6. GlaxoSmithKline

GlaxoSmithKline's Shingrix took off in 2019, but supply constraints are limiting growth. (Eric Sagonowsky)

2019 revenue: $43.26 billion (£33.8 billion)
2018 revenue: $40.96 (£30.8 billion)
Headquarters: Brentford, United Kingdom

GlaxoSmithKline was among the standout performers for Big Pharma in 2019, and much of its growth came thanks to the expectation-beating launch for shingles vaccine Shingrix.

Since its approval in 2018, the vaccine has performed so well that demand has outstripped supply, limiting the growth potential—for now. Last year, the shot still generated £1.8 billion (about $2.3 billion).

Going forward, GSK expects to make small capacity gains for the shot until a new bioreactor opens in 2024. That will deliver a much larger supply and fuel the global rollout. Until then, GSK execs have said the company is making as much of the vaccine as possible.

Elsewhere in the company’s portfolio last year, pharmaceutical sales were flat at constant exchange rates, while consumer healthcare grew thanks to its acquisition of Pfizer’s unit in August. All told, sales were up 8% at constant exchange rates to £33.8 billion. For conversions, FiercePharma utilized the rates GSK provided in its annual report.

The loss of Advair exclusivity hurt the company during the year, but growth for other respiratory medicines Trelegy, Ellipta and Nucala helped its top line.

RELATED: Glaxo sees enormous Shingrix potential, but a supply gap still stands in the way

GSK’s consumer healthcare spinoff is another ongoing storyline for the company. In late 2018, the company and Pfizer unveiled their plan to join their consumer units for a planned spinoff. And in early 2020, the drugmaker disclosed more details of the plan.

GSK is setting out on a two-year journey toward splitting its R&D-focused business from consumer healthcare. The company has started a strategic review of its dermatology group as well.

RELATED: GlaxoSmithKline's spinoff plan is here—and it may not be limited to consumer health

Like other major pharma companies, GSK is either considering or is in the process of offloading certain units to focus on innovative drugs. Pfizer is a notable peer working to recfocus by merging its Upjohn group with generics giant Mylan. Merck & Co. is also spinning off certain units.

6. GlaxoSmithKline