Summit Therapeutics (SMMT) has seen a significant rise in its stock price, jumping 55% early pre-market, following the presentation of new data on its lung cancer treatment. This development has raised questions about the future of Merck's (MRK) Keytruda, a leading cancer drug. Merck's stock, in contrast, has dropped 4.5% in response to the news. Analysts speculate that Merck may need to consider acquisitions, such as obesity-focused Viking Therapeutics (VKTX), to offset potential revenue losses from Keytruda. Merck needs to replace about 30 billion in revenue by 2030, and there are few companies it can acquire for around 15 billion to meet this target. The market is closely watching how Merck will respond to this competitive pressure.