Familial amyloid polyneuropathy (FAP) or transthyretin (TTR) amyloid neuropathy is a genetic disorder caused by the deposition of insoluble amyloid fibrils around the peripheral nerves and in various tissues, including the heart muscle. Transthyretin is a transporter of retinol and thyroid hormone; majority of which is made in liver and small amount of the protein is made in brain and eyes.
The prevalence of familial amyloid polyneuropathy is very low across the globe. According to a review article published in The Lancet Neurology, although FAP cases has been reported throughout the world, but in Europe there exists strong genotypic heterogeneity. The article also mentions that 30 different TTR gene variants are reported in Japan and France.
Currently over 30 different proteins are found to cause amyloid deposition. Familial amyloid polyneuropathy is characterized by slowly progressive, peripheral sensorimotor polyneuropathy and autonomic dysfunction. Symptoms for the disorder include limb weakness, and loss of sensation in case of peripheral neuropathy, bowel disturbance and sexual dysfunction in case of autonomic neuropathy. Cardiomyopathy may also cause heart dysfunction and even failure. Patients with familial amyloid polyneuropathy are born with a mutation in the TTR gene which leads to the disorder. Although majority of the symptoms are experience in the middle age, some patients may experience a symptomless condition and my just transfer the mutated gene to their offspring. The disorder is mainly diagnosed through tissue biopsy of abdominal fats, heart or rectum. Genetic tests are also recommended for detecting mutation in TTR gene.
Liver transplant has proved to be the most successful cure for the disorder. But with long waiting periods for liver transplants, there is a need for effective treatment of familial amyloid polyneuropathy. In Europe, only one drug has been approved for the treatment of FAP- Vyndaqel (tafamidis) by Pfizer. However the drug is under Phase III clinical trials to seek U.S. FDA approval. It has also been found that nonsteroidal anti-inflammatory drug (NSAID) diflunisal is effective in restricting the progression of neurological impairment. Although not FDA approved, the drug is prescribed by many physicians as an off label prescription. In 2014, GlaxoSmithKline paid U.S. based Isis Pharmaceuticals USD 1 million for the advancement of the Phase III study of ISIS-TTRRx in patients with familial amyloid polyneuropathy. ISIS-TTRRx is an antisense drug which reduces the amount of mutant. Treatment with ISIS-TTRRx lowers the amount of disease causing protein found in the blood.
Although many companies initiate clinical studies in future, drug approval is subjected to various uncertainties. Due to high cost of the treatment, a small portion of the probable customer base is actually able to afford the treatment. This is a major restraint for development of the market in developing countries.
Owing to early initiation of the market in the European countries, currently Europe leads the familial amyloid polyneuropathy market. As Vyndaqel (tafamidis) receives approval from regulatory authorities in the U.S. the market is expected to grow rapidly as cost of drugs in the U.S. is higher as compared to Europe. Moreover as companies succeed in research activates, more product will be added to the market. Advent of gene therapy is also expected to boost the market growth in the future.
This research report analyzes this market on the basis of its market segments, major geographies, and current market trends. Geographies analyzed under this research report include