Praxis wields the axe as lead depression drug fails

Shares in Praxis Precision Medicines were in freefall today after the company's efforts to develop a new therapy for major depressive disorder (MDD) ended in failure, forcing a restructuring and staff cuts.

The selloff followed the announcement of the phase 2/3 Aria study results with PRAX-114 as a monotherapy for MDD, which showed the GABA positive allosteric modulator was unable to show a significant benefit on any of the study's primary and secondary endpoints.

It's an unexpected development for the programme, formerly billed as a potential blockbuster, given that PRAX-114 is in a similar class to Sage Therapeutics and Biogen's zuranolone, which was filed for approval as an MDD treatment last month.

As with zuranolone, much of the interest in PRAX-114 was focused on its ability to achieve a rapid reduction in MDD symptoms, which isn't generally possible with standard monoamine-based antidepressants.

The drug was however unable to achieve a significant change from baseline in the 17-item Hamilton Depression Rating Scale total score on day 15, Aria's main outcome measure.

Praxis has lost no time in calling a halt to all other studies of its lead drug, in MDD as well as other indications including  post-traumatic stress disorder and essential tremor, and said it would make "a reduction in the company's workforce", without giving further details.

That and the layoffs should save enough money to keep the company going into 2024, it said in a statement. At the end of last year it reported cash and investments of $276 million that would last until the middle of 2023.

With PRAX-222 all-but defunct, it is turning its attention PRAX-944, a T-type calcium channel blocker in phase 2 for essential tremor, and persistent sodium current blocker PRAX-562 for epilepsy in phase 2.  Results in both studies are due before the end of this year.

Praxis chief executive Marcio Souza said he was "surprised and disappointed" by the results, but added that Praxis "is committed to our mission to help people suffering from CNS disorders."

The failure of PRAX-114 removes a potential rival to zuranolone, although there have been questions raised about the latter's commercial potential, as its effects seem to kick in quickly – within three days – but also start to tail off within a couple of weeks.

Shares in Praxis were down 77% following the announcement.