Belimumab efficacy is 'mild' but market potential still great†: anticipating us approval of the first lupus drug since 1957.

Speaking for the inThought Expert Discussion Series in February, Dr George Tsokos mirrored the opinion of many lupus thought leaders: Human Genome Sciences (HGS) and GlaxoSmithKline's (GSK) belimumab (Benlysta®) was likely to be approved by the US FDA and, despite modest efficacy, will be used by a large proportion of lupus patients. Dr Tsokos praised HGS and GSK's clinical trial program for belimumab, noting that huge trials and unique trial endpoints were needed to demonstrate the drug's efficacy, allowing it to succeed where so many other lupus drugs have failed. Still, belimumab's trial design may not become standard in future lupus trials - questions about identification of appropriate lupus patients with active disease, trial endpoints, and subgrouping lupus patients remain. Although Dr Tsokos does not expect other agents currently being tested in lupus trials to be significantly more efficacious than belimumab, his research suggests that significantly better results could be obtained using agents targeting interleukin-17, spleen tyrosine kinase (SYK), and calcium/calmodulin-dependent protein kinase type IV (CaMKIV). In line with Dr Tsokos' comments and consistent with inThought's outlook for belimumab, the US FDA granted approval for belimumab in March 2011, making it the first new lupus drug to be approved in more than 50 years. inThought projects US sales of $1.1 billion for belimumab by 2017. † Adapted and reproduced from Weintraub B. Benlysta Efficacy is "Mild" but Market Potential Still Great: Anticipating U.S. Approval of the First Lupus Drug Since 1957. inThought Research, 2011 Feb 24.