One-year response rates -- the study's primary goal -- were 43% in the high-dose Benlysta group, compared with just 34% of those on standard treatment.
By 76 weeks, the gap had narrowed: 39% of patients on high-dose Benlysta responded vs. 32% of those on placebo, a difference that could have been due to chance.
Similarly, at one year, patients taking Benlysta had fewer disease flare-ups and fewer severe flare-ups. And they reported less fatigue. By 76 weeks, the figures between the high-dose Benlysta and standard treatment groups were similar, says researcher Richard Furie, MD, a rheumatologist from North Shore-Long Island Jewish Health System. He has received funding from for Human Genome Sciences Inc. and GlaxoSmithKline, which are developing the drug and funded the studies.
And although Benlysta was associated with a reduction in steroid use at one year, that advantage too seemed to wane at 76 weeks. One of the most important goals of treatment is to get patients off steroids, which cause many undesirable side effects, including bloating, weight gain, acne, and high blood pressure.
Merrill says, "It could be [patients] did very, very well on standard therapy. We don’t know how the drug would do against nothing. In any lupus treatment, when you get close to a 40% [response rate], you are doing very, very well.
"If [standard] treatment is in the 30%-40% range, you have a problem analyzing your data. ... The problem is the standard treatment group, not the drug," she says.
Benlysta for Lupus: Side Effect Profile
Nearly all patients in both the studies being considered by the FDA panel -- whether they were given Benlysta or placebo -- experienced some side effect, including headache, muscle pain, upper respiratory tract infection, urinary tract infection, and influenza.
However, "treatment with [Benlysta] appeared to be associated with an increase in death, serious adverse events, infections and serious infections, and neurologic and psychiatric adverse events/serious adverse events, including three suicides in Benlysta-treated patients," the FDA reviewers write.
Says Merrill, "In some of the areas where this drug was tested, those infections are not as uncommon as in the U.S. I looked at these data, and I thought they were low, terrific. ... The infections were well within the bounds of any other biologic [agent] and look better than most."