TORONTO, Canada, and HOUSTON, Texas — October 26, 2026
Medicenna Therapeutics Corp. (TSX: MDNA; OTCQB: MDNAF), a clinical-stage immunotherapy company developing engineered Superkines for cancer and autoimmune diseases, announced new preclinical findings for MDNA209, its investigational cytokine-based CD122 superantagonist. The data were presented by Dr. Minh D. To at the Promises of Treg and Interleukin-2 Therapies Conference in Paris, France, on October 23, 2026. MDNA209 demonstrated high-affinity binding to CD122, blocking signaling pathways activated by interleukin-2 (IL-2) and interleukin-15 (IL-15), which can contribute to excessive immune-cell activity. In two aggressive mouse models of acute graft-versus-host disease (aGvHD), long-acting MDNA209 improved disease symptoms and extended median survival approximately three- to fourfold compared with control groups. Median survival reached 23.5 and 26 days, respectively, compared with seven days in both control groups. The findings support further investigation of MDNA209 for autoimmune and inflammatory conditions, although the results remain preclinical and clinical benefit in humans has not been established.
MDNA209 Demonstrates Potent CD122 Blockade and Immune Modulation
Medicenna reported that MDNA209 binds strongly to CD122, also known as the IL-2 receptor beta subunit, preventing formation of the receptor complex required for IL-2 and IL-15 signaling. In studies using human peripheral blood mononuclear cells, the candidate inhibited signaling in activated CD8-positive T cells and natural killer cells, both of which can contribute to inflammatory responses and tissue damage. In one human T-cell signaling assay, MDNA209 was approximately 150 times more potent than the anti-CD122 antibody Mikβ1 and 10 times more potent than a daclizumab biosimilar comparator. The treatment also inhibited immune-cell expansion driven by IL-2 and IL-15 and reduced IL-2-induced interferon-gamma release, an inflammatory signal associated with tissue injury. Additionally, four days of treatment did not reduce the viability of regulatory T cells, which play an important role in controlling excessive immune responses. These findings indicate that MDNA209 may offer a differentiated approach to regulating immune activity through a shared receptor target.
Preclinical GvHD Models Show Extended Survival
The candidate was evaluated in two aggressive mouse models of acute graft-versus-host disease, a potentially life-threatening complication of donor stem-cell transplantation in which donor immune cells attack the recipient’s tissues. Long-acting MDNA209 improved disease symptoms and significantly extended median survival in models involving partially or fully mismatched donor-recipient transplants. Median survival increased to 23.5 days in one model and 26 days in the other, compared with seven days in each control group. Researchers also observed recovery of body weight following the initial loss associated with donor-cell transplantation. In laboratory mixed lymphocyte reaction experiments using human immune cells from unrelated individuals, MDNA209 inhibited immune-cell expansion, providing additional evidence of activity in a system relevant to donor-recipient immune responses. Although these results strengthen the preclinical rationale for CD122 blockade, further studies are needed to determine dosing, safety and potential effectiveness in people with autoimmune or inflammatory diseases.
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Medicenna Advances Its Superkine Platform for Autoimmune Diseases
Medicenna is developing MDNA209 as a potential first-in-class, long-acting Superkine designed to inhibit both IL-2 and IL-15 signaling through CD122. The company believes its engineered cytokine platform may offer flexibility beyond approaches that target CD122 using conventional antibodies. Interest in this pathway has increased following clinical developments involving CD122-blocking therapies for autoimmune conditions and strategic activity in the sector. Medicenna is also advancing MDNA11, an IL-2 Superkine being evaluated in clinical studies for advanced cancers, alongside other engineered immunotherapy candidates. The company stated that MDNA209 may have partnership potential as development progresses. However, MDNA209 remains in preclinical development, and its safety and efficacy have not yet been established in clinical trials. Future research will be needed to assess its therapeutic potential and determine whether the encouraging laboratory and animal findings translate into meaningful outcomes for patients.
Source:Medicenna Therapeutics, Press release
