Mendus presented positive new clinical data from a Phase II clinical trial investigating vididencel as a maintenance treatment in acute myeloid leukaemia (AML). Sweden-based biopharma company announced the results at the European Hematology Association (EHA) 2023 Hybrid Congress.
Vididencel is an allogenic and leukemic cell-based relapse vaccine that expresses co-stimulatory molecules resembling activated dendritic cells and tumour-associated antigens.
Phase II results
The primary endpoint of the trial evaluated measurable residual disease (MRD) response in patients with AML in complete remission (CR) and with the presence of MRD. As of the cut-off date on 22 November 2022, 20 patients were evaluable for the MRD response assessment.
The data analysis showed that 14 patients remained in CR. Out of those, five patients converted to MRD negative, and two patients had at least a ten-fold decrease in MRD levels. Seven patients had stable MRD levels, while six relapsed in the first 32 weeks.
In addition, the data demonstrated that vididencel increased levels of activated cancer-killing T cells and reduced the levels of immune-suppressive T cells in the majority of the patients.
Patients with an MRD response had the highest levels of functional tumour antigen-specific T cells. This patient cohort also demonstrated a trend towards higher levels of circulating antigen-presenting cells (APCs) and B cells following the treatment.
The open-label trial (NCT03697707) investigated two doses of vididencel, also known as DCP-001. In the first cohort, ten patients received 25E6 DCP-001 cells per vaccination while ten patients in the second cohort received 50E6 DCP-001 cells per vaccination. All patients received two booster vaccinations of 10E6 cells.
What’s coming next
The median relapse-free survival (RFS) rate has not been reached yet, however, Mendus estimated that a 12-month RFS will be 64% in its EHA 2023 poster. A 12-month overall survival (OS) is estimated to be 85.3%.
Chief medical officer Dr Jeroen Rovers said that the company continues to evaluate patients in long-term follow-up with updated survival results expected in Q4 2023. Rovers also teased about an upcoming Phase II trial, which will investigate vididencel in combination with oral azacitidine as the current standard of care in AML maintenance.
Last week, Mendus announced its alliance with NorthX Biologics to co-establish a cell therapy manufacturing unit for vididencel in Sweden. The manufacturing facility will be used for large-scale production of the medication.
