It is currently looking unlikely that Chiesi’s Lamzede will become routinely available on the NHS for patients with alpha-mannosidosis, after cost-regulators issued a preliminary rejection of the drug.

Just 25 people in England are thought to have alpha-mannosidosis, a very rare inherited enzyme condition that causes cell damage through build-up of mannose-rich oligosaccharides in many organs and tissues of the body.

Symptoms include facial and skeletal deformities, mental health difficulties, reduced lung function because of an enlarged liver and spleen, and immunodeficiency with recurring infections.

Currently there are no pharmacological/drug treatments that alter the disease course, with treatment strategies focusing on managing symptoms and improving quality of life.

Lamzede (velmanase alfa) is an enzyme replacement therapy given lifelong once a week by intravenous infusion at a dose of 1 mg/kg.

However, while clinical trial evidence suggests that it is a potentially promising treatment, the National Institute for Health and Care Excellence concluded that the size and nature of any clinical benefits are “highly uncertain both in the short and long term, because of important limitations/uncertainties in the trial evidence.”

The draft guidelines also highlight uncertainties in the economic modeling, in particular that it is based on expert opinion rather than clinical evidence.

Consequently, it calculated cost-effectiveness estimates for Lamzede to overshoot that range normally considered acceptable for highly specialised technologies.

Earlier this year, Lamzede was granted marketing approval in Europe under ‘exceptional circumstances’ according to the EU legislation, which aim to enable treatment of extremely rare disorders for which traditional large-scale clinical studies are not feasible.