Table 1.

Summary of cellular assays for ABBV-428 showing MSLN-dependent enhancement of immune cell activations

–MSLN (EC50, nmol/L)+MSLN (EC50, nmol/L)
Agonistic assayAssay readoutABBV-927ABBV-428ABBV-428 (+sol MSLN)ABBV-927ABBV-428ABBV-428 (+sol MSLN)
B cellCD860.90 ± 0.726.0 ± 3.84.8 ± 4.30.78 ± 0.600.006 ± 0.0120.10 ± 0.12
CD830.60 ± 0.5411 ± 6.812 ± 4.70.60 ± 0.660.66 ± 0.620.18 ± 0.18
Proliferation3.6 ± 3.28.3 ± 7.20.18 ± 0.062.4 ± 0.96
moDCCD830.72 ± 0.90.82 ± 0.240.42 ± 0.362.4 ± 2.1
IL12 p7011 ± 5.39.2 ± 7.61.44 ± 0.96
  • NOTE: B cells and moDC were cultured alone (−MSLN) or with MSLN-expressing cells (+MSLN). ABBV-428 was either added alone or premixed with 300 nmol/L of soluble MSLN (+sol MSLN). Readouts of in vitro activity were monitored, and the data are indicated as mean ± SEM (n = 5). EC50, half maximal concentration; ∞, infinite.