Excerpts from the EMEA press release (dated 17th February) on the withdrawal of the marketing application for Vorinostat MSD:
The European Medicines Agency (EMEA) has been formally notified by Merck Sharp & Dohme Ltd of its decision to withdraw its application for a centralised marketing authorisation for the medicine Vorinostat MSD (vorinostat), 100 mg hard capsules.
Vorinostat MSD was expected to be used for the treatment of patients with advanced stage cutaneous T-cell lymphoma (CTCL) who have progressive, persistent or recurrent disease, and who have failed at least two prior systemic therapies.
In its official letter, the company stated that the withdrawal of the application was based on the CHMP’s view that the data provided were not sufficient to allow the Committee to conclude on a positive benefit-risk balance for Vorinostat MSD at that time.
Mechanism of action of vorinostat, from the National Cancer Institute:
A synthetic hydroxamic acid derivative with antineoplastic activity. Vorinostat, a second generation polar-planar compound, binds to the catalytic domain of the histone deacetylases (HDACs). This allows the hydroxamic moiety to chelate zinc ion located in the catalytic pockets of HDAC, thereby inhibiting deacetylation and leading to an accumulation of both hyperacetylated histones and transcription factors. Hyperacetylation of histone proteins results in the upregulation of the cyclin-dependant kinase p21, followed by G1 arrest. Hyperacetylation of non-histone proteins such as tumor suppressor p53, alpha tubulin, and heat-shock protein 90 produces additional anti-proliferative effects. This agent also induces apoptosis and sensitizes tumor cells to cell death processes. Vorinostat crosses the blood-brain barrier.