Niacin Modulates Immune Responses in a Phase I Dose-Escalation Clinical Trial of Newly Diagnosed Glioblastoma.

BACKGROUND AND

OBJECTIVES

Glioblastoma, a highly aggressive and uniformly lethal brain tumor, resists current treatments and immunotherapies by creating a potently immunosuppressive microenvironment. The objective of this study was to determine whether niacin modulates systemic immunity in patients with newly diagnosed glioblastoma.

METHODS

In a first-in-human phase I clinical trial (NCT04677049), we investigated the immunologic effects of niacin administration alongside standard-of-care surgery and chemoradiation in patients with newly diagnosed glioblastoma.

RESULTS

Niacin treatment increases the frequencies of circulating memory T cells and natural killer cells while decreasing nonclassical monocytes. Furthermore, niacin elevated serum levels of the proinflammatory cytokine interleukin (IL)-12p70 and granulocyte colony-stimulating factor and reduced growth-regulated α protein.

DISCUSSION: These data demonstrate that niacin induces systemic immunomodulatory effects in patients with glioblastoma, shifting the immune landscape toward an antitumor profile and supporting further evaluation of niacin as a potential therapeutic adjunct.

TRIAL REGISTRATION INFORMATION: This ongoing study was registered as NCT04677049 on March 1, 2021, with the first patient enrolled on March 18, 2021.

CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that niacin dose escalation modulates immune response in patients with glioblastoma treated with standard of care, including maximal safe resection, concurrent radiation and temozolomide, and adjuvant temozolomide administration. This is a Class IV study because it is an open-label trial with no blinding or comparison group.