A novel xenograft mouse model for testing approaches targeting human kappa light-chain diseases.

Patients with immunoglobulin (Ig) light-chain (LC) diseases such as LC light-chain amyloidosis die with organ failure and need new therapies. We sought a model to test anti-LC siRNA delivery to human plasma cells, requiring circulating LC, in vivo indicators of tumor presence, and capacity for multiple injections of delivery vehicle. The JJN-3 human myeloma reporter cell line expressing firefly luciferase (FFL) implanted intraperitoneally (IP) in the NOD scid γ (NSG) mouse has a 90% prompt tumor-take, rapid LC production, and in vivo indicators of tumor measurable on day 5 post-implant (κ LC, bioluminescent signal, and soluble B-cell maturation antigen [sBCMA]) with median day 5 serum levels of κ LC of 1482 ng/mL (range, 255-4831) and robust correlations with all in vivo indicators.