Benlysta: Limited Efficacy for Lupus?

Benlysta is a new lupus treatment being made by Human Genome Sciences along with GlaxoSmithKline.  It is a fully human monoclonal antibody that targets the B-lymphocyte stimulator – BLYS for short – and has shown some efficacy in trials to date.

Our analysis, however, is that the results are lackluster and, unfortunately, likely to mean not so great efficacy in a clinical setting.

Let’s start at the beginning.

Systemic lupus erythematosus is an autoimmune connective tissue disorder where the body attacks itself.  It has strange and unpredictable symptoms and has a chronic, relapsing nature which makes treatment a challenge.

Up to 1.5 million Americans have some form of lupus, but the amount with serious symptoms is probably not that high.

The current treatments for lupus are limited and not so great.  They are commonly used off-label and can cause side effects over use.  For several decades, due to the complex nature of the condition, there has been no new treatment for lupus.

Benlysta is part of a growing trend of using monoclonal antibodies to treat disease.  Antibodies are a lot like heat-seeking missiles generated by your body.  They are Y shaped and have specific targets that, once they find, they bind to.

Benlysta targets B-lymphocytes which play a role in generating immune responses.  Theoretically this should provide significant clinical benefit.  Results have not been so great.

One of the first major studies into Benlysta showed no superiority over placebo.  Instead of dropping the project, the company looked at the study and changed its design to improve how their treatment works.  They developed an individual responder index to measure improvement, removed participants who were non-seropositive and changed some of the time related measures.

The next two Phase III trials had better results.  One, the BLISS-52, had 865 participants and 51.4% response rate on 1mg/kg dose and a much better 57.6% response to a 10mg/kg dose.  And the BLISS-76 of 819 patients had 40.6% response to the lower and 43.2% response to the higher dose.

The bad news?  In both trials, the response rate was not that much better than placebo – 46.3% responded to placebo in the first, and 33.8% in the second study.  That’s about a 10% difference in efficacy from placebo to treatment.

We also noticed that the treatment did not have any difference in steroid reductions compared to placebo.

These data indicate that Benlysta may not be the most effective treatment while likely being somewhat better than placbeo.

Sources:

1) Re-evaluation of biologic therapies in systemic lupus erythematosus
2) Human Genome Sciences trial data wow lupus community