Autologous DC cancer vaccines are drawn with problems

It is common knowledge that DCs from one human being injected into another (allogeneic DCs) as foreign material will be eliminated by the host’s immune system. Thus, allogeneic DCs have generally been considered unable to use as vaccine cells and research has been focused on activating and loading the cancer patients’ own (autologous) DCs with tumor antigens in vitro. However, this artificial DC preparation in vitro seems to be insufficient since only about 0.5 - 4 % of re-injected autologous DCs are able to migrate to the draining lymph nodes for activation of the immune system. Furthermore, since autologous DC cancer vaccines have to be tailor made for each individual patient there are several other drawbacks. Creating a new, unique vaccine for each patient is:

• Complex
• Time consuming
• Expensive
• Physically stressful for the sick patients

Immunicum is unique in developing an immunotherapy based on injecting antigens with allogeneic DCs as adjuvant

Immunicum develops an allogeneic DC cancer vaccine that activates the immune system for effective destruction of tumor cells and inhibition of future tumor growth. White blood cells from healthy donors are loaded with tumor specific antigens in vitro and treated with the enzyme neuraminidase. Since the vaccine cells can be loaded with different antigens, it is possible to tailor the vaccines for prophylactic and therapeutic treatment of all types of cancers as well as of infectious diseases such as HIV, malaria, and tuberculosis. 

Immunicum takes advantage of the fact that allogeneic DCs will be regarded as highly “dangerous” foreign material once injected into another human being. As foreign invaders, allogeneic DCs will induce a highly inflammatory milieu at the vaccination site, containing several chemokines and cytokines that are capable of recruiting the patients’ own monocytes and subsequently also capable of differentiating and maturing these recruited monocytes into highly activated DCs. The patients’ recruited DCs will then engulf the invading allogeneic vaccine cells and in this way become loaded with tumor-specific antigens. Thus, the inflammation that allogeneic DCs superiorly induce is used to recruit, activate, and load the patients’ own DCs with tumor antigens in vivo (in the patient) instead of artificially creating mature DCs in vitro (in the test tube). This natural process of DC activation will most likely optimally prepare the patients’ own DCs for efficient migration to the draining lymph nodes where they can trigger the immune system against harmful substances.

This working hypothesis has now been verified in a rat cancer model in which tumor growth of mammary tumors was significantly reduced by therapeutic vaccinations (Cancer Immunology and Immunotherapy 2008,57,suppl1, p10). Immunicum is now looking to initiate clinical trials to further validate allogeneic DC-based vaccines’ potential for treating cancer.

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Advantages of allogeneic DC-based vaccines

Immunicum's vaccine concept is expected to superiorly activate the immune system against harmful substances. Furthermore, the vaccine can easily be thawed and injected into the patients directly after diagnosis, which gives a simple vaccination procedure that can be performed in public and private health care centers.

Since Immunicum’s vaccine does not have to be individually prepared for each specific patient, it also allows for large scale production with subsequent lower manufacturing costs. In addition, the vaccine can be frozen and shipped across great distances, which further enhances its commercial viability.