Sequential axitinib and survivin vaccination unlock curative PD-1 immunotherapy in renal carcinoma

Area of Science:

• Immunotherapy
• Renal Cell Carcinoma
• Cancer Treatment Sequencing

Background:

• Metastatic renal cell carcinoma (mRCC) treatment combining VEGFR tyrosine-kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) shows limited complete response rates.
• Optimizing therapeutic synergy in mRCC requires novel strategies beyond current combination therapies.
• The sequence of therapeutic interventions significantly impacts treatment efficacy in preclinical cancer models.

Purpose of the Study:

• To investigate the impact of treatment sequencing on the efficacy of combining VEGFR blockade, vaccination, and PD-1 inhibition in metastatic renal cell carcinoma.
• To elucidate the mechanistic basis for optimizing synergistic immunotherapy in a preclinical mRCC model.
• To establish a framework for a curative immunotherapy strategy in renal carcinoma.

Main Methods:

• Utilized an orthotopic RENCA (renal cell carcinoma) mouse model to evaluate different sequences of axitinib (VEGFR inhibitor), a survivin-based long-peptide vaccine (SVX), and anti-PD-1 blockade.
• Assessed tumor vasculature, hypoxia, myeloid subsets, T-cell infiltration (CD4+ and CD8+), and polyfunctional cytokine/chemokine profiles.
• Analyzed the temporal coordination of vascular reprogramming, antigen-specific priming, and checkpoint blockade.

Main Results:

• Short-term axitinib preconditioning transiently remodeled tumor vasculature, reduced hypoxia, and decreased suppressive myeloid cells, creating an immune-permissive window.
• Administering the SVX vaccine during this window induced strong Th1-polarized CD4+ and cytotoxic CD8+ T-cell responses.
• The triple regimen (axitinib + [SVX + anti-PD-1]) administered sequentially achieved durable tumor control and a high rate of complete responses, outperforming other sequences.

Conclusions:

• Temporal coordination of vascular reprogramming, tumor-antigen vaccination, and PD-1 blockade is critical for achieving synergistic immunotherapy effects in renal carcinoma.
• The optimal sequence involves axitinib preconditioning followed by concomitant vaccination and PD-1 blockade.
• This mechanistically grounded strategy converts immune-excluded tumors into a T-cell-dominated, cytotoxic niche, offering a potential curative approach for renal carcinoma.