Pain relief typically kicked in within two to four hours, according to Vertex, and VX-540 was also associated with manageable side effects, mainly minor complaints like nausea, headache ...

Vertex began researching the drug in the 2000s ... constipation, itching, rash and headache. "The new medication has side effect profiles that are inherently, not only different, but don't ...

The agency approved it based on two Phase III studies showing the drug to be as effective as another combination therapy at improving lung function.