Phase 3 readout keeps Amgen in pole position for CGRP migraine drug

Drug is odds on for approval even though data were not "overwhelmingly positive"

Amgen has firmed up its lead in the race to bring the first CGRP inhibitor to market for migraine after presenting positive results from its two phase 3 trials.

The full set of data from the STRIVE and ARISE studies of erenumab (AMG334)—reported at the American Academy of Neurology (AAN) meeting in Boston—don't quite match up the strong clinical benefit seen in mid-stage trials, but leave "no doubt that that erenumab will receive regulatory approval," according to analysts at Leerink who say this could now occur next year.

The data from the two studies were not "overwhelmingly positive," say Leerink's Geoffrey Porges and Bradley Canino,  but clearly show that Amgen's drug is better than placebo when it comes to reducing monthly migraine days and showed that the drug had "excellent safety and tolerability."

In STRIVE, for example, a 70-mg dose of the antibody reduced the number of days in a month with migraine attacks by 1.4 compared to placebo, with a 140-mg dose cutting this measure by 1.9 days. Overall, 60% of people on Amgen's drug experienced a 50% or greater reduction in migraine days.

The analysts suggest the reductions are comparable to those seen with Alder Biopharmaceuticals' eptinezumab in phase 2 but not quite as good as Eli Lilly's galcanezumab and Teva's TEV-48125 in mid-stage testing—with the obvious caveat that no definitive clinical comparison can be made in the absence of head-to-head trials. Phase 3 data on the other three CGRPs is due in the next 12-18 months.

"In our opinion, the data establish CGRP blockade as an effective migraine prevention approach and we believe that as the first-ever mechanism-specific treatment approach, there is a very high probability that erenumab receives regulatory approval," they write in a research note, adding that Amgen has "started ahead [and] finished ahead in CGRP."

In common with comments from analysts at Bernstein made earlier this week when Amgen handed over a larger chunk of marketing rights to partner Novartis, Leerink thinks however that some of the predictions for erenumab peak sales are overblown.

The two analysts are predicting sales could reach $1.5 billion in 2025, an estimate they say is around a third lower than a consensus their peers, but they reckon that "with the right reimbursement and promotion strategy, and strong and coordinated execution by Novartis … and Amgen, this product should become a significant part of the CGRP market."

Last year, Decision Resources predicted that the overall migraine market will grow from approximately $3 billion in 2015 to more than $10 billion in 2025 in the U.S., France, Germany, Italy, Spain, the U.K. and Japan, with the CGRP inhibitors accounting for $4.5 billion of that total.