GSK Acquisition Deal Strains FTSE 100

A $10.6 billion bet on lung cancer therapeutics by GSK rattled the FTSE 100 on Tuesday, dragging the index down 0.3% to close at 10,341 points by 0810 GMT. The pharmaceutical giant’s aggressive play to acquire U.S. developer Nuvalent prompted a sharp investor reaction that outweighed broader market movements.

Editorial·June 9, 2026·reads: 1,110

The acquisition underscores GSK’s intent to secure a stronger foothold in the high-stakes oncology market, where competition for innovative lung cancer treatments is intensifying. While the pharmaceutical heavyweight struggled under the weight of its own expansion strategy, the midcap FTSE 250 index managed to decouple from the slump, posting a modest gain of 0.2%. This divergence highlights a split sentiment between the index-heavy firms and the more resilient, domestically focused mid-tier companies.