Human Genome Sciences has presented promising long-term, mid-stage data on its investigational lupus drug belimumab, which is partnered with GlaxoSmithKline.

The data, presented at the Congress of the European League Against Rheumatism (EULAR) meeting in Copenhagen, comes from a four-year Phase II trial. It showed that belimumab, formerly known as LymphoStat-B but now to be called Benlysta, was associated with sustained improvement in disease activity and was generally well tolerated in combination with standard of care in patients with serologically-active systemic lupus erythematosus (SLE).

Based on the results, “the apparent durability of clinical effect and the favourable safety profile observed for belimumab” suggest that it has “the potential to become an important new treatment for patients with SLE,” said Joan Merrill, a study investigator and professor at University of Oklahoma Health Sciences Center. Two Phase III trials, the largest-ever conducted in lupus patients, are underway _with the _first data expected in July 2009.

HGS and GSK have been developing Benlysta since August 2006 and the firms believe that it could represent a breakthrough in the treatment of the disease, for which no new drug has been approved by the US Food and Drug Administration in more than fifty years. It is estimated that 1.5 million people in the USA, and five million worldwide, suffer from various forms of lupus, including SLE.