"But with just a 10% difference effect size between the two arms, people say this is a weak effect, making all patients a little better," Dr. van Vollenhoven said. "But there could be at least two other explanations. One is that this is a very good medication, but only for some patients. In practice we would have to figure out who these patients are and that they should be getting this treatment. Another is that in these huge trials there is a lot of static – if you’re measuring with an instrument that’s not very good, you won’t get a strong signal."
Dr. van Vollenhoven said that in his clinical practice, "we have found that the patient who has low complement and anti-DNA antibodies plus active disease and are on steroids have a pretty good likelihood of benefiting from belimumab, and that’s how we have been using it in our practice. And we are seeing good results."
Dr. van Vollenhoven has served as an adviser or consultant for Abbott, Bristol-Myers Squibb, GlaxoSmithKline, Merck Sharp & Dohme, Pfizer, Roche, and UCB Pharma. Dr. Lightstone has received support from Genentech, Roche, Biogen Idec, Aspreva, and GlaxoSmithKline.