GSK (LSE:GSK) has agreed its largest-ever acquisition, a $10.6 billion purchase of U.S.-based biotechnology company Nuvalent, as the pharmaceutical group seeks to accelerate the rebuilding of its oncology business and strengthen its position against industry leaders such as AstraZeneca and Roche.
The transaction, internally known as Project Nashville, will add two late-stage lung cancer therapies to GSK’s pipeline, both of which could receive regulatory approval in the United States later this year. The company expects the acquisition to be completed during the third quarter.
The move aligns closely with the strategy of Chief Executive Officer Luke Miels, who took over at the start of 2026 and has identified oncology as a key area for long-term growth. GSK exited the sector a decade ago as part of a more than $16 billion asset swap with Novartis, and the company has spent recent years rebuilding its presence in cancer treatment through targeted acquisitions and licensing agreements.
Beyond expanding its oncology footprint, the acquisition is expected to help offset future revenue pressures associated with the loss of exclusivity on HIV treatments, particularly dolutegravir, later this decade. Analysts estimate GSK’s pharmaceutical sales will reach approximately £34 billion ($45.53 billion) this year.
The Nuvalent transaction follows a series of smaller oncology investments, including the $5.1 billion acquisition of Tesaro in 2018, the nearly $2 billion purchase of Sierra Oncology and several multi-billion-dollar licensing agreements.
“Our strategy has been a brick-by-brick building approach,” Miels told a group of journalists on Tuesday after the Nuvalent deal was announced.
A Significant Step in GSK’s Oncology Rebuild
Industry observers view the acquisition as a major milestone in GSK’s return to oncology.
James Eugene, an analyst at GSK shareholder Verso Investment Management, described Nuvalent as “a very large brick” in the company’s broader oncology strategy.
Other investors echoed that assessment.
“The scale is obviously much larger than what GSK has done historically,” said Elena Meng, portfolio manager at Gabelli Funds, which holds U.S.-listed GSK depositary receipts, adding the oncology strategy itself was established.
“What’s new is the size of the commitment.”
According to a person familiar with the transaction, several pharmaceutical companies had shown interest in Nuvalent, helping to explain the roughly 40% premium paid over the biotech firm’s closing share price prior to the announcement.
The source said Nuvalent had attracted attention from large drugmakers for at least 18 months because it was one of a limited number of biotechnology companies with late-stage oncology assets approaching potential regulatory approval.
Rebuilding After an Earlier Exit
For some investors, GSK’s renewed focus on oncology represents a reversal of a strategic decision made in 2015 under former CEO Andrew Witty, when the company chose to leave the sector and concentrate on vaccines, respiratory medicines and consumer healthcare.
The process of returning to oncology began under Emma Walmsley, who became chief executive in 2017 and initiated a series of acquisitions aimed at rebuilding the franchise.
“It was definitely a mistake in 2015 to sell the oncology franchise,” Markus Manns, portfolio manager at GSK shareholder Union Investment, said.
Manns believes the Nuvalent assets offer a lower-risk opportunity capable of generating peak annual sales of between $3 billion and $4 billion, helping to compensate for future declines in HIV-related revenues. He also sees the deal as supporting GSK’s ambition to achieve £40 billion in annual sales by 2031.
Competing in a Crowded Oncology Market
While GSK has no ambition to match the breadth of oncology portfolios maintained by Merck, AstraZeneca or Roche, management sees significant growth opportunities in selected cancer markets. The addition of Nuvalent strengthens that strategy through two advanced lung cancer treatments targeting ROS1-positive and ALK-positive mutations.
“A specialty business without an oncology component is not a complete proposition,” the drugmaker’s chief scientific officer Tony Wood told Reuters before the deal.
The company will now need to demonstrate that the therapies can compete effectively against established treatments marketed by Pfizer and Roche, while also proving favourable tolerability profiles for patients.
Analysts at Barclays said the acquisition appeared strategically sound but noted that neither therapy currently appears to have “mega blockbuster” status.
GSK believes the opportunity could be larger than headline patient numbers suggest if the treatments enable younger and more active patients to remain on therapy for extended periods with fewer side effects than existing options.
Nevertheless, some investors believe further acquisitions may be required for GSK to become a major force in oncology.
“GSK is playing catchup,” said Ketan Patel, fund manager at London-based family investment office Whitefriars, referring to the leadership positions held by Roche and Merck.
“I think they are way behind and unlikely to catch up to those names, and will in all probability have to pay up to play in the same arena.”
