Study of the Effect of Velaglucerase Alfa (VPRIV®) on Bone-related Pathology in Treatment-naïve Participants With Type 1 Gaucher Disease

BMD of the LS was measured by DXA, and the results was converted to Z-scores appropriate for age, sex, and race. The Z-score indicated the number of standard deviations away from a reference population in the same age range, race and with the same sex. A Z-score of 0 was equal to the mean. Negative numbers indicated values lower than the mean and positive numbers indicated values higher than the mean. Baseline was defined as last data collected prior to the first administration of study drug. Change From baseline in LS BMD Z-score at Week 51 was reported. ITT Population was defined as all enrolled subjects who received at least one study drug infusion (full or partial). Here, "number of subjects analysed" signifies subjects who were evaluable for this endpoint.

Bone mineral density of the LS was measured by DXA, and the results was measured in gram per square centimeter (g/cm^2). Baseline was defined as last data collected prior to the first administration of study drug. Change From baseline in LS BMD at Week 51 and EOS (Week 103) was reported.

BMB score was a semi-quantitative magnetic resonance imaging (MRI) scoring system for assessing the extent of bone marrow involvement in Gaucher disease. BMB Score was measured using magnetic resonance imaging (MRI), range 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. Baseline was defined as last data collected prior to the first administration of study drug. Change from baseline in total BMB Score at Week 51 and EOS (Week 103) was reported.

Blood samples were collected for measurement of hemoglobin concentration. Baseline was defined as last data collected prior to the first administration of study drug. Change from baseline in hemoglobin concentration at Week 13, 25, 37, 51, 65, 77, 89, and EOS (Week 103) was reported.

Blood samples were collected for measurement of platelet count. Baseline was defined as last data collected prior to the first administration of study drug. Change from baseline over time in platelet count at Week 13, 25, 37, 51, 65, 77, 89, and EOS (Week 103) was reported.

Normalized liver volume was measured by abdominal MRI. Baseline was defined as last data collected prior to the first administration of study drug. Liver volume has been normalized for percent (%) body weight. Liver size relative to body weight = (Liver volume [cubic centimeter (cc)]/Body weight [kg])*100. Change from baseline in normalized liver volume at Week 51 and EOS (Week 103) was reported.

Normalized spleen volume was measured by MRI. Spleen volume was normalized for % of body weight. Spleen size relative to body weight= (Spleen volume [cc]/Body weight [kg])*100. Baseline was defined as last data collected prior to the first administration of study drug. Change from baseline in normalized spleen volume at Week 51 and EOS (Week 103) was reported.

Bone pain was measured by questions taken from the Brief Pain Inventory-short form (BPI-SF). Pain severity was evaluated based on the average of 4 questions from BPI-SF (Questions 3 through 6) assessing worst pain, least pain, average pain, and pain right now, each rated on a scale from 0 (no pain) to 10 (pain as bad as you can imagine) with mild pain- score (1 to 4), moderate pain- score (5 to 6), and severe pain score (7 to 10). Overall severity score was calculated as average of 4 questions ranging from 0 (no pain) to 10 (pain as bad as you can imagine). A negative change from baseline score indicates improvement. Baseline was defined as last data collected prior to the first administration of study drug. Change from baseline in severity of bone pain at Week 51 and EOS (Week 103) was reported.

Bone pain interference was measured by questions taken from the BPI-SF. Pain interference was evaluated based upon average of 7 questions from BPI-SF (9A through 9G) regarding the extent to which pain interfered with daily activities, including general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life in the last 24 hours, each rated on a scale from 0 (does not interfere) to 10 (completely interferes). Overall pain interference score was calculated as average of 7 questions ranging from 0 (does not interfere) to 10 (completely interferes). A negative change from baseline score indicates improvement. Baseline was defined as last data collected prior to the first administration of study drug. Change from baseline in bone pain interference score at Week 51 and EOS (Week 103) was reported.

Overall fatigue was measured by the BFI. BFI was a 9-item questionnaire developed to assess subjective fatigue. Each question asked the respondent to rate the level of their experienced fatigue over the past 24 hours on an 11-point (0-10) scale. First 3 questions measure fatigue severity at current, usual, and worst levels, respectively, with 0 indicating "no fatigue" and 10 indicating fatigue "as bad as you can imagine". Next 6 questions assessed the level fatigue interference with daily activities included general activity, mood, walking ability, normal work (both inside and outside the home), relations with other people, and enjoyment of life. A score of 0="no interference" while a score of 10="complete interference. Overall fatigue score was calculated as average score of all 9 items on the BFI ranging from 0="no fatigue" to 10="as bad as you can imagine".

WHO BMD Classifications (Normal Bone Density, Osteopenia, Osteoporosis), bone mineral density was classified based on LS BMD T-scores. BMD T-score was a comparison of an individual's BMD compared to "normal". Also, BMD T-score is the standard deviation of the difference between measured BMD and that of the healthy young adult "normal". The T-score scale was as follows: -1 and above=normal, -1 to -2.5=osteopenia (below normal and may lead to osteoporosis), and -2.5 and below=osteoporosis. Number of participants with shift in WHO BMD classifications based on LS T-Scores at Week 51 and EOS (Week 103) were reported.

An adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. A TEAE was defined as any AE that occurred on or after the time of the first infusion of study drug until 30 days after the last infusion of study drug. Number of participants with TEAEs were reported.

Anti-velaglucerase alfa antibody included anti-velaglucerase antibodies (ADA) and neutralizing anti-velaglucerase antibodies (NAb). The Anti-velaglucerase antibody status was summarized as categorical variable by positive and negative. Number of participants who developed positive anti-velaglucerase alfa antibody were reported.