After two years of Cerdelga (eliglustat) therapy, patients with Gaucher disease (GD) type 1 maintained or improved their spleen or liver health, and their red blood cell and platelet counts, according to a new study of real-world data.
The findings applied to patients who had not undergone any GD treatment, and those who switched from enzyme replacement therapy (ERT) to Cerdelga.
The study, “Real‐World Effectiveness of Eliglustat in Treatment‐Naïve and Switch Patients Enrolled in the International Collaborative Gaucher Group Gaucher Registry,” was published in the American Journal of Hematology.
GD is characterized by a build-up of toxic levels of glucocerebroside, a fatty component of cell membranes. Mutations in a gene called GBA, which provides instructions for an enzyme known as beta-glucocerebrosidase, prevent the breakdown of glucocerebroside.
The standard care for people with GD has been ERT, which seeks to provide functioning beta-glucocerebrosidase.
Cerdelga (developed by Sanofi Genzyme) is an approved therapy for adults with GD type 1, currently available in more than 55 countries, including the U.S.
The medicine is a substrate reduction therapy, as it reduces the production of glucocerebroside by partially blocking the enzyme glucosylceramide synthase.
“Following drug approval, it is prudent to evaluate ‘real–world’ safety and effectiveness outside of the clinical trial setting, where patients are selected based on specific inclusion and exclusion criteria and treatment compliance is generally very high,” the study stated.
Therefore, researchers at Sanofi Genzyme, along with scientists at academic institutions in the U.S. and Germany, collaborated to analyze the effectiveness of Cerdelga in patients enrolled in the International Collaborative Gaucher Group (ICGG) Gaucher Registry (NCT00358943).
The registry, sponsored by Sanofi Genzyme, is an international database with information from more than 6,000 GD patients in 60 countries, covering clinical and therapeutic characteristics.
Data were available for 231 patients, including 19 with no prior GD treatment (treatment-naïve) and 212 who had been treated with ERT — 94% with Cerezyme (imiglucerase) — and switched to Cerdelga. Mean age at diagnosis ranged from 15 in the 36 patients who had undergone spleen removal to 26 in treatment-naïve participants.
After two years on Cerdelga, treatment-naïve patients showed significant increases in hemoglobin levels by 1 g/dL, platelet count improved by 38%, spleen volume decreased by 53%, and liver volume decreased by 8%, but that was not considered statistically significant. Notably, hemoglobin is the protein in red blood cells that carries oxygen throughout the body.
Among the patients who switched from ERT and did not have their spleen removed, Cerdelga therapy further decreased spleen volume by 15%. While most patients who switched from ERT did not have low red blood cell and platelet counts, or enlarged spleens or livers at baseline, there was no change in their health status after two years of therapy.
Overall, the vast majority of patients maintained normal baseline clinical values after two years on Cerdelga, and most of the changes were shifts from a more severe to less severe disease category. Also, all patients maintained or improved their spleen/liver enlargement status, 98% in their anemia status, and 93% in thrombocytopenia status.
Scores for lumbar spine abnormalities showed no change in treatment-naïve patients or participants switching from ERT who underwent spleen removal. However, those who had not undergone splenectomy and were treated with ERT showed significant improvement.
In a subset of six patients who rapidly metabolized Cerdelga — known as CYP2D6 ultra-rapid metabolizers and for whom Cerdelga is not recommended due to insufficient data — four maintained hemoglobin levels and platelet counts after two years of therapy.
While median chitotriosidase values — a biomarker for Gaucher — decreased by 78% in treatment-naïve patients, 24% in non-splenectomized patients switching from ERT, and 38% in those also switching but after spleen removal, the individual chitotriosidase levels varied markedly, the scientists said.
Finally, quality of life — as assessed with the Short-Form (SF-36) Health Survey — showed that scores remained within the normal range throughout treatment in a subset of previously treated participants.
“[Cerdelga] treatment outcomes in the real-world setting of the ICGG Gaucher Registry are consistent with those reported in the pivotal clinical trials, demonstrating long-term benefit in treatment-naïve patients and ERT switch patients in keeping with established therapeutic goals for Gaucher disease type 1,” the researchers wrote.