Gilead Sciences' (NASDAQ:GILD) quarterly updates have almost become boring. The biotech's fourth-quarter results announced in February, for example, were similar to results from last year: HIV sales up, with hepatitis C virus (HCV) sales, total revenue, and earnings down.

There were probably few who expected a significantly different story when Gilead announced its 2018 first-quarter results after the market closed on Tuesday. However, this time there was a twist -- a negative one. Here are the highlights. 

Businessman drawing red line pointing downward on top of down-trending bar chart

Image source: Getty Images.

Gilead Sciences' results: The raw numbers

Metric 

Q1 2018 

Q1 2017 

Year-Over-Year Change

Sales

$5.09 billion $6.51 billion

(21.8%)

Net income from continuing operations

$1.54 billion $2.7 billion

(43.1%)

Adjusted earnings per share (EPS)

$1.48 $2.23

(33.6%)

Data source: Gilead Sciences.

What happened with Gilead Sciences this quarter?

It's no surprise why Gilead's sales again dropped significantly: The company's HCV franchise continued to lose ground. For the first time since 2014, Sovaldi didn't even merit a line item in Gilead's quarterly results. Sales for Harvoni plunged 75% year over year to $348 million.

The biggest HCV disappointment, though, was that first-quarter sales for Epclusa dropped 40% year over year to $536 million. AbbVie's Mavyret appears to be stealing a big chunk of market share from Epclusa and Gilead's other HCV drugs. Mavyret emerged as the biggest story in AbbVie's first-quarter results, with the company reporting net HCV revenue of $919 million.

What about Gilead's newest HCV drug, Vosevi? The drug generated sales of $107 million. However, that reflected a 37% decline from the fourth quarter of 2017. There just weren't any bright spots in the first quarter with Gilead's HCV products.

While falling HCV sales were expected (although perhaps not quite as much as what Gilead reported), the company threw a curveball with its HIV franchise results. Overall HIV sales grew, but only by 0.37% year over year.

TAF-based drugs Genvoya, Descovy, and Odefsey continued to enjoy strong momentum. Gilead reported first-quarter sales for Genvoya of $1.08 billion, up nearly 41% over the prior-year period. Descovy generated sales of $361 million, a 44% year-over-year increase. Sales for Odefsey came in at $342 million, nearly 51% higher than the prior-year period.

The problem, though, was that revenue from Gilead's older TDF-based drugs fell by nearly as much as the newer drugs gained. Truvada held up relatively well, with first-quarter sales of $652 million, down almost 9% year over year. However, sales for Atripla, Complera/Eviplera, Stribild, and Viread plunged in the first quarter.

Gilead launched Biktarvy after winning FDA approval in February, but the drug was only on the market for around six weeks during the quarter. Sales for Biktarvy totaled $35 million. 

Three other drugs also saw revenue growth in the first quarter. Sales for angina drug Ranexa jumped 27% year over year to $195 million. Fungal infection drug Ambisome's sales grew 16% over the prior-year period to $107 million. CAR-T drug Yescarta generated sales of $40 million. This was the first time Gilead provided detailed results for Yescarta, which won FDA approval in October for treatment of large B-cell lymphoma.

Looking forward

This wasn't a great quarter for Gilead Sciences. However, the company reaffirmed its full-year 2018 guidance provided in February. Gilead still expects to generate net product sales between $20 billion and $21 billion this year.

There are three things investors can especially look forward to. First, management continues to expect Gilead's HCV market share to stabilize in mid-2018. This stabilization might not help with the biotech's second-quarter results, but it could make a difference in the third and fourth quarters.

Second, Biktarvy's momentum should pick up tremendously beginning in the second quarter. Although some patients will switch from Gilead's other HIV drugs to Biktarvy, the overall impact for Gilead should be positive.

Third, Gilead could use its big cash stockpile to make another acquisition. The company reported $32.1 billion in cash, cash equivalents, and marketable securities as of March 31, 2018. That's down $4.6 billion from the end of 2017 because Gilead paid off term loans for its acquisition of Kite.

Gilead has announced a couple of partnerships recently, including a collaboration with Sangamo Therapeutics to use gene editing to develop cell therapies for cancer treatment and a deal with Alphabet's subsidiary Verily to research immunological and molecular drivers of inflammatory diseases. However, so far in 2018, the biotech hasn't moved forward with a major acquisition. But the potential for one or more deals certainly exists.

Suzanne Frey, an executive at Alphabet, is a member of The Motley Fool's board of directors. Keith Speights owns shares of AbbVie, Alphabet (A shares), and Gilead Sciences. The Motley Fool owns shares of and recommends Alphabet (A and C shares) and Gilead Sciences. The Motley Fool has the following options: short May 2018 $85 calls on Gilead Sciences. The Motley Fool has a disclosure policy.