Tumor penetration of AMSA in man.

4'-(9-Acridinylamino)-methanesulfon-m-anisidide (AMSA) has shown significant antitumor activity against several murine tumors and leukemias. During its Phase I and II clinical trial, we were able to obtain tumors, plasma, and CSF specimens from patients who received varying doses of AMSA, as well as patients who received high doses and had autologous bone marrow rescue. The drug was analyzed chromatographically. The tumor to plasma drug concentration ratios ranged from 200% to 486%, apparently independent of dose and sampling time. Because AMSA was not detected in the CSF, the drug may not be effective in the treatment of meningeal metastasis. High-dose AMSA therapy with bone marrow rescue did not result in significantly higher AMSA concentrations in the tumor, nor did it elicit favorable response.