Benlysta’s approval was itself a landmark, being the first such drug approved in decades. Its use has grown slowly and steadily over time, falling just shy of blockbuster sales last year.

The drug’s market is expected to expand rapidly, however. Consultants Global Data forecast global sales of lupus drugs amounting to $1.6 billion in 2028, a 6% annual growth rate, as Saphnelo reaches the market and other drugs gain approval. Numerous drugs are in development to treat lupus, including Eli Lilly’s Olumiant, Roche’s Gazyvaro and the experimental agent dapirolizumab from UCB.

Saphnelo looked like it might not advance to market when the pivotal TULIP 1 trial failed to meet its primary goal in 2018. However, a year later a second trial called TULIP 2 succeeded using another endpoint that included more components. In that study, 48% of patients randomized to take Saphnelo were defined as responders, significantly more than the 32% in the group given placebo.

Significantly more patients taking Saphnelo reduced their use of steroids to control disease symptoms, as well as experienced reduction in skin disease. However, treatment didn’t decrease the number of swollen or tender joints reported.

AstraZeneca didn’t announce when Saphnelo will launch or what price it will set. A spokesperson didn’t respond to BioPharma Dive’s request for comment.

GlaxoSmithKline charged Medicare about $28,000 per patient on Benlysta, although that figure doesn’t include any manufacturer rebates.