sPD-1 as a biomarker for melanoma?

IRVINE, Calif.—AIVITA Biomedical, Inc. has announced the publication of an article, entitled “Preliminary observations on soluble programmed death-1 protein as a prognostic and predictive biomarker in patients with metastatic melanoma treated with patient-specific autologous vaccines,” in the oncology journal Oncotarget. Robert O. Dillman, M.D., chief medical officer at AIVITA, authored the article, as well as other key members of the AIVITA team.

The article suggests that because of its role as an immune checkpoint, levels of soluble programmed cell death protein-1 (sPD-1) could be useful as a prognostic biomarker or predictive biomarker in cancer patients treated with vaccines. The authors theorized that very low blood levels of sPD-1 may indicate the lack of an existing anti-cancer immune response, while very high levels may indicate an active immune response that is suppressed. In between these extremes, a decrease in PD-1 following cancer vaccine injections may indicate an enhanced immune response that has not been suppressed.

Blood samples were obtained at baseline and four weeks later during a randomized trial, in which patients with metastatic melanoma were treated with either AIVITA’s immunotherapy, or an active control article. Median survival was more than twice as long in patients treated with AIVITA’s immunotherapy.

The combination of a very low baseline sPD-1 or absence of a very high PD-1 at baseline, followed by a decline in sPD-1 at week 4 of the study, was predictive of surviving 3 or more years in patients treated with AIVITA’s immunotherapy, but not in patients treated with the control article. Among patients treated with AIVITA’s immunotherapy, these sPD-1 criteria appropriately classified 80% of 3 year survivors, and 86% of patients who did not survive three years.

“These observations suggest that sPD-1 may be a useful biomarker for melanoma patients being treated with our platform immunotherapy, and/or to predict efficacy after only three injections,” said Dillman. “We look forward to confirming these results in larger studies and investigating whether it can predict response in other cancers.”

AIVITA is currently conducting three clinical studies investigating its platform immunotherapy in patients with ovarian cancer, glioblastoma and melanoma.