It's been an up-and-down kind of year for Bristol-Myers Squibb (NYSE:BMY). Early in 2017, investors were concerned after the company opted not to pursue accelerated approval for a combination of Opdivo and Yervoy in first-line non-small cell lung cancer (NSCLC). Those worries largely evaporated, though, and BMS stock eventually went on to generate nice year-to-date gains.

Now, however, worries are resurfacing. Bristol-Myers Squibb announced its third-quarter results before the market opened on Thursday, with an immediate drop in its share price. Here are the highlights of those results -- and whether investors really need to be concerned this time around.

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By the numbers

First of all, Bristol-Myers Squibb's third-quarter results weren't all bad. The drugmaker reported revenue of $5.3 billion. Not only was that a respectable increase of 7% compared to the prior-year period, but it beat the consensus analysts' estimate of $5.2 billion.

The bottom-line numbers weren't as positive. BMS announced third-quarter GAAP earnings of $845 million, or $0.51 per share, down 29% year over year. Non-GAAP earnings of $1.2 billion, or $0.75 per share, looked a little better. However, the third-quarter result still reflected a 3% decline from the prior-year period and missed the average Wall Street estimate of $0.77 per share.

Bristol-Myers Squibb's updated full-year 2017 outlook was also something of a mixed bag. The company lowered its 2017 GAAP earnings per share (EPS) guidance from between $2.66 and $2.76 to between $2.36 and $2.46. On the other hand, BMS upped its full-year non-GAAP EPS from between $2.90 and $3.00 to between $2.95 and $3.05.

One area where BMS saw clear improvement was in its cash position. The drugmaker reported cash, cash equivalents, and marketable securities totaling $9.65 billion at the end of the third quarter. That's up from $9.09 billion at the end of the second quarter.

Behind the numbers

Let's first address the elephant in the room -- or, rather, in the results. Why did Bristol-Myers Squibb's earnings fall? The GAAP figure dropped mainly because of the company's $310 million acquisition of IFM Therapeutics. This deal is also the primary reason behind why BMS lowered its GAAP earnings outlook for full-year 2017.

However, the IFM acquisition doesn't explain the company's non-GAAP earnings miss. The bottom line (no pun intended) is that BMS simply spent more than it did in the prior-year period. But that spending isn't where you might expect. Marketing, selling, and administrative expenses remained flat at $1.1 billion. Research and development expenses rose, adjusting for the IFM deal but not by a lot. Instead, the main culprit behind lower earnings was a 20% jump in cost of goods sold.

On a positive note, anticoagulant Eliquis and cancer drug Opdivo are flat-out rocking. BMS reported revenue for Eliquis in the third quarter of $1.2 billion -- up 39% year over year. Opdivo's sales came in at $1.3 billion, a 38% increase versus the prior-year period.

Bristol-Myers Squibb's other top brands also performed well. Sales for autoimmune disease drug Orencia grew to $632 million, roughly 12% higher compared to the third quarter of 2016. Cancer drugs Sprycel, Yervoy, and Empliciti all posted solid single-digit percentage year-over-year sales growth. Although revenue for the company's older anti-viral drugs continued to fall, BMS' other products more than offset those declines.