As agreed, TopAlliance will make a prepayment of $3.29 million to Leto Laboratories and will pay no more than $147.17 million in total for milestone payment and technical service fee as pre-marketing development, launch, and post-marketing sales of this drug move along. In addition, TopAlliance will pay Leto Laboratories a sales commission of 6%- 8% on the net sales revenue starting from LTC002’s commercialization.

Interleukin-2 (IL-2) is a globular glycoprotein vital in maintaining the function of T lymphocytes and natural killer (NK) cells. Produced mainly by activated T cells, IL-2 promotes T cell proliferation and differentiation, maintains T cell activity, stimulates the production, proliferation, and activation of NK cells, induces the production of cytotoxic T lymphocytes (CTL), as well as induces and activates lymphokine-activated killer cells (LAK) and tumor-infiltrating lymphocytes. Therefore, it has excellent antiviral and anticancer effects and potential for broad clinical applications.

According to the announcement of TopAlliance, the currently marketed wild-type IL-2 products, when at low doses, will preferentially bind to high-affinity receptors on the surface of Treg cells, producing immunosuppression and limiting the therapeutic effect. Whereas high doses of IL-2 will neutralize the immunosuppression brought about by Treg activation by activating a large number of effector T cells, but resulting in higher toxicity and more side effects, as well as apoptosis.

Leto Laboratories is dedicated to the research and development of polypeptide and enzyme-based protein drugs in life sciences, possessing polypeptide and enzyme-based molecular design and manufacturing technologies. This LTC002 project, developed by Leto Laboratories, is currently under preclinical development.

According to the announcement, Leto Laboratories innovated a unique approach to eliminate the binding to the IL2 Rα. It introduced additional disulfide bonds to IL-2 itself which not only enables IL-2 to be more structurally stable but also forms a barrier that allows it to disrupt the binding to IL-2Ra with minimal alteration. Though the mutated molecules are unable to bind to endogenous α receptors in vivo, they can still bind to β and γ receptor subunits. Therefore, lowering or eliminating the interaction of IL-2 with α receptor subunits can be important in promoting therapeutic efficacy and reducing side effects of treatment in cancer patients.

Note: This article is intended to present developments in pharmaceutical and healthcare research, not a recommendation for treatment options. Please visit a hospital if you are looking for treatment recommendations.