Amgen's Aimovig, under fire from Lilly, loses grip on CGRP share

Amgen had a head start with its first-to-market CGRP launch Aimovig, but its rivals are giving the company some fierce competition.

As of the week ended Aug. 23, Aimovig now holds less than half of the total CGRP market, a first for the drug. In recent weeks, it had been hovering at or above 50%.