Nitisinone is in clinical development for the treatment of alkaptonuria. Alkaptonuria is a rare metabolic disorder, in which patients lack a functional enzyme that prevents the body fully breaking down two amino acids called tyrosine and phenylalanine. This results in a build-up of a chemical called homogentisic acid (HGA) in the body, which is deposited as black pigment in tissues, in a process called ochronosis. This results in dark colouration of urine, joint problems, breathing difficulties and heart, kidney and prostate problems. In the later stage, patients may experience physical disability and inability to perform daily activities. Early recognition and management of alkaptonuria is desirable to slow the progression of this disease.
Nitisinone, which is administered orally, works by blocking the production of the HGA molecule, and early trial evidence confirms a reduction in HGA levels and suggests the nitisinone could slow down or stop the disease and may partially reverse ochronosis. If licensed, nitisinone may provide the first pharmacological treatment option for patients with alkaptonuria who do not have any approved treatment.
Treosulfan in addition to fludarabine is in clinical development for paediatric non-malignant disease prior to allogeneic stem cell transplant. Treosulfan is a medicine given to patients before they have a bone marrow transplant from a donor known as ‘allogeneic haematopoietic stem cell transplantation’. It is used as a ‘conditioning’ treatment to clear the patient’s bone marrow and make room for the transplanted bone marrow cells, which can then produce healthy blood cells. Treosulfan is used together with another medicine called fludarabine for the treatment of a variety of disorders that require a bone marrow transplant.