Xeris Pharma's auto-injector-friendly diazepam wins FDA fast-track tag in cluster seizures

Xeris' high-concentration, low-volume diazepam can be administered across a range of injection sites and works at just a single dose—providing a convenience edge over other formats, the company hopes. (Pixabay/geralt).(Pixabay / geralt)

Xeris Pharmaceuticals last year snared approval for its first drug, a shelf-stable glucagon injector for hypoglycemia. Now it's deploying its formulation tech to hit another target—epilepsy—and the FDA has taken notice. 

Chicago-based Xeris scored an FDA fast-track designation for its injectable diazepam formulation to treat acute repetitive seizures, also known as cluster seizures, the company said

Aiming to deliver the drug using an auto-injector, Xeris hopes to improve on the usability of current diazepam-based cluster seizure treatments—a mix of rectal gels, suppositories and, more recently, a nasal spray—by offering epilepsy patients a swift and easy-to-use option not unlike the ubiquitous epinephrine injector EpiPen, CEO Paul Edick said in an interview. 

Earlier this year, the company shared phase 1b data with the FDA showing its intramuscular formulation worked on par with Valeant Pharmaceutical's diazepam rectal gel, Diastat, and also maintained higher concentrations in the bloodstream over the course of 24 hours.

On the back of those data, the agency cleared Xeris to jump straight into phase 3, said Ken Johnson, SVP of clinical development, regulatory, quality assurance and medical affairs.

While Xeris is now in a position to kick off its phase 3 at any time, it has chosen to hunt for a development partner first—someone who could help take the formulation through late-stage testing, develop the auto-injector device pairing and eventually commercialize the product, SVP of investor relations and corporate communications Allison Wey said. 

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More than 2.7 million people in the U.S. have epilepsy, with roughly 200,000 new diagnoses each year, Xeris said in its release. It estimates that 30% to 40% of those patients aren't getting adequate seizure control from oral therapy, which puts them at risk for breakthrough seizures.

While a number of drugs have emerged to treat cluster seizures, including Neurelis' diazepam nasal spray Valtoco, approved in January, those formulations don't account for the difficulty of administering a drug to a patient who's actively convulsing, Edick said. 

Xeris' high-concentration, low-volume formula, on the other hand, can be administered across a range of injection sites and works at just a single dose—providing a convenience edge over other formats, which require patients on higher regimens to take multiple doses, he said. 

It could also top higher-volume injections—often painful, time-consuming, and less reliable than the small, concentrated dose Xeris hopes to offer, Medical Director Anh Nguyen said. Previous attempts have largely come up short because diazepam doesn't dissolve easily, Nguyen added—something Xeris aims to counteract with its XeriSol technology, designed to boost drugs' solubility and improve their stability in solution. 

RELATED: Xeris' glucagon injection Gvoke gains heat with HypoPen auto-injector launch

Meanwhile, Xeris last September scored its first FDA nod for another XeriSol-based product: A shelf-stable glucagon injector pen, Gvoke, approved to treat hypoglycemia in diabetes patients over the age of two.