Breast cancer vaccine completes preclinical proof-of-concept study

Breast cancer vaccine candidate OQR200, developed by OncoQR, has successfully completed a proof-of-concept study in non-human primates (NHPs).

In the study, the vaccine elicited the expression of very high levels of polyclonal antibodies targeting multiple epitopes on Her2/neu. These epitopes include those two which are recognised by current blockbuster monoclonal antibodies Herceptin and Perjeta and which lead to ADCC (antibody dependent cytotoxicity).

In addition, antibodies against Her2/neu epitopes so far not targeted by any licensed therapy were induced. These new epitopes allow tumour cell killing through complement activation (CDC), confirming the superior mode of action of polyclonal responses over current monoclonal treatments.

On top of the antibody response, OQR200 simultaneously induced polyclonal cellular immune responses to the breast cancer antigen, activating both helper T-cells and cytotoxic T-cells. The candidate therefore mobilises and boosts the patient's complete immunological repertoire to combat the cancer cells.

“We are very pleased that this study has proven that OQR200 induces both high levels of antibodies and T-cell responses to Her2/neu-cancer cells," said Dr Geert C Mudde, CSO of OncoQR. “The results of this study show that compared to other drugs, OQR200 is capable of mobilising and boosting both arms of the immune system against cancer cells: cellular and humoral immunity. Such a two-pronged approach is considered critical to prevent 'tumour escape', a major limitation of current antibody treatments.

“Equally important for the clinical potential of our technology is the fact that the strong and broad immune reaction OQR200 induces is reversible, as the body will return to its natural state of tolerance for the auto-antigen after the end of the vaccination schedule when immunisation pressure is released. In addition, this also means that the immune response can be fined-tuned on a patient-by-patient basis to reach the individually desired optimal levels by shortening or increasing the time period between immunisations of the patient."

“We are delighted that we could move OQR200 from drawing board to preclinical proof of concept in just eight months," said Christof Langer, CEO of OncoQR. “Our next goal is to find adequate partners that will help bring this promising breast cancer vaccine to the clinic as fast as possible."

OncoQR plans to use its S-TIR technology, which underlies OQR200, to initiate the development of further adjustable cancer immunotherapies against undisclosed clinically validated targets