Preclinical development of a 3rd-generation interleukin-2 targeted to inflammatory sites

As major players in the regulation of immune responses, regulatory T cells (Tregs) are important therapeutic targets for autoimmune and inflammatory diseases. Interleukin-2 (IL-2) used at low doses (IL-2LD) stimulate and expand Tregs in vivo. While 1st-generation native IL-2LD are currently under extensive clinical evaluation, pharmaceutical companies are developing 2nd-generation IL-2 muteins with improved half-life and activity.

We aim to develop 3rd-generation IL-2 specifically targeting inflammatory sites (IL-2IT) by using antibodies (Abs) against oxidation specific epitopes (OSE) that are both universal markers and mediators of inflammation. IL-2-OSE-Ab fusion proteins should allow dampening of local inflammation by a double-hit mechanism involving Ab neutralization of pro-inflammatory OSE and IL-2 stimulation of Tregs.

As a proof of concept, we designed a first IL-2IT in which an IL-2N88R mutein is fused to an scFv from a prototypic anti-OSE Ab. This IL-2IT (i) binds to IL-2 receptors and OSE, (ii) has an extended half-life and (iii) superior therapeutic efficacy compared to native IL-2 in mice.

Our general objectives are to design an optimized IL-2IT by testing combinations of different anti-OSE Ab with IL-2 and IL-2 muteins, and to complete its preclinical development in mice and macaques.

We will validate the use of IL-2IT in cardiovascular diseases (CVD), i.e. atherosclerosis, vasculitis, myocardial infarction and SLE-associated CVD, as these conditions have been shown to be improved by Treg infusions, native IL-2 and OSE-Abs in mice.

Carried by leading experts in the use IL-2, OSE-Abs, models of CVD, and clinical trials with native IL-2, the successful validation of an IL-2IT will open a new era for highly selective and effective immunotherapies based on Treg stimulation for diseases that represent a leading cause of death and morbidity. Furthermore, it will validate the broader concept of targeting any therapeutic molecule to inflammatory sites.