Months af­ter Fir­dapse mak­er Cat­a­lyst Phar­ma­ceu­ti­cals filed a law­suit against the FDA, the Flori­da com­pa­ny on Wednes­day said the drug had failed a piv­otal tri­al in pa­tients af­flict­ed with con­gen­i­tal myas­thenic syn­dromes (CMS), an um­brel­la term for rare neu­ro­mus­cu­lar dis­or­ders com­pris­ing a spec­trum of more than 50 ge­net­ic de­fects.

The drug, known chem­i­cal­ly as am­i­fam­pri­dine, was sanc­tioned for use in adult Lam­bert-Eaton myas­thenic syn­drome (LEMS) pa­tients in No­vem­ber 2018. The com­pa­ny is work­ing on ex­pand­ing the la­bel to in­clude pa­tients with CMS, MuSK-pos­i­tive myas­the­nia gravis (MuSK-MG) and spinal mus­cu­lar at­ro­phy (SMA).

Cat­a­lyst es­ti­mates that there are be­tween 1,000 and 1,500 CMS pa­tients in the Unit­ed States — there are at least 600 fam­i­lies with af­fect­ed in­di­vid­u­als who have been rep­re­sent­ed in sci­en­tif­ic lit­er­a­ture, ac­cord­ing to the NIH. Pa­tients with CMS car­ry mu­ta­tions in genes en­cod­ing pro­teins es­sen­tial for neu­ro­mus­cu­lar trans­mis­sion.

Cat­a­lyst’s late-stage study test­ed the drug against a place­bo in ge­net­i­cal­ly con­firmed CMS pa­tients. 20 pa­tients aged two and above were en­rolled in the tri­al, and 16 were ran­dom­ized. The drug failed to meet the main goal of sub­ject glob­al im­pres­sion (SGI) scale, a mea­sure used by clin­i­cians to rate the sever­i­ty of the ill­ness at the time of as­sess­ment, rel­a­tive to the clin­i­cian’s past ex­pe­ri­ence with pa­tients with the same di­ag­no­sis.

The com­pa­ny’s shares $CPRX slipped about 12.3% to $5 in pre­mar­ket trad­ing.

The sec­ondary end­point of mus­cle func­tion mea­sure (MFM) across all test­ed sub­types was al­so not met, al­though in­di­vid­ual pa­tient im­prove­ments were ob­served in some pa­tient sub-groups, the com­pa­ny said.

“Due to the small pa­tient preva­lence, the low num­ber of pa­tients test­ed, and het­ero­gene­ity of the dis­ease with a wide range of vari­a­tion in clin­i­cal pre­sen­ta­tion across its more than 50 sub­types, it was chal­leng­ing to demon­strate a sta­tis­ti­cal­ly sig­nif­i­cant ben­e­fit across mul­ti­ple sub­types,” Steven Miller, Cat­a­lyst’s COO and CSO said in a state­ment.

The com­pa­ny will meet the FDA be­fore the end of 2019 to fig­ure out the next steps for the CMA pro­gram. Mean­while, the Cat­a­lyst ex­pects to re­port da­ta from the MuSK-MG tri­al as well as re­sults from its SMA proof of con­cept study in the first half of next year.

Hav­ing launched in Jan­u­ary, Fir­dapse gen­er­at­ed about $41.3 mil­lion in sales in the first half of this year. Be­fore the drug (which car­ries an av­er­age an­nu­al list price of $375,000) was ap­proved by the FDA, hun­dreds of pa­tients had been able to ac­cess a sim­i­lar drug from com­pound­ing phar­ma­cies for a frac­tion of the cost, or Ja­cobus’ for free, as part of an FDA-rat­i­fied com­pas­sion­ate use pro­gram.

But the ap­proval of the Cat­a­lyst drug — ac­com­pa­nied by mar­ket ex­clu­siv­i­ty span­ning sev­en years — ef­fec­tive­ly pre­clud­ed Ja­cobus and com­pound­ing phar­ma­cies from sell­ing their ver­sions.

Then, in an un­ex­pect­ed twist, the FDA en­dorsed New Jer­sey-based Ja­cobus’ ver­sion in pe­di­atric pa­tients, on the ba­sis of adult da­ta — a move that could spark off-la­bel pre­scrip­tion in adults (As far as the FDA is con­cerned, doc­tors can pre­scribe drugs for off-la­bel use when they judge that it is med­ical­ly ap­pro­pri­ate for their pa­tient). Adding fu­el to the fire, Ja­cobus’s drug, Ruzur­gi, car­ries a list price that is less than half of Fir­dapse’s. Cat­a­lyst main­tains that typ­i­cal­ly, cov­ered pa­tients pay less than $10 per month out-of-pock­et.

In an in­ter­view with End­points News ahead of Cat­a­lyst’s third-quar­ter re­sults ex­pect­ed mid-No­vem­ber, chief Patrick McE­nany said that the Ruzur­gi ap­proval has trig­gered a “trick­le of ero­sion” on its LEMS pa­tient base. “It was not un­ex­pect­ed,” he said.

In June, Cat­a­lyst filed a law­suit against the health reg­u­la­tor — ef­fec­tive­ly ac­cus­ing the agency of bow­ing to po­lit­i­cal pres­sure sur­round­ing sky­rock­et­ing drug prices. Un­der fed­er­al law, the agency is meant to treat all com­pa­nies in the same man­ner. Cat­a­lyst has as­sert­ed the agency un­der­mined its or­phan drug ex­clu­siv­i­ty, and vi­o­lat­ed fed­er­al law by play­ing fa­vorites in the con­text of a hy­per­vig­i­lant pric­ing en­vi­ron­ment.

Since losing a controversial court case over orphan drug exclusivity last year, the FDA’s Office of Orphan Products Development has remained entirely silent on orphan exclusivity for any product approved since last November, leaving many sponsors in limbo on what to expect.

That silence means that for more than 70 orphan-designated indications for more than 60 products, OOPD has issued no public determination on the seven-year orphan exclusivity in the Orange Book, and no new listings of orphan exclusivity appear in OOPD’s searchable database, as highlighted recently by George O’Brien, a partner in Mayer Brown’s Washington, DC office.

As the global biologics market is expected to hit nearly the half-trillion-dollar mark this year, new JAMA research points to the importance of timely biosimilar entry, particularly as fewer biosimilars are entering the US than in Europe, and as monthly treatment costs for biosimilars were “substantially higher” in the US compared with Germany and Switzerland.

Among the three countries, biosimilar market share at launch was highest in Germany, but increased at the fastest rate in the US, the authors from the University of Zurich’s Institute of Law wrote in JAMA Network Open today.

The European Medicines Agency said Friday that it’s pulling from all European markets pholcodine-containing medicines, which are an opioid used in adults and children for the treatment of dry cough and in combo with other drugs as a treatment for cold and flu.

The decision to pull the medicines comes as the EMA points to the results from the recent ALPHO study, which show that use of pholcodine during the 12 months preceding anesthesia is linked to a risk of an anaphylactic reaction related to the neuromuscular blocking agents (NMBAs) used (with an adjusted OR of 4.2, and a 95% confidence interval of 2.5 to 6.9).