It’s déjà vu for Marnius Pharmaceuticals. For the second time this year, the company’s seizure med Ztalmy missed in a phase 3 study, this time prompting it to cut off further development of the drug.
In Marnius’ TrustTSC study, Ztalmy (ganaxolone) didn’t meet its primary endpoint of percent change in tuberous sclerosis complex (TSC)-associated seizure frequency, the company reported. While reductions in seizure frequency “favored” the treatment arm, the trial didn’t achieve statistical significance with a median reduction of 19.7% compared with placebo’s 10.2%.
“As the first controlled trial in TSC that allowed enrollment of patients taking a range of concomitant antiseizure medications, which included mTOR inhibitors and cannabidiol, these data represent a significant advancement in our understanding of the use of ganaxolone with other standard of care treatments,” CEO Scott Braunstein, M.D., said in a company release. “We are disappointed that the results of the TrustTSC trial are not likely to be sufficient for an sNDA filing.”
Marinus’ share price nosedived nearly 80% on Thursday to $0.34 compared with Wednesday’s closing price of $1.69. The company had been gearing up to file a bid with the FDA for the TSC use in April 2025 with launch planning “underway” for a 2025 commercial launch, it said in its August second-quarter earnings release.
Now, the drugmaker is discontinuing further Ztalmy development along with other cost-cutting measures such as a workforce reduction and tapped Barclays to help “explore strategic alternatives” to maximize value for shareholders. It will still support the drug’s commercial growth in its approved indication as a three-times-daily option for seizures associated with CDKL5 deficiency disorder, for which more than 200 patients are using Ztalmy to treat, Marinus noted.
The latest results are yet another blow to struggling Marinus. Earlier this year, Ztalmy in an intravenous formulation met only one of its two primary endpoints in a study weighing its potential to treat refractory status epilepticus (RSE). That readout came days after shareholders filed a class action lawsuit accusing the company of “securities fraud or other unlawful business practices.”
Still, the company was holding out hope for the RSE indication as recently as August, when it planned to request an FDA meeting to discuss “next steps.”
Over the second quarter, the Ztalmy maker pulled $8 million in sales for the drug, representing an 87% climb from last year’s second quarter. Marinus said it was “on track” to achieve between $33 million and $35 million in full-year Ztalmy sales and expected the $64.7 million in cash and equivalents it had as of June to fund operations through the second quarter of 2025.