Table 1

Efficacy of treatment regimens in MC38-hMSLN tumor-bearing mice

Treatment group
Efficacy studyT:C ratio
(day 15)		Mice with total tumor eradication
(day 110)
Vehicle–1/12
Radiolabeled isotype control (1×250 kBq/kg)0.760/12
MSLN-TTC (1×250 kBq/kg)0.38*2/12
Anti-PD-L1 (1.5 mg/kg, Q3/4D)0.426/12
Anti-PD-L1 (0.75 mg/kg, Q3/4D)0.642/12
Anti-PD-L1 (0.35 mg/kg, Q3/4D)1.030/12
MSLN-TTC (1×250 kBq/kg)+anti-PD-L1 (1.5 mg/kg, Q3/4D)0.08***,†††,‡7/12
MSLN-TTC (1×250 kBq/kg)+anti-PD-L1 (0.75 mg/kg, Q3/4D)0.13***,†††,§4/12
MSLN-TTC (1×250 kBq/kg)+anti-PD-L1 (0.35 mg/kg, Q3/4D)0.33*,§§1/12
Sequencing studyT:C ratio
(day 19)
Vehicle–
MSLN-TTC (1×250 kBq/kg)0.30***
Anti-PD-L1 (1.5 mg/kg, Q3/4D)0.37***
MSLN-TTC (day 8)+anti-PD-L1 (1.5 mg/kg, Q3/4D from day 8)0.04***,‡‡
MSLN-TTC (day 15)+anti-PD-L1 (1.5 mg/kg, Q3/4D from day 8)0.35***,‡
MSLN-TTC (day 8)+anti-PD-L1 (1.5 mg/kg, Q3/4D from day 15)0.30***

  • Statistical analysis was performed using linear models with weighted least squares.

  • T:C ratios and numbers of tumor-free survivors are shown. The determined T:C ratios from the sequencing study are presented in the lower part of the table.

  • *P<0.05, ***P<0.001 compared with vehicle.

  • †††P<0.001 compared with isotype control.

  • ‡P<0.05, ‡‡P<0.01 compared with corresponding MSLN-TTC monotherapy.

  • §P<0.05, §§P<0.01 compared with corresponding anti-PD-L1 monotherapy.

  • MSLN-TTC, mesothelin-targeted thorium-227 conjugate; PD-L1, programmed death receptor ligand 1; T:R, treatment:control.