The pregnane X receptor has been identified as a potential target.Neural stem cells have also been investigated in an animal model, and clear evidence of life extension in the mouse model has been shown.Low cholesterol diets are often used, but there is no evidence of efficacy.Gene therapy is being used clinically to treat genetic diseases including haemophilia and spinal muscular atrophy. It has been used preclinically, in a mouse model of Niemann-Pick type C, using an adeno-associated virus derived viral vector has been shown to extend lifespan following injection into the lateral ventricles of the neonatal brain. In a separate proof-of-concept study a similar vector, but with a modified capsid capable of delivering genes to the central nervous system following intravenous injection, was given to Niemann-Pick type C mice at around four weeks of age; this resulted in extended lifespan and improved weight gain. Prognosis
The lifespan of patients with NPC is usually related to the age of onset. Children with antenatal or infantile onset usually succumb in the first few months or years of life, whereas adolescent and adult onset forms of Niemann–Pick type C have a more insidious onset and slower progression, and affected individuals may survive to the seventh decade. Adult cases of NPC are being recognized with increasing frequency. It is suspected that many patients affected by NPC are undiagnosed, owing to lack of awareness of the disease and the absence of readily available screening or diagnostic tests. For the same reasons the diagnosis is often delayed by many years.
The diagnosis can be confirmed by identifying mutations in the NPC1 or NPC2 genes in 80–90% of cases. This specialized testing is available at Thomas Jefferson University Lysosomal Disease Testing Lab and the Mayo Clinic. Treatment
There is no known cure for Niemann–Pick type C, nor is there any FDA-standard approved disease modifying treatment. Supportive care is essential and substantially improves the quality of life of people affected by NPC. The therapeutic team may include specialists in neurology, pulmonology, gastroenterology, psychiatrist, orthopedics, nutrition, physical therapy and occupational therapy. Standard medications used to treat symptoms can be used in NPC patients. As patients develop difficulty with swallowing, food may need to be softened or thickened, and eventually, parents will need to consider placement of a gastrostomy tube (g-tube, feeding tube). Arimoclomol
In 2014, the European Medicines Agency (EMA) granted orphan drug designation to arimoclomol for the treatment of Niemann–Pick type C. This was followed in 2015 by the U.S. Food and Drug Administration (FDA). Dosing in a placebo-controlled phase II/III clinical trial to investigate treatment for Niemann–Pick type C (for patients with both type C1 and C2) using arimoclomol began in 2016. Arimoclomol, which is orally administered, induces the heat shock response in cells and is well tolerated in humans. In 2018, the Sponsor announced the trial did not meet either its primary or secondary endpoints. On July 17, 2021, the US Food and Drug Administration rejected the New Drug Application for Arimoclomol, and issued a complete response letter to the company Sponsor.