What happened Shares of generic biologics developer Coherus Biosciences (NASDAQ: CHRS) rose over 22% today after the the company announced second-quarter 2017 financial results and the filing of a petition to invalidate certain Amgen (NASDAQ: AMGN) patents pertaining to the manufacture of Enbrel. If the United States Patent and Trademark Office rules in favor of the biosimilar company, it could open up a sizable revenue stream. Coherus Biosciences isn't stopping at Enbrel, though. The company had a busy second quarter and, judging by its guidance, expects to keep busy through the first half of 2018 by taking aim at other high-profile blockbuster biologics on the market. As of 11:05 a.m. EDT, the stock had settled to a 16.3% gain. Image source: Getty Images. So what Investors will notice that total revenue for the second quarter of 2017 was just $1.4 million, which is a steep drop-off from the year-ago period, which brought in $14.1 million. The difference can be attributed to an agreement with Shire to market a biosimilar to Enbrel that was terminated in the third quarter of 2016. All marketing rights were retained by Coherus Biosciences, and the company realized, all at once, $162 million in deferred revenue that had built up over time. Things have been slow since. However, the previous agreement with Shire focused on Europe, Brazil, Canada, and other territories, so the new petition announced today is a step toward allowing Coherus Biosciences to market its biosimilar to patients in the United States -- a larger market. The biosimilars developer also reminded investors of progress in the following programs: Neulasta biosimilar candidate: Received complete response letter from the FDA regarding its Biologics License Application, announced completion of talks with Amgen over pricing. Coherus Biosciences expects to resubmit the BLA in the U.S. by the end of 2017 and expects a separate positive opinion in Europe during the first half of 2018. Humira biosimilar candidate: Received ruling from U.S. PTO in favor of its petition to invalidate claims of several AbbVie patents. Coherus Biosciences expects to submit a BLA in the first half of 2018. Now what Coherus Biosciences expects to be working through regulatory issues for its Enbrel biosimilar for much of 2018 and, in a best-case scenario, its Humira biosimilar would hit the market in 2019. The progress is encouraging, but biosimilars are complex drugs, and innovator drug owners such as Amgen and AbbVie have fought hard to keep their monopolies intact for as long as possible. That means investors shouldn't expect progress to happen too quickly. 10 stocks we like better than Coherus BioSciencesWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Coherus BioSciences wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of August 1, 2017Maxx Chatsko has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.