Dr. Fahar Merchant reports

MEDICENNA THERAPEUTICS DOSES FIRST PATIENT IN PHASE 2 MONOTHERAPY DOSE EXPANSION PORTION OF THE ABILITY STUDY EVALUATING MDNA11 IN SELECT TYPES OF SOLID TUMORS

Medicenna Therapeutics Corp. has dosed the first patient in the phase 2 monotherapy dose expansion portion of the phase 1/2 Ability (a beta-only IL-2 immunotherapy) study evaluating MDNA11, a long-acting, beta-only interleukin-2 (IL-2) superagonist.

"We are excited to dose our first patient in phase 2 clinical trial as we build critical momentum for MDNA11, a potentially best-in-class, next-generation IL-2 superagonist for the treatment of advanced solid tumours," said Dr. Fahar Merchant, PhD, president and chief executive officer of Medicenna. "Dosing the first patient in the phase 2 monotherapy dose expansion portion of the Ability study is an important milestone that follows encouraging therapeutic activity and tolerability observed during the phase 1 dose escalation study. Having established the optimal dosing regimen, we look forward to reporting initial results from the monotherapy and combination arms of the phase 2 dose expansion portion of the study in the first half of 2024. The combination arm of the trial evaluating MDNA11 with pembrolizumab is expected to commence by the end of this year."

In the phase 1 monotherapy dose escalation portion of the study, which evaluated 20 patients, MDNA11 was well tolerated with promising single-agent activity. As of the data cut-off date of June 20, 2023, responses included one confirmed durable (greater than one year) partial response in a heavily pretreated patient with metastatic pancreatic cancer who continues on treatment with MDNA11 and six patients with stable disease. Of note, one patient with melanoma experienced prolonged stable disease, which lasted over 1.5 years.

The Ability-1 study (NCT05086692) is a global, multicentre, open-label study that assesses the safety, tolerability, pharmacokinetics, pharmacodynamics and anti-tumour activity of MDNA11 as monotherapy or in combination with pembrolizumab (Keytruda). In the monotherapy dose expansion of the phase 2 study, up to 40 patients are expected to be enrolled and administered MDNA11 (90 mug/kg) intravenously once every two weeks. The expansion cohorts in the monotherapy arm of the study include advanced melanoma, non-melanoma skin cancer or MSI-high (microsatellite instability) or mismatch repair (MMR) deficient cancers.

About MDNA11

MDNA11 is an intravenously administered, long-acting, beta-only recombinant interleukin-2 (rIL-2) specifically engineered to overcome the shortcomings of rhIL-2 (aldesleukin) by preferentially activating immune effector cells (CD8+ T-cells and NK cells) responsible for killing cancer cells, with minimal or no stimulation of immunosuppressive Tregs. These unique proprietary features of the IL-2 superkine have been achieved by incorporating seven specific mutations and genetically fusing it to a recombinant human albumin scaffold to improve the pharmacokinetic (PK) profile and pharmacological activity of MDNA11 due to albumin's natural propensity to accumulate in highly vascularized sites and tumour-draining lymph nodes. MDNA11 is currently being evaluated in the phase 1/2 Ability-1 study as both a monotherapy and in combination with pembrolizumab (Keytruda).

About Medicenna Therapeutics Corp.

Medicenna Therapeutics is a clinical-stage immunotherapy company developing engineered cytokines, called superkines, designed to improve the specificity, function and safety profile of unmodified interleukins. Medicenna owns diverse platforms licensed from Stanford University to develop a pipeline of superkine candidates: interleukin-2 (IL-2), IL-4 and IL-13 superagonists and antagonists. MDNA11, a potential best-in-class, next-generation IL-2 superagonist targeting solid tumours, is currently in a phase 2 monotherapy dose expansion trial and expected to begin a phase 2 pembrolizumab combination trial in the fourth quarter of 2023. Medicenna's IL-4-empowered superkine, bizaxofusp (MDNA55), has completed a phase 2b trial for recurrent glioblastoma and holds fast-track and orphan drug status from the U.S. Food and Drug Administration (FDA) and FDA/European Medicines Agency, respectively. Medicenna also creates bifunctional superkine immunotherapies (BiSKITs), which have demonstrated superior anti-tumour activity in preclinical studies, even in hard-to-treat cold tumours.

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