Alder CEO Randall Schatzman

Alder Therapeutics ($ALDR) posted positive--and competitive--data for their Phase IIb study of a new CGRP drug for migraine, keeping it in the hectic race aimed at coming up with the first new drug approval in the crowded space. And investors responded by driving up Alder shares by 55% in early trading this morning.

The Bothell, WA-based biotech says that their 300-mg and 100-mg doses of an intravenous injection of ALD403 reduced the average number of migraines 75% among 33% and 31% of the patients taking those two doses, respectively, hitting the primary endpoint in the trial. And the developer added that their data indicate that the drug can be given on a quarterly basis, making it competitive with some major league rivals in the field now positioning themselves for the market.

Their two doses, along with a 30-mg group, also hit a secondary endpoint for an immediate and durable drop in migraine days from the start of the 12-week study period. And 8%, 5% and 4% of the 300-mg, 100-mg and 30-mg drug arms were free of migraines through the quarter. A 10-mg dose was judged subpar.

"Evaluation of ALD403 continues to exhibit a potential best-in-class profile, which includes immediate, significant and durable migraine prevention with infrequent quarterly dosing," said CEO Randall Schatzman in a statement. "Today's data also support our quarterly dosing strategy via a single intravenous, subcutaneous or intramuscular injection. With our commitment to the accelerated development of ALD403 reinforced by today's positive results, we look forward to advancing our development plan, and assuming FDA approval, independently marketing ALD403 in the U.S. to meet the critical medical needs of the 13 million patients nationwide who are candidates for migraine prevention therapy."

Little Alder is likely going to face some heavyweight competition with its drug. Teva ($TEVA) already posted positive Phase IIb data from their study of the CGRP therapy TEV-48125. Eli Lilly (LY2951742) and Amgen (AMG334) are also racing along with their own late-stage efforts, as everyone looks to drugs that target calcitonin gene-related peptide, or CGRP, a chemical involved in inflammation and pain signaling.

As often happens in a Phase III showdown, the developers are already trying to position themselves with better dosing schedules and easier administration. To that end, Alder reported some encouraging bioavailability numbers for a subcutaneous version of their drug. But as ISI Evercore's Umer Raffat notes this morning, the data don't align neatly, as the developers produce a mixed bag of results on headache days, migraines and more, using different standards on the severity of the migraines being treated.

"TEVA reported their data on a monthly basis," notes Jefferies' Brian Abrahams, "but averaging out the 50% and 75% responder rates for each month at TEVA's go-forward dose, the rates look generally comparable to what ALDR showed (16% and 14% for TEVA). Still, comparisons are limited by: 1) unknown differences in baselines (ALDR's patients may have been sicker); 2) Total quarterly dosing for TEVA in ph.II was ~4-12x higher than for ALDR at ALDR's potential quarterly SC doses; and 3) TEVA calculated their data slightly differently (reductions in moderate to severe headache days, vs. reduction in overall migraine days over the 12 weeks)."

That will all be sorted out in Phase III now, as payers brace for a new generation of migraine drugs for a tough-to-treat affliction.

- here's the release