GSK plc (LON:GSK) has emerged as one of the most impressive performers in the FTSE 100 healthcare sector over the past year, delivering a share price gain of roughly 43% for investors. The British pharmaceutical and biotechnology company has benefited from strong demand for specialty medicines, expanding oncology treatments, and an increasingly productive research pipeline.

Following the strategic spin-off of its consumer healthcare business, the company has transformed itself into a focused biopharmaceutical and vaccines leader, allowing management to prioritise higher-growth therapeutic areas. Strong financial results, improved profitability, and a clear long-term growth roadmap have all contributed to the stock’s recent re-rating.

This comprehensive analysis examines the key factors behind GSK’s share price surge and evaluates whether the FTSE 100 pharmaceutical giant still offers long-term investment potential.

Company Overview: What Does GSK plc Do?

GSK plc (LON:GSK) is one of the world’s largest pharmaceutical and biotechnology companies, headquartered in London and operating in more than 150 countries worldwide. The company focuses on developing innovative medicines and vaccines to address major global health challenges.

The business is structured around three primary divisions:

  1. Specialty Medicines
    High-value therapies targeting respiratory diseases, immunology and inflammation, HIV, and oncology.
  2. Vaccines
    One of the world’s leading vaccine portfolios, including treatments for shingles, meningitis, and respiratory viruses.
  3. General Medicines
    Established pharmaceuticals addressing chronic and infectious diseases.

The company employs more than 65,000 people globally and continues to invest billions annually into research and development to build one of the industry’s most robust drug pipelines.

A major turning point occurred in 2022, when GSK demerged its consumer healthcare business into Haleon, enabling the company to focus entirely on high-growth biopharmaceutical innovation.

Key Reasons Behind GSK’s 43% Share Price Growth

  1. Exceptional Growth in Specialty Medicines

The largest driver of GSK’s recent performance has been the rapid expansion of its Specialty Medicines division, which delivered 17% sales growth in 2025 to £13.5 billion.

Within this segment, multiple therapeutic areas achieved strong double-digit growth:

  • Respiratory, Immunology & Inflammation: £3.8 billion (+18%)
  • HIV treatments: £7.7 billion (+11%)
  • Oncology portfolio: £2.0 billion (+43%)

These medicines typically command higher margins and longer product lifecycles compared with traditional pharmaceuticals. As the segment expands, it is significantly improving GSK’s overall profitability and growth profile.

Importantly, the diversified nature of the portfolio reduces dependence on a single blockbuster drug — a major risk factor for pharmaceutical companies.

  1. Strong Overall Revenue and Profit Growth

GSK reported total revenue of £32.7 billion in 2025, representing 7% growth at constant exchange rates.

Key financial highlights included:

  • Core operating profit: £9.8 billion (+11%)
  • Core earnings per share: 172p (+12%)
  • Cash generated from operations: £8.9 billion
  • Free cash flow: £4.0 billion

These results demonstrated that the company’s strategy of prioritising high-value specialty medicines and vaccines is translating into stronger profitability and improved margins.

  1. Productive R&D Pipeline and Drug Approvals

Investor confidence has also been boosted by GSK’s improving research productivity.

During 2025, the company secured five major regulatory approvals, highlighting the strength of its late-stage pipeline.

Recent approvals and developments include:

  • EU approval of Exdensur (depemokimab) for severe asthma
  • Expanded use of Nucala (mepolizumab) for COPD treatment
  • Wider approval of Arexvy, the RSV vaccine
  • New infectious disease treatments targeting antibiotic resistance

The company also continues to pursue strategic partnerships and acquisitions to expand its therapeutic reach.

For example, in 2026 GSK announced the $950 million acquisition of biotech firm 35Pharma to strengthen its respiratory pipeline and address pulmonary hypertension.

  1. Strategic Transformation Into a Focused Biopharma Company

The 2022 Haleon spin-off fundamentally reshaped GSK’s business model.

Previously, the company operated a large consumer health division alongside pharmaceuticals. By separating this unit, GSK became a pure biopharmaceutical company, allowing management to:

  • Increase R&D investment
  • Focus on high-growth therapeutic areas
  • Improve operating efficiency
  • simplify corporate structure

The market has increasingly rewarded this strategic clarity with a higher valuation multiple.

  1. Strong Vaccine Portfolio

Vaccines remain a critical pillar of GSK’s long-term strategy.

In 2025, the vaccines division generated £9.2 billion in revenue, supported by strong demand for products such as:

  • Shingrix – shingles vaccine
  • Meningitis vaccines
  • Arexvy – respiratory syncytial virus (RSV) vaccine

Although vaccine demand fluctuates in certain markets, the segment provides stable cash flow and global health exposure, helping balance the company’s specialty medicines business.

  1. Positive Long-Term Growth Guidance

Alongside its 2025 results, GSK reaffirmed its long-term financial outlook.

Management guidance includes:

2026 Outlook

  • Revenue growth: 3–5%
  • Core operating profit growth: 7–9%

Long-Term Target

  • More than £40 billion in annual revenue by 2031

This long-term roadmap provides strong visibility for institutional investors seeking stable compounding returns.

Strategic Growth Drivers for the Next Decade

Several structural trends support GSK’s long-term growth strategy.

Expansion of Oncology Treatments

The company is rebuilding its oncology portfolio with drugs such as Jemperli and Ojjaara, alongside renewed momentum for the cancer treatment Blenrep.

HIV Franchise Leadership

Through its subsidiary ViiV Healthcare, GSK remains a global leader in HIV treatments, including long-acting injectable therapies.

Respiratory and Immunology Innovation

New treatments targeting asthma, COPD, and autoimmune diseases represent major future revenue drivers.

Vaccine Innovation

GSK continues to develop next-generation vaccines addressing respiratory viruses, bacterial infections, and global health threats.

Potential Risks for Investors

Despite its strong outlook, GSK investors should remain aware of several risks.

  1. Patent Expirations
    Pharmaceutical companies regularly face revenue declines when key patents expire.
  2. Drug Pricing Pressures
    Government healthcare systems and insurers increasingly negotiate lower prices.
  3. Clinical Trial Risks
    Drug development carries high failure rates, and unsuccessful trials can damage valuations.
  4. Regulatory Delays
    Approval timelines can be unpredictable across different regions.
  5. Competitive Landscape
    The oncology and immunology markets are highly competitive, with major global rivals investing heavily.

Investment Summary: Is GSK plc a Good Pharmaceutical Stock?

The 43% share price rise of GSK plc (LON:GSK) reflects a company that has successfully repositioned itself as a focused, growth-oriented biopharmaceutical leader.

Key investment highlights include:

  • Rapid growth in specialty medicines
  • Strong vaccine portfolio
  • Improving R&D productivity
  • Clear long-term revenue targets
  • Consistent cash generation and dividends

While pharmaceutical investing always carries risk, GSK’s diversified therapeutic portfolio and strong pipeline suggest the company remains well positioned to deliver steady long-term growth.

For investors seeking exposure to defensive healthcare stocks within the FTSE 100, GSK continues to represent a compelling opportunity.

Frequently Asked Questions (FAQ)

What does GSK plc do?

GSK plc (LON:GSK) is a global pharmaceutical and biotechnology company that develops medicines and vaccines for infectious diseases, HIV, respiratory conditions, immunology disorders, and cancer.

Why has GSK’s share price risen significantly?

The share price increase has been driven by strong specialty medicines growth, rising oncology sales, solid financial results, new drug approvals, and improved investor confidence following the company’s strategic transformation.

What were GSK’s 2025 financial results?

In 2025 GSK reported:

  • Revenue: £32.7 billion
  • Specialty medicines: £13.5 billion (+17%)
  • Core operating profit: £9.8 billion (+11%)
  • Core EPS: 172p (+12%)

What is GSK’s long-term growth target?

The company aims to generate more than £40 billion in annual revenue by 2031, supported by specialty medicines, vaccines, and new product launches.

Is GSK plc the same as GlaxoSmithKline?

Yes. The company was previously called GlaxoSmithKline but rebranded to GSK plc following the spin-off of its consumer healthcare business in 2022.