Another newly analyzed secondary end point was the response rate per treatment cycle in PREEMPT. Dr. Dodick reported that 49% of participants responded to the first Botox injection with at 50% or greater reduction in their frequency of headache days per month. An additional 11% achieved this benchmark only after the second treatment cycle, and another 10% did so after the third.
"Just because a patient doesn’t respond to one injection doesn’t mean we shouldn’t try a second. I generally don’t go beyond two nonresponding injections. But don’t stop after one," he urged.
That advice is consistent with the results of an appraisal by the U.K. National Institute for Health and Clinical Excellence (NICE), which deemed Botox for chronic migraine "an appropriate use of NHS [National Health Service] resources," with the proviso that the treatment be stopped if it hasn’t achieved a 30% reduction in the number of headache days per month after two cycles.
THE PREEMPT trials and the new secondary analyses were sponsored by Allergan. Both Dr. Dodick and Dr. Rothrock reported receiving research funds from and consulting for the company.