Sales of drugs to treat systemic lupus erythematosus (SLE) are set to soar from just $900 million in 2012 to $4 billion by 2022, according to new forecasts.

GlaxoSmithKline’s Benlysta (belimumab), the first biologic drug approved for the disease, will be the primary driver of market growth in the US, France, Germany, Italy Spain, the UK and Japan, where its sales will reach $1.1 billion in 2022, says the study, from Decision Resources.

However, physician perceptions of Benlysta’s modest efficacy and slow onset to action and its restrictive label – which does not include patients with severe, active renal and central nervous system (CNS) disease – leave opportunity for emerging agents with better efficacy profiles and acceptable safety to gain market share, it also predicts.

In the B-cell modulator class alone, the anticipated entry of UCB’s epratuzumab, Eli Lilly’s tabalumab and Anthera Pharmaceuticals’ blisibimod will drive sales of $1.1 billion by 2022, accounting for almost 30% of total SLE sales, the study forecasts. Concerns regarding safety will initially limit uptake of these new agents but, as physicians gain experience towards the end of the forecast period, they may see use ahead of Benlysta, it goes on, adding that, a class, the B-cell modulators will account for 65% of total market sales in 2022.

Decision Resources is also predicting that uptake of Bristol-Myers Squibb’s Orencia (abatacept) for the treatment of lupus nephritis, beginning in 2018, will be a significant driver of the SLE market. While Orencia’s market share in 2022 will be modest, the anticipated high price of the 30mg/kg dose of the drug currently being tested in Phase III trials will drive its sales to account for approximately 19% of total SLE sales in 2022, it says.

“Benlysta has received a lukewarm reception to the SLE market, owing primarily to physician perceptions of its modest efficacy, slow onset to action and inability to be used in the high-unmet-need population of patients with severe, life-threatening organ involvement,” according to Decision Resources analyst Laura Croal.

“Owing to its high price in a largely generic market, Benlysta will lead market sales in 2022 on the strengths of its excellent safety profile, demonstrated efficacy in pivotal trials and first-to-market advantage. However, the drug will be vulnerable to emerging agents with acceptable safety profiles that demonstrate improvements in these key perceived weaknesses,” Dr Croal forecasts.