Amgen's migraine drug gains momentum in a crowded race

Amgen ($AMGN) says that its experimental migraine drug boosted its response rate among patients over a full year of therapy, a little bit of an edge that could help it compete against a group of rivals now hustling ahead with pivotal studies.

After 52 weeks, says the Big Biotech, 70 mg of AMG334 cut the number of migraine days per month by 4.9 in a Phase II study, working off a baseline average of 8.7 mean monthly migraines. That's a step up from the 3.4-day reduction seen at week 12, which produced about a one-day benefit after factoring in the placebo response of 2.28 days. There was no placebo arm in the open-label extension study.

"We did observe a numeric improvement in the reduction of monthly migraine and responder rates from weeks 12 to 52, and demonstrated that there is no "wearing off" effect with prolonged treatment," noted Rob Lenz, Amgen's global development lead for AMG334, in an email to FierceBiotech. "It is not certain what the underlying explanation is for this trend of increasing effect over time, but this will be formally tested in a Phase III study, which has a 6 month double blind period. In the current study, subjects can continue receiving monthly injections of AMG 334 for up to 5 years in that trial, and we will conduct additional analyses at later time points (e.g. 18 month, 2 year) once sufficient numbers of subjects have reached those time points."

None of this, though, is happening in a vacuum. A couple of days ago Teva ($TEVA) noted that its migraine drug TEV-48125 had achieved a near 6-day reduction, working with a patient group that had a much higher baseline and an average placebo response of 3.34 days. At 225 mg, Teva's drug registered a 2.8-day improvement for migraine sufferers. As Evercore ISI analyst Umer Raffat noted, that rate easily beat out Amgen's earlier number, along with improvements over a rival drug from Alder Biopharmaceuticals ($ALDR) as well as Eli Lilly ($LLY), which plans to spell out its data on Saturday.

With so many companies all competing in the same field with comparable drugs, the race is on to see which therapy is the best. They may all be approvable, but these companies are clearly already considering pricing as payers look to leverage the competition for lower prices.

All of these companies have touted mid-stage successes with the same class of drug. They've been working with antibodies that tackle calcitonin gene-related peptide (CGRP), a chemical that influences the pain signaling linked to migraines and cluster headaches. There's also been earlier-stage research to suggest other drug targets that may eventually prove more effective than CGRP. 

Amgen also reported that 62% of the AMG334 patients demonstrated a greater than 50% reduction in migraine days at 52 weeks, with 38% getting a 75% or better response and one in 5 declaring that they were free of migraines.

Amgen is moving on into Phase III later this year, according to a spokesperson.

- here's the release