Medicenna Therapeutics Corp. announced that clinical data from the Phase 1/2 ABILITY (A Beta-only IL-2 ImmunoTherapY) study of MDNA11, the Company's long-acting IL-2 super-agonist, have been featured in a poster presentation at the 9th Annual Frontiers in Cancer Immunotherapy Meeting. The meeting, organized by the New York Academy of Sciences, is taking place both virtually and in-person from May 9 ­ 11, 2022.

The presentation featured both, previously announced data from the ABILITY study's initial dose escalation cohorts showing dose-dependent stimulation of anti-cancer immune cells with MDNA11 treatment (doses ranging from 3 µg/kg to 30 µg/kg administered every 2 weeks), as well as new pharmacokinetic (PK) and pharmacodynamic (PD) analyses from the first 8 patients with treatment refractory solid tumors. Key findings from the new analyses include: MDNA11 treatment led to a dose-dependent expansion of cancer fighting lymphocytes (>200% increase at 30 µg/kg) and no significant increases in eosinophil count when compared to baseline. Extremely high eosinophil count is associated with severe toxicity and is a known side effect of high-dose recombinant human IL-2 (Proleukin®).

MDNA11 treatment potently activated anti-cancer CD8 T cells by increasing (a) their population by >3-fold, and (b) boosting their activation as shown by increase in both, CD25+ and ICOS+ CD8+ T cells. IL-2, MDNA11 did not induce an increase in ICOS+ Treg cells. ICOS+ Treg cells are highly immunosuppressive and associated with lack of response to high dose IL-2 immunotherapy.

MDNA11 has shown a favorable and consistent pharmacokinetic profile following multiple doses suggesting that it may not be generating anti-drug antibodies associated with immunogenicity. Granulysin expressing immune cells also increased by 3-fold in a dose-dependent manner. Granulysin is a potent agent causing cancer specific cell death and is associated with better patient outcomes.

Enrollment into the study's fourth dose escalation cohort is ongoing. An initial update on efficacy data from the ABILITY study is expected in mid-2022.