GSK Passive Income Stock Makes the August ISA Top 10 Despite Patent Headwinds

GSK (LSE: GSK) has been appearing regularly as a passive income stock in the August top-ten most-bought lists on popular ISA platforms, and the reasons for that investor interest hold up under scrutiny. The share price has gained 27% over the past twelve months, putting 250 shares at around £4,705 at the time of writing, versus £3,673 a year ago. The forward dividend yield for the current year sits at 3.6%, which is not a headline number, but the longer thesis is more interesting than that single figure suggests.

What the Q2 2026 Numbers Actually Show

GSK’s Q2 2026 results showed total sales of £8.4 billion, up 5% year-on-year. Specialty Medicines led the way at £3.8 billion, up 14%, while Vaccines contributed £2.3 billion, up 8%. General Medicines fell 9% to £2.3 billion, a decline that captures the core tension in the GSK investment case.

That General Medicines weakness is largely about dolutegravir, GSK’s flagship HIV franchise. Dolutegravir-based treatments generated £1.4 billion in Q2 2026 revenue alone, according to FierceBiotech. The US composition-of-matter patent expires in April 2028, with the European equivalent following in July 2029, per GSK’s own HIV pipeline transcript. The US accounts for approximately 60% of dolutegravir-based revenue, Europe approximately 40%. That cliff is real, and management is not pretending otherwise.

GSK as a Passive Income Stock: The Cost-Savings Bridge

CEO Luke Miels addressed the dolutegravir patent window directly in the Q2 2026 update, saying: ‘To fund investment in the late-stage portfolio and R&D, we are starting a 3-year cost savings programme to simplify the organisation and to reallocate capital and resources. Savings will primarily be reinvested, with some used to improve margins and profitability in the dolutegravir patent expiry period.’

The programme targets £1.9 billion in annual savings by 2029, against expected one-time costs of £2.4 billion, according to Yahoo Finance UK’s reporting on the launch. Approximately 45% of the savings are expected to come from better procurement, per Miels on the Q2 earnings call. Alongside the cost programme, GSK plans to build a new research-and-development centre in Cambridge, moving onto the university town’s biomedical campus, as reported by the Wall Street Journal. The direction of travel is clearly toward reinvesting savings into the late-stage pipeline rather than protecting the near-term dividend.

That raises the obvious question about the payout. Management’s stated position, from the FY 2025 results announcement, is that dividends remain an essential component of total shareholder return, with a progressive policy guided by a 40% to 60% payout ratio through the investment cycle. The full-year 2025 dividend was 66p per share, with 2026 guidance of 70p per share. Analysts forecast dividends to rise 18.7% between 2025 and 2028, which is the kind of compounding rate that changes the income calculus over a five-to-ten year holding period.

There is a £2 billion share buyback programme running alongside the dividend, commenced in Q1 2025, which adds a further layer of capital return. Beyond the patent window, GSK has set a target of more than £40 billion in annual revenue by 2031, per Reuters reporting on recent pipeline activity. The patent expiry years of 2028 to 2030 sit squarely in the middle of that growth trajectory, which is precisely why the cost-savings bridge matters.

Where the Thesis Could Break

The risk is straightforward: if dolutegravir revenue erodes faster than the cost savings materialise, or if late-stage pipeline candidates disappoint, the 40% to 60% payout ratio commitment will come under pressure. Pharmaceuticals development is cyclical in the way that few other sectors are. A drug can take a decade to reach market and carries patent life measured in years, not decades. That structural reality is why GSK suits patient capital more than it suits income investors hunting high near-term yields.

The 3.6% forward yield will not satisfy everyone. But for a long-term holder, the combination of a progressive dividend policy, a £1.9 billion savings programme bridging the patent gap, and a £40 billion-plus revenue target for 2031 represents a coherent, if demanding, set of conditions to track. The next meaningful test arrives when the 2028 US patent expiry hits and the market can see whether the pipeline has genuinely filled the gap.