Here’s Why Mylan Has Something to Be Happy About Today by Lucinda Shen @FortuneMagazine August 24, 2016, 5:30 PM EDT E-mail Tweet Facebook Linkedin Share icons Shares of Teva Pharmaceuticals Industries teva took a dip during trading hours Wednesday, moving as low as 6% off, after a federal agency invalidated two of the patents protecting one of its major breadwinners: Copaxone. The multiple sclerosis treatment accounts for roughly 20% of Teva’s revenue. But on Wednesday, the U.S. Patent and Trademark Office’s Patent Trial and Appeal Board decided to strike down two of the three patents behind the medication, according to Mylan Pharmaceuticals myl , which petitioned, alongside Amneal, to invalidate those patents. The patent board is expected to release its decision for that final patent as well on Thursday. Those three patents, which were set to end in 2030, apply specifically to the 40-milligram dosage of Copaxone, three times weekly. That precise dosage however brought in sales of $3.5 billion in the 12 months ending June, according to IMS Health. According to Bloomberg, Teva has roughly 80% of its patients on that dosage, as cheaper generic versions of the drug from Novartis and Momenta using a lower dosage on a daily basis, are also pressuring sales. For Mylan, the news is likely a welcome relief from the barrage of public criticism directed at the company’s pricing of EpiPens. Shares of the $23 billion pharmaceutical company have plunged 11% since the market’s open on Monday. Though should the final patent backing Teva’s Copaxone fall, Mylan still has to get approval from the U.S. Food and Drug Administration before it can put reap the benefits. Mylan currently is seeking approval for its three times per week, 40 milligram generic version of Copaxone.