Medicenna Therapeutics completes MDNA11 dose escalation

Medicenna Therapeutics announced a clinical update on the monotherapy dose escalation portion of the first-in-human, Phase 1/2 ABILITY Study in patients with advanced solid tumors, as its drug candidate MDNA11, a beta-only, long-acting IL-2 super-agonist, advances to the monotherapy dose expansion phase. The main objectives of the dose escalation stage of the Phase 1/2 ABILITY study were to evaluate MDNA11’s safety, tolerability, pharmacokinetics and pharmacodynamics, and preliminary anti-tumor activity to inform RDE selection in patients with advanced cancers that were refractory to up to 4 different lines of systemic therapy. Key findings from the dose escalation portion of the study include: Favorable safety profile: MDNA11 was generally well tolerated across cohorts, with the majority of adverse events being grade 1 or 2, with no grade 4 or 5 AEs. Promising single-agent activity and durable tumor control: Several patients exhibited encouraging evidence of single-agent activity with tumor control observed in 7 of 19 evaluable patients. Confirmed partial response to single-agent MDNA11 in a highly aggressive tumor type: A patient in cohort 4 with metastatic pancreatic ductal adenocarcinoma, who had failed to respond to multiple prior systemic therapies, continues to show tumor shrinkage of all metastatic lesions in the liver after each successive scan. The most recent scan, showed an 80% decrease in total tumor size with complete regression of 2 out of 3 lesions. This patient continues on study treatment with MDNA11. Prolonged stable disease in metastatic melanoma progressed on prior immune checkpoint inhibition: A patient in cohort 2, having failed prior immunotherapy, experienced stable disease for 84 weeks. Pharmacodynamic data on effector anti-tumor immune cells continue to support the mechanistic rationale for MDNA11’s promising anti-tumor activity, with MDNA11 inducing robust expansion of a population of potent activated CD8+T cells and increasing NK cells, but with limited expansion of Tregs which can suppress anti-tumor immunity. Selection of specific cancers for evaluation in the monotherapy dose expansion phase was determined based on clinical data available from the ABILITY Study, discussions with Medicenna’s Clinical Advisory Board and other expert KOLs, and an understanding of the immunobiology of the selected tumor types and the potential for MDNA11 monotherapy in the post-checkpoint inhibitor setting. The following tumor types will be recruited in the dose expansion phase of the study: Melanoma and Non-Melanoma Skin Cancers and Microsatellite Instability-High or deficient DNA mismatch repair cancers. This population was selected to determine if the response achieved in the PDAC patient may have been due to the MSI-H profile. The PDAC patient unequivocally progressed on Keytruda, which is approved for MSI-H cancers.