MMAF (MonoMethyl auristatin F), an antimitotic agent, inhibits cell division by blocking the polymerization of tubulin.

H3397 cells:105 nM.

MMAF shows in vitro cytotoxicity against a panel of cell lines. The IC50 values for Karpas 299, H3396, 786-O and Caki-1 are 119, 105, 257, and 200 nM, respectively. Targeted MMAF is much more potent than the free drug, and that cAC10 conjugates of MMAF display pronounced activities. On a molar basis, the cAC10-L1-MMAF4 is an average of over 2200-fold more potent than free MMAF and is active on all the CD30-positive cell lines tested[1].

The maximum tolerated dose in mice of MMAF (>16 mg/kg) is much higher than MMAE (1 mg/kg). cAC10-L1-MMAF4 has an MTD of 50 mg/kg in mice and 15 mg/kg in rats. The corresponding cAC10-L4-MMAF4 ADC was much less toxic, having MTDs in mice and rats of >150 mg/ kg and 90 mg/kg in rats, respectively[1].

Cells are treated with serial dilutions of test molecules and incubated 4-6 days depending on cell line. Assessment of cellular growth and data reduction to generate IC50 values is done using Alamar Blue dye reduction assay[2].