Alexion’s successor to Soliris hits co-primary endpoints in a pivotal, but can’t surpass the big blockbuster

With a group of rivals pressing in from every side, looking to capture a piece of Alexion’s $ALXN blockbuster market for the rare disease trendsetter Soliris, researchers for the biotech say the first of two pivotal studies for PNH came through with non-inferior data on their next-gen drug dubbed ALXN1210. That should leave the company on track for a badly needed regulatory filing later this year.

John Orloff

But, the paroxysmal nocturnal hemoglobinuria drug also failed a key measure of superiority, leaving Alexion touting the similarities of the two therapies and an easier dosing schedule that may leave quite a few supporters a wee bit dissatisfied.

The co-primary endpoints in the study were transfusion avoidance and lactate dehydrogenase (LDH) normalization, stacked alongside four key secondary endpoints. The analysis on superiority quickly broke down on the examination of breakthrough hemoloysis: 4% of patients given and 10.7% for patients treated with Soliris. That delivered a failed p value of 0.074, halting the superiority review and leaving some analysts a bit frustrated.

Under new management after CEO Ludwig Hantson swept the old crew out, the biotech has concentrated heavily on ALXN1210 to save the company’s only big franchise. At $542,640 a year, Soliris remains one of the 10 most expensive therapies on the planet and Alexion’s cash cow.

The stock spiked on the news, picking up a 9% gain mid-morning as investors absorbed the data.

Geoffrey Porges, Leerink

Leerink’s Geoffrey Porges led the cheering section this morning, but also noted that the trial fell well short of a complete success.

This consistent picture of positive trends in favor of ALXN1210 should reassure investors that Alexion’s 2nd generation product is indeed better than Soliris; we expect the stock to react positively to this disclosure, although controversy will still exist about whether 1210 could have shown superiority in a larger trial, and whether the upcoming switch study could still meet the higher hurdle.

R&D chief John Orloff said:

Soliris has established a high bar for efficacy. Achieving non-inferiority on both co-primary and all key secondary endpoints, as well as seeing numeric results in favor of ALXN1210, in such a rigorous study met a very high hurdle. We look forward to regulatory submissions of ALXN1210 in PNH in the U.S., EU, and Japan in the second half of 2018.

Porges and allies believe the data sets up 1210 for a near certain approval, guarding the company’s franchise for many more years. But Alexion isn’t operating alone here anymore. Several rivals are well along with new PNH drugs that they believe can outperform Soliris, and now 1210.

One of those rivals is Apellis $APLS, which completed a $150 million IPO last November. In 3 patients never treated with Soliris, investigators reported that all of them experienced a quick correction on a key biomarker for lactate dehydrogenase, or LDH, after being treated with the biotech’s drug. In 6 patients not responding well to Soliris, the average hemoglobin level was brought up an average of 36%, LDH was corrected and transfusions dropped from 3.4/month on eculizumab monotherapy to 0.3/month when APL-2 was added to eculizumab. And the biotech raised no unusual red flags on the safety side. Now it’s aiming at a pivotal of its own.

The big question at Alexion remains open. What will Hantson do with the pipeline now? He has sought to streamline development efforts and quite a few analysts are pressing hard to make them diversify beyond PNH.

The best place to read Endpoints News? In your inbox.

Comprehensive daily news report for those who discover, develop, and market drugs. Join 47,300+ biopharma pros who read Endpoints News by email every day.

Free Subscription

Research Scientist - Immunology
Recursion Pharmaceuticals Salt Lake City, UT
Director of Operations
Atlas Venture Cambridge, MA

Visit Endpoints Careers ->