Listing of pediatric patients with ITP who developed postbaseline anti-romiplostim binding antibodies in clinical trials
| Patient no. (n = 25) . | At first detection of anti-romiplostim binding antibodies . | After detection of first anti-romiplostim binding antibodies . | ||||
|---|---|---|---|---|---|---|
| Treatment week . | Romiplostim dose (µg/kg) . | Cumulative romiplostim dose (µg/kg) . | Platelet count (×109/L) . | AEs* . | Platelet response† n1/N1 (%) . | |
| Transient antibodies‡ (n = 14) | ||||||
| 1 | 12 | 5 | 49 | 189 | — | 117/117 (100) |
| 2 | 107 | 6 | 594 | 94 | Hypersensitivity: rash | 360/360 (100) |
| 3 | 139 | 10 | 1370 | 79 | — | 291/293 (99) |
| 4 | 52 | 8 | 344 | 173 | — | 75/75 (100) |
| 5 | 75 | — | 675 | — | — | — |
| 6 | 12 | 1 | 12 | 143 | — | 156/156 (100) |
| 7 | 104 | 10 | 864 | 27 | — | 28/39 (72) |
| 8 | 96 | 10 | 858 | 32 | — | 63/63 (100) |
| 9 | 51 | 9 | 394 | 178 | — | 105/105 (100) |
| 10 | 51 | 10 | 345 | 111 | — | 84/84 (100) |
| 11 | 52 | 10 | 469 | 77 | — | 16/17 (94) |
| 12 | 52 | 5 | 242 | 387 | — | 48/48 (100) |
| 13 | 51 | 10 | 320 | 146 | — | 28/31 (90) |
| 14 | 148 | 4 | 300 | 48 | — | 12/12 (100) |
| Persistent antibodies (n = 11)§ | ||||||
| 15 | 64 | 7 | 291 | 201 | — | — |
| 16 | 104 | 1 | 102 | 98 | — | 5/5 (100) |
| 17 | 25 | 8 | 108 | 35 | — | 143/144 (99) |
| 18 | 67 | — | 596 | 16 | — | 0/1 (0) |
| 19 | 12 | 8 | 47 | 25 | Bleeding: contusion, petechiae | 1/57 (2) |
| 20 | 148 | 10 | 1341 | 38 | — | 11/11 (100) |
| 21 | 76 | 8 | 520 | 192 | Bleeding: petechiae | 23/51 (45) |
| 22 | 100 | 10 | 940 | 178 | — | 57/57 (100) |
| 23 | 52 | 10 | 447 | 38 | — | 89/108 (82) |
| 24 | 76 | 7 | 389 | 52 | — | 37/37 (100) |
| 25 | 76 | 5 | 295 | 61 | — | 81/81 (100) |
| Median | 67 | 8 | 389 | 87 | — | 100% |
| Range | 12-148 | 1-10 | 12-1370 | 16-387 | — | 0%-100% |
| Patient no. (n = 25) . | At first detection of anti-romiplostim binding antibodies . | After detection of first anti-romiplostim binding antibodies . | ||||
|---|---|---|---|---|---|---|
| Treatment week . | Romiplostim dose (µg/kg) . | Cumulative romiplostim dose (µg/kg) . | Platelet count (×109/L) . | AEs* . | Platelet response† n1/N1 (%) . | |
| Transient antibodies‡ (n = 14) | ||||||
| 1 | 12 | 5 | 49 | 189 | — | 117/117 (100) |
| 2 | 107 | 6 | 594 | 94 | Hypersensitivity: rash | 360/360 (100) |
| 3 | 139 | 10 | 1370 | 79 | — | 291/293 (99) |
| 4 | 52 | 8 | 344 | 173 | — | 75/75 (100) |
| 5 | 75 | — | 675 | — | — | — |
| 6 | 12 | 1 | 12 | 143 | — | 156/156 (100) |
| 7 | 104 | 10 | 864 | 27 | — | 28/39 (72) |
| 8 | 96 | 10 | 858 | 32 | — | 63/63 (100) |
| 9 | 51 | 9 | 394 | 178 | — | 105/105 (100) |
| 10 | 51 | 10 | 345 | 111 | — | 84/84 (100) |
| 11 | 52 | 10 | 469 | 77 | — | 16/17 (94) |
| 12 | 52 | 5 | 242 | 387 | — | 48/48 (100) |
| 13 | 51 | 10 | 320 | 146 | — | 28/31 (90) |
| 14 | 148 | 4 | 300 | 48 | — | 12/12 (100) |
| Persistent antibodies (n = 11)§ | ||||||
| 15 | 64 | 7 | 291 | 201 | — | — |
| 16 | 104 | 1 | 102 | 98 | — | 5/5 (100) |
| 17 | 25 | 8 | 108 | 35 | — | 143/144 (99) |
| 18 | 67 | — | 596 | 16 | — | 0/1 (0) |
| 19 | 12 | 8 | 47 | 25 | Bleeding: contusion, petechiae | 1/57 (2) |
| 20 | 148 | 10 | 1341 | 38 | — | 11/11 (100) |
| 21 | 76 | 8 | 520 | 192 | Bleeding: petechiae | 23/51 (45) |
| 22 | 100 | 10 | 940 | 178 | — | 57/57 (100) |
| 23 | 52 | 10 | 447 | 38 | — | 89/108 (82) |
| 24 | 76 | 7 | 389 | 52 | — | 37/37 (100) |
| 25 | 76 | 5 | 295 | 61 | — | 81/81 (100) |
| Median | 67 | 8 | 389 | 87 | — | 100% |
| Range | 12-148 | 1-10 | 12-1370 | 16-387 | — | 0%-100% |
MedDRA, Medical Dictionary for Regulatory Activities.
Bleeding AEs (defined as at least 1 event from MedDRA hemorrhages [Standardized MedDRA Query]) or hypersensitivity AEs (defined as at least 1 event from the Standardized MedDRA Queries for anaphylactic reaction, anaphylactic-anaphylactoid shock conditions, angioedema, or hypersensitivity) that started or worsened within 30 days after antibody detection (within 30 days of the date of collection of a sample that tested positive for antibodies).
Platelet response was defined as a weekly platelet count ≥50 × 109/L during the treatment period without a rescue medication in the past 4 weeks (n1)/total number of weekly platelet counts (N1).
Negative result at the patient’s last time point tested.
Positive result at the patient’s last time point tested.