Ionis, AstraZeneca change a key trial, fueling more questions about a genetic heart disease

Four months after teaming up on an alliance worth as much as $3.5 billion, Ionis Pharmaceuticals and partner AstraZeneca have altered a clinical trial at the center of their deal, announcing Friday plans to extend the size and length of an ongoing Phase 3 study in an inherited heart disease known as transthyretin amyloidosis cardiomyopathy.