Bristol Myers Squibb (NYSE:BMY) announced its first-quarter results before the market opened on Thursday. The big pharma company did exactly what it needed to, delivering strong growth and handily beating analysts' estimates.

The consensus Wall Street expectation was that BMS would report adjusted earnings of $1.49 per share. The drugmaker's actual Q1 adjusted EPS came in at $1.72, up 56% year over year.

Revenue growth was even more impressive. The average analyst estimate called for Q1 revenue of slightly over $10 billion. BMS reported Q1 revenue of nearly $10.8 billion, an 82% jump from the prior-year period. What fueled this skyrocketing revenue growth? Here are the three top reasons. 

Rocket soaring above a red line trending upward

Image source: Getty Images.

1. The Celgene acquisition

By far the biggest factor driving Bristol Myers Squibb's revenue higher in the first quarter was the acquisition of Celgene. This deal, which closed in November 2019, generated 71% of BMS' year-over-year revenue increase.

The biggest moneymaker that the Celgene deal brought to BMS was Revlimid. Sales for the blood cancer drug in Q1 totaled $2.9 billion. Another blood cancer drug, Pomalyst/Imnovid, generated Q1 sales of $713 million. Solid-tumor drug Abraxane raked in sales of $300 million during the first quarter.

In addition to these blockbusters, BMS has several new products on the market thanks to the Celgene buyout. First-quarter sales for myelofibrosis drug Inrebic were $12 million. Reblozyl, approved by the Food and Drug Administration in November 2019 for treating anemia related to beta-thalassemia and approved last month for anemia related to myelodysplastic syndromes, generated Q1 sales of $8 million. BMS hasn't begun to market recently approved multiple sclerosis drug Zeposia because of the COVID-19 pandemic.

2. Core products

Bristol Myers Squibb delivered 13% year-over-year revenue growth on a pro forma basis that assumes its acquisition of Celgene (and the associated divestiture of Otezla) occurred on Jan. 1, 2019. Several of the company's core products that it had before buying Celgene performed quite well in the first quarter.

Blood thinner Eliquis was the biggest winner, with Q1 sales soaring 37% year over year to $2.6 billion. First-quarter sales for immunology drug Orencia totaled $714 million, up 12% from the prior-year period. Leukemia drug Sprycel generated Q1 sales of $521 million, a 14% year-over-year increase. Sales for multiple myeloma drug Empliciti jumped 17% year over year in Q1 to $97 million.

Perhaps the biggest disappointment for BMS was Opdivo. Sales for the blockbuster cancer immunotherapy slipped 2% year over year to nearly $1.8 billion. The company also continued to experience sales declines for its established brands, including hepatitis B drug Baraclude.

3. COVID-19

Some companies in the healthcare sector saw weaker-than-expected revenue due to the COVID-19 pandemic. Not Bristol Myers Squibb: Its sales increased as a result of the coronavirus outbreak.

BMS said that the pandemic boosted its revenue in the first quarter by around $500 million. Without these added sales, the company's pro forma revenue growth would have been 8% instead of 13%.

What happened? There were some concerns in the early days of the COVID-19 outbreak that supply chains could be disrupted. This led to buyers of some prescription drugs stocking up their inventories. 

Looking ahead

Bristol Myers Squibb continues to expect full-year 2020 revenue between $40 billion and $42 billion. It also still looks for adjusted EPS for the full year between $6 and $6.20. A key assumption in this guidance is that the peak impact of the COVID-19 pandemic will occur in Q2, with business beginning to return to normal in the third quarter.

The drugmaker also has several important pipeline developments on the way. It expects an FDA decision for an Opdivo-Yervoy combo as a first-line treatment for non-small-cell lung cancer by Aug. 6. A decision for liso-cel in treating large B-cell lymphoma is now expected by Nov. 16, after the FDA pushed back its review process by three months. Bristol Myers Squibb also hopes to receive FDA approval for CC-486 as a maintenance treatment of adult patients in remission with acute myeloid leukemia by Sept. 30.