Hatch-Waxman litigation is back on the rise, particularly in the U.S. District Court for the District of Delaware, according to Lex Machina’s annual report on litigation involving generic drugs.

Suits filed in response to Abbreviated New Drug Applications (ANDA) were a pocket of strength in an otherwise declining patent litigation landscape. ANDA suits rose 29 percent to 417 in 2017, though that number remains below the 2015 peak of 475 suits, according to the report.