Did the temporary shortage in supply of imiglucerase have clinical consequences? Retrospective observational study on 34 italian Gaucher type I patients.

Background. Enzyme Replacement Therapy (ERT) is the standard of care in Gaucher disease. The effects of withdrawal or reduced doses are debated, thus a retrospective cohort study was conducted to investigate clinical and laboratory differences in 34 Gaucher type 1 patients experiencing an ERT dosage reduction after the forced temporary imiglucerase shortage in 2009. Methods. Haemoglobin concentration, leukocytes and platelets counts, and chitotriosidase activity were assessed at baseline and after 6 and 12 months (t0, t6, t12), while bone pain, energy, work or school performance, concentration, memory and social life every 3 months. Results. The cohort was made up of 18 males and 16 females (medians: age 41.8 years, therapy duration 14.1 years, dosage reduction 35.5%). Haemoglobin, leukocytes and platelets remained substantially stable, while chitotriosidase activity showed an increase, especially after t6. Age, splenectomy or genotype were not associated with laboratory parameters changes, except for a significant median increase of chitotriosidase activity in non-splenectomised patients after 12 months (p = 0.01). At 3, 6, 9 and 12 months, more than 50% patients reported at least one problem in subjective well-being (56%, 65%, 70%, 58%, respectively), while bone pain occurred or worsened in 13/33, 13/32, 7/28 and 5/26 patients, respectively. No bone crises were reported. Conclusions. Drug reduction did not induce substantial modification in the laboratory values but seems to have influenced the well-being perception of some Gaucher patients. Thus, bone pain, general health and quality of life should be carefully monitored during ERT reductions.