Catalyst Pharmaceuticals hit by FDA extra studies request for Firdapse


Two months ago the FDA slapped a Refuse to File letter on Catalyst Pharmaceuticals’ ($CPRX) rare disease drug Firdapse--and the woe keeps raining down as the U.S. regulator now wants the biotech to undertake more trials.

Firdapse, which has seen a “Breakthrough” designation and been given orphan status, is designed to treat Lambert-Eaton myasthenic syndrome (LEMS)--a rare neuromuscular disease that gradually robs patients of their mobility.

In one Phase III trial on 38 LEMS sufferers, the treatment met its co-primary endpoints of improving physician-rated and patient-reported symptoms of the disease--significantly beating out placebo while proving safe and well-tolerated.

But one late-stage study by the Coral Gables, FL-headquartered biotech was deemed “not sufficiently complete” by the FDA in February this year, leading to its CLR and a major tanking of its shares.

Today, the regulator has more bad news: In order for it to resubmit a New Drug Application for Firdapse, it will also need to submit positive results from an “additional adequate and well-controlled study in patients with LEMS.”

The FDA has told the biotech that it is open to “discuss a study design that could efficiently accomplish the requirement with a small, short-term study.” But it gets worse, as the regulator also wants several more “short-term toxicology studies,” which the biotech said in a statement are expected to start soon. This will further delay any market entry for the drug, and likely add significant extra costs to its R&D program.

The drug is also being studied in patients with MuSK-Antibody Positive Myasthenia Gravis and this year, Catalyst also expects to complete a clinical trial of Firdapse for pediatric patients with CMS. The FDA’s request does not affect these trials. 

BioMarin ($BMRN) has marketed the drug in Europe since 2009, and, in out-licensing Firdapse to Catalyst in 2012, took a $5 million stake in the biotech.

The drug has however proved controversial. As TheStreet's Adam Feuerstein has previously reported, a family-owned outfit called Jacobus Pharmaceuticals has been giving away doses of 3,4-Dap--a treatment similar to Firdapse--for more than 20 years. That drug has never secured FDA approval and thus can't be sold legally in the U.S.

Firdapse, if approved, will likely demand an orphan price tag just to replace an effective treatment that's currently free. Analysts have predicted a peak annual sales range from $300 - $900 million--which would put the drug’s price at anything from $37,500 to well over $100,000 per LEMS patient, per year. 

Catalyst has said however that, should it gain approval, it will discount the drug heavily if a patient struggles substantially to pay it. 

The company in a statement that it: “Believes that it has the cash resources required to complete the additional studies, as well as funding operations.”

The biotech, which currently has around $52 million available, was down by more than 54% in pre-market trading on the news.