On Aug. 31, 2021, Delaware court found Vasostrict® patents not infringed in a Hatch-Waxman litigation.

Plaintiffs (Par Pharma / Endo) sued Defendant (Eagle Pharma) for infringement of US 9,744,209 and US 9,750,785 patents expiring on Jan. 30, 2035 as Defendant filed ANDA with USFDA to market generic version. The #785 patent is directed to specified vasopressin compositions and the #209 patent is directed to methods of increasing blood
pressure using such compositions. Both patents require that the vasopressin compositions have a pH of between 3.7 and 3.9. Defendant’s ANDA specification (both release & stability) contains pH of between 3.4 and 3.6. Eagle manufactured 17 batches of its ANDA product, out of which one batch pH was drifting towards 3.7 when stored in refrigerated conditions. After an investigation, it was found that the batch was released at the upper limit of the pH specification, at a pH of 3.64. Therefore, Eagle “optimized” its manufacturing process “to assure tighter control of pH.” Eagle also represented in its ANDA that it will use its optimized manufacturing process to manufacture its ANDA product.

Court said that the principle that an ANDA filer is bound by the representations and specifications in its ANDA is central to the infringement inquiry. And if an ANDA specification describes a product that either necessarily infringes an asserted patent or necessarily does not infringe the patent, the specification dictates the outcome of the infringement analysis. Par argued that pH stability data for the “optimized” batches shows that pH continues to “drift” after release, by as much as 0.06 pH units. But, Court said that the data do not establish that Eagle’s optimized ANDA product has the “drift” problem. Eagle’s optimized manufacturing process achieved its goal of assuring a tighter control over pH. Par is correct that pH measurements for the tested batches varied over the course of the batches’ shelf lives. But this variability does not make it more likely than not that Eagle’s ANDA product will meet the claimed pH limitation. Moreover, Par adduced at trial no evidence from which it could be reasonably inferred that Eagle believes it is not legally bound by the stability pH specification in its ANDA. Par failed to establish by a preponderance of the evidence that Eagle would distribute a generic version of Vasostrict® that does not meet the 3.4-3.6 stability pH specification in its ANDA; and therefore, necessarily, Par failed to prove by a preponderance of the evidence that Eagle’s ANDA product will infringe the 3.7-3.9 pH limitation in the asserted claims.