Miglustat in Tangier disease (MUSTANG)

BACKGROUND: Tangier disease is an ultra-rare inborn error of metabolism, leading to neuropathy and cardiac disease. The only established treatment is low fat diet – but this slows the disease rather than curing it. A patient with Tangier disease in Italy was given Miglusat due to a misdiagnosis, and this had a dramatic effect on her disease state.

Given this experience, and knowledge of the disease process, we would like to try this drug with a patient with Tangier disease from England who is developing a progressive neuropathy.

AIM: To determine, in a single patient, whether Miglusat can produce improvement in his neuropathy caused by Tangier disease. DESIGN: A single subject experiment, of ABAB design. SETTING: An outpatient department in England. INTERVENTION: Miglusat, 200mg by mouth, three times a day, plus usual care COMPARATOR: Usual care

OUTCOMES: 9-hole peg test (dexterity), hand grip strength and 3-point pinch strength, 6-minute walk test / 10-metre walk test, quality of life, activities of daily living, Adverse events. Mechanistic: lysosomal volume and lipid analysis in B cells, biomarkers POWER: We have >90% power to show minimum important differences in the 9-hole peg test, and grip strength.

PROJECT TIMETABLE: 3 months set up, 6 months on drug, 6 months off drug, 6 months on drug, 6 months off drug, 3 months to close the project, analyse, and deliver a report to NHS England. Total: 30 months. IMPACT: The results will directly impact NHS England’s decision to commission Miglusat for this patient.