Figure 6
Assessing objective responses of PCT-bearing C.IL6Myc mice to treatment with the next-generation proteasome inhibitor, ixazomib. (a) FDG-PET imaging schedule of tumor-bearing mice (n=6) undergoing treatment with ixazomib. PET scans at baseline before commencement of therapy are indicated by black squares. Treatment scans are depicted by blue squares. The number of drug applications between PET scans is indicated in blue; the cumulative, total number is indicated vertically on the right. Mouse age and number are displayed horizontally and vertically on the left, respectively. Ixazomib was dissolved in 5% hydroxypropyl-β-cyclodextrin (5% HPβCD) and administered in the lateral tail vein at 7 mg/kg body weight. Mouse 21 was found dead in cage just before the scheduled second treatment scan (black cross symbol). (b) Kaplan–Meier curve demonstrating survival of ixazomib-treated mice included in (a). Mouse numbers are indicated in red. (c) Serial coronal maximal projection PET images of mice treated with ixazomib. All images were normalized to a SUVmax of 3. Mice 16–20 achieved tumor remission upon treatment with drug, but mouse 21 had refractory disease. (d) Three-dimensional renderings of integrated PET/CT images of an IL6Myc mouse that has received four treatments with ixazomib. Decreases in FDG uptake in peripheral and abdominal lymph nodes reflect response to treatment, whereas increases indicate tumor relapse.
