Endo International can’t stop Vasostrict generic
The US District Court for the District of Delaware has ruled that one of Endo International’s pharma units cannot stop a generic of its blood pressure drug Vasostrict (vasopressin injection) from being made.
Endo’s subsidiary Par Pharmaceuticals failed to convince the court’s chief judge Colm Connolly that a planned generic from Eagle Pharmaceuticals would infringe two patents related to the drug.
The memorandum opinion submitted on Tuesday, August 31, found that Eagle did not infringe claims 1, 4, 5 and 7 of US patent 9,744,209 and claims 1, 5 and 8 of the 9,750,785 patent.
Eagle had filed a counterclaim asserting that the two patents were invalid, but as Connolly found that they would not be infringed by a generic, the validity was not addressed.
The court asked that the parties submit proposed orders so it could reach a final judgment by September 10, 2021.
Eagle arguments
Eagle stipulated before trial that its Abbreviated New Drug Application (ANDA) product infringes every limitation of the asserted claims except the pH limitation.
Therefore, the discussion of infringement focused on whether Eagle’s ANDA is “more likely than not” to have a pH between 3.7 and 3.9.
In order to comply with its ANDA specifications, Eagle’s generic version needed to have a pH of 3.4 to 3.6 at the time of its release. Eagle said that it asked the Food and Drug Administration (FDA) to only approve the drug if the pH does not fall between 3.7 and 3.9, therefore a judgment of noninfringement “must necessarily ensue”.
However, Par argued that Eagle’s ANDA had a “drift problem” in which the pH levels tended to rise when stored in refrigerated conditions. It also claimed that Eagle’s original specifications of the drug outlined a pH upper limit of 3.64, just 0.01 pH unit under the range of infringement.
In the short discussion, Connolly said that Par’s claims were “neither undisputed nor correct”, citing pH measurements taken from Eagle’s batches that demonstrated no drift, and said that Eagle was making “too much of too little” in respect to the 3.64 upper limit.
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