Shreds of Tregs: French biotech wins Medicxi backing to kill the rogue immunosuppressive agent to fight cancer
Existing CD25 drugs tend to thwart IL-2 signaling, which is imperative to shaping the body’s immune response. But a French drug developer thinks it has found a way to snuff out regulatory T cells (known to contribute to the early establishment and progression of tumors) by targeting CD25 without disturbing IL-2, and now has €18.5 million in its coffers to prove it.
The Parisian company, Alderaan Biotechnology, is still very early in its journey. The Series A round of funding from Advent France Biotechnology (AFB) and Medicxi will be used to complete the preclinical development of its regulatory T cell (Tregs) depleting CD25-specific antibody and take it into the clinic by 2022.
An unshackled immune system can be as dangerous as a weak one. Tregs are designed to police the immune system into working as needed, but on the flip side, in the tumor microenvironment, they contribute to disease progression by suppressing the body’s immune response. CD25 is not only a marker for Tregs but is also key for the maintenance and function of these cells. Meanwhile, along with CD122 and CD132, CD25 forms the high-affinity receptor for interleukin(IL)-2, which is a growth factor for T cells.
“What we’re doing with our antibody is that we target CD25 in a way that can kill regulatory T cells in the tumor, so there is an elimination of those Tregs that are known to be immunosuppressive — but since our antibodies have the specificity to spare the IL-2 receptor, it does not block IL-2 signaling,” chief Arnaud Foussat explained in an interview with Endpoints News.
“This is critical because the old CD25 antibodies (such as Roche’s daclizumab and Novartis’ Simulect) that have been developed — they are blocking IL-2, which means they are anti-inflammatory by nature, and this is not good for oncology.”
The approach sounds a lot like the one taken by the British biotech, Tusk Therapeutics, which was swallowed by Roche in 2018.
Alderaan, which also has an even earlier stage asset designed to boost natural killer (NK) cell cytotoxic activity in cancer, was founded in 2017. That year, it received €1.5 million in seed funding in a round led by AFB.