SJG-136 is a DNA cross-linking agent, with an XL 50 of 45 nM for pBR322 DNA. SJG-136 has potent antitumor activity. In Vitro SJG-136 (dimer 5) is a DNA cross-linking agent, with an XL 50 (concentration of agent required for 50% cross-linking of pBR322 DNA) of 45 nM for pBR322 DNA. SJG-136 is cytotoxic to ovarian cell lines, such as A2780 (IC 50 , 22.5 pM), A2780cisR (IC 50 , 24 pM), CH1 (IC 50 , 0.12 nM), CH1cisR (IC 50 , 0.6 nM), and SKOV-3 (IC 50 , 9.1 nM). SJG-136 (SG2000) also reduces the viability of a panel of canine cancer cells, with GI 50 values ranging from 0.33 - >100 nM after a 1 h exposure, and In Vivo SJG-136 shows more potent antitumor effect against CMeC-1 tumour at 0.30 mg/kg than 0.15 mg/kg either as a single dose or administered once a week for three weeks via dosed intravenously in mice. SJG-136-induced H2AX phosphorylation shows good correspondence, but less sensitivity, than measurement of foci. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal administration A homogenous suspension of 5 × 10 6 exponentially growing canine melanoma cells in serum free RPMI 1640 tissue culture medium is injected subcutaneously into CD1 Nu/Nu immunocompromised female mice . The mice are divided into five groups of ten mice, with equivalent mean tumour volumes for each group. SJG-136 is given intravenously into the tail vein to four of these groups and vehicle control is administered to the fifth group. SJG-136 injections are prepared in 0.9 % NaCl and 1 % DMSO vehicle . Animals are weighed prior to the injection to determine the volume of SJG-136 required (0.1 mL/10 g body weight) which is given IV in the tail vein. Control group mice are given an IV injection of the vehicle solution; mice in groups one and two are given a single treatment of SJG-136, 0.15 mg/kg and 0.30 mg/kg respectively; mice in groups four and five are given 0.15 mg/kg and 0.30 mg/kg respectively, every seven days for a total of three treatments . aladdin has not independently confirmed the accuracy of these methods. They are for reference only. Form:Solid IC50& Target:Pyrrolobenzodiazepines