Many drugmakers enjoyed banner years in 2020. Amgen (NASDAQ:AMGN) wasn't one of them. Its shares slipped nearly 5%, while the S&P 500 index soared 16%. That loss landed Amgen a spot on the infamous "Dogs of the Dow" list of the Dow Jones Industrial Average's worst performers.

The big biotech announced its fourth-quarter results after the market close on Tuesday. Were those results good enough to provide a spark to Amgen's shares? Not really. Here are the highlights from Amgen's Q4 update.

Scientist looking through a microscope

Image source: Getty Images.

By the numbers

Amgen generated revenue of $6.6 billion in the fourth quarter, up 7% year over year. This narrowly beat the average analyst estimate of $6.58 billion. 

The company announced net income of $1.6 billion, or $2.76 per share, in the fourth quarter based on generally accepted accounting principles (GAAP). This represented a decline from GAAP earnings of $1.7 billion, or $2.85 per share, reported in the same quarter of 2019.

Amgen's story was better from a non-GAAP perspective, though. The biotech reported adjusted non-GAAP earnings of $3.81 per share, up from $3.64 per share in the prior-year period. This result also easily beat the consensus Wall Street adjusted earnings estimate of $3.39 per share.

Behind the numbers

There was both good news and bad news for Amgen in the fourth quarter. Let's start with the bad news.

Sales for the company's top-selling drug, Enbrel, fell 5% year over year to $1.24 billion. Several of Amgen's other products also experienced sales declines, including Aranesp, Epogen, Neulasta, and Parsabiv. Sales for blockbuster osteoporosis drug Prolia also slipped slightly from the prior-year period.

The good news, though, was that quite a few of Amgen's relatively newer products performed well. The biotech's biosimilars ranked near the top of the list, with sales for Amjevita, Kanjinti, and Mvasi soaring 45%, 53%, and 233%, respectively. The biggest newcomer for Amgen, though, was Otezla, which the company acquired from Celgene in November 2019. Sales for the autoimmune totaled $2.2 billion.

However, some of Amgen's newer drugs didn't deliver sizzling growth. For example, sales of migraine drug Aimovig and osteoporosis drug Evenity climbed only 6% year over year.

Looking ahead

Amgen expects that revenue for full-year 2021 will be between $25.8 billion and $26.6 billion. The company anticipates GAAP earnings per share (EPS) of $12.12 to $13.17, with adjusted non-GAAP EPS between $16.00 and $17.00. This guidance wasn't overly impressive, which explains why shares of the biotech slipped in after-hours trading on Tuesday despite Amgen's revenue and earnings beats.

There probably won't be a big sales boost in the first quarter. Amgen stated that it anticipates lower Q1 sales for Aimovig, Otezla, and Enbrel due to the impact of benefit plan changes, reset deductibles, and other factors that are standard for early in each year.

Perhaps the best chances for catalysts for the biotech stock will come from its pipeline progress. Amgen hopes to win regulatory approvals for sotorasib in treating non-small cell lung cancer and for Repatha in treating pediatric patients with rare genetic disease heterozygous familial hypercholesterolemia. The company also plans to submit for regulatory approvals for tezepelumab in treating severe asthma and for Otezla in treating plaque psoriasis.