Calicheamicin

Cell experiment:

The enhancement of the CDC effect is studied in a similar way in the presence of CMC-544 or G5/44. Specifically, after cells are incubated with or without CMC-544 (5 ng/mL calichemicin DMH) or G5/44 at 37°C for 2 h, they are washed three times to remove unbound antibodies. The viability of cells before incubation with CMC-544 is 99.8%. After the cells are re-incubated in CMC-544- and rituximab-free medium at 37°C for 0-48 h, CDC is analyzed.

Animal experiment:

Cohorts of tumor-bearing mice (140-180 mm3) are randomized into study groups of 6 to 10 based on the number of available mice. The IDBS electronic notebook statistical package, Biobook, is used for automated animal randomization. Animals are dosed by intraperitoneal injection (or intravenously for 144580) twice a week for 4 cycles with ADC, or once a week for 2 cycles with 1.5 mg/kg doxorubicin for breast PDX tumors or 5 mg/kg Cisplatin for ovarian PDX. Study groups are followed until either individual mice or entire cohort measurements reach 1,200 mm3, at which point sacrifice is indicated. Tumor regression is defined as a reduction in mean tumor volume after dosing. In cases where tumors regress, time to progression (TTP) is determined to be the number of days between the first dose and the time at which mean tumor volume significantly increase (regrow) after regression.

References:

[1]. Damelin M, et al. Anti-EFNA4 Calicheamicin Conjugates Effectively Target Triple-Negative Breast and Ovarian Tumor-Initiating Cells to Result in Sustained Tumor Regressions. Clin Cancer Res. 2015 Sep 15;21(18):4165-73
[2]. de Vries JF, et al. The novel calicheamicin-conjugated CD22 antibody inotuzumab ozogamicin (CMC-544) effectively kills primary pediatric acute lymphoblastic leukemia cells. Leukemia. 2012 Feb;26(2):255-64
[3]. Takeshita A, et al. CMC-544 (inotuzumab ozogamicin), an anti-CD22 immuno-conjugate of calicheamicin, alters the levels of target molecules of malignant B-cells. Leukemia. 2009 Jul;23(7):1329-36.