Discovery of mesothelin and exploiting it as a target for immunotherapy.
We have recently reported that an immunotoxin targeting mesothelin produced durable major tumor regressions in patients with extensive treatment-refractory mesothelioma. These unprecedented tumor responses have prompted us to review how mesothelin was discovered and the advances that led to these tumor responses. This review is not comprehensive but focuses on major developments over the past 20 years since mesothelin was first identified in our laboratory. Mesothelin is a cell-surface glycoprotein whose expression in normal human tissues is restricted to mesothelial cells. Because it is highly expressed by many solid tumors, it is an attractive immunotherapy target. Antibody-based therapies currently in clinical trials include an immunotoxin, a chimeric monoclonal antibody, and an antibody drug conjugate. In addition, a mesothelin tumor vaccine and a mesothelin- chimeric antigen receptor are being evaluated in the clinic. SS1P, an anti-mesothelin immunotoxin, was the first mesothelin-directed therapy to enter the clinic, and its use showed that mesothelin-targeted therapy was safe in patients. More importantly, our recent work has shown that SS1P in combination with pentostatin and cyclophosphamide can result in durable tumor regression in patients with advanced mesothelioma and opens up the possibility that such an approach can benefit patients with many common cancers.
Authors' Affiliation: Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland pastani@mail.nih.gov hassanr@mail.nih.gov.
Ira
I
Pastan
Authors' Affiliation: Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland pastani@mail.nih.gov hassanr@mail.nih.gov.
Raffit
R
Hassan
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000627:therapeutic use; D019496:Cancer Vaccines / Q000276:immunology / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D004353:Drug Evaluation, Preclinical; D058851:GPI-Linked Proteins / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D000922:Immunotoxins / Q000276:immunology / Q000627:therapeutic use; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism; D000090204:Mesothelin; D058990:Molecular Targeted Therapy
D000911:Antibodies, Monoclonal; D019496:Cancer Vaccines; D058851:GPI-Linked Proteins; D000922:Immunotoxins; D008562:Membrane Glycoproteins; D000090204:Mesothelin