Safety, Efficacy and Pharmacokinetics of Doxycycline Plus Tauroursodeoxycholic Acid in Transthyretin Amyloidosis

Inclusion Criteria: * Histochemical diagnosis of amyloidosis as based on detection by polarizing microscopy of green birefringent material in Congo red-stained tissue specimens; * Molecular definition of the transthyretin (TTR) mutation or immunohistochemical staining of amyloid fibrils with anti-TTR antibody; * ECOG performance status (PS) 0, 1, 2; * New York Heart Association (NYHA) class ≤III * Systolic blood pressure ≥100 mmHg (standing) * Must have symptomatic organ involvement with amyloid to justify therapy; must have evidence of neuropathy and/or cardiomyopathy progression after liver transplantation performed since at least one year. * Contraception for women of childbearing potential. Medically approved contraception could include abstinence. A negative serum pregnancy test is required prior to initiation of treatment with study medication. Exclusion Criteria: * Liver transplantation in the previous 12 months or liver transplantation anticipated in less than 6 months; * ALT and/or AST ≥ 2 x Upper Normal Limit (UNL); * Alkaline phosphatase ≥ 2 x UNL; * Creatinine clearance \< 30 ml/min; * Any other lab values that in the opinion of the investigator might place the subject at unacceptable risk for participation in the study; * Echocardiographic ejection fraction \< 50%; * Other neuropathies, due to vitamin B12 deficiency, alcoholism, hypothyroidism, uremia, diabetes mellitus, vasculitides; * History of poor compliance; * History of hypersensitivity to any of the ingredients of the study therapies; * Use of any investigational drug, device (or biologic) within 4 weeks prior to study entry or during the study.