Two Japanese medical institutions are planning to develop tailored drugs for patients with genetic disorders in the hope of finding treatment for extremely rare diseases, a leading project member said Sunday.
The project involving Tokyo Medical and Dental University and the National Center of Neurology and Psychiatry will search for rare diseases that have the potential to be treated by nucleic acid drugs, a new emerging class of therapeutics, from a database of around 2,250 patients.
The development will be carried out based on technology that targets the expression of disease-causing proteins in the mutated gene. Pharmaceutical companies are reluctant to develop medicines for extremely rare diseases because of the costs and difficulties regarding business viability. Such drugs have already been administered in the United States.
"We hope to discover whether we can make effective patient-tailored nucleic acid drugs, and find as many people as possible who can be treated," said Takanori Yokota, a professor of neurology and neurological science at Tokyo Medical and Dental University. He is a leading member of the project.
Participants will be selected from patients registered in the Initiative on Rare and Undiagnosed Diseases, a project that analyzes the genes of people whose disease cannot be identified, or for which no treatment is known.
The initiative covers a wide range of disorders including neurological, cardiac, and metabolic abnormalities, cataloging over 1,700 related gene sequences.
Around 70 percent of the diseases are seen in only one or two family lines in Japan, with many lacking any effective treatment.
In addition to the causative gene, factors such as age, the severity of symptoms, and the speed at which the disease is progressing will be taken into account when choosing candidate patients for which to develop nucleic acid drugs.
As a synthetic method for nucleic acid drugs has already been established, treatment can be completed in around six months once the target gene is sequenced.
But several challenges remain, such as high costs, with treatment currently estimated at around 100 million yen ($750,000) per patient, as well as how to evaluate the safety of the drugs.
In contrast to conventional medicine, the tailored nature of nucleic acid drugs means their efficacy and safety cannot be evaluated in clinical trials where one group receives the drug and the other a placebo.
