Orphan Drug Status Recommended for Pridopidine in Europe

A branch of the European Medicines Agency (EMA) has recommended that Prilenia’s investigational therapy pridopidine be designated an orphan medicine to treat people with amyotrophic lateral sclerosis (ALS).

Medicines with the potential to become safe and effective treatments for rare, life-threatening, or chronically debilitating conditions affecting no more than one in every 2,000 people are eligible for orphan drug designation in Europe.

The status provides a medication’s developer with several incentives meant to speed the therapy’s path to market. These include assistance with trial protocols and a 10-year period of market exclusivity upon approval.

“This positive opinion from the EMA further validates the potential for pridopidine to impact the devastating course seen in patients with ALS,” Michael Hayden, PhD, Prilenia’s CEO and co-founder, said in a press release.

The designation is expected to be given within 30 days of the positive opinion, which was issued by the EMA’s Committee for Orphan Medicinal Products (COMP).

Pridopidine is an oral therapy designed to protect nerves from damage by binding and activating the sigma-1 receptor on nerve and glial cells (a type of nerve support cell). This receptor regulates biological mechanisms — such as clearance of toxic proteins, energy production, and reduction of inflammation and cellular stress — that are needed for the survival and function of nerve cells.

According to Prilenia, mutations that completely eliminate the activity of this receptor are known to cause severe juvenile forms of ALS.

Given as a small capsule twice daily, pridopidine has been found safe and well-tolerated in more than 1,300 study participants, causing side effects that are similar to those observed with a placebo, the company states on its website.

The treatment also demonstrated neuroprotective benefits in several ALS preclinical models, leading to preserved integrity of neuromuscular junctions — the connections between nerve and muscle cells — and reduced muscle atrophy (shrinkage).

The COMP based its decision on this preclinical data showing a potential to preserve motor function, which the committee considers an unmet medical need. COMP also considered this potential effect an advantage over currently available treatments.

Pridopidine is one of the four therapies currently included in the HEALEY ALS platform trial (NCT04297683), which is investigating multiple potential disease treatments at the same time to speed the development of those most promising, while significantly lowering study costs.

Pridopidine’s trial arm (NCT04615923), which enrolled its first participant in January, will include 160 adults with sporadic or familial ALS who will receive either placebo or 45 mg of the investigational therapy, twice daily for 24 weeks. 

Enrollment for ridopidine and other study arms is ongoing at 54 sites across the U.S.; more information is available here. Results are expected in the third quarter of 2022.

“We are encouraged by pridopidine’s diverse effects favorably impacting neurodegeneration in ALS models and look forward to the trial readout later next year,” Hayden said.

Pridopidine already holds orphan drug designation for the treatment of Huntington’s disease in both the U.S. and Europe and is being investigated in a Phase 3 trial in Huntington’s.