The indenoisoquinolines are a novel class of non-camptothecin topoisomerase I (Top1) inhibitors whose mechanism of action involves trapping the covalent complex formed between DNA and Top1 during cellular processes. As an ongoing evaluation of the indenoisoquinolines for Top1 inhibition and anticancer activity, indenoisoquinoline analogs have been screened in the National Cancer Institute's hollow fiber assay (HFA). Some of the derivatives demonstrated significant activity at intraperitoneal and subcutaneous fiber placement sites, along with net cancer cell kill in one or more cell lines.