).

Bayer also alleged that Processes 1 and 2 infringed EP'974, as – in its view – they used 5-β-OH-DRSP in an isolated form as a starting material.

In turn, the defendants alleged that the claims of EP'840 and EP'974 must be interpreted in light of the patent descriptions, and that the starting compound (5-β-OH-DRSP) should therefore be deemed to be free of drospirenone (EP'840) and drospirenone and impurities (EP'974). Thus, the defendants alleged that Processes 1 and 2 fell outside the scope of Bayer's patents, as they used a mixture of 5-β-OH-DRSP, drospirenone and impurities.

With regard to the non-infringement of EP'840 by Process 2, the defendants also argued that the use of pyridine and water cannot under any circumstances be deemed an equivalent substitution of the use of p-toluensulfonic acid.

Alternatively, and only if the court followed Bayer's broad interpretation of the patents, the defendants alleged that the patents were invalid.


In its judgment, which was deliberated by the three patent judges, the court upheld the defendants' arguments. It based its decision mainly on the following grounds:

  • When determining the scope of protection conferred by a patent, claims must be interpreted in light of the patent's description.
  • In light of the above, Process 2 did not infringe EP'840. Further, pyridine and p-toluensulfonic acid cannot be regarded as equivalents.
  • The 5-β-OH-DRSP in isolated form element of EP'974 should be construed as being free of drospirenone. Therefore, Processes 1 and 2 did not infringe EP'974, as they did not use the same starting material.
  • Claim 1 of EP'840, interpreted according to the description, protects a process for the manufacture of drospirenone in which the starting compound (5-β-OH-DRSP) must be free of drospirenone.
  • Process 1 did not infringe EP'840, as p-toluensulfonic acid is added to a mixture of 5-β-OH-DRSP and drospirenone.

In addition to the above, the court confirmed the argument raised by the defendants that Bayer Hispania has no legal standing to sue, as it is not an exclusive licensee of the patents.

Overall, the court dismissed Bayer's infringement actions, awarding legal costs in favour of the defendants.

Bayer can appeal the judgment before the Barcelona Court of Appeal.

For further information on this topic please contact Ignacio Pontijas at Grau & Angulo by telephone (+34 91 353 36 77) or email ([email protected]). The Grau & Angulo website can be accessed at www.gba-ip.com.