Repurposing ospemifene for potentiating an antigen-specific immune response

Area of Science:

• Immunology
• Pharmacology
• Oncology

Background:

• Ospemifene, an established treatment for postmenopausal symptoms, is being investigated for its immunomodulatory properties.
• Its potential as an immune modulator, particularly in combination with cancer vaccines, requires thorough preclinical evaluation.

Purpose of the Study:

• To assess the immunomodulatory activity of ospemifene when administered with a peptide cancer vaccine.
• To explore the effects of ospemifene on T-cell activation, immune response, and cytotoxic T-lymphocyte activity in preclinical models.

Main Methods:

• Preclinical studies in mice evaluated ospemifene's effects on immune responses to a peptide cancer vaccine.
• Various oral dosing schedules (chronic, intermittent, pretreatment) and doses of ospemifene were employed.
• Immune responses were assessed through in vitro cytokine expression and in vivo antigen-specific immune response and cytotoxic T-lymphocyte activity.

Main Results:

• Ospemifene induced key TH1 cytokines (interferon gamma, interleukin-2) in vitro, potentially via phosphoinositide 3-kinase and calmodulin pathways.
• Combination therapy with ospemifene and a peptide cancer vaccine significantly enhanced antigen-specific immune response and cytotoxic T-lymphocyte activity.
• Different dosing schedules demonstrated distinct effects: pretreatment activated naive T-cells, intermittent dosing modulated tolerance, and chronic dosing reduced pro-inflammatory cytokines.

Conclusions:

• Ospemifene exhibits dose- and schedule-dependent immunomodulatory activity.
• This activity can be leveraged to enhance the efficacy of antigen-specific cancer vaccines.
• Ospemifene presents a promising approach for tailoring and augmenting cancer immunotherapy for diverse malignancies.