Table 2.
Patient baseline characteristics and patient-reported outcome and ambulatory function scores at baseline
| Characteristic/outcome | Burosumab (n=68) | Placebo (n=66) | Total cohort (N=134) | Treatment extension cohort (n=119)* |
| Baseline characteristic | ||||
| Age, years | ||||
| Mean (SD) | 41.3 (11.6) | 38.7 (12.8) | 40.0 (12.2) | 40.5 (12.2) |
| Range | 20.0–63.4 | 18.5–65.5 | 18.5–65.5 | 18.5–65.5 |
| Female, n (%) | 44 (64.7) | 43 (65.2) | 87 (64.9) | 77 (64.7) |
| Geographic region, n (%) | ||||
| North America/Europe | 58 (85.3) | 58 (87.9) | 116 (86.6) | 101 (84.9) |
| Asia | 6 (8.8) | 5 (7.6) | 18 (13.4) | 18 (15.1) |
| Height (cm), mean (SD)† | 152.2 (9.5) | 152.7 (11.8) | 152.4 (10.7) | 152.1 (11.0) |
| BMI, mean (SD)† | 30.0 (7.5) | 30.6 (7.8) | 30.3 (7.6) | 30.6 (7.8) |
| Serum phosphate (mg/dL), mean (SD) | 2.0 (0.3) | 1.9 (0.3) | 2.0 (0.3) | 2.0 (0.3) |
| WOMAC, mean (SD) | ||||
| Total score | 51.8 (18.3) | 46.2 (17.7) | 49.1 (18.2) | 49.2 (18.4) |
| Physical functioning | 50.8 (19.7) | 43.9 (19.9) | 47.4 (20.0) | 47.6 (20.3) |
| Stiffness | 64.7 (20.3) | 61.4 (20.8) | 63.1 (20.5) | 62.6 (20.8) |
| Pain | 50.7 (18.0) | 48.0 (15.5) | 49.3 (16.8) | 49.3 (16.8) |
| Pain scores | ||||
| BPI-SF worst pain (average) | ||||
| Mean (SD) | 6.8 (1.3) | 6.5 (1.4) | 6.7 (1.4) | 6.7 (1.4) |
| ≤6.0, n (%) | 15 (22.1) | 23 (34.8) | 38 (28.4) | 33 (27.7) |
| >6.0, n (%) | 53 (77.9) | 43 (65.2) | 96 (71.6) | 86 (72.3) |
| BPI-SF worst pain (greatest) | ||||
| Mean (SD) | 8.1 (1.2) | 8.0 (1.5) | 8.0 (1.3) | 8.0 (1.3) |
| BPI-SF pain interference, mean (SD) | 5.2 (2.2) | 4.8 (2.2) | 5.0 (2.2) | 5.1 (2.2) |
| Any pain medication use, n (%) | 47 (69.1) | 44 (66.7) | 91 (67.9) | 81 (68.1) |
| Opioid use, n (%) | 17 (25.0) | 13 (19.7) | 30 (22.4) | 26 (21.8) |
| Fatigue scores, mean (SD) | ||||
| BFI global fatigue | 5.4 (2.0) | 4.9 (1.9) | 5.1 (2.0) | 5.1 (2.0) |
| BFI worst fatigue (average) | 6.9 (1.7) | 6.7 (1.5) | 6.8 (1.6) | 6.9 (1.6) |
| BFI worst fatigue (greatest) | 8.2 (1.4) | 8.2 (1.3) | 8.2 (1.3) | 8.2 (1.4) |
| BFI fatigue interference | 5.0 (2.3) | 4.5 (2.3) | 4.8 (2.3) | 4.8 (2.3) |
| Ambulatory function, mean (SD) | ||||
| 6MWT distance walked, m | 356.8 (109.5) | 367.4 (103.4) | 362.0 (106.3) | 358.9 (108.3) |
| 6MWT percentage predicted distance, % | 51.4 (15.8) | 52.3 (14.9) | 51.8 (15.3) | 51.5 (15.7) |
WOMAC range, 0–100, where 0 represents best health; BPI-SF range, 0–10, with 10 indicating worst pain; BFI range, 0–10, with 10 indicating worst fatigue.
*Subjects who completed the 96-week study extension period.
†Height and BMI were not recorded at baseline for one participant in each group.
6MWT, 6 min walk test; BFI, Brief Fatigue Inventory; BMI, body mass index; BPI-SF, Brief Pain Inventory-Short Form; WOMAC, Western Ontario and the McMaster Universities Osteoarthritis Index.