Beaten-up healthcare stocks can rebound in the blink of an eye, making them a great place to look for unusual growth opportunities. Keeping with this theme, I think Bristol-Myers Squibb (NYSE: BMY) and Gilead Sciences (NASDAQ: GILD) are worthwhile long-term buy and holds right now after their disappointing performance this year. Dynavax Technologies Corporation (NASDAQ: DVAX), on the other hand, should probably be avoided following its recent regulatory setback. Here's why. Image source: Getty Images. The market may be overreacting to Bristol's setback in lung cancer Bristol's shares have lost 27% from their highs this year, thanks to Opdivo's flame-out in front-line non-small-cell lung cancer (NSCLC). The long and short of it is that this high-dollar indication could have put Opdivo in the running for the best-selling drug in the world by perhaps 2020. A deeper peek under the hood of this top drugmaker, though, reveals a company that's starting to fire on all cylinders -- despite Opdivo's inability to breakthrough in front-line NSCLC. Turning to the details, Bristol's core group of growth products that includes Opdivo, the blood thinner Eliquis, and the rheumatoid arthritis drug Orencia are all generating double-digit sales growth at the moment, and this trend is expected to carry over into 2017. Equally as important, Bristol has gotten its costs under control, with its non-GAAP operating expenses expected to be roughly flat through to 2020. That's a key issue for a company with a host of newly launched products and a robust clinical pipeline. As Bristol offers a slightly above-average dividend yield of 2.72%, an improving fundamental picture, and a diverse revenue mix, I think this recent sell-off presents a compelling buying opportunity for patient investors. Gilead should be nearing a bottom Gilead has now shed a jaw-dropping $48 billion in value from its high earlier this year, sparked by the hefty decline in its flagship hepatitis C franchise, especially in terms of Harvoni's U.S. sales. Although the biotech sports one of the lowest forward price-to-earnings ratios in the industry at 6.6, the market is apparently punishing the company for its unwillingness to spend at least some of its $30 billion-plus in cash on a tuck-in acquisition -- or perhaps three. And, to be brutally honest, the market's dire outlook may not be entirely unjustified, given that Gilead's pipeline has turned into a factory of sadness this year -- churning out failure after failure. Apart from its pipeline woes and hepatitis C belly-flop this year, Gilead is arguably a classic value story. The core concept is that the hepatitis C market should stabilize in 2017, and the company's multi-pronged approach to the untapped $15 billion non-alcoholic steatohepatitis market is essentially being assigned a valuation of $0 by the market right now. So while it would be nice to see Gilead break with tradition and pay for some much-needed revenue, I think this stock is markedly undervalued based on its strong cash flows, enormous cash position, and fairly broad pipeline that sports several potential blockbusters. Dynavax's value proposition is unclear following Heplisav's latest setback I previously bought into Dynavax's compelling value proposition based on the commercial potential of its experimental hepatitis C vaccine, Heplisav-B. After the vaccine's second FDA rejection in three years, however, I now think this ship has sailed. Image Source: Getty Images. As a refresher, the FDA issued yet another complete response letter for Heplisav's regulatory application last month because of a lack of information on a number of key safety issues and post-marketing commitments. However, Dynavax's management isn't confident that it can address these outstanding issues without a partner -- and they're probably right. First off, Heplisav has now undergone multiple large pivotal-stage trials, which should be more than sufficient to meet the FDA's requirements. So this latest rejection seems to point toward management's inexperience at dealing with regulatory filings in general -- meaning that it may be high time to bring in a partner to push this long-awaited vaccine over the goal line. To do so, though, the biotech is probably going to have to sign away most of Heplisav's revenue in exchange for some modest milestone payments. Worst still, Dynavax isn't exactly in a position of strength from which to negotiate terms, implying that any licensing deal would probably be back-loaded, coming with only a small upfront cash payment. In all, Dynavax is far from being dead in the water, but it no longer offers a rich value proposition that offset its inherent risks. 10 stocks we like better than Gilead Sciences When 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 Gilead Sciences 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 Nov. 7, 2016 George Budwell has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Gilead Sciences. 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