Dive Brief:
- On Friday, the Food and Drug Administration approved the first treatment for seizures associated with a rare genetic disease that can impair brain function and development.
- The treatment, which will be sold by Pennsylvania-based Marinus Pharmaceuticals under the brand name Ztalmy, is approved specifically for patients two years and older with cyclin-dependent kinase-like 5 deficiency disorder — or "CDD" for short. Marinus' drug works by regulating neurotransmission, and in a key clinical trial was significantly better than a placebo at lowering the number of major motor seizures experienced by hard-to-treat CDD patients.
- Marinus plans to launch its drug in July with an initial price of $2,425 per bottle, or $133,000 per year for the average patient. The company is mostly targeting patients 2 to 21 years old who aren't responding to current treatments — a population of about 2,000, according to its estimates. In clearing Ztalmy, the FDA also granted Marinus a type of regulatory fast pass that can be use to speed the review time on another approval application. The company intends to sell the pass, which analysts say could be worth $100 million or more.
Dive Insight:
Nearly 20 years since its founding, Marinus is now bringing its first product to market. Analysts at the investment firms SVB Leerink and Jefferies predict sales of Ztalmy as a CDD treatment could reach $100 million at their peak, though they would likely grow higher if Marinus' additional development plans succeed.
The company wants to show its drug can treat rare epilepsies beyond CDD. Already, Marinus is sponsoring a late-stage study of Ztalmy in patients with tuberous sclerosis complex, or TSC, with results expected in the first half of 2024. And it sees another opportunity in Lennox-Gastaut syndrome, a seizure disorder for which there are several FDA-approved treatments, including one from GW Pharma that was the centerpiece of the biotech's recent $7 billion sale to Jazz Pharmaceuticals.
Marinus is also trying to develop an intravenous version of Ztalmy to treat acute seizure disorders. There, one of the company's top targets is "status epilepticus," which it claims is the second most common neurological emergency in the U.S., with 150,000 cases annually.
A late-stage study evaluating Ztalmy in patients with status epilepticus began in late 2020. While results were expected early this year, Marinus disclosed in February that they won’t become available until the back half of 2023. Executives blamed the delay on the impact of the omicron coronavirus variant on hospital resources, and an "unexpected interruption" of the materials needed for the clinical supply of the intravenous form of Ztalmy.
The update was "clearly disappointing news for many investors," Marc Goodman, an SVB Leerink analyst, wrote in a note to clients last week.
Investors may still be holding onto some doubts about Marinus, as company shares were down almost 12% late Monday morning, to trade at about $8.80 apiece.