GSK (LSE:GSK) has spent the past few years rebuilding itself around a clear set of priorities: specialty medicines, vaccines and HIV. The 2025 numbers, published in early 2026, suggest the strategy is working in some areas more clearly than others, with oncology surging and vaccines being the swing Factor for the medium-term outlook. For UK investors, GSK is now one of the more interesting big-cap pharmaceutical names in the FTSE 100.

After the consumer health Business was demerged as Haleon, GSK pitched itself to investors as a more focused biopharma company with deeper exposure to fast-growing therapy areas. The 2025 prints provide some of the strongest evidence to date that this strategy is bearing fruit, particularly in oncology where two drugs in particular have generated outsized growth.

For UK shareholders, the implications cut across both income and growth angles. The Dividend remains a meaningful part of the Equity story, but the path to mid-single-digit Revenue growth and high-single-digit core EPS growth in 2026 also offers something for investors who want exposure to specialty pharmaceuticals through a UK-listed name.

Key takeaways

  • GSK reported 2025 total sales of £32.7 billion ($44.8 billion) at constant exchange rates, up 7% versus 2024, according to the company.
  • Oncology sales grew 43% to just under £2 billion, driven by Jemperli up 89% to £861 million and Ojjaara/Omjjara up 60% to £554 million, as last reported.
  • HIV sales reached £7.7 billion (+11%) in FY2025.
  • Vaccines sales were £9.2 billion (+2%), with Shingrix at £3.6 billion (+8%).
  • GSK declared a Q1 2026 dividend of 17p, with 70p expected for the full year 2026.
  • GSK is guiding 2026 turnover growth of 3% to 5%, with core operating profit and core EPS growth of 7% to 9%, according to the company.

Why investors are watching this FTSE 100 stock

Investors are watching GSK because the company has moved from being seen as a structurally challenged big pharma name to one with a credible specialty medicines growth story. The headline reason: oncology revenue up 43% in 2025, anchored by Jemperli and Ojjaara, and an HIV Franchise that is still expanding despite a competitive landscape. Combined with a long-duration vaccines portfolio, GSK now has multiple distinct growth pillars rather than a single concentrated bet.

At the same time, vaccines are the more nuanced piece of the story. Shingrix continues to grow, but Arexvy and parts of the flu portfolio have faced challenges, including harder-to-reach consumers and competitive pressure. How GSK manages these dynamics will materially influence how investors think about the medium-term picture.

A third reason GSK keeps coming back to investor screens is the pipeline. Bepirovirsen, a potential functional cure for hepatitis B, has had regulatory filings accepted in the US, EU, China and Japan, according to the company, and pipeline-bolstering deals have added ozureprubart in food allergies and HS235 in pulmonary hypertension. Each of those could open up a meaningfully new therapy area for GSK if late-stage development is successful.

Recent share price performance

Where the shares sit now

GSK trades on the London Stock Exchange under the ticker GSK, with an ADR listing in New York under the same ticker. The shares are a core constituent of the FTSE 100 pharmaceuticals sector and tend to trade with reference to clinical pipeline updates, regulatory milestones and quarterly trading results.

The FTSE 100 has two big pharma heavyweights, GSK and AstraZeneca, each with very different therapeutic mixes and pipeline profiles. GSK s recent operational performance has changed the way some investors compare the two, although AstraZeneca remains the larger market cap of the pair.

What has been driving the move

Recent share price moves have been shaped by the strong 2025 results, the 2026 guidance and quarterly updates, including a Q1 2026 update which the company described as a strong start to the year. Investor focus has been on three areas: the pace of oncology growth, the size and trajectory of HIV revenues, and the read-through from Vaccine Demand in the US and elsewhere.

Legal newsflow has also been a periodic driver, with various litigation-related items affecting reported Earnings in some quarters. UK investors have at times had to look through these movements to assess the underlying operating trajectory.

How it compares within the FTSE 100

Within the FTSE 100, GSK is most directly compared with AstraZeneca, the other UK-listed big pharma, and with Haleon, the consumer health spin-out. Internationally, investors benchmark GSK against other global specialty pharmaceutical and vaccine companies. The valuation multiples investors apply to GSK tend to be sensitive to perceived pipeline risk and to specific blockbuster trajectories.

Business performance and earnings

GSK s 2025 performance was led by specialty medicines, with oncology a stand-out. Jemperli (dostarlimab), GSK s anti-PD-1 antibody, reached £861 million in 2025, an 89% increase, according to the company. Ojjaara/Omjjara (momelotinib) in myelofibrosis reached £554 million, up 60%. These two drugs in particular illustrate how GSK has built credibility in oncology after years where the unit was viewed as smaller and less differentiated than its competitors.

HIV remains a major franchise, with sales reaching £7.7 billion in 2025, up 11%. This is significant because HIV had been viewed by some investors as a maturing area, but the 2025 print suggests there is still meaningful momentum in the portfolio. Long-acting injectable products and combination regimens have been part of GSK s pitch for sustained HIV growth.

Vaccines, with £9.2 billion in 2025 sales (+2%), are the more mixed part of the story. Shingrix continued to grow, reaching £3.6 billion (+8%), while Arexvy declined 18% to £0.1 billion in the period reported, reflecting seasonality, harder-to-reach consumers and competitive pressure for influenza vaccines, according to the company. GSK has flagged that activation of harder-to-reach consumers remains a key operational challenge in the vaccines franchise.

In its Q1 2026 results, GSK described a strong start to 2026 with continued momentum in specialty medicines and a reaffirmation of its medium-term outlook. Investors will be watching whether oncology growth can sustain its strong pace and whether vaccines momentum returns through the year.

Reported earnings can also be affected by one-off items such as legal settlements, licensing fees and inventory adjustments, so the underlying core measures management uses to communicate performance are particularly important for analysts trying to model the trajectory. Investors who follow GSK closely typically look at constant-currency growth alongside the reported numbers to strip out FX noise.

On Research and Development, GSK has continued to invest in late-stage Assets across oncology, immunology, HIV and respiratory. The decision to bolt on pipeline assets in food allergies and pulmonary hypertension reflects management s view that selective M&A can complement organic R&D in areas where the existing pipeline is thinner. Each of these areas represents a multi-year Capital commitment, with payoffs that depend on clinical and regulatory outcomes.

Dividends and Shareholder returns

GSK declared a Q1 2026 dividend of 17p per share, with 70p expected for the full year 2026, according to the company. According to publicly available market data, the trailing Dividend Yield has been around 3.4%, with the precise figure varying with the share price. UK investors typically watch GSK for income alongside its pipeline-led growth potential.

The combination of dividend and growth-oriented R&D Investment is a deliberate part of GSK s positioning. Unlike some peers that have focused more aggressively on share Buybacks, GSK has tended to emphasise a steady dividend plus reinvestment into pipeline and bolt-on M&A. That balance is reviewed by the board each year and can be adjusted depending on cash generation and capital needs.

Dividend policy can be reset, and the actual full-year payout depends on the board s discretion, business performance and cash generation. As ever, past distributions are not a reliable guide to future returns.

Valuation and market position

GSK trades at valuation multiples that reflect both its current earnings base and the market s assessment of pipeline risk. Big pharma valuation is heavily influenced by Patent cliffs, late-stage clinical readouts and regulatory decisions, all of which can move multiples significantly in either direction.

In market-position terms, GSK has strong positions in HIV, shingles vaccination, respiratory and increasingly in immuno-oncology and certain rare-disease segments. Pipeline acquisitions completed during 2025 added new best-in-class assets, including ozureprubart in food allergies and HS235 in pulmonary hypertension, according to the company. Bepirovirsen, GSK s potential functional cure for hepatitis B, had regulatory filings accepted in the US, EU, China and Japan.

For investors looking at relative valuation, the question is whether the market is fairly pricing the combination of oncology growth, HIV resilience and vaccines uncertainty. Each quarter brings fresh data points that can swing that assessment in either direction.

Sector trends shaping GSK

Several broad themes are shaping GSK s near-term performance:

  • Specialty medicines mix: Investors prefer specialty franchises with strong patent protection over primary-care portfolios with limited differentiation.
  • Vaccine policy: Vaccine recommendations, particularly in the US, can have significant Volume effects on products like Arexvy.
  • Patent cliffs: As with all big pharma names, future patent expiries on key drugs need to be offset by new launches.
  • M&A and licensing: Pipeline-bolstering deals have become a recurring feature, including GSK s recent moves into food allergies and pulmonary hypertension.
  • Pricing scrutiny: Drug pricing pressure, especially in the US, remains a structural theme for the entire sector.

Risks to watch

GSK has a number of company-specific risks worth following:

  • Clinical trial outcomes: Pipeline drugs can succeed or Fail at late-stage trials, with material implications for forecasts.
  • Regulatory decisions: Approvals, label changes and recommendation updates from bodies such as the FDA, EMA and MHRA can move the stock.
  • Competition: Oncology, HIV and vaccine markets all feature well-resourced peers, and competitive dynamics evolve quickly.
  • Litigation: Pharmaceutical companies face product Liability and other litigation that can carry significant financial implications.
  • Currency exposure: Sterling reporting against a heavily dollar-denominated revenue base can introduce reported Volatility.
  • Manufacturing and Supply: Complex biologic and vaccine supply chains can be affected by capacity, quality and regulatory inspection outcomes.