Pfizer, Medivation Initiate Phase 3 Trial Of Dimebon

Pfizer and Medivation have initiated the phase 3 trial of the investigational drug dimebon (latrepirdine) in patients with Huntington disease. The international safety and efficacy trial, known as HORIZON, is designed to evaluate the potential benefits of dimebon on cognition in patients with Huntington disease. The companies also announced that the FDA has granted orphan drug designation to dimebon, for the treatment of Huntington disease.

Lynn Seely, chief medical officer for Medivation, said: “Based on the promising results of our Phase 2 trial of dimebon in Huntington disease, we are pleased to advance dimebon into late-stage clinical development. Huntington disease is a fatal genetic disease for which no medications are currently approved by the FDA to treat the cognitive impairment associated with the condition.”

Orphan drug designation entitles Pfizer and Medivation to a seven-year period of marketing exclusivity in the US for dimebon, if approved by FDA, for the treatment of Huntington disease. It also enables the companies to apply for research funding, tax credits for certain research expenses, and a waiver from the FDA’s application user fee.