Background The term ultra-rare diseases has been coined to describe very infrequent diseases. The European Union defines them as those whose prevalence is less than 1 per 50 000 inhabitants.

Purpose Describe ultra-rare diseases treated in our hospital and analyse the budgetary impact.

Material and methods Descriptive analysis of a cohort of seven patients suffering from an ultra-rare disease in a third-level hospital during 2016.

Results The hospital serves a population of 5 00 000 inhabitants. It currently treats seven patients suffering from an ultra-rare disease: one patient with Matoteaux Lamy disease (mucopolysaccharidosis type IV), two patients with Gaucher syndrome, two patients with paroxysmal nocturnal haemoglobinuria (PNH), one patient with atypical haemolytic uremic syndrome (SHUa) and one patient with Hunter’s disease.

The drugs with high budgetary impact used to treat these diseases are: gasulfase 5 mg/ml for Matoteaux Lamy disease, imiglucerase 400 U/vial for Gaucher syndrome, eculizumab 300 mg/30 ml for PNH and for SHUa, and idursulfase for Hunter’s disease.

The following table shows the average monthly consumption of these drugs and their cost:

In total, the monthly cost is €199,029.94 (€2,388,359.24 per year). This represents approximately 4% of the hospital’s annual drug budget.

Conclusion Complexity and high cost of treatment of ultra-rare diseases makes their management a challenge, both clinically and logistically. The pharmacy service is in charge of ensuring the availability of drugs necessary for the treatment of these patients, and must also perform a correct pharmacotherapeutic follow-up.

Reference and/or Acknowledgements 1. Conference of orphan drug and rare diseases, Hospital la Paz, Madrid2017.

No conflict of interest