The largest-ever rise in the number of active R&D companies, particularly in China, helped propel an unprecedented increase in the size of the biopharma pipeline in 2019.

Biopharma companies struggle with which trials, if any, to pause or delay. Lilly said it wants to ease the burden on health care facilities, while Galapagos said its choice is related to patient safety.

The butterfly effect is an elegant analogy to describe the seemingly unpredictable and far-reaching implications of a relatively small and inconsequential event. The FDA’s approval of Aduhelm is not so much a butterfly gently flapping its wings, but rather a sonic boom emanating from a jet engine. Most immediately, it provides a new therapeutic option for millions of patients in dire need of hope, vindicating Biogen’s faith with a revenue stream running into many billions of dollars. Longer-term the reverberations may be felt across the entire industry, throwing into question the evidentiary requirement for drug development.