Protein Kinase Inhibitor H89 Enhances the Activity of Pseudomonas Exotoxin A-Based Immunotoxins.

ABSTRACT: HA22 (Moxetumomab pasudotox) is a recombinant immunotoxin (RIT), composed of an anti-CD22 Fv fused to a truncated portion of Pseudomonas exotoxin A. HA22 is in clinical trials to treat patients with hairy cell leukemia and acute lymphoblastic leukemia (ALL). LMB-11 is an improved variant of HA22 with reduced immunogenicity, has a longer half-life in the blood and high activity in vitro and in a Burkitt lymphoma model in vivo Searching for RIT enhancing combination therapies, we found the protein kinase A inhibitor H89 to enhance LMB-11 and HA22 activity 5- to 10-fold on ALL cell lines and on patient-derived ALL samples. In addition, H89 increased the activity of mesothelin-targeting RITs SS1P (38-fold) and RG7787 (7-fold) against the cervical cancer cell line KB31. Unexpectedly we found th

SUBMITTER: Liu X 

PROVIDER: S-EPMC4873377 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature