A Comparison of Concurrent and Delayed Tests for Antitumor Activity of L-Asparaginase.

Abstract

Delayed testing is compared to concurrent testing for the evaluation of chemotherapeutic agents using samples of L-asparaginase as test materials. A large difference in the detection of the antitumor activity of the agents was found, depending upon the method of testing. Guinea pig serum L-asparaginase was quite effective in repressing tumor development when administered within an hr. of tumor inoculation while an L-asparaginase (EC-2) from Escherichia coli was not. The delayed test (treatment given 7 days after tumor inoculation), showed that EC-2 was able to induce complete remission of an established transplant of each of the 3 lymphoid tumors tested (EARAD1, 6C3HED, and P1798). These results draw attention to the value of the delayed test for the screening of potential chemotherapeutic agents.