Summit Therapeutics' stock surges as lung-cancer treatment vies with Merck's blockbuster

By Eleanor Laise

Experimental drug compares favorably against Keytruda in late-stage trial, Summit says

Shares of Summit Therapeutics Inc. (SMMT) jumped more than 270% Thursday after the company said its experimental cancer drug outperformed Merck & Co. Inc.'s blockbuster Keytruda in a late-stage clinical trial.

The trial compared the Summit drug, ivonescimab, with Keytruda in patients with non-small cell lung cancer whose tumors have positive expression of the protein PD-L1. Ivonescimab showed a statistically significant improvement in progression-free survival across patient subgroups, including those with high and low PD-L1 expression, Summit said in a release.

Miami-based Summit said it does not know of any previous phase 3 trials in non-small cell lung cancer that showed a statistically significant improvement over Keytruda in a head-to-head comparison. Summit believes the results are "the beginning of a paradigm change for treatment options for patients living with cancer," Robert Duggan, chairman and CEO, said in a statement.

Lung cancer is the leading cause of cancer deaths in the U.S., according to the Centers for Disease Control and Prevention. Roughly 80% to 85% of lung cancers are non-small cell lung cancer.

Summit said it plans to pursue development of ivonescimab in non-small cell lung cancer as well as other tumor types.

Keytruda, Merck's top-selling drug, generated over $25 billion in sales last year, up 19% from a year earlier.

Merck shares (MRK), which had gained ground earlier Thursday, dropped after the Summit announcement and finished the day down 1.1%.

Summit shares are up 318% in the year to date, while the S&P 500 SPX has climbed 9.8%.

-Eleanor Laise

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05-30-24 1629ET

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