Trial Outcomes & Findings for Phase 3b Study to Evaluate Skeletal Response to Eliglustat in Adult Patients Who Completed Phase 2 or Phase 3 Studies (NCT NCT02536755)

The study was conducted at 4 active sites in 3 countries. A total of 33 participants were screened between 27 October 2015 and 07 June 2017, of which 2 participants were screen failures as the selection criteria were not met.

A total of 31 participants who completed one of the Phase 2 (GZGD00304 \[NCT00358150\]) or Phase 3 studies (GZGD02507 \[ENGAGE; NCT00891202\], GZGD02607 \[ENCORE; NCT00943111\], or GZGD03109 \[EDGE; NCT01074944\]) were enrolled in this current study (EFC13781) considered as an extension of these previous studies, and received treatment with eliglustat in the current (EFC13781) study.

Phase 3b Study to Evaluate Skeletal Response to Eliglustat in Adult Patients Who Completed Phase 2 or Phase 3 Studies

Mobility, i.e., ability to walk was assessed as a part of Gaucher disease assessment in participants. In this outcome measure, number of participants with their different mobility status along with the use of mobility aids (unrestricted mobility, walks with difficulty, walks with orthopaedic aid, requires wheelchair, bedridden) at specified time points were reported. Baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Bone pain was assessed as a part of Gaucher disease assessment in participants. Participants were categorized as none (no bone pain), very mild bone pain, mild bone pain, moderate bone pain, severe bone pain and extreme bone pain during the past 4 weeks at each specified visit. In this outcome measure, number of participants with different level of bone pain during the past 4 weeks at specified time points were reported. Baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Bone crisis was assessed as a part of Gaucher disease assessment in participants. Acute, excruciating episodic bone pain is characteristic of Gaucher bone crisis, which typically causes periosteal elevation, elevated white blood cell count, fever, or debilitation lasting several days or longer and requires treatment with immobilization of the affected area, and opioid analgesics. Participants were categorized as 0= no bone crisis, 1= 1 bone crisis, 2= 2 bone crisis and \>=3 = more than 3 bone crisis during the assessment period. In this outcome measure, number of participants with different bone crises levels at specified time points were reported. Baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Bone marrow burden (BMB) scores indicate the degree of bone marrow infiltration. BMB score was measured using MRI (magnetic resonance imaging (MRI), ranged from 0 (no abnormalities) to 8 points (severe disease) for the lumbar spine and from 0 (no abnormalities) to 8 points (severe disease) for the femurs. The total BMB score was calculated as the sum of scores for femur and lumbar spine regions which ranged from 0 (no abnormalities) to 16 (severe disease) points. A higher BMB score signified more severe bone marrow involvement. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Bone marrow burden (BMB) scores indicate the degree of bone marrow infiltration was measured using MRI, ranged from 0 (no abnormalities) to 8 points (severe disease) for the lumbar spine and from 0 (no abnormalities) to 8 points (severe disease) for the femurs. The total BMB score was calculated as the sum of scores for femur and lumbar spine regions which ranged from 0 (no abnormalities) to 16 (severe disease) points. A higher BMB score signified more severe bone marrow involvement. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

Bone Mineral Density (BMD) measurements of the spine and bilateral femur were acquired by dual energy X-Ray absorptiometry (DXA) scan. Worst total femur at Baseline refers to the "worst" diseased left or right femur at Baseline. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

BMD measurements of the spine and bilateral femur were acquired by DXA scan. Worst total femur at Baseline refers to the "worst" diseased left or right femur at baseline. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

BMD measurements of the spine and bilateral femur were acquired by DXA scan. The T-score bone density categories were: normal (score \>-1), osteopenia (score -2.5 to \<=-1), and osteoporosis (score \<= -2.5). Worst total femur at Baseline refers to the "worst" diseased left or right femur at baseline. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

BMD measurements of the spine and bilateral femur were acquired by DXA scan. The T-score bone density categories were: normal (score \>-1), osteopenia (score -2.5 to \<=-1), and osteoporosis (score \<= -2.5). Worst total femur at Baseline refers to the "worst" diseased left or right femur at baseline. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

BMD measurements of the spine and bilateral femur were acquired by DXA scan. The Z-score bone density categories were: normal (score \>-2) and below normal (score \<=-2). Worst total femur at Baseline refers to the "worst" diseased left or right femur at baseline. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

BMD measurements of the spine and bilateral femur were acquired by DXA scan. The Z-score bone density categories are: normal (score \>-2) and below normal (score \<=-2). Worst total femur at Baseline refers to the "worst" diseased left or right femur at baseline. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

Osteonecrosis was assessed by bone MRI and X-Ray for spine and by MRI for femur. Total number of new or worsening osteonecrosis events among all the participants with corresponding assessment at specified time points were reported in this outcome measure. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Fracture was assessed by bone MRI and X-Ray for spine and by MRI for femur. Total number of new or worsening fracture events among all the participants with corresponding assessment at specified time points were reported in this outcome measure. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Infarcts were assessed by bone MRI and X-Ray for spine and by MRI for femur. Total number of new or worsening infarcts events among all the participants with corresponding assessment at specified time points were reported in this outcome measure. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Lytic Lesions were assessed by bone X-Ray for spine. Total number of new or worsening lytic lesions events among all the participants with corresponding assessment at specified time points were reported in this outcome measure. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Observed annual incidence rate was estimated using the total number of events divided by the total years of follow-up in each specified year (for all participants). Osteonecrosis was assessed by bone MRI and X-Ray for spine and by MRI for femur.

Observed annual incidence rate was estimated using the total number of events divided by the total years of follow-up in each specified year (for all participants). Fracture was assessed by bone MRI and X-Ray for spine and by MRI for femur.

Observed annual incidence rate was estimated using the total number of events divided by the total years of follow-up in each specified year (for all participants). Infarcts were assessed by bone MRI and X-Ray for spine and by MRI for femur.

Observed annual incidence rate was estimated using the total number of events divided by the total years of follow-up in each specified year (for all participants). Lytic Lesions were assessed by bone X-Ray for spine.

MIP-1β considered a biomarker of active bone disease, was assayed from plasma. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

MIP-1β considered a biomarker of active bone disease, was assayed from plasma. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

P1NP, a marker of bone formation was assayed from plasma. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

P1NP, a marker of bone formation was assayed from plasma. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

CTx, a marker of bone resorption was assayed from plasma. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

CTx, a marker of bone resorption was assayed from plasma. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

Chitotriosidase biomarker was assayed from plasma. Chitotriosidase biomarker levels for participants who were CYP2D6 non-Ultra Rapid Metabolizers (non-URM) was reported in this outcome measure. For this outcome measure, baseline refers to the study baseline, which was defined as status at study entry.

Chitotriosidase biomarker was assayed from plasma. Chitotriosidase biomarker levels for participants who were CYP2D6 non-URM was reported in this outcome measure. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study. Data for this outcome measure was planned to be collected and analyzed in reference to eliglustat baseline separately for Phase 2, ENGAGE and EDGE studies (GD treatment naïve participants) and from ENCORE study (participants switched from ERT).

Glucosylceramide (GL-1) biomarker was assayed from plasma. GL-1 biomarker levels for participants who were CYP2D6 non-URM was reported in this outcome measure. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Glucosylceramide (GL-1) biomarker was assayed from plasma. GL-1 biomarker levels for participants who were CYP2D6 non-URM was reported in this outcome measure. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study. Data for this outcome measure was planned to be collected and analyzed in reference to eliglustat baseline separately for participants from Phase 2, ENGAGE and EDGE studies (GD treatment naïve participants) and from ENCORE study (participants switched from ERT).

Lyso-GL-1 biomarker was assayed from plasma. Lyso-GL-1 biomarker levels for participants who were CYP2D6 non-URM was reported in this outcome measure. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

Lyso-GL-1 biomarker was assayed from plasma. Lyso-GL-1 biomarker levels for participants who were CYP2D6 non-URM was reported in this outcome measure. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study. Data for this outcome measure was planned to be collected and analyzed in reference to eliglustat baseline separately for participants from Phase 2, ENGAGE and EDGE studies (GD treatment naïve participants) and from ENCORE study (participants switched from ERT).

The 36-Item Short-Form Health Survey (SF-36) is standardized survey evaluating 8 aspects of functional health and well-being. Physical Component Summary (PCS) with 4 sub-scales: physical function, role limitations due to physical problems, bodily pain, and general health perception; and Mental Component Summary (MCS) with 4 sub-scales: vitality, social function, role limitations due to emotional problems, and mental health. Summations of item scores of the same sub-scale give the sub-scale scores, which are transformed into a range from 0 to 100; 0= worst and 100=best outcome. Both PCS and MCS range from 0 to 100 with higher scores indicating better physical and mental health. For this outcome measure, baseline refers to the current study baseline, which was defined as status at this study (EFC13781) entry.

SF-36 is a standardized survey evaluating 8 aspects of functional health and well-being. PCS with 4 sub-scales: physical function, role limitations due to physical problems, pain, and general health perception; and MCS with 4 sub-scales: vitality, social function, role limitations due to emotional problems, and mental health. Summations of item scores of same sub-scale give the sub-scale scores, which are transformed into range from 0 to 100; 0= worst, and 100=best outcome. Both PCS and MCS range from 0 to 100, higher scores indicating better physical and mental health. For this outcome measure, baseline refers to the eliglustat baseline, which was defined as participant's status at the time of first dose of eliglustat in the previous Phase 2 or Phase 3 study.

An adverse event (AE) was defined as any untoward medical occurrence in a participant who received study drug and did not necessarily had to have a causal relationship with the treatment. A serious adverse event (SAE) was any untoward medical occurrence that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, was a medically important event. TEAEs were defined as AEs that developed, worsened or became serious during the treatment-emergent period (time from the first administration of the investigational medicinal product (IMP) to the last administration of the IMP + 5 days).