Mendus AB announced compelling long-term survival data for its lead immunotherapy vididencel in acute myeloid leukemia (AML) patients, with all patients showing confirmed tumor antigen-specific T cell responses remaining alive at long-term follow-up. The data, presented at the European Hematology Association (EHA) conference, strengthen the case for vididencel as a maintenance therapy for AML patients at high risk of relapse.
Strong Survival Signal in High-Risk AML Population
The ADVANCE II Phase 2 trial enrolled AML patients in first complete remission following intensive induction chemotherapy who were diagnosed with measurable residual disease (MRD), a condition associated with increased relapse risk. At a median follow-up of 31.6 months for the total study population, 14 of 20 patients remained alive, with relapse-free survival reaching 30.4 months.
The most striking finding emerged from immune response analysis. All patients who developed confirmed tumor antigen-specific T cell responses following vididencel treatment remained alive in long-term follow-up at the time of data readout. The analysis revealed significantly better survival in patients with confirmed tumor antigen-specific T cell responses compared to those without such responses.
"The observation that functional immune responses occur in AML patients following vididencel treatment, despite the nature of the disease and preceding treatment with intensive induction chemotherapy, is encouraging," said Jeroen Rovers, Chief Medical Officer of Mendus. "The data strongly supports the use of vididencel as a maintenance immunotherapy for AML, based on long-term survival benefit related to active immunity against residual disease."
Broad Immune Activation Mechanism
The immunological analysis revealed that vididencel treatment resulted in an overall improvement of immune status, with responses involving both T cells and B cells. Immune responses against at least one tumor antigen were observed in the majority of patients following treatment. Durable clinical remissions were also associated with increased levels of circulating B cells.
Patients with multiple T cell responses over time and above-median B cell levels all experienced long-term clinical remissions. The data indicate that the breadth of the immune response contributes to long-term disease control and survival in AML, with vididencel inducing relevant active immunity that results in long-lasting immune control over residual disease.
Advancing Toward Pivotal Development
Based on the encouraging immunological data, Mendus is preparing for pivotal-stage development in AML. The company has received ethics committee approval for the Phase 2 AMLM22-CADENCE trial, which will study vididencel in combination with oral azacitidine, currently the only approved AML maintenance therapy.
The CADENCE trial, conducted in collaboration with the Australasian Leukaemia and Lymphoma Group (ALLG), will initially recruit 40 patients across up to nine participating clinical centers, with potential expansion to 100 patients subject to positive safety analysis. Mendus has established large-scale vididencel manufacturing capabilities with NorthX Biologics, completing the first full-scale technology transfer runs in the second quarter of 2024.
The company expects vididencel to be ready for pivotal-stage development in AML in the second half of 2025, based on timelines for clinical trial protocol development, regulatory interactions, and implementation of large-scale GMP manufacturing.
Expanding Applications Beyond AML
Mendus is also exploring vididencel's potential in ovarian cancer through the fully recruited ALISON Phase 1 trial with 17 participants. Data presented at the ESMO Gynaecological Cancers congress showed T cell responses against multiple documented ovarian cancer antigens in the majority of patients (10/15) evaluated. At week 22, 10 patients had stable disease while 7 patients had imaging-confirmed recurrence.
The company's pipeline also includes ilixadencel, an intratumoral immune primer being studied in soft tissue sarcomas as part of the REGOMUNE trial in collaboration with Institut Bergonié in France. The trial will combine ilixadencel with immune checkpoint inhibitor avelumab and tyrosine kinase inhibitor regorafenib in up to 43 patients, with initial clinical data anticipated in the first half of 2026.
