Effect of placebo or belimumab plus standard therapy at Week 52 on preexisting antibody titers to pneumococcal, tetanus, and influenza vaccines in patients vaccinated prior to Day 0 and not revaccinated during the study.
| Standard Therapy + Placebo | Standard Therapy + Belimumab 1 mg/kg | Standard Therapy + Belimumab 10 mg/kg | |
|---|---|---|---|
| Pneumococcal vaccine antigen, n†† | 26 | 27 | 22 |
| 1 (1): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 10/12 (83) | 20/23 (87) | 12/13 (92) |
| 3 (3): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 18/20 (90) | 19/20 (95) | 15/15 (100) |
| 4 (4): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 9/10 (90) | 17/18 (94) | 5/6 (83) |
| 8 (8): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 17/17 (100) | 21/21 (100) | 16/18 (89) |
| 9 (9N): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 17/17 (100) | 21/21 (100) | 12/13 (92) |
| 12 (12F): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 4/9 (44) | 16/16 (100)† | 4/7 (57) |
| 14 (14): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 22/22 (100) | 20/21 (95) | 18/19 (95) |
| 19 (19F): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 23/23 (100) | 22/22 (100) | 15/16 (94) |
| 23 (23F): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 19/20 (95) | 20/21 (95) | 14/14 (100) |
| 26 (6B): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 17/17 (100) | 21/22 (96) | 11/13 (85) |
| 51 (7F): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 20/20 (100) | 26/26 (100) | 17/19 (90) |
| 56 (18C): no. with titer ≥ LLOQ/no. with level ≥ LLOQ at baseline (%)* | 22/23 (96) | 24/24 (100) | 17/17 (100) |
| Tetanus toxin, n†† | 33 | 32 | 23 |
| No. with titer ≥ 0.50 IU/ml/no. with titer ≥ 0.50 IU/ml at baseline (%) | 22/26 (85) | 24/25 (96) | 11/14 (79) |
| Influenza antigens, 2006–7 vaccine, n †† | 16 | 23 | 12 |
| New Caledonia: no. with titer > 1:10/no. with level > 1:10 at baseline (%) | 15/16 (94) | 21/22 (96) | 12/12 (100) |
| Wisconsin: no. with titer > 1:10/no. with level > 1:10 at baseline (%) | 16/16 (100) | 22/22 (100) | 12/12 (100) |
| Malaysia: no. with titer ≥ 1:10/no. with level > 1:10 at baseline (%) | 16/16 (100) | 22/22 (100) | 11/11 (100) |
| Influenza antigens, 2007–8 vaccine, n †† | 29 | 40 | 27 |
| Solomon Island 1,2,3: no. with titer > 1:10/no. with level > 1:10 at baseline (%) | 28/28 (100) | 39/39 (100) | 27/27 (100) |
| Wisconsin 1,2,3: no. with titer > 1:10/no. with level > 1:10 at baseline (%) | 29/29 (100) | 39/39 (100) | 25/25 (100) |
| Malaysia 1,2,3: no. with titer > 1:10/no. with level > 1:10 at baseline (%) | 28/28 (100) | 33/34 (97) | 26/27 (93) |
↵* No. with antipneumococcal IgG level ≥ 0.3 μg/ml at Week 52/no. with level ≥ 0.3 μg/ml at baseline;
↵† p < 0.05.
↵†† Numbers of patients with data available. The p values for comparison of proportions of patients maintaining antibody levels ≥ LLOQ or achieving adequate response levels are from Fisher’s exact test for belimumab vs placebo. IgG: immunoglobulin G: LLOQ: lower limit of quantitation.