Labeling can address the failure of clinical trials for Human Genome Sciences' Benlysta (belimumab) to study the biologic in the broad population of lupus patients, FDA's Arthritis Advisory Committee concluded Nov. 16.

With a directive to the agency to craft such labeling, the panel voted 13 to 2 in favor of approving the monoclonal antibody, which would be the first drug approved by FDA for lupus in more than five decades.

A major concern for panel members was the scarcity in the two pivotal trials of patients with severe lupus kidney disease or active central nervous system lupus. Rather, the most commonly involved organ systems in patients at baseline were musculoskeletal and mucocutaneous (Also see "Variety of Issues Undermine Efficacy Data As FDA Takes Benlysta To Advisory Panel" - Pink Sheet, 12 November, 2010.).

Because of the limited patient population in the trials, it is difficult to extrapolate the data to the larger lupus population, David Pisetsky, M.D., Duke University Arthritis Center, said. "Non-renal, non-CNS disease is all we've been able to look at because of the study design. ...This really does have to be clarified in a very significant way to avoid the perception that it's really for all active [lupus]. ...There have to be a lot of limitations here."

Christy Sandborg, M.D., Stanford University, urged a more cautious approach to labeling so it is not "overly restrictive." Benlysta is likely to be used in patients with CNS and renal lupus, she said, and suggested that labeling "actually state that these were populations that were not specifically tested."

An initial vote on the drug's efficacy had elicited a more mixed vote, with 10 panel members saying the drug is effective and five saying it is not. But several members explained that their negative vote was based on the drug's failure to demonstrate efficacy for the requested indication for reduction of disease activity in adult patients with active, autoantibody-positive systemic lupus erythematosus in combination with standard therapy.

In light of that, Curtis Rosebraugh, Director of the Office of Drug Evaluation II, simplified the question to avoid confusion, "If you think this should be on the market, vote yes, and then tell us what you think the label should be if you don't agree with the indication."

Panel members accepted the safety of the drug by a near-unanimous vote of 14 to 1.

Benlysta is a first-in-class monoclonal antibody that targets the protein B-lymphocyte stimulator. HGS and GlaxoSmithKline are co-developing and co-commercializing the biologic.

- Cathy Dombrowski (c.dombrowski@elsevier.com )

HGS/GSK's Benlysta Gets Advisory Panel Backing For Lupus Labeling That Reflects Trials' Limitations

More from Archive

More from Pink Sheet