With inter partes reviews (IPR) once feared as patent killers, the mere fact that an IPR petition challenging a drug or device patent had been filed with the U.S. Patent and Trademark Office was enough to send a company’s stock tumbling. That initial fear has “kind of ebbed and flowed” over the past 12 years as the patent reviews established by the America Invents Act have come of age, Aziz Burgy, a partner and patent litigator at Axinn, Veltrop & Harkrider LLP, told BioWorld.