Results from the ongoing Gaucher Outcome Survey (GOS) continue to provide new insights into Gaucher disease (GD) characteristics, as well as improved assessments of treatment patterns and long-term global outcomes.
The GOS (NCT03291223) is an international, observational disease registry promoted by Shire, a biotech focused on rare diseases, for patients with a confirmed Gaucher diagnosis. The survey was started in 2010 to assess the natural history and long-term safety and effectiveness of treatments in Gaucher patients.
“Registries can provide a valuable source of real-world data for rare conditions like GD, where data collection from clinical trials would be challenging,” the researchers wrote in an article on the GOS. “As an ongoing registry, the structure and design of GOS is evolving in order to reflect the changing demographic characteristics of the GD population and to present data on relevant clinical outcomes.”
The most recent GOS data was reported in the study “Demographics and patient characteristics of 1,209 patients with Gaucher Disease: Descriptive analysis from the Gaucher Outcome Survey (GOS),” which appeared in the American Journal of Hematology.
As of February 2017, a total of 1,209 patients from 11 countries — Argentina, Brazil, France, Israel, Italy, Paraguay, Poland, Russia, Spain, the U.K., and the U.S. — were included in the study. Most of the participants are from Israel (44.3%) and from the United States (31.4%).
The patients had a median age at GOS entry of 40.4 years and 44.1% were male. The vast majority of the patients had been classified as having type 1 GD (91.5%); only four patients had type 2 GD, and 37 had type 3 GD. Approximately half the patients (55.8%) were of Ashkenazi Jewish ethnicity.
Genetic analysis of the GBA gene for identification of the mutations responsible for the development of Gaucher disease revealed that 374 patients had two copies (one from each parent) of the N370S variant, which is a milder GD type 1 mutation. Although other mutations and combinations were also detected, the N370S/N370S combination was the most prevalent. However, considerable genetic variability between countries was reported.
About 19.7% of Gaucher patients underwent surgical removal of the spleen, either a partial or total splenectomy.
Registry of GD-specific treatments revealed that 73.4% of patients in the GOS had received prior treatments at some time, while 14.4% of patients were untreated. No information relative to treatment was available in 12.2% of cases.
The most widely used medicines were Cerezyme (imiglucerase, 66.2%), Vpriv (velaglucerase alfa, 57.2%), Ceredase (alglucerase, 11.5%), Elelyso (taliglucerase alfa, 10.5%), and Zavesca (miglustat, 10.3%).
Evaluation of hemoglobin levels and platelet counts revealed levels close to normal for most of the enrolled patients. Also, no significant liver changes in volume were reported. These results may be a consequence of prior treatments that could have helped to manage the symptoms of the disease.
However, spleen volume measured at GOS entry was found to be almost the double in Israeli patients compared to patients elsewhere. The researchers believe this could be explained by the fact that these patients had greater disease severity, with 84.5% of patients having a moderately increased spleen (splenomegaly), but also differences in treatment dosage and regimens.
A total of 413 patients had at least one skeletal abnormality detected by imaging methods, among the most common being bone marrow infiltration, bone deformities, bone tissue death, and fractures. Bone pain was reported in 111 patients, of whom 20 had severe pain, according to their physician assessment.
“The aim of this analysis was to provide an overview of GOS and present baseline demographic and disease characteristics of participating patients to help improve the understanding of the natural history of GD and inform the overall management of patients with the disease,” the researchers said.