Drug treatments from Bristol-Myers Squibb (BMY) and Merck (MRK) created to battle lung cancer both topped expectations in lung cancer, the companies said Monday, but Bristol shares plunged after Merck's combination proved to be stronger. Overall survival, although preliminary, was also favorably impacted by the O/Y combination.
If validated by more tests, targeting patients with high TMB could eventually be a way for Bristol-Myers to differentiate itself from its biggest rival, Merck & Co., which uses a different measure.
Merck's Keytruda with chemotherapy showed "practice-changing" results in a study presented at the American Association for Cancer Research meeting. Bristol-Myers said in February that the trial succeeded, but didn't provide specifics. Credit Suisse said before the data were released that Bristol-Myers could fall as much as 6 percent if the results were disappointing.
Bristol-Myers' and Merck's drugs belong to a new class of treatments that help the body's immune system attack and kill cancer cells.
"I don't anticipate there will be any immediate impact on prescribing use or doctors' behavior", said Roy S. Herbst, head of oncology at Yale Cancer Center in New Haven, Connecticut.
While good news for Bristol-Myers, it may not be enough to leapfrog Merck.