Medicenna Presents Updated Results of Single Agent MDNA11 Anti-tumor Activity from Dose Escalation and Ongoing Dose Expansion of the Phase 1/2 ABILITY-1 Study at the 2024 Annual Meeting of the American Association for Cancer Research (AACR)

100% reduction of target lesions in one melanoma and one pancreatic cancer patient observed among 4 Partial Responses (PR) to date which include 2 of 4 evaluable dose expansion patients and 2 of 2 MSI-H patients

Durable stable disease (SD) in 3 melanoma patients for 6 to 18 months with concomitant tumor shrinkage

With response rate and clinical benefit rate increasing to 29% and 50% (4 PR, 3 SD), respectively, MDNA11 continues to demonstrate compelling single-agent activity in the ABILITY-1 study amongst high-dose phase-2 eligible patients (N=14) who have failed checkpoint inhibitor therapies

MDNA11 is generally well tolerated with no dose-limiting toxicities or vascular leak syndrome reported in any of the dose escalation cohorts

Medicenna believes that these data reaffirm the differentiated and promising therapeutic activity, safety, PD and PK profile of MDNA11 in patients with advanced solid tumors who have failed multiple prior lines of therapies

TORONTO and HOUSTON, April 09, 2024 (GLOBE NEWSWIRE) -- Medicenna Therapeutics Corp. (“Medicenna” or the “Company”) (TSX: MDNA), a clinical-stage immunotherapy company focused on the development of Superkines, presented updated clinical results from the monotherapy dose escalation and ongoing expansion portions of the Phase 1/2 ABILITY-1 (A Beta-only IL-2 ImmunoTherapY) study evaluating MDNA11, a long-acting ‘beta-enhanced not-alpha’ interleukin-2 (IL-2) super-agonist, in patients with advanced solid tumors, at the 2024 Annual Meeting of the American Association for Cancer Research (AACR) held in San Diego, CA, on April 9^th, 2024.

“Although early, we have been impressed with MDNA11’s single agent activity demonstrating a response rate of 29% and clinical benefit rate of 50% in patients with advanced solid tumors who have all failed prior immunotherapies,” said Fahar Merchant, Ph.D., President and Chief Executive Officer of Medicenna. “We are very encouraged by a new partial response in a 85 year-old MSI-High patient with small bowel cancer and are particularly pleased with 100% reduction of all baseline target lesions in two of the four partial responders which includes a pancreatic cancer and a melanoma patient. MDNA11 continues to demonstrate its best-in-class potential. To further expedite the study, new sites in the US and Korea have started enrolment in the ongoing monotherapy expansion and combination escalation arms of the ABILITY-1 study as we look forward to reporting additional data at a medical conference in the first half of 2024.”