DCprime, the front-runner in the field of relapse vaccines, announced the presentation of preclinical proof-of-concept results at the 34th Annual Meeting of the Society for Immunotherapy of Cancer (SITC), Nov. 6-10 in Fort Washington, MD, USA. The data presented at SITC demonstrate the possibility to elicit and direct a robust immune response to the tumour site using the Company’s DCOne® cell line as a carrier for intra-tumoral delivery of foreign antigens in two well-established tumour mouse models. The full poster will be provided after the conference on the company’s website.
“While we continue developing product candidates focused on the relapse vaccine window, today’s publication shows the great versatility of the DCOne platform and the variety of approaches we utilize, on our own and together with partners. Combining a vaccination against a highly-immunogenic foreign antigen and planting the same antigen directly into the tumour-microenvironment using our DCOne cell line as a vehicle represents a lean and elegant therapeutic strategy to break immunotolerance. Tumour marking in this fashion could overcome several of the practical and commercial challenges that patient-specific neoantigen approaches face and could also be applied to tumour types with a low mutational burden.”
Erik Manting PhD, CEO of DCprime.
The therapeutic strategy described in DCprime’s SITC presentation is based on two key elements: inducing immunity against a foreign antigen and flagging the tumour as a target for the induced immune response with the same foreign antigen. For this proof-of-concept study, keyhole limpet hemocyanin (KLH) was used as the foreign antigen and A375 melanoma or U87-MG glioblastoma cells were subcutaneously engrafted into CD34-humanised NCG mice to establish the solid tumour models. All mice - treatment arm and control group - received intraperitoneal vaccination with the KLH protein while the tumour marking in the treatment population was done by injecting DCOne mDC cells loaded with KLH protein directly into the tumour. DCprime reported reduced tumour growth in both A375 and U87-MG tumour models following vaccination with KLH and tumour marking compared to the mice injected with PBS. The results show comparable levels of anti-KLH IgM antibody concentration between both treatment groups (U87-MG and A375 mice) and the PBS control group over time. Notably, mice from the KLH/KLH loaded DCOne-treated group produced significantly more anti-KLH IgG antibodies than the PBS control group confirming that the vaccination approach triggered a robust humoral immune response with long-term immunity and reactivity towards the antigen used for tumour marking.
DCprime will continue to explore this and other novel concepts to expand its therapeutic pipeline into solid tumours. Most recently, the company initiated a research collaboration with the Department of Obstetrics and Gynecology at the University Medical Center of Groningen (UMCG) to design a novel relapse vaccine approach for ovarian cancer and to prepare for a clinical trial in this indication. Additionally, the company’s development program in haematological malignancies continues with DCprime’s lead relapse vaccine candidate DCP-001 currently being evaluated in an international Phase II trial in AML patients who are ineligible for hematopoietic stem cell transplantations.
DCprime is the front-runner in the field of relapse vaccines, a new class of oncology vaccines administered after standard of care therapy to delay or prevent disease recurrence. Our lead product is a whole-cell based vaccine addressing blood cancers with a high risk of relapse. We are pursuing similar vaccination approaches for solid tumors. We believe relapse vaccines will improve survival by putting the patient’s immune system back in control