Purdue Pharma sued Collegium for infringement of U.S. Patent Nos. 9,522,919 and 9,073,933, which relate to oxycodone hydrochloride compositions and formulations. The suit is based on Collegium’s submission of a supplemental New Drug Application seeking approval for revised labeling for Collegium’s Xtampza® oxycodone extended release capsules. Purdue has been pursuing claims against Xtampza® for some time now, beginning in March 2015, and most recently on September 21, 2017, as discussed here.