TORONTO and HOUSTON — December 10, 2025 — Leads & Copy —
Medicenna Therapeutics Corp. (TSX: MDNA, OTCQX: MDNAF) presented updated clinical data from the ongoing Phase 1/2 ABILITY-1 study evaluating MDNA11 in patients with advanced solid tumors at the European Society of Medical Oncology (ESMO) Immuno-Oncology Congress 2025.
MDNA11 demonstrated durable anti-tumor activity in phase-2 eligible expansion cohorts, enriched for immune checkpoint resistant melanoma, MSS endometrial cancer, MSI-H and TMB-H cancers. The monotherapy expansion cohorts, irrespective of tumor type, included patients who had progressed on immune checkpoint inhibitors (ICI). These patients treated with MDNA11, as the next treatment following progression on ICI, had an objective response rate (ORR) of 42% and a disease control rate (DCR) of 83%.
Monotherapy expansion cohorts demonstrated ORRs of 38% in melanoma and 22% in MSI-H, corresponding to DCRs of 75% and 78%, respectively. MDNA11 in combination with KEYTRUDA (pembrolizumab) showed ORR and DCR of 50% and 75%, respectively, for MSS endometrial cancer while MSS TMB-H tumors demonstrated ORR and DCR of 25% and 88%, respectively. Monotherapy and combination treatment achieved durable responses in multiple advanced metastatic tumors, including pancreatic, breast, colorectal, endometrial, bladder, anal cancer and melanoma.
MDNA11 demonstrated a significant association between disease control (CR, PR and SD) and overall survival (OS) in both monotherapy and combination cohorts among patients treated within the Biological Effective Dose Range (BEDR) of MDNA11 with or without KEYTRUDA. Tumor control (responders and those with stable disease) was associated with significantly prolonged median overall survival (mOS) in both monotherapy and combination cohorts. The preliminary recommended dose for expansion for both monotherapy and combination arms was established at 90 µg/kg Q2W with the BEDR set at 60 to 120 µg/kg (Q2W and Q3W).
In the monotherapy cohorts, patients with disease control (N=24) had a median OS of 120.2 weeks compared with 28.6 weeks in those without disease control (N=24). In the combination cohorts, patients with disease control (N=27) had a median OS that was not yet reached compared with 26 weeks in those without disease control (N=18).
MDNA11 continues to demonstrate a manageable safety profile both as a single agent and in combination with KEYTRUDA. Over 90% of treatment-related adverse events (TRAEs) were Grade 1-2 and transient, typically resolving within 48 hours. No dose-limiting toxicities (DLTs) were observed with MDNA11 at doses up to 120 µg/kg in monotherapy or in combination with KEYTRUDA and Grade 3-4 events were mainly laboratory abnormalities without clinical sequelae.
Medicenna will host a live webinar to discuss the updated data with its management team, the presenting Principal Investigator, and commentary from key opinion leaders. A replay of the webinar will also be available on Medicenna’s website following the event.
MDNA11, a long-acting ‘beta-enhanced not-alpha’ interleukin-2 (IL-2) super-agonist, is being evaluated as a monotherapy or in combination with Merck’s anti-PD-1 therapy, KEYTRUDA® (pembrolizumab). Medicenna’s first-in-class targeted PD-1 x IL-2 bispecific, MDNA113, is in development for solid tumors and was designed using the Company’s proprietary BiSKITs™ (Bifunctional SuperKine ImmunoTherapies) and T-MASK™ (Targeted Metalloprotease Activated SuperKine) platforms. Medicenna’s IL-4 Empowered Superkine, bizaxofusp (formerly MDNA55), has been studied in 5 clinical trials enrolling over 130 patients, including a Phase 2b trial for recurrent GBM, the most common and uniformly fatal form of brain cancer.
ABILITY-1 (NCT05086692) is a global, multi-center, open-label study that assesses the safety, tolerability, pharmacokinetics, pharmacodynamics and anti-tumor activity of MDNA11 as monotherapy or in combination with KEYTRUDA (pembrolizumab). In the combination dose escalation portion of the Phase 2 study, patients have been enrolled and administered ascending doses of MDNA11 intravenously in combination with KEYTRUDA.
Medicenna is a clinical-stage immunotherapy company focused on developing novel, highly selective versions of IL-2, IL-4 and IL-13 Superkines and first-in-class Empowered Superkines.
Shushu Feng
Investor Relations, Medicenna Therapeutics
(416) 964-5442
ir@medicenna.com
Source: Medicenna Therapeutics
