Repurposing of Mirtazapine for the Management of Orphan Diseases-Progressive Multifocal Leucoencephanlophaty (PML) & Quality of Life Assessment of Oral cancer Patients After Mandibular Resections Using Uwqol (V4) Questionnaire: Reconstruction with Pectoralis Major Myocutaneous Flap.

Abstract

Orphan diseases are the ones which affect fewer numbers of patients. The definition of orphan diseases varies from country to country. As per USA, An orphan disease is defined as a condition that affects fewer than 200,000 people nationwide. The major challenges associated with orphan drug development are less number of affected patients, high cost, unknown aetiology of diseases, limited information etc. Hence, taking the very fact into consideration, a new field that has come into existence is Drug Repositioning/Repurposing. By definition, Drug repositioning (also known as Drug repurposing, Drug re-profiling, Therapeutic switching and Drug re-tasking) is the application of known drugs and compounds to new indications (i.e., new diseases). Progressive Multifocal Leucoencephalopathy is a serious brain disorder caused by JC Virus. It is an orphan disease having very less number of patients. The aim of this study is to carry out thorough literature search and to find drug regimen for the treatment of PML. Objectives:  To review already existing drugs for their suitability for the treatment of Progressive Multifocal Leucoencephalopathy.  Identify one potential medication for Orphan designation in PML. Search Strategy: A complete meta-analysis was carried out and drugs already used for PML were searched along with proposed drug for the treatment. Suitable proofs were collected to show its efficacy and among them a drug with best outcomes and strong evidences was taken for further investigation Results: Many drugs were screened but due to lack of proper evidences they were not taken for further studies.Among them Mirtazapine showed positive outcomes in case reports. It completely cures infection of the initial stages. Mirtazapine has been used as an off label treatment for management of progressive multifocal Leucoencephalopathy. Many case reports showed positive outcomes of Mirtazapine and the virus infection gets fully cured at the initial stages of the infection. Mirtazapine also shows promising results when used in combination therapy. Thus Mirtazapine was further investigated and a clinical trial design of Mirtazapine was proposed as till date no clinical trial has been conducted on Mirtazapine for the management of PML.Conclusions: IL-7 and Imatinib are drugs already orphan designated for the treatment of PML, but they are associated with some toxicity. Based on the evidences available Mirtazapine showed a positive ray of hope for the treatment of PML and can be repurposed and designated for PML. We hope that the trial design can be taken up by some company and Mirtazapine gets an orphan drug designation for Progressive Multifocal Leucoencephalopathy in near future.