Participants will be randomly allocated to one of 3 treatment groups: Lu AG09222 high dose, Lu AG09222 low dose, or placebo, in a ratio of 2:1:2.
Researchers are trying to learn whether a drug called Lu AG09222 can help prevent migraine headaches for people who have not been helped by other treatments that are used to prevent migraines.~People who join this trial have tried 2 to 4 other medications to prevent their migraines, but these medications have not helped them.~When the trial is over, researchers will use this information to find out if the number of migraine days decreased more for the participants who got either dose of Lu AG09222 than for the participants who got the placebo.