Belimumab Reduces Lupus Flares in a Phase III Clinical Trial
- Belimumab, a BLyS-specific inhibitor, reduces disease activity, flares, and prednisone use in patients with active SLE: efficacy and safety results from the phase 3 BLISS-52 study. (2009).
American College of Rheumatology Abstracts LB1.
What is the topic?
Belimumab (also known as Benlysta™) is being studied in Phase III clinical trials to see whether it might be effective for lupus. Belimumab specifically inhibits a protein called B lymphocyte stimulator, or BLyS, which increases the survival and activity of immune cells called B cells, which are known to be hyperactive in lupus. Belimumab is a human antibody, which looks very similar to the antibodies made by the immune system to protect people from infections. Most antibodies made during infections have varying structures so they can target different parts of a virus or bacteria. Belimumab only targets BLyS, so it is called a "monoclonal" antibody. Belimumab is in a class of treatments called monoclonal antibodies in which the cleverness of the human immune system has been used as the inspiration for the way a new biologic drug is constructed.
What did the researchers hope to learn?
The researchers wanted to find out if belimumab was better than placebo at reducing lupus disease activity and if it could accomplish this with reasonable safety.
Who was studied?
This study took place in South America, the Pacific Rim, India, and Eastern Europe. 865 patients with active lupus were studied.
How was the study conducted?
Patients participated in a Phase III, 52-week, double-blind clinical trial. "Double-blind" means that neither the patient nor the doctor knew whether the patient would be getting the real treatment (belimumab at one of two doses) or placebo, which is inactive treatment that should have no effects. All patients continued to get their usual background medications for lupus and, during the first part of the study, if a person was not doing well, then they were allowed to have certain kinds of increased background medicine. The idea was to see whether people who got belimumab would do better than those who did not, as measured by improvement in lupus activity, and whether those who entered the study on significant doses of steroids could taper down to a very low dose by the end of the study.
What did the researchers find?
The researchers found that belimumab (both 1 and 10 mg/kg doses) reduced lupus disease activity and flares, as compared to placebo. In addition, both doses of belimumab allowed more people to taper down to very low dose steroids as compared to placebo. Belimumab was well-tolerated and did not cause increased side effects as compared to placebo.
What were the limitations of the study?
The 10 mg/kg dose of belimumab did not appear to reduce the need for prednisone any more than the 1 mg/kg dose. However, it may have had a little more effect at reducing disease activity. The differences between the numbers of patients who got better in the treatment and placebo groups were not high. However, because patients in the placebo group were allowed to increase their background treatments during the study, this should not be surprising. With this kind of study, you can prove that a treatment is effective, but it is hard to know how effective.
What do the results mean for you?
In early 2010, the Food and Drug Administration is expected to begin considering whether it will be possible to approve belimumab for the treatment of lupus. If approved, belimumab become available to patients outside of studies in the near future and might help to make the disease more manageable and, in some patients, might reduce the need for background medications such as prednisone.