The FDA approved amifampridine for the treatment of adults with Lambert-Eaton myasthenic syndrome on November 29, 2018.In February 2019, U.S. Senator Bernie Sanders questioned the high price ($375,000) charged by Catalyst Pharmaceuticals for Firdapse.In May 2019, the privately held US company Jacobus Pharmaceutical, Princeton, New Jersey gained approval by the FDA for amifampridine tablets (Ruzurgi) for the treatment of LEMS in patients 6 to less than 17 years of age. This is the first FDA approval of a treatment specifically for pediatric patients with LEMS. Firdapse is only approved for use in adults. Although Ruzurgi has been approved for pediatric patients, this approval makes it possible for adults with LEMS to get the drug off-label. Jacobus Pharmaceutical had been manufacturing and giving it away for free since the 1990s. The FDA decision dropped the stock of Catalyst Pharmaceuticals. The companys stock price has dropped about 50%. Research
Amifampridine has also been proposed for the treatment of multiple sclerosis (MS). A 2002 Cochrane systematic review found that there was no unbiased data to support its use for treating MS. There was no change as of 2012. References
External links
"Amifampridine". Drug Information Portal. U.S. National Library of Medicine. "Amifampridine phosphate". Drug Information Portal. U.S. National Library of Medicine.
Dermatologists and allergists professional societies, the American Academy of Dermatology, and the American Academy of Allergy, Asthma, and Immunology, have protested the inclusion of the black box warning. The AAAAI states "None of the information provided for the cases of lymphoma associated with the use of topical pimecrolimus or tacrolimus in AD indicate or suggest a causal relationship." Pharmacology
Pimecrolimus is an ascomycin macrolactam derivative. It has been shown in vitro that pimecrolimus binds to FKBP1A and also inhibits calcineurin. Thus pimecrolimus inhibits T-cell activation by inhibiting the synthesis and release of cytokines from T-cells. Pimecrolimus also prevents the release of inflammatory cytokines and mediators from mast cells.Pimecrolimus, like tacrolimus, belongs to the ascomycin class of macrolactam immunosuppressives, acting by the inhibition of T-cell activation by the calcineurin pathway and inhibition of the release of numerous inflammatory cytokines, thereby preventing the cascade of immune and inflammatory signals. Pimecrolimus has a similar mode of action to that of tacrolimus but is more selective, with no effect on dendritic (Langerhans) cells. It has lower permeation through the skin than topical steroids or topical tacrolimus although they have not been compared with each other for their permeation ability through mucosa. In addition, in contrast with topical steroids, pimecrolimus does not produce skin atrophy. References
External links
FDA News
NPS RADAR
Article about American Academy of Dermatology speaking out against black box warning Archived 2008-04-07 at the Wayback Machine
Report of the Calcineurin Task Force of the ACAAI and AAAAI