To the Editor:
We would like to thank Figueroa-Parra et al. for their critical evaluation of our work and for acknowledging its potential clinical relevance.1 One issue raised by Figueroa-Parra et al. was an apparent discrepancy in the number of patients who received belimumab 200 mg subcutaneously and the number of patients of Asian descent in our current analysis2 compared with 2 previous analyses using some of the same belimumab trial datasets.3,4 This is unfortunately correct because the tables presented in the 2 previous papers had a numerical mistake.3,4 The correct numbers are provided in Table 1 and are compared directly with those of our current study. Importantly, the main findings and conclusions of these papers are not affected by the corrections.
Table 1.
Contributing randomized controlled trials and numbers of Asian patients and patients receiving belimumab subcutaneously across reports
| Clinical trials and BILAG-E populations | Parodis et al.2 | Gomez et al.3 and Jägerback et al.4 |
|---|---|---|
| BLISS-52; NCT00424476 | Included | Included |
| BLISS-76; NCT00410384 | Included | Included |
| BLISS-NEA; NCT01345253 | Included | Included |
| BLISS-SC; NCT01484496 | Included | Included |
| EMBRACE; NCT01632241 | Included | Not included |
| Patients with renal BILAG-E at baseline | ||
| Total; N | 1844 | 1674 |
| Asian; n (%) | 396 (21.5%) | 412 (24.6%) |
| Belimumab SC 200 mg/week; n (%) | 343 (18.6%) | 348 (20.8%) |
BILAG, British Isles Lupus Assessment Group; NEA, Northeast Asia; SC, subcutaneous.
Figueroa-Parra et al. correctly point out that there was an imbalance in mycophenolate and oral cyclophosphamide use between those who developed de novo renal flares (n = 24; 17.6% and n = 6; 4.4%, respectively) and those who did not (n = 127; 7.4% and n = 15; 0.9%, respectively); and that this may indicate that patients had lupus nephritis in the past.1 We advocate that because mycophenolate and cyclophosphamide are commonly used to treat various manifestations of systemic lupus erythematosus, it would be imprudent to infer a patient’s past medical history based on their current therapy. Nonetheless, to provide further confidence that patients with prior kidney disease were excluded, an additional level of stringency was applied to our dataset. Patients included also had to have a 0 score in the kidney components of the SLEDAI-2K along with a BILAG-E classification.
Finally, Figueroa-Parra et al. suggest that adding a stratification analysis by study and renal BILAG score would be helpful in excluding individuals who may have had previous kidney involvement.1 However, given the rarity of de novo renal flare in our pooled cohort (n = 136; 7.4%), we respectfully disagree and suggest that our analyses were facilitated by the multidimensionality of the pooled study population, including its ethnic diversity.
References
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