Intratumoral immunotherapy with mRNAs encoding chimeric protein constructs encompassing IL-12, CD137 agonists, and TGF-β antagonists

Assunta Cirella; Elixabet Bolaños; Carlos Luri-Rey; Claudia Augusta Di Trani; Irene Olivera; Gabriel Gomis; Javier Glez-Vaz; Beatrice Pinci; Saray Garasa; Sandra Sánchez-Gregorio; Arantza Azpilikueta; Iñaki Eguren-Santamaria; Karmele Valencia; Belén Palencia; Maite Alvarez; Maria C Ochoa; Álvaro Teijeira; Pedro Berraondo; Ignacio Melero

doi:10.1016/j.omtn.2023.07.026

Intratumoral immunotherapy with mRNAs encoding chimeric protein constructs encompassing IL-12, CD137 agonists, and TGF-β antagonists

Mol Ther Nucleic Acids. 2023 Jul 28:33:668-682. doi: 10.1016/j.omtn.2023.07.026. eCollection 2023 Sep 12.

Authors

Assunta Cirella^{1

2}, Elixabet Bolaños^{1

2}, Carlos Luri-Rey^{1

2}, Claudia Augusta Di Trani^{1

2}, Irene Olivera^{1

2}, Gabriel Gomis¹, Javier Glez-Vaz^{1

2}, Beatrice Pinci¹, Saray Garasa¹, Sandra Sánchez-Gregorio^{1

2}, Arantza Azpilikueta^{1

2}, Iñaki Eguren-Santamaria^{1

2}, Karmele Valencia^{3

4}, Belén Palencia¹, Maite Alvarez^{1

2

4}, Maria C Ochoa^{1

2

4}, Álvaro Teijeira^{1

2

4}, Pedro Berraondo^{1

2

4}, Ignacio Melero^{1

2

4

5

6

7

8}

Affiliations

¹ Program of Immunology and Immunotherapy, Cima Universidad de Navarra, 31008 Pamplona, Spain.
² Navarra Institute for Health Research (IDISNA), 31008 Pamplona, Spain.
³ Program of Solid Tumors, Cima Universidad de Navarra, 31008 Pamplona, Spain.
⁴ Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), 28029 Madrid, Spain.
⁵ Department of Immunology and Immunotherapy, Clínica Universidad de Navarra, 31008 Pamplona, Spain.
⁶ Department of Oncology, Clínica Universidad de Navarra, 28027 Madrid, Spain.
⁷ Centro Del Cancer de La Universidad de Navarra (CCUN), 31008 Pamplona, Spain.
⁸ Nuffield Department of Medicine (NDM), University of Oxford, Oxford OX3 7BN, UK.

Abstract

Intratumoral immunotherapy strategies for cancer based on interleukin-12 (IL-12)-encoding cDNA and mRNA are under clinical development in combination with anti-PD-(L)1 monoclonal antibodies. To make the most of these approaches, we have constructed chimeric mRNAs encoding single-chain IL-12 fused to single-chain fragment variable (scFv) antibodies that bind to transforming growth factor β (TGF-β) and CD137 (4-1BB). Several neutralizing TGF-β agents and CD137 agonists are also undergoing early-phase clinical trials. To attain TGF-β and CD137 binding by the constructions, we used bispecific tandem scFv antibodies (taFvs) derived from the specific 1D11 and 1D8 monoclonal antibodies (mAbs), respectively. Transfection of mRNAs encoding the chimeric constructs achieved functional expression of the proteins able to act on their targets. Upon mRNA intratumoral injections in the transplantable mouse cancer models CT26, MC38, and B16OVA, potent therapeutic effects were observed following repeated injections into the tumors. Efficacy was dependent on the number of CD8⁺ T cells able to recognize tumor antigens that infiltrated the malignant tissue. Although the abscopal effects on concomitant uninjected lesions were modest, such distant effects on untreated lesions were markedly increased when combined with systemic PD-1 blockade.

Keywords: 4-1BB; CD137; IL-12; MT: Delivery Strategies; TGF-β; local immunotherapy; mRNA.