Bolstered by promising PhIIb snapshot, uniQure plays catch-up with Spark in the race to a hemophilia B gene therapy
The pivotal lead switch that uniQure executed late last year appears to have paid off, as the gene therapy pioneer offers some positive, if early, numbers for its tweaked hemophilia B treatment.
Among three patients treated with AMT-061 in the dose-confirmation study, researchers reported a mean factor IX level that represented 31% of normal levels at six weeks, exceeding the 12% commonly regarded as sufficient to substantially reduce spontaneous bleeds. A quick breakdown by individual showed FIX activity in the first patient was 37% of normal 10 weeks after administration; in the second patient, 23% at week 8; and the third, 30% at week 6.
Happy to hear that none of the patients received factor infusions, experienced reported bleeding events or required immunosuppression, investors sent the stock up $QURE 39%.
It’s also music to the ears of some supportive analysts, who are calling the results “very good” and “a clear positive” and largely agreeing with execs that a “mild, asymptomatic and transient increase in liver enzyme levels” observed in the trial was not a cause for concern.
The results affirm uniQure’s competitive position with Spark Therapeutics, which is also developing a hemophilia B therapy to follow up its historic retina eye disease treatment.
Edward Nash of SunTrust notes:
As a reference, SPK-9001 from Spark showed in a Phase I/II study that the range of FIX activity levels was between 14% and 68% at Week 6 and between 16% and 78% at Week 8.
Another detail that may separate uniQure from Spark, Leerink’s Joseph Schwartz points out, is that AMT-061 may be able to target a broader spectrum of patients. Two of the three patients in uniQure’s Phase IIb trial were enrolled after previously screen-failing another gene therapy study due to pre-existing neutralizing antibodies to a different AAV vector. In fact, execs were so confident about the AAV5 vector they have vowed not to exclude any patients on the patients of pre-existing neutralizing antibodies.
Amsterdam- and Lexington, MA-based uniQure replaced its lead program, AMT-060, with AMT-061 last October, claiming that a new gene variant called FIX-Padua introduced in the tweaked asset will boost FIX activity while keeping the same delivery tech and manufacturing process.
“Based on the long-term FIX data from our Phase I/II trial of AMT-060, where we saw FIX activity levels continue to increase beyond the levels achieved at six to ten weeks, we are hopeful that we will continue to see similar trends in these patients,” said CMO Robert Gut in a statement.
Catching up with Spark and its Big Pharma allies at Pfizer, uniQure plans to begin dosing for a Phase III study in Q1 2019.