London, June 22, 2026, 15:08 BST
- GSK trades about 0.6% lower near 1,914 pence, lagging a rising FTSE 100.
- FDA grants priority review to neonatal Tivicay PD application, with an August 25 decision target.
- A cluster of regulatory decisions now matters more than the narrow near-term sales effect of the paediatric filing.
GSK plc shares traded lower on Monday even after its HIV unit secured an accelerated US regulatory review for a wider use of Tivicay. The stock, listed as LSE:GSK, was around 1,914 pence in afternoon dealings, roughly 0.6% below Friday’s close, while the FTSE 100 gained about 0.6%.
The muted reaction reflects the size of the immediate opportunity. Extending Tivicay to newborns would close an important treatment gap, but it would not by itself offset the looming 2028 loss of US exclusivity for dolutegravir. HIV remains central to GSK: the division generated £1.8 billion in first-quarter sales, about 24% of the group total, and grew 10% at constant exchange rates.
ViiV Healthcare, majority owned by GSK, said the US Food and Drug Administration accepted its application to extend Tivicay PD to newborns from birth and granted priority review. The agency set August 25 as its target action date. European regulators also validated an application covering neonatal use. A priority review gives the FDA a shorter timetable for medicines considered capable of offering a significant treatment advance.
The filing draws on an international paediatric study and modelling of how infants absorb and process the medicine. ViiV reported target drug exposure in full-term newborns and no new safety findings compared with older children. Jean van Wyk, ViiV’s chief medical officer, said newborns had “historically had the fewest age-appropriate treatment options.”
The more useful market signal is the regulatory calendar forming behind the announcement. GSK won US approval last week for Utebzi, the first oral carbapenem antibiotic cleared for complicated urinary-tract infections. Tivicay’s August date will be followed by expected September and November decisions for two lung-cancer drugs owned by Nuvalent, which GSK has agreed to acquire. That concentration of decisions turns the second half of 2026 into a test of regulatory execution rather than simply quarterly sales momentum.
GSK is paying $10.6 billion for Nuvalent, or about $9.4 billion after acquired cash. The company expects the deal to add to revenue and operating profit in 2027, but not to core earnings per share until 2029. It has warned of low-single-digit percentage dilution to core earnings between 2026 and 2028.
That timing explains some of the market caution. James Eugene, an analyst at shareholder Verso Investment Management, called Nuvalent “a very large brick” in GSK’s oncology rebuild. Elena Meng, a portfolio manager at Gabelli Funds, said: “What’s new is the size of the commitment.” Reuters
The competitive gap is large. Oncology contributed about 6% of GSK sales last year, compared with 44% at AstraZeneca. Nuvalent’s neladalkib would also have to win share against established ALK lung-cancer medicines including Pfizer’s Lorbrena and Roche’s Alecensa.
But the risks run both ways. The neonatal Tivicay application still requires approval, while its limited age extension cannot remove the broader dolutegravir patent pressure. Nuvalent adds debt and near-term earnings dilution before its products have been fully approved or launched, leaving GSK exposed to regulatory delays, weaker-than-expected uptake and pricing competition.
For investors, Monday’s filing is therefore less an earnings catalyst than an early marker in a tightly packed sequence. The stock’s next sustained move is likely to depend on whether GSK can convert those decision dates into launches before the HIV patent cliff begins to bite.
