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) - Seite 2

Key findings from the monotherapy dose escalation and ongoing expansion portions of the ABILITY-1 study at the time of data cut-off (i.e. March 22, 2024) include:

Acceptable safety profile: No dose limiting toxicity (DLT) reported and no evidence of vascular leak syndrome (VLS). The vast majority (95%) of treatment-related adverse events (TRAEs) were of grade 1-2 and resolved within 48 hours; grade 3 TRAEs mainly constituted asymptomatic transient LFT elevations; no grade 4 or 5 events were reported.

Encouraging single-agent anti-tumor activity at doses of ≥ 60 µg/kg in phase 2 eligible patients (N=14) who were all resistant to immune checkpoint inhibitors:

• Partial response reported for four patients with aggressive tumor types who had progressed on prior checkpoint inhibitors:
  
  
  • A pancreatic ductal adenocarcinoma (MSI-H) patient with primary resistance to pembrolizumab who was treated with MDNA11 (60 µg/kg) showed 100% resolution of all baseline lesions at week 66. A new lymph node lesion developed during a 8-week MDNA11 treatment break (vacation) was treated with a single course of radiotherapy prior to resumption of MDNA11. All baseline lesions remained completely resolved and the new lymph node lesion was <10 mm (considered physiological per RECIST v1.1), and MDNA11 treatment ended at week 90 while follow-up continues.
    
  • A patient with cutaneous melanoma progressed on dual checkpoint inhibitors, was treated with MDNA11 (90 µg/kg), and showed 100% resolution of the target lesion at weeks 28 and 36 with continuing reduction of the non-target lesions. Patient remains on MDNA11 treatment.
    
  • A second checkpoint-resistant cutaneous melanoma patient (nivolumab & rechallenge) showed partial response on MDNA11 (90 µg/kg) with a 31.25% reduction of target lesion at week 12 following pseudo-progression at week 8. A new lymph node lesion developed at week 16 while baseline target and non-target lesions remained stable or decreased. Patient remains on MDNA11 treatment.
    
  • An 85-year-old small bowel cancer (MSI-H) patient with secondary resistance to pembrolizumab showed partial response on MDNA11 (90 µg/kg) at week 20 with 37% reduction in target lesions. Patient remains on MDNA11 treatment.
    
    
• Durable stable disease (SD) for ≥ 24 weeks with shrinkage of target lesions observed in three metastatic melanoma patients: