Research & Development

The core technology: Using a malaria protein to identify and capture Circulating Tumour Cells (CTCs)

VarCT Diagnostics technology is founded on discoveries made in the search for malaria vaccines. Malaria parasites multiply in red blood cells. To avoid being filtered through the spleen, the parasites express proteins anchoring infected red blood cells to the vascular lining. One such protein, VAR2CSA binds parasites in the placenta by recognizing a distinct type of chondroitin sulfate A, named oncofetal CSA. By catching growth factors and promoting cell motility, oncofetal CSA ensures that the placenta can grow fast and invade uterine tissue. Fast growth and invasiveness are features shared between cancer and placenta.

Recent research has discovered that expression of oncofetal CSA indeed is a common factor shared by the placenta and most types of cancers. It has been demonstrated that VAR2CSA binds to cancer cells of epithelial and mesenchymal origin, as well as to cells that have undergone epithelial- to mesenchymal transition. Oncofetal CSA has not been detected on any normal cell type investigated to date, which makes oncofetal CSA a very promising target for e.g., detection and capturing of circulating tumour cells (CTCs), as well as other diagnostic applications.

Oncofetal CSA can also be utilized for targeting of anti-cancer drugs, a concept that is explored by VAR2 Pharmaceuticals. A recombinant form of VAR2CSA, rVAR2, has been developed to be used as the backbone for development of both therapeutic and diagnostic products. Our proprietary rVAR2 proteins bind with high affinity and specificity to the oncofetal CSA, which we have utilized to develop protocols for enrichment of CTCs from cancer patient blood samples. The data at hand suggests that using rVAR2-based binding of CTCs enables the capturing of a wider – and proposedly more relevant for diagnosis of cancer – population of circulating cancer cells. This holds a promise for that rVAR2-based CTC isolation could become a broadly applicable tool for early screening and detection of cancer, enabling choice of the best possible treatment and unprecedented outcomes for the patients.

Patents covering the use of rVAR2 and oncofetal fCSA for diagnosis of cancer have been issued in the USA, EU and Australia. Prosecution is ongoing in other major markets.

Cancer and liquid biopsy

Despite significant advances in the treatment of cancer over the last decades, the number of people dying of the disease reached 8.2 million globally in 2012 (latest data from the World Health Organisation) and is expected to increase in the future.

It is well-known that the chance of surviving cancer is better when the disease is detected early and therefore new diagnostic methods enabling early diagnosis are in demand. Many attempts have been made to develop simple and minimally invasive methods for cancer diagnosis, by analysing relevant biomarkers in the blood or other body fluids (liquid biopsy). Such methods could potentially enable earlier diagnosis of cancer, or even be applied for screening people at risk of developing cancer, in a cost-effective way.

The two main liquid biopsy approaches in development are sequencing of circulating tumour DNA and isolation and analysis of CTCs. The two approaches have their unique merits and are likely to be complementary strategies in future cancer diagnosis. Other approaches for liquid biopsies are also under investigation.