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Repositioning of Amantadine and phenytoin: patent protected strategies

Repositioning (or repurposing) of old not-patent protected drugs in new, off label indications leads to quick development times and cheaper developments. However, one needs to overcome a number of hurdles to reach a successful repurposing of such old drugs.

Athors are quite experienced in repositioning phenytoin anno 2017 as a topical analgesic.

In the enclosed paper, (Clinical Investigation, Lond.) (2017) 7(1), 011-016) I discuss two examples to solve this problem based on patents: phenytoin cream for neuropathic pain and amantadine extended release for dyskinesia and other neurological disorders, and discuss amantadine, its history of repositioning and its patents in more detail. Both molecules are respectable old compounds, phenytoin was synthesized more than a century ago, and amantadine in the 50s of last century.

ADS-5102 and phenytoin cream

ADS-5102 is currently Adamas’ end of phase III owned product, amantadine in a new formulation,  and is positioned by the company as an extended-release version of amantadine, intended for once daily administration at bedtime.

We have developed patent protected topical creams based on phenytoin and co-analgesics such as ketamine for the treatment of a variety of neuropathic pain syndromes, such as pain in diabetic neuropathy, chemotherapy induced neuropathy, chronic idiopathic axonal neuropathy, CRPS and small fibre neuropathy.

You can find the repositioning paper here: repositioning-pheny-am-2017

May 2017, Prof. dr. Jan M. Keppel Hesselink