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GSK Stock Down 14% in Six Months: Time to Buy, Hold or Exit?

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Key Takeaways

  • GSK's Specialty Medicines sales rose 14% in the first half of 2026, led by broad therapy-area growth.
  • Dolutegravir's 2028-2029 LOE threatens potential sales from key HIV products.
  • GSK expects more than 20 Phase III starts in 2026 as it expands investment in oncology and respiratory drugs.

GSK (GSK - Free Report) shares have lost 13.8% in six months despite solid underlying operating performance. Although second-quarter core sales rose 5%, core operating profit increased 7% and 2026 guidance was reaffirmed, GSK’s stock weakness over the past six months largely reflects investor concerns about the company’s medium-term growth outlook.

The approaching dolutegravir loss of exclusivity (LOE) during 2028–2030 threatens a major source of GSK’s highly profitable HIV revenues and raises questions about how quickly newer products can replace the lost sales. The company also faces continued declines in General Medicines. Pipeline setbacks also raise concerns, such as the recent discontinuation of camlipixant.

The pullback in GSK shares may leave investors wondering whether to exit the stock, hold their positions, or use the dip as an opportunity to accumulate more shares.

Let's discuss GSK’s strengths and weaknesses in detail to better understand how to play the stock in such a scenario.

GSK Specialty Medicines Unit Drives Top-Line Growth

GSK is witnessing increased sales growth of its Specialty Medicines unit, particularly reflecting successful new launches in Oncology and long-acting HIV medicines. Sales are rising in all areas: HIV, Respiratory, Immunology & Inflammation (RI&I), as well as Oncology. Sales of the Specialty Medicines unit rose 14% at CER in the first half of 2026, driven by double-digit growth in all therapy areas — HIV, RI&I and Oncology.

In the segment, while products like Nucala, Dovato and Benlystaare key top-line drivers, new long-acting HIV medicines, Cabenuva and Apretude, as well as new oncology drugs Jemperli and Ojjaara, are also witnessing strong patient demand and contributing to top-line growth.

GSK’s long-acting injectable medicines (Cabenuva, Apretude) are seeing strong demand trends. Around 25-30% of GSK’s total HIV sales come from new long-acting injectables for treatment and prevention.

In 2026, the company expects sales in the Specialty Medicines segment to rise in a low double-digit percentage at CER. Specialty Medicines, which now accounts for more than 40% of GSK’s sales, is expected to be more than 50% of GSK’s total revenues by 2031.

GSK’s New Drugs & Promising Pipeline Key to Long-Term Growth

GSK’s recent launches and approvals are broadening its growth base, with Blenrep, Exdensur, Ojjaara, Apretude and Penmenvy among the key newer products. In 2026, approvals for Jideytro, Utebzi and Lynavoy added further growth opportunities. Blenrep is expected to be a major growth driver over the next 3-4 years.

GSK is increasing R&D investment in promising new long-acting and specialty medicines in RI&I, Oncology and HIV areas. The company claims it has more than doubled the number of phase II and phase III assets with blockbuster potential since 2022.

GSK is significantly increasing the number of phase III starts in 2026. It now expects more than 20 phase III starts in 2026, more than twice the 10 originally contemplated. Oncology, respiratory and hepatology account for much of the incremental investment.

Regulatory applications seeking approval of bepirovirsen for chronic hepatitis B and neladalkib, an ALK inhibitor for non-small cell lung cancer (NSCLC), are under review in the United States and some other countries. FDA decisions on both are expected later this year.

Some key pipeline candidates in late-stage development are efimosfermin for metabolic dysfunction-associated steatohepatitis or MASH, velzatinib for second-line gastrointestinal stromal tumor and antibody drug conjugates risvutatug rezetecan and mocertatug rezetecan for some cancer indications.

GSK is also developing innovative ultra-long-acting HIV regimens for treatment and prevention (also called PrEP), which can extend the dosing intervals of the injections. GSK expects to launch twice-yearly long-acting injectables for treatment and PrEP between 2028 and 2030. GSK is also conducting studies to evaluate the use of Blenrep combinations in early treatment lines through the DREAMM clinical program.

In 2025, GSK strengthened its pipeline, particularly in RI&I and oncology, through 10 M&A deals. The positive trend of M&A deals continued in 2026 with acquisitions like 35Pharma and Nuvalent.

Supported by its new product launches and robust pipeline progress, GSK expects sales to be more than £40 billion by 2031.

Upcoming LOE of Dolutegravir

Patents protecting dolutegravir, which is the backbone of several of GSK’s leading HIV medicines, including Tivicay, Triumeq and Dovato, are expected to begin expiring in major markets around 2028-2029, opening the door for generic competition. GSK’s dolutegravir-based products generated £2.74 billion of sales in the first half of 2026. It remains to be seen if GSK can grow its long-acting HIV franchise and next-generation pipeline quickly enough to replace the potential lost revenues due to dolutegravir LOE.

General Medicines is Becoming a Drag

Sales in GSK’s General Medicines segment declined 7% in the first half of 2026 due to ongoing generic erosion and competitive pressure across mature respiratory and other established products. Sales of key drug Trelegy Ellipta declined 3% in the first half of 2026 due to Medicare benefit design changes and unfavorable pricing/channel mix pressures. GSK expects this business to decline by mid-single digits to low-single digits in 2026

GSK’s Price Performance, Valuation & Estimate Movement

GSK stock has risen 2.5% so far this year compared with the industry’s growth of 13.9%.

GSK Stock Outperforms Industry

Zacks Investment ResearchImage Source: Zacks Investment Research

GSK stock is trading at an attractive valuation relative to the industry. Going by the price/earnings ratio, the company’s shares currently trade at 10.12 on a forward 12-month basis, lower than 18.69 for the industry. The stock, however, trades above its 5-year mean of 9.92. The stock is much cheaper than several other large drugmakers like Eli Lilly (LLY - Free Report) , Novo Nordisk (NVO - Free Report) , AbbVie (ABBV - Free Report) , J&J, AstraZeneca and others.

GSK Stock Valuation

Zacks Investment ResearchImage Source: Zacks Investment Research

The Zacks Consensus Estimate for earnings has declined from $4.84 to $4.80 per share for 2026, while that for 2027 has declined from $5.15 to $5.05 per share over the past 30 days.

Estimates for GSK

Zacks Investment ResearchImage Source: Zacks Investment Research

Stay Invested in GSK Stock

In addition to the upcoming LOE of the dolutegravir HIV franchise and pricing and generic pressures in GenMed, GSK faces its share of pipeline setbacks. Among more recent pipeline setbacks, in July 2026, GSK discontinued development of camlipixant in chronic cough as the CALM-1 and CALM-2 pivotal studies demonstrated limited efficacy. Estimates have declined recently due to costs related to the Nuvalent acquisition, which closed in July.

However, the company is consistently growing its sales and profits, mainly driven by its fast-growing Specialty Medicines segment. The HIV business is seeing strong momentum while oncology continues to grow. Vaccine sales in the United States have also improved in 2026 after its sales declined in 2025. Its pipeline depth is another key strength, with several late-stage programs across vaccines, respiratory diseases, infectious diseases, oncology and immunology.

We suggest investors who own this Zacks Rank #3 (Hold) stock stay invested for now, considering the potential for steady sales and profit improvement in the coming years. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

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