I think the market is fairly large, given that systemic lupus is pretty common, roughly 75 cases per 100,000 population, and somewhere around 40-60% of patients with SLE will develop lupus nephritis.  That would be about 250,000 SLE cases in USA alone, maybe half of which have, or will develop LN.  I have read that the globally reachable market for LN is approx $1.1 billion. Much more common in women than men, and more common in non-whites.  Current treatments are only somewhat effective, and depend on what stage the LN has reached.  Given the safety and efficacy of Lupkynis, it should reach a substantial portion of LN patients. Otsuka should be a good ex-USA partner, they have expertise in kidney disease.

Was disappointed the dry eye trial didn't work out, but there are lots of autoimmune related diseases.  It will be interesting to see what they target as a possible 2nd indication for this drug.  I have read they are investigating proteinuric kidney diseases.