In the United States, a rare disease is one that affects fewer than 200,000 people. In the European Union it is defined as one that affects fewer than 5 in 10,000 people. Given a current estimation of the US population is about 327 million, that equates to about 5 in 8, 175, so the definitions in the US and Europe are, broadly speaking, very similar. Although rare in themselves, it is estimated that there are about 6-8,000 known rare diseases, a number that would appear to be increasing at a rate of some 5 per week, based on literature reports. There may be as many as 300 million world wide sufferers of so-called “rare diseases” So although each individual disease may be rare, the burden of rare diseases is massive. The bulk of rare diseases are genetic and represent a series of difficult to treat drug targets. In the USA, the definition of rare disease was developed as part of the Orphan Drug Act (1983) which was a response to the Pharmaceutical industry’s perceived lack of interest in developing therapies for diseases with little chance of a return on investment. Policies were developed to incentivize companies to work in these relatively financially unattractive areas. The articles I have selected for this month are related to the topic of rare diseases and orphan drugs and if my selection falls at times a little outside of this definition, I apologize in advance. Even if they do, I hope that you find them interesting and informative.
The first article, “Acceleration of Rare Disease Therapeutic Development: A Case Study of AGIL-AADC” is by Sonya Das, Samuel Huang and Andrew W.Lo from MIT. They point out that therapies for rare diseases are challenging, both scientifically and financially to develop and describe a case study of a collaboration between Agilis Biotherapeutics, The National Taiwan University and the Therapeutics for Rare and Neglected Diseases at the NIH. The authors highlight those factors that have allowed this collaboration to advance successfully at a very rapid pace, through the use of Agilis’s adeno-associated virus (AAV) gene therapy for brain disorders to treat the ultra-rare disorder, AADC deficiency.
The second article by Yvonne Schuller, Maarten Arends, Simon Körver, Mirjam Langeveld and Carla E.M. Hollak of the University of Amsterdam, Netherlands entitled: “Adaptive pathway development for Fabry disease: a clinical approach” examines the approach of treating the rare disease, Fabry disease (a lysosomal storage disorder) through the use of enzyme replacement therapy. The authors point out that there although the approach was heralded by initial optimism, real world experience has now tempered this enthusiasm and the actual evidence for efficacy is limited. They point out that the involvement of patients, payers and other related bodies through the use of adaptive pathways might have assisted in ERT development at all stages of the value pathway.
The final article from Melina Mottin, Joyce V.V.B. Borba, Rodolpho C. Braga, Pedro H.M. Torres, Matheus C. Martini, Jose Luiz Proenca-Modena, Carla C. Judice, Fabio T.M. Costa, Sean Ekins, Alexander L. Perryman and Carolina Horta Andrade, scientists from various institutions, entitled: “The A-Z of Zika drug discovery”. I guess this doesn’t qualify as a rare disease, so please forgive me, but I think the article highlights a disease of the developing rather than developed world and perhaps does not attract the attention of the Pharmaceutical industry in the way that other diseases might. The article highlights the recent developments in the search for effective drug compounds, through novel approaches, repositioning and identification of targets. Definitely worth a read, whether or not you work in the Zika field.
Steve Carney was born in Liverpool, England and studied Biochemistry at Liverpool University, obtaining a BSc.(Hons) and then read for a PhD on the Biochemistry and Pathology of Connective Tissue Diseases in Manchester University, in the Departments of Medical Biochemistry and Histopathology. On completion of his PhD he moved to the Kennedy Institute of Rheumatology, London, where he worked with Professor Helen Muir FRS and Professor Tim Hardingham, on the biochemistry of experimental Osteoarthritis. He joined Eli Lilly and Co. and held a number of positions in Biology R&D, initially in the Connective Tissue Department, but latterly in the Neuroscience Department. He left Lilly to take up his present position as Managing Editor, Drug Discovery Today, at Elsevier. Currently, he also holds an honorary lectureship in Drug Discovery at the University of Surrey, UK. He has authored over 50 articles in peer-reviewed journals, written several book chapters and has held a number of patents. Although the Editor ended up on the cutting-room floor for the blockbuster film “Rocketman”, the band that he fixed occupied a significant role in the opening scene of the movie.